Panasonic 3-Way Service Manual

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Page 1

SERVICE MANUAL

U-72MF1U9 U-72MF1U9E U-96MF1U9 U-96MF1U9E**

3WAY VRF SYSTEM

Model No.

Outdoor Units

9672Class

Model Name

Refrigerant R410A is used in the outdoor units. * Salt-Air Damage Resistant Specifications.

U-72MF1U9 U-72MF1U9E

U-96MF1U9 U-96MF1U9E

Indoor Units

Class 9 12 15 18 2419 36 54487

4-Way Cassette

4-Way Cassette 60×60

1-Way Cassette

Low Silhouette Ducted

Slim Low Static Ducted

High Static Pressure

Ducted

Ceiling

Wall Mounted

Floor Standing

Concealed Floor

Standing

** Necessary to install the External Electronic Expansion Valve Kit (Optional:CZ-P56SVK1U).

85464849301000

S-07MD1U6

S-07MF1U6

S-07MM1U6

S-07MK1U6

S-07MP1U6

S-07MR1U6

S-09MD1U6

S-09MF1U6

S-09MM1U6

S-09MK1U6

S-09MP1U6

S-09MR1U6

S-12MU1U6

S-12MY1U6

S-12MD1U6

S-12MF1U6

S-12MM1U6

S-12MT1U6

S-12MK1U6

S-12MP1U6

S-12MR1U6

S-15MF1U6

S-15MM1U6

S-15MP1U6

S-15MR1U6

S-18MU1U6

S-18MY1U6

S-18MF1U6

S-18MM1U6

S-18MT1U6

S-18MK1U6

S-18MP1U6

S-18MR1U6

S-19MS1U6**

S-24MU1U6

S-24MF1U6

S-24MT1U6

S-24MK1U6

S-24MP1U6

S-24MR1U6

S-36MU1U6

S-36MF1U6

S-36ME1U6

REFERENCE NO.

S-48MF1U6

S-48ME1U6

S-54MF1U6

SM830201-00

Page 2

IMPORTANT! Please Read Before Starting

This air conditioning system meets strict safety and operating standards. As the installer or service person, it is an important part of your job to install or service the system so it operates safely and efficiently.

For safe installation and trouble-free operation, you must:

Carefully read this instruction booklet before beginning. Follow each installation or repair step exactly as shown. Observe all local, state, and national electrical codes. Pay close attention to all warning and caution notices

given in this manual.

This symbol refers to a hazard or

WARNING

CAUTION

If Necessary, Get Help

These instructions are all you need for most installation sites and maintenance conditions. If you require help for a special problem, contact our sales/service outlet or your certified dealer for additional instructions.

In Case of Improper Installation

The manufacturer shall in no way be responsible for improper installation or maintenance service, including failure to follow the instructions in this document.

SPECIAL PRECAUTIONS

WARNING

Do not supply power to the unit until all wiring and tubing • are completed or reconnected and checked.

Highly dangerous electrical voltages are used in this • system. Carefully refer to the wiring diagram and these instructions when wiring. Improper connections and inadequate grounding can cause accidental injury or death.

•

Ground the unit following local electrical codes. Connect all wiring tightly. Loose wiring may cause •

overheating at connection points and a possible fire hazard.

To prevent possible hazards from insulation failure, • the unit must be grounded.

When Transporting

Be careful when picking up and moving the indoor and outdoor units. Get a partner to help, and bend your knees when lifting to reduce strain on your back. Sharp edges or

When Wiring

ELECTRICAL SHOCK CAN CAUSE SEVERE PERSONAL INJURY OR DEATH. ONLY A QUALIFIED, EXPERIENCED ELECTRICIAN SHOULD ATTEMPT TO WIRE THIS SYSTEM.

unsafe practice which can result in severe personal injury or death.

This symbol refers to a hazard or unsafe practice which can result in personal injury or product or property damage.

thin aluminum fins on the air conditioner can cut your fingers.

When Installing…

Select an installation location which is rigid and strong enough to support or hold the unit, and select a location for easy maintenance.

…In a Room

Properly insulate any tubing run inside a room to prevent “sweating” that can cause dripping and water damage to

walls and floors.

Keep the fire alarm and the air

CAUTION

…In Moist or Uneven Locations

Use a raised concrete pad or concrete blocks to provide a solid, level foundation for the outdoor unit. This prevents water damage and abnormal vibration.

…In an Area with High Winds

Securely anchor the outdoor unit down with bolts and a metal frame. Provide a suitable air baffle.

…In a Snowy Area (for Heat Pump-type Systems)

Install the outdoor unit on a raised platform that is higher than drifting snow. Provide snow vents.

outlet at least 5 feet away from the unit.

When Connecting Refrigerant Tubing

Ventilate the room well, in the event that is refrigerant • gas leaks during the installation. Be careful not to allow contact of the refrigerant gas with a flame as this will cause the generation of poisonous gas.

Keep all tubing runs as short as possible.• Use the flare method for connecting tubing.• Apply refrigerant lubricant to the matching surfaces of •

the flare and union tubes before connecting them, then tighten the nut with a torque wrench for a leak-free connection.

Check carefully for leaks before starting the test run.•

When performing piping work do • not mix air except for specified refrigerant (R410A) in refrigeration cycle. It causes capacity down, and risk of explosion and injury due to high tension inside the

WARNING

Do not leak refrigerant while piping work for an • installation or re-installation, and while repairing refrigeration parts. Handle liquid refrigerant carefully as it may cause

frostbite.

refrigerant cycle. Refrigerant gas leakage may • cause fire. Do not add or replace refrigerant •

other than specified type. It may cause product damage, burst and injury etc.

Page 3

When Servicing

Turn the power OFF at the main power box (mains) • before opening the unit to check or repair electrical parts and wiring.

Keep your fingers and clothing away from any moving • parts.

Clean up the site after you finish, remembering to check • that no metal scraps or bits of wiring have been left inside the unit being serviced.

WAR NI NG

Do not clean inside the indoor and • outdoor units by users. Engage authorized dealer or specialist for cleaning.

In case of malfunction of this • appliance, do not repair by yourself. Contact to the sales dealer or service dealer for a repair.

Others

CAUTION

Do not touch the air inlet or the

• sharp aluminum fins of the outdoor unit. You may get injured. Ventilate any enclosed areas when • installing or testing the refrigeration system. Escaped refrigerant gas, on contact with fire or heat, can produce dangerously toxic gas.

Confirm after installation that no • refrigerant gas is leaking. If the gas comes in contact with a burning stove, gas water heater, electric room heater or other heat source, it can cause the generation of poisonous gas.

Do not touch the air inlet or the

• sharp aluminum fins of the outdoor unit. You may get injured. Do not sit or step on the unit, • you may fall down accidentally.

Do not stick any object into the • FAN CASE. You may be injured and the unit may be damaged.

Check of Density Limit

The room in which the air conditioner is to be installed requires a design that in the event of refrigerant gas leaking out, its density will not exceed a set limit.

The refrigerant (R410A), which is used in the air conditioner, is safe, without the toxicity or combustibility of ammonia, and is not restricted by laws imposed to protect the ozone layer. However, since it contains more than air, it poses the risk of suffocation if its density should rise excessively. Suffocation from leakage of refrigerant is almost non-existent. With the recent increase in the number of high density buildings, however, the installation of multi air conditioner systems is on the increase because of the need for effective use of floor space, individual control, energy conservation by curtailing heat and carrying power, etc. Most importantly, the multi air conditioner system is able to replenish a large amount of refrigerant compared to conventional individual air conditioners. If a single unit of the multi air conditioner system is to be installed in a small room, select a suitable model and installation procedure so that if the refrigerant accidentally leaks out, its density does not reach the limit (and in the event of an emergency, measures can be made before injury can occur).

ASHRAE and the International Mechanical Code of the ICC as well as CSA provide guidance and define safeguards related to the use of refrigerants, all of which define a Refrigerant Concentration Level (RCL) of 25 pounds per 1,000 cubic feet for R410A refrigerant. For additional guidance and precautions related to refrigerant safety, please refer to the following documents:

International Mechanical Code 2009 (IMC-2009) (or more recently revised) ASHRAE 15 ASHRAE 34

Page 4

Precautions for Installation Using New Refrigerant

1. Care regarding tubing

1-1. Process tubing

Material: Use C1220 phosphorous deoxidized copper specified in JIS H3300 “Copper and Copper Alloy Seamless Pipes and Tubes.” For tubes of ø7/8" (ø22.22 mm) or larger, use C1220 T-1/2H material or H material, and do not bend the tubes.

Tubing size: Be sure to use the sizes indicated in the table below.

Use a tube cutter when cutting the tubing, and be sure to remove any flash. This also applies to distribution joints (optional).

When bending tubing, use a bending radius that is 4 times the outer diameter of the tubing or larger.

Use sufficient care in handling the tubing. Seal the tubing ends with caps or tape to prevent dirt, moisture, or other foreign substances from entering. These substances can result in system malfunction.

Unit: in. (mm)

OMaterial

over 5/128 (1.0)

1/2 H, H

7/8 (22.22) 1 (25.4) 1-1/8 (28.58) 1-1/4 (31.75) 1-1/2 (38.1) 1-5/8 (41.28)

5/128 (1.0) 5/128 (1.0) 5/128 (1.0) 3/64 (1.1)

over 3/64 (1.15)

Unit: in. (mm)

over

3/64 (1.20)

Copper tube

CAUTION

Outer diameter 1/4 (6.35) 3/8 (9.52) 1/2 (12.7) 5/8 (15.88) 3/4 (19.05)

Wall thickness 1/32 (0.8) 1/32 (0.8) 1/32 (0.8) 5/128 (1.0)

Material

Outer diameter

Wall thickness

1-2.

Prevent impurities including water, dust and oxide from entering the tubing. Impurities can cause R410A refrigerant deterioration and compressor defects. Due to the features of the refrigerant and refrigerating machine oil, the prevention of water and other impurities becomes more important than ever.

2. Be sure to recharge the refrigerant only in liquid form.

2-1.

Since R410A is a non-azeotrope, recharging the refrigerant in gas form can lower performance and cause defects in the unit.

2-2. nce decreases when gas leaks, collect the remaining

Since refrigerant composition changes and performa refrigerant and recharge the required total amount of new refrigerant after fixing the leak.

3. Different tools required

3-1.

Tool specifications have been changed due to the characteristics of R410A. Some tools for R22- and R407C-type refrigerant systems cannot be used.

R407C tools

New

Item

Manifold gauge Yes No Types of refrigerant, refrigerating machine

Charge hose Yes

Vacuum pump Use a conventional vacuum pump if it is equipped

Leak detector Leak detectors for CFC and HCFC that

Flaring oil For systems that use R22, apply mineral oil (Suniso oil)

* Using tools for R22 and R407C and new tools for R410A together can cause defects.

compatible

tool?

with R410A?

Yes

Yes No

Yes

oil, and pressure gauge are different.

To resist higher pressure, material must be changed.

with a check valve. If it has no check valve, purchase and attach a vacuum pump adapter.

react to chlorine do not function because R410A contains no chlorine. Leak detector for HFC134a can be used for R410A.

to the flare nuts on the tubing to prevent refrigerant leakage. For machines that use R407C or R410A, apply synthetic oil (ether oil) to the flare nuts.

Remarks

Manifold gauge

Vacuum pump

Outlet Inlet

iii

Page 5

3-2. Use R410A exclusive cylinder only.

New refrigerant R410A cannot be used for earlier models

1. Compressor specifications are different.

If recharging a R22 or R407C compressor with R410A, durability will significantly decrease since some of the materials used for compressor parts are different.

2. Existing tubing cannot be used (especially R22).

Completely cleaning out residual refrigerating

machine oil is impossible, even by flushing.

Val ve

Single-outlet valve

(with siphon tube) Liquid refrigerant should be recharged with the cylinder standing on end as shown.

Liquid

3. Refrigerating machine oil differs (R22).

Since R22 refrigerating machine oil is mineral oil, it does not dissolve in R410A. Therefore, refrigerating machine oil discharged from the compressor can cause compressor damage.

R22 refrigerating machine oil Mineral oil (Suniso oil)

R407C refrigerating machine oil Synthetic fluid (ether oil)

R410A refrigerating machine oil Synthetic fluid (ether oil)

Page 6

—

Section 1: CONTROL FUNCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

2. Selecting Outdoor Unit for Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

3. Compressor Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

4. Special Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

5. Other Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16

6. Operation of Solenoid Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17

7. Outdoor Unit Electronic Control Valves [MOV1, MOV2, MOV4] . . . . . . . . . . . . . . . . . . . . 1-19

8. Outdoor Fan Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21

9. Demand Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22

10. Indoor Unit Control of the Electronic Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23

11. Solenoid Valve Kit Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25

12. Indoor Special Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26

13. Discharge Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27

14. Current Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28

15. Low Oil Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29

16. Pressure Sensor Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-30

17. Backup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31

18. Service Maintenance Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33

19. Other Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36

Section 2: OUTDOOR UNIT REPAIR PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

1. Removing Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2. Removing Electrical Component Box and Duct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

3. Discharging Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

4. Backup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

5. Recovering Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

6. Checking for Leakage After Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

7. Evacuating System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

8. Charging Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

9. Pumping Out Refrigerant from Outdoor Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

10. Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

11. High and Low Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35

12. Replacing 4-way valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36

Section 3. OUTDOOR UNIT MAINTENANCE REMOTE CONTROLLER . . . . . . . . . . . . 3-1

1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

2. Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3. Ordinary Display Controls and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

4. Monitoring Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

5. Outdoor Unit Alarm History Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

6. Mode Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

Page 7

Section 4. REMOTE CONTROLLER FUNCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

1. Simple Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

2. Detailed Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

3. Remote Controller Servicing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

Section 5. TROUBLE DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

1. Contents of Remote Controller Switch Alarm Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

2. Outdoor Unit Control Panel LED Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

3. Remote Controller Servicing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

4. 3-WAY VRF Alarm Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

5. Blinking Inspection Display on the Remote Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27

6. Inspection of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28

7. Test Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29

8. Thermister Characteristics Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30

Page 8

Page 9

3-WAY VRF SYSTEM

Contents

Control Functions

1. CONTROL FUNCTIONS

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

2. Selecting Outdoor Unit for Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

3. Compressor Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

4. Special Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11

5. Other Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16

6. Operation of Solenoid Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17

7. Outdoor Unit Electronic Control Valves [MOV1, MOV2, MOV4] . . . . . . . . . . . . . . . . 1-19

8. Outdoor Fan Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21

9. Demand Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22

10. Indoor Unit Control of the Electronic Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . 1-23

11. Solenoid Valve Kit Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25

12. Indoor Special Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-26

13. Discharge Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27

14. Current Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-28

15. Low Oil Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-29

16. Pressure Sensor Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-30

17. Backup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31

18. Service Maintenance Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-33

19. Other Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-36

1 - 1

Page 10

3-WAY VRF SYSTEM

1. Introduction

The 3-WAY VRF is a system that allows multiple outdoor units to be connected. The outdoor units all contain inverter compressors, and the system does not utilize the sub units that were used in earlier systems. The outdoor unit where the unit No. is set to “1” includes the CCU (command controller unit) functions that are used to control the entire system. As a result, the system will not operate if no outdoor unit has been set as unit No. “1.”

Required settings for Test Run

Outdoor unit No. 1 Outdoor unit Nos. 2

At time of shipment On-site setting At time of shipment On-site setting System address 1 System 1 ~ 30 1 Not necessary No. of indoor units 1 1 ~ 40 units 1 Not necessary No. of outdoor units 1 1 ~ 3 units 1 Not necessary Unit No. 1 Unit No. 1 1 Unit Nos. 2

This system can be expanded to connect a maximum of 3 outdoor units. (The system maximum capacity is 24 To n. )

The CCU functions are disabled at all units except the unit that is set as unit No. 1. Therefore no problems will result even if the system address, No. of indoor units, and No. of outdoor units settings are made at the other units. However, making these settings may be convenient for manual backup operation, as it eliminates the necessity of making the settings again if unit No. 1 fails. (If unit No. 1 fails, and the power supply to it is interrupted, it will be necessary to set a different unit as unit No. 1 in order to use manual backup operation.)

Control Functions

1 - 2

Page 11

3-WAY VRF SYSTEM

2. Selecting an Outdoor Unit for Operation

Control Functions

2-1. Outdoor Unit Operating Rules

Because in this system all outdoor units contain an inverter compressor, ordinarily there is no absolute order of priority for compressor operation. Therefore there is no order of priority for the outdoor units. However, it is possible to operate the outdoor units in sequence, beginning with unit No. 1, by using the outdoor unit maintenance remote controller to change the outdoor unit EEPROM settings.

* For information concerning EEPROM settings, refer to the field application functions.

2-2. Delayed Start of Outdoor Units

(1) Delayed start of outdoor units in the same system If it is necessary to operate the compressors simultaneously at multiple outdoor units, each outdoor unit will

start, beginning with unit No. 1, after a delay of a number of seconds equivalent to the outdoor unit address. The units do not start simultaneously.

This is in order to reduce the load on the power receiving equipment.

Outdoor unit

address 1

Starts after 1 second Starts after 2 seconds

(2) Delayed start for each system At the time of factory shipment, delayed start for each system is not set to occur. Therefore when systems are

linked and multiple systems are selected for start simultaneously by the central control device, all systems will begin operating simultaneously. For this reason, a function is included to delay the start time for each system address when systems are linked and multiple systems are selected for start by the central control device. In order to enable this delay time, it must be set in the EEPROM for each system. Those systems where this setting has been made will start after a delay according to their system addresses.

* For information concerning EEPROM settings, refer to the field application functions.

Outdoor unit

address 2

2-3. Outdoor Unit Stop Rules

(1) Simultaneous stop of multiple outdoor units When all outdoor units, or multiple outdoor units, must stop, the units stop at the same time. However,

depending on the communications timing, a difference of approximately 10 seconds may occur.

(2) Stopping individual outdoor units

●

The last unit to stop operating is the outdoor unit that contains the inverter compressor with the shortest

amount of operating time.

●

If the indoor load decreases, and it becomes necessary to reduce the number of operating outdoor units, the

compressors are stopped individually, in sequence. When all compressors installed in an outdoor unit have stopped, that outdoor unit also stops.

1 - 3

Page 12

3. Compressor Control

3-1. Compressors Mounted in the Outdoor Units

[U-72MF1U9, U-72MF1U9E, U-96MF1U9, U-96MF1U9E]

Capacity 72 96

Installed

compressor

Compressor 1 Rotary DC Inverter DC Inverter

Compressor 2 Scroll

–

hp = horsepower

Compressor 2 Compressor 1Compressor 1

5 hp

Constant

speed

3-WAY VRF SYSTEM

Control Functions

INVINV

Type 96Type 72

3-2. Compressor Selection Rules

Because all outdoor units in this system contain an inverter compressor, ordinarily there is no absolute order of priority for compressor operation.

(1) Normal compressor operation sequence (set at time of shipment) At least one inverter compressor is always operating in order to make fine adjustments to the system

lower-limit capacity. When multiple outdoor units are connected, each unit contains an inverter compressor. Therefore, the inverter which operates is the inverter with the shortest amount of operating time. After the first inverter compressor has started, the remaining inverter compressors and constant-speed compressors start operating in order of the compressors which have the shortest amount of operating time.

* Immediately after installation, all compressors have an operating time of zero. In this case, the compressors

start in the following sequence: Inverter compressor > Constant-speed compressor.

<Details> The A/C units are selected with consideration for the maximum load. Therefore, in most cases the maximum

capacity is not required. Ordinarily, the operating range of an inverter compressor is approximately 25 Hz – 90 Hz, however operating efficiency declines somewhat in the high-frequency operating range. With consideration for these characteristics, control of inverter compressors in this system is divided into two ranges, according to the frequencies. Ordinarily, for reasons of efficiency, the upper limit for operation is approximately 50 Hz. If greater capacity is required, the next compressor is started. When all compressors are operating and greater capacity is required, the inverter compressors are operated at frequencies above approximately 50 Hz. This control may increase the lifetimes of the inverter compressors and refrigerant oil.

* If the number of connected outdoor units is small, the number of inverter compressors is also small. Therefore,

the compressors may operate at a high frequency even when the load is not large.

(2) Sequential operation beginning from unit No. 1 By using the outdoor unit maintenance remote controller to change the outdoor unit EEPROM settings, it is

possible to start the units in sequence, beginning from unit No. 1. * For information concerning EEPROM settings, refer to the field application functions.

1 - 4

Page 13

3-WAY VRF SYSTEM

3. Compressor Control

Control Functions

3-3. Compressor Capacity Control

The compressor operating conditions vary depending on the indoor unit operating conditions and on the effects of indoor heat load, outside temperature, and other factors. Unit No. 1 (CCU) calculates the required capacity according to these operating conditions, and allocates the capacity requirement among the outdoor units, according to the compressor start/stop rules. Fine adjustments to system capacity control are made by the inverter compressors. (Depending on the conditions, all inverter compressors may be operating for fine adjustment.)

3-4. Inverter Compressor Capacity Control

(1) The inverter compressor has a center limit value and upper limit value for the operating frequency. These limits

are set for each outdoor unit capacity.

(2) The inverter frequency during operation may be lower than the frequency listed above due to overload current

protection control. In this case, the inverter frequency lower limit is 22 Hz.

* If Quiet mode is selected, the inverter may stabilize at a frequency lower than those stated above.

For information about Quiet mode, refer to the field application functions.

3-5. Forced Compressor Stop

After a compressor stops, it will not start for a period of 3 minutes (3 minutes forced OFF). However, this does not apply when the compressor was forced to stop as the result of a control operation during the special controls (start control, defrost control, refrigerant oil recovery control, etc.) which are described later.

3-6. Roadmap Control

(1) The below controls are performed according to the pressure sensor on the outdoor unit, and the 2 temperature

sensors attached to the indoor unit heat exchanger. * With roadmap control, the pressure detected by the pressure sensor is converted to saturation temperature.

A temperature that has been converted to saturation temperature is called the pressure sensor temperature. (2) These controls are performed every 30 seconds. (3) The temperatures used to determine the area (A, AB, B, C) for the evaporation temperature control shown in

the figure on the next page, and for condensation temperature control, may vary depending on the relationships among factors including the difference between the room temperature setting and the indoor unit air intake temperature (= air intake temperature difference) and the difference between the air discharge temperature

setting and the air discharge temperature (= air discharge temperature difference). (4) Definitions of evaporation temperature and condensation temperature Evaporation temperature (Te): Lowest heat exchanger temperature (E1, E3) at any indoor unit

Condensation temperature (Tc): Highest temperature among the outdoor unit pressure sensor temperature and

the heat exchanger temperatures (E1) at all indoor units where the heating thermostat is ON. Ordinarily, this is the outdoor unit pressure sensor temperature. (If multiple outdoor units are connected, this is the highest outdoor unit pressure sensor temperature.)

* E3 temperature is not used for condensation temperature detection, because it may indicate the temperature

of superheated gas.

1 - 5

Page 14

3-WAY VRF SYSTEM

3. Compressor Control

3-6-1. Evaporation Temperature (Te) Control: Control of Indoor Units Operating in Cooling Mode

60.8

˚F

Horsepower increase permitted

51.9

51.8 Horsepower increase permitted

41.1

41.0 Horsepower increase prohibited

35.6

Horsepower decrease

35.4

Depending on the maximum requirement level of the indoor unit, the judgment

temperatures for each area may vary as shown in the figure (example).

Area A

Area AB

Area B

Area C

(1) For indoor units that are operating in Cooling mode, if one unit is selected for a test run, then the air

intake temperature difference (difference between the room temperature setting and indoor unit air intake temperature) is ignored, and areas B and C are considered to be area A for control purposes. (This is used for additional charging, test run checks, etc.) For this reason, vapor may be discharged if the test run continues for a long period of time, however this does

not indicate a problem. In addition, the test run is canceled automatically after 1 hour. (2) Even within the same area, the compressor capacity varies depending on the refrigerant temperature. (3) For 6 minutes after the compressors start, area C is considered to be area B for control purposes. (4) During special control, control of the compressor capacity according to Te is not performed. (5) If the thermostat turns OFF while Te is within area C, the next time the compressor starts it may restart from a

lower capacity. (6) When the area changes to area C, area C is considered to be area B for control purposes for the first 6

minutes, even if the horsepower is the minimum value within the range where capacity control is possible

(operation with inverter frequency of 25 Hz only). Subsequently if C area continues, the thermostat turns OFF.

53.6

51.8

45.5

Maximum requirement level [L]

41.0

35.6

Control Functions

1 - 6

Page 15

3. Compressor Control

3-6-2. Condensation Temperature (Tc) Control:

Control when there are indoor units operating in Heating mode

3-WAY VRF SYSTEM

Control Functions

PX = 125.6 ˚FPXThermostat OFF

–0.1

Horsepower decrease

118.5

118.4 Horsepower increase

prohibited

116.6

116.4 Horsepower increase

permitted

113.0

112.8 Horsepower increase

permitted

Depending on the maximum requirement level of the indoor unit, the judgment temperatures for each area may vary as shown in the figure (example).

Area D

Area C

Area B

Area AB

Area A

109.4

107.6100.4

98.6 0

Maximum requirement level [L]

15 30

118.4

116.6

(1) For indoor units which are operating in Heating mode, if one unit is selected for a test run, the air intake

temperature difference is ignored, however Tc control is performed according to the figure above in order to

prevent excessive load. (This is used for test run checks, etc.) (2) Even within the same area, the compressor capacity varies depending on the refrigerant temperature. (3) Temperature PX is the coefficient value used to correct for any deviation with the high pressure or condensation

temperature. It may vary. (At the time of shipment it is 125°F.) (4) If the condensation temperature (Tc) enters area D and the thermostat turns OFF, the next time the compressor

starts it may restart from a lower capacity. (5) When the area changes to area C, area C is considered to be area B for control purposes for the first 6

minutes, even if the horsepower is the minimum value within the range where capacity control is possible

(operation with inverter frequency of 25 Hz only). Subsequently if C area continues, the thermostat turns OFF.

3-6-3. Control of condensation temperature and evaporation temperature during mixed cooling/heating

operation

During mixed cooling/heating operation, the control maintains a heat balance with a target evaporation temperature (Te) for the Cooling mode indoor units of 35 ~ 42°F and a target condensation temperature (Tc) for the Heating mode indoor units of 116 ~ 118°F.

Heat balance control is performed by varying the compressor capacity and heat discharge (heat intake) of the heat exchanger.

(1) Increasing/decreasing the compressor capacity

• When evaporation temperature (Te) is high and condensation temperature (Tc) is low

This occurs when both the cooling capacity (heat intake) and the heating capacity (heat discharge) are low. The compressor capacity and the circulation flow of refrigerant are increased in order to lower the evaporation temperature (Te) and raise the condensation temperature (Tc).

• When evaporation temperature (Te) is low and condensation temperature (Tc) is high

This occurs when both the cooling capacity (heat intake) and the heating capacity (heat discharge) are high. The compressor capacity and the circulation flow of refrigerant are decreased in order to raise the evaporation temperature (Te) and lower the condensation temperature (Tc). * Under conditions other than those listed above, the capacity of the outdoor unit heat exchanger is adjusted.

In some cases the heat exchanger capacity may also be adjusted at the same time when the compressor capacity is varied.

1 - 7

Page 16

3. Compressor Control

Compressor Control Table

Low Condensation Temp. [Tc] High

3-WAY VRF SYSTEM

Control Functions

AUP

High

Evaporation Temp. [Te]

Low

slow_UP Target

not_UP

STOP

DOWN

Evaporation temperature (Te) and condensation temperature (Tc) areas A, B, C, and D are the same as for evaporation temperature control and condensation temperature control.

(2) Increasing/decreasing the heat exchanger capacity (when the outdoor unit heat exchanger is functioning as a

condenser)

• Primarily when both the evaporation temperature (Te) and condensation temperature (Tc) are high

This occurs when the cooling capacity (heat intake) is low and the heating capacity (heat discharge) is high. The outdoor heat exchanger capacity is increased, increasing the system condensation capacity and lowering the condensation temperature (Tc). The amount of heat discharge at the outdoor unit heat exchanger increases, increasing the heat intake at the Cooling mode indoor units and lowering the evaporation temperature (Te).

• Primarily when both the evaporation temperature (Te) and condensation temperature (Tc) are low

This occurs when the cooling capacity (heat intake) is high and the heating capacity (heat discharge) is low. The outdoor heat exchanger capacity is decreased, decreasing the system condensation capacity and raising the condensation temperature (Tc). The amount of heat discharge at the outdoor unit heat exchanger decreases, decreasing the heat intake at the Cooling mode indoor units and raising the evaporation temperature (Te).

Outdoor Unit Heat Exchanger Control Table (when the outdoor unit heat exchanger is functioning as a condenser)

High

Evaporation Temp. [Te]

Low

Low Condensation Temp. [Tc] High

STAY

DOWN

Target

STAY

Compressor stop

STAY

1 - 8

Page 17

3-WAY VRF SYSTEM

3. Compressor Control

(3) Increasing/decreasing the heat exchanger capacity (when the outdoor unit heat exchanger is functioning as an

evaporator)

• Primarily when both the evaporation temperature (Te) and condensation temperature (Tc) are low

This occurs when the cooling capacity (heat intake) is high and the heating capacity (heat discharge) is low. The outdoor heat exchanger capacity is increased, increasing the system evaporation capacity and raising the evaporation temperature (Te). The amount of heat intake at the outdoor unit heat exchanger increases, increasing the heat discharge at the Heating mode indoor units and raising the condensation temperature (Tc).

• Primarily when both the evaporation temperature (Te) and condensation temperature (Tc) are high

This occurs when the cooling capacity (heat intake) is low and the heating capacity (heat discharge) is high. The outdoor heat exchanger capacity is decreased, decreasing the system evaporation capacity and lowering the evaporation temperature (Te). The amount of heat intake at the outdoor unit heat exchanger decreases, decreasing the heat discharge at the Heating mode indoor units and lowering the condensation temperature (Tc).

Outdoor Heat Exchanger Control Table (when the outdoor heat exchanger is functioning as an evaporator)

Low Condensation Temp. [Tc] High

Control Functions

High

Evaporation Temp. [Te]

Low

STAY

Target

STAY

DOWN

STAY

Compressor stop

STAY

3-6-4. Protection control

Protection control consists of 2 types of protection: air discharge temperature protection and current protection. The limit values from this protection control are incorporated into the output compressor capacity increase/decrease values that were calculated from control based on the temperature at the indoor unit heat exchanger (roadmap control).

* In some cases, the control shown below may stop the compressor, issue a warning, or reduce the compressor

capacity.

(1) Air discharge temperature protection During operation when only a single outdoor unit is installed, the air discharge temperature level is determined

(the highest value is used), and the compressor capacity is limited, by using the air discharge temperature of

the operating compressor (as shown in the tables below).

Air discharge temperature level: Highest level among the air discharge temperature levels of all compressors

Air discharge temp. level Discharge temp. Horsepower limit

The values shown in the table above are reduced to the values calculated by roadmap control.

212 ~ Less than 217

208 ~ Less than 212

221

219

217

Less than 208

1 - 9

Decrease by 2 horsepower

Decrease by 1 horsepower

Decrease by 0.5 horsepower

Prohibit horsepower increase

Permit horsepower increase

No control

Page 18

3-WAY VRF SYSTEM

4. Special Controls

(2) Current protection Inverter compressor current control is composed of primary current control and secondary current control.

Current protection control for the inverter compressor is performed by self-protection in the inverter circuit, and

does not increase or decrease the compressor capacity.

Primary current Secondary current

Control Functions

– 75 or (302 °F) Thermostat OFF

– 48 or above Thermostat OFF

26.5 25 ~ 32.5 Horsepower decreased

25 24 ~ Less than 25 Prohibit horsepower increase

24 Less than 24 Permit horsepower increase

3-6-5. Roadmap control after trip

When restarting after trip stop occurs, the horsepower may increase slowly depending on the trip counter value. (1) If Trip counter = 1, the horsepower increases at a speed that is 1/2 of ordinary roadmap control. (2) If Trip counter = 2, the horsepower increases at a speed that is 1/3 of ordinary roadmap control. The trip counter is cleared if no trip occurs within 10 minutes after operation starts.

Operation stops instantaneously due

to activation of hybrid IC

Thermostat OFF. Operation stops for

100 ms for current protection

1 - 10

Page 19

3-WAY VRF SYSTEM

4. Special Controls

In addition to ordinary heating and cooling operation, this system also includes the following 3 types of special controls for control of the system as a whole.

1. Tube refrigerant recovery control

2. System refrigerant oil recovery control

3. Defrost control

Control Functions

4-1. Tube Refrigerant Recovery Control

This control recovers refrigerant from the tubing when the microcomputer is initialized immediately after power-ON, after warning output occurs, and after a set amount of time has elapsed (standard = 60 minutes) when all outdoor units are stopped. This control is intended to recover refrigerant if refrigerant has accumulated somewhere in the tubing when the units have been stopped for long periods, as well as to compensate for tubing thermal loss during heating start, and is also used for oil recovery.

(1) Control when the outdoor unit heat exchanger is acting as a condenser (when all units are in Cooling mode or

at start of mixed operation when the cooling load is high)

Control time 60 seconds Outdoor units All outdoor units operate at maximum horsepower. Electronic control valve Valves at all indoor units operate at a ﬁ xed pulse according to the indoor unit capacity.

Indoor units

* When the above operation is ﬁ nished, normal operation starts at the horsepower determined by the indoor units

where thermostats are ON.

RAP valve kit Valve kits at all indoor units operate in Cooling mode (ON status).

Fan

Fan operates at the set fan speed, stops, or operates at L speed, depending on the indoor unit operation mode.

(2) Control when outdoor unit heat exchanger is acting as a condenser (when all units are in Cooling mode or at

start of mixed operation when cooling load is high)

Control time Minimum 1 min – Maximum 10 min [until max (pressure sensor temp., E1) ≥ 95°F] Outdoor units All outdoor units operate at maximum horsepower. Electronic control valve Valves at all indoor units operate at 480 pulses.

Indoor units

* When the above operation is ﬁ nished, normal operation starts at the horsepower determined by the indoor units

where thermostats are ON.

RAP valve kit Valve kits at all indoor units operate in heating mode (ON status).

Fan

Fan operates at the set fan speed, stops, or operates at L speed, depending on the indoor unit operation mode.

4-2. System Refrigerant Oil Recovery Control

4-2-1. System refrigerant oil recovery cycle

This control is performed using the cooling cycle during cooling operation and using the heating cycle during heating operation.

4-2-2. Start of system refrigerant oil recovery control

When the oil level in an operating compressor changes to 0, the compressor stops after 120 seconds. If this compressor repeats this operation 3 times and the oil level does not reach 2, system refrigerant oil recovery control is started.

* When the compressor has stopped because the oil level is 0, a count is added to the alarm counter. The counter

for this compressor is not cleared unless the oil level for that compressor reaches 2, or else alarm output occurs.

1 - 11

Page 20

3-WAY VRF SYSTEM

4. Special Controls

4-2-3. Flow of system refrigerant oil recovery control

(1) Simplified flow of system refrigerant oil recovery control System refrigerant oil recovery control follows this flow: Normal operation → 3-minute stop (May stop for 6 minutes.) → System refrigerant oil recovery control (Max. 3

minutes) → 3-minute stop → Normal operation

(2) Cooling cycle

Control time Maximum 3 minutes (Stops once before and once after control.)

Outdoor units All outdoor units operate at maximum horsepower.

Electronic control valve Valves at all indoor units operate at a ﬁ xed pulse according to the indoor unit capacity.

Indoor units

(3) Heating cycle

Indoor units

RAP valve kit Valve kits at all indoor units operate in Cooling mode (OFF status.)

Fan

Control time Maximum 3 minutes (Stops once before and once after control.) Outdoor units All outdoor units operate at maximum horsepower. Electronic control valve Valves at all indoor units operate at 480 pulses.

RAP valve kit Valve kits at all indoor units operate in Heating mode (ON status).

Fan

Fan operates at the set fan speed, stops, or operates at L speed, depending on the indoor unit operation mode.

Control Functions

4-3. Defrost Control

4-3-1. Defrost control method

This system uses the following 2 defrost methods. (1) If there is 1 outdoor unit in the refrigerant system: Reverse cycle defrost (2) If there are 2 or more outdoor units in the refrigerant system: Outdoor unit cycle defrost

4-3-2. Constraint conditions

(1) Frost detection does not occur for 5 minutes after operation starts. (2) Defrost does not begin again for 35 minutes of A/C operation after defrost was once completed. (3) If all indoor units are stopped while defrost control is in effect, or if the outdoor unit is stopped due to protection

control or another reason, then defrost control will not start for a minimum of 10 minutes after restart occurs.

1 - 12

Page 21

3-WAY VRF SYSTEM

4. Special Controls

4-3-3. Frost detection

(A) Frost detection does not occur for 5 minutes after operation starts. (B) Frost is detected when either condition 1 or 2 below is met.

Condition 1: L2 line or below is detected twice, each time continuously for 4 minutes, when the compressor is

operating.

Condition 2: L1 line or below is detected for a total of 60 minutes when the compressor is operating.

Heat exchange liquid temperature ˚F

Defrosting operation

42.8

end temperature

(The end temperature is different from the above detection temperature.)

Control Functions

–6.5

–9

–13

The frost detection area is located under the thick lines

External temperature ˚F

4-3-4. Outdoor units where defrost occurs

Even if the total time has not reached 35 minutes, if there is 1 or more outdoor units that fulfills the defrost detection conditions, all operating outdoor units perform defrost control at the same time.

* Defrost control is also performed at outdoor units where the outdoor unit heat exchanger is not functioning as an

evaporator (such as stopped outdoor units).

4-3-5. Reverse cycle defrost

Reverse cycle defrost is performed in systems where only 1 outdoor unit is connected to the refrigerant system.

• Defrost flow E: Evaporator operation C: Condenser operation E→C: Switching from evaporator operation to condenser operation C→E: Switching from condenser operation to evaporator operation

Defrost preparation Defrost in progress Defrost end

Outdoor unit status E→CE

Stopped indoor units E E E E

Indoor units where fan is operating E E E E

Cooling mode indoor units

Heating mode indoor units

Thermostat ON E E E E Thermostat OFF E E E E Thermostat ON C→EC Thermostat OFF C→EC

Compressor Stopped Operating Operating Stopped

Time 1 min 1 min Max. 12 min 1 min

→

Defrost end

→

EE E

→

EE E

judgment

C→E

→ →

C C

* With type E1, E → C occurs for 3 minutes after defrost ends. Therefore the thermostat remains OFF for 3

minutes.

1 - 13

Page 22

3-WAY VRF SYSTEM

4. Special Controls

4-3-6. Outdoor unit cycle defrost

Outdoor unit cycle defrost is performed in systems where 2 outdoor units are connected to the refrigerant system. (1) Description of outdoor unit cycle defrost

With this defrost method, when 1 outdoor unit operates in defrost mode (heat exchanger operating as a

condenser), another outdoor unit operates as an evaporator in the same way as in ordinary heating mode. In this way, the other outdoor unit is heating the unit where defrost is occurring. When 1 outdoor unit completes defrost, the other outdoor unit performs defrost in the same way. Because the amount of time that the unit operates as an evaporator is very short, there is little danger of frost forming again quickly. Rather, because the heat source is very powerful, it is possible to shorten the defrost operating time.

(2) Defrost sequence Outdoor unit cycle defrost is always completed in 2 defrost operations. (A) When there are 2 outdoor units

Control Functions

Defrost

outdoor unit

First operation Second operation

Evaporator outdoor unit

Switch

Evaporator

outdoor unit

Defrost

outdoor unit

• Defrost flow E: Evaporator operation C: Condenser operation S: Shut off E→C: Switching from evaporator operation to condenser operation C→E: Switching from condenser operation to evaporator operation

Defrost

preparation

Outdoor unit(s) where defrost occurs ﬁ rst E→CC C→EE

Outdoor unit(s) where defrost occurs second E E

Stopped indoor units S S S S S

Indoor units where fan is operating S S S S S

Cooling mode indoor units

Heating mode indoor units

Compressor Operating Operating Stopped Operating Stopped

Thermostat ON E E E E E Thermostat OFF E E E E E Thermostat ON C C C C C Thermostat OFF C C C C C

Time 1 min Max. 7 min 1 min Max. 7 min 1 min

Defrost in

progress

Defrost end judgment

Switch

E→CC C→E or S

Defrost in

progress

Defrost end judgment

Defrost

preparation

E or S

* With type E1, E → C occurs for 3 minutes after defrost ends. Therefore the thermostat remains OFF for 3

minutes.

1 - 14

Page 23

3-WAY VRF SYSTEM

4. Special Controls

4-3-7. Defrost end judgment conditions

Defrost ends when either of the below defrost end judgment conditions is met. Condition 1: The temperatures are 42.8°F or higher at all temperatures sensors installed on the outdoor unit heat

exchangers. However, if there is any other outdoor unit where the defrost end condition has not been met, defrost control continues for all outdoor units, and system defrost control is not ended.

Condition 2: The maximum defrost time listed in the table above has elapsed.

4-3-8. System defrost end

When all outdoor units where defrost control is in effect have met the defrost end conditions, defrost control is ended for the system.

Control Functions

1 - 15

Page 24

5. Other Controls

5-1. Oil Control

5-1-1. Oil level

3-WAY VRF SYSTEM

Control Functions

Oil level

2 Sufficient

Meaning Oil state Assessment

This is the normal operating state of the system and not a problem.

Check that oil control recovers oil.

Check that system oil recovery control restores the oil level.

Slightly

low

Extremely

low

There is more than an adequate amount of oil in the compressor.

The compressor may contain an adequate amount of oil, but it may also contain less than an adequate amount of oil.

There is not enough oil in the compressor.

The compressor contains enough oil when the oil level is in the range between level 2 and until it has just become

1. Thus oil level 1 does not mean that the compressor is empty of oil. When the compressor reaches oil level 0 during operation, the system is likely to run out of oil within 5 to 10 minutes. Check for oil leaks and make sure that refrigerant pipes are intact.

5-1-2. Oil level detection

Excess oil in the compressor is sent by bypass via a capillary tube to the low-pressure circuit. The temperature detected by a temperature sensor is used to determine whether it is oil (warm) or refrigerant (cold).

5-1-3. Self-separator oil recovery control

* When a low oil level is detected, this control recovers the oil which has accumulated in that oil separator and

sends it to the compressor.

(1) Operation when oil level is 1 30 seconds after the oil level changes from 2 to 1, both the balance valve and recovery valve turn ON for up to

2 minutes. However, if the oil level becomes 2 during these 2 minutes, this control is stopped. When this control has been stopped, it will not restart for 3.5 minutes unless the oil level becomes 0.

(2) Operation when oil level is 0 Both the balance valve and recovery valve turn ON and remain ON.

5-1-4. Unit refrigerant oil recovery control – utilizing balance tubes

* If the low oil level continues, that outdoor unit (oil-receiving outdoor unit) receives a supply of oil from operating

outdoor units where the oil level is not low (oil-supply outdoor units).

(1) Control at the oil-supply outdoor unit begins 3 minutes after the oil level at the outdoor unit changes to 0 or 1.

Oil supply is performed for a maximum of 5 minutes from each unit.

(2) When oil supply is ended, oil supply from that outdoor unit will not occur again for a period of [(No. of outdoor

units – 1) x 5 minutes]. In addition, oil supply is ended if the oil-receiving outdoor unit oil level changes to 2, or if the oil-supply outdoor unit oil level becomes low.

(3) The supply of oil is received from 1 unit at a time, in sequence, according to the order of priority of their inverter

compressors.

(4) Operation during unit refrigerant oil recovery

(A) Oil-receiving outdoor unit

The recovery valve turns ON and remains ON. * Because self-separator oil recovery may occur simultaneously at the same unit, both the balance valve

and recovery valve turn ON at this time.

(B) Oil-supply outdoor unit

The balance valve turns ON and remains ON. The bypass valve repeatedly turns ON and OFF according to a fixed cycle. * When the balance valve is ON, the oil in the oil separator is discharged into the balance tube. The bypass

valve releases high-pressure gas which forces this oil toward the oil-receiving outdoor unit, and flushes out the balance tubes. The operation of this bypass valve allows oil to be supplied even when there is a difference in height between the outdoor units.

5-1-5. Indoor unit refrigerant oil self-recovery control

Refer to the items concerned with indoor unit special control.

1 - 16

Page 25

3-WAY VRF SYSTEM

6. Operation of Solenoid Valves

Control Functions

6-1. Refrigerant Control Valve [RCV]

The main purpose of this valve is to detect the flow of refrigerant (refrigerant volume) on the indoor-unit side when the outdoor unit heat exchanger is functioning as a condenser. When the valve determines that there are signs of a low refrigerant level, refrigerant is supplied from the receiver tank to the system.

(1) The OFF conditions take priority over the ON conditions for this valve. (2) This valve is OFF when the outdoor unit is stopped. (3) This valve is ON when special control is in progress. (4) Control during normal operation

(A) Cooling operation

●

This valve turns ON when symptoms of insufficient refrigerant gas occur at an

indoor unit.

●

This valve turns ON when the outdoor air temperature is 59°F or below. (Under

these conditions the high pressure is low and refrigerant flow becomes poor.)

●

This valve turns OFF when symptoms of refrigerant overcharge are detected at

the outdoor unit.

(B) Mixed cooling/heating operation

●

The RCV turns ON at stopped outdoor units when the heat exchanger at

another outdoor unit is functioning as a condenser.

6-2. Refrigerant Balance Valve [RBV] – Gas Purge Valve

The main purpose of this valve is to detect the flow of refrigerant (refrigerant volume) on the indoor-unit side when the outdoor unit heat exchanger is functioning as an evaporator. When the valve determines that there are signs of excess refrigerant, refrigerant is recovered at the receiver tank. This valve is ON during heating operation and when the outdoor unit heat exchanger is functioning as an evaporator during mixed heating/cooling operation. It also turns ON in order to recover refrigerant at the outdoor unit after heating operation is stopped. * This valve is never ON at the same time as the RCV.

(1) The OFF conditions take priority over the ON conditions for this valve. (2) This valve turns ON for 30 – 50 seconds after the outdoor unit stops, and then turns OFF. (3) This valve turns ON once after the outdoor unit starts.

(A) Heating operation

●

This valve turns ON when poor refrigerant flow at an indoor unit is detected,

and when symptoms of overcharge are detected. After the valve turns OFF, it will not turn ON again for 15 minutes.

(B) Mixed heating/cooling operation

●

This valve turns ON when poor refrigerant flow at an indoor unit is detected,

and when symptoms of overcharge are detected, if the heat exchanger at the

outdoor unit is functioning as an evaporator. (4) This valve turns OFF when an abnormal drop in discharge gas temperature is detected. (5) This valve turns OFF when a drop in the detected receiver tank temperature

continues for a set length of time, and when liquid back-flow is judged to be occurring.

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Page 26

6. Operation of Solenoid Valves

6-3. Balance Valve (BALV)

This valve moves some of the oil from the oil separator to the balance tube. (1) When unit is stopped

This valve is always OFF. (2) When unit is operating

(A) This valve is ON when separator oil self-recovery control is in progress. (B) This valve is ON when unit refrigerant oil recovery control is in progress (oil-supply unit). (C) This valve turns ON for 30 seconds each time a constant-speed compressor starts. (D) This valve turns ON for 60 seconds after defrost control ends.

6-4. Recovery Valve (ORVR)

This valve recovers refrigerant oil from the balance tube to the compressor. (1) When unit is stopped

This valve is always OFF. (2) When unit is operating

(A) This valve is ON when separator oil self-recovery control is in progress. (B) This valve is ON when unit refrigerant oil recovery control is in progress (oil-receiving unit). (C) This valve is ON when control for insufficient gas is in progress. (D) This valve turns ON for 60 seconds after a constant-speed compressor starts. (E) This valve turns ON for 120 seconds after defrost control ends. (F) This valve turns ON for 10 seconds after the outdoor unit stops. (G) This valve remains OFF at all times other than (A) – (F) above.

3-WAY VRF SYSTEM

Control Functions

6-5. Bypass Valve (BPV)

This valve flushes the oil from the balance tubes. In addition, it is used for recovering refrigerant from stopped outdoor units during cooling operation.

(1) When unit is stopped This valve is always OFF.

(2) When unit is operating This valve is ON at the oil-supply outdoor unit when unit refrigerant oil recovery control is in progress.

* This valve repeatedly turns ON/OFF at regular intervals during unit refrigerant oil recovery control. (It is not

constantly ON.)

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3-WAY VRF SYSTEM

7. Outdoor Unit Electronic Control Valves [MOV1, MOV2, MOV4]

Control Functions

7-1. Types of Electronic Control Valves

[U-72MF1U9, U-72MF1U9E, U-96MF1U9, U-96MF1U9E]

Capacity 72 96

Electronic control valve

Electronic control valve 1

Electronic control valve 2

Electronic control valve 4

Heat exchanger 1 valve

Heat exchanger 2 valve

For SC circuit

Heat exchanger 1 valve

Heat exchanger 2 valve

For SC circuit

7-2. Power Initialization

If no indoor units have started (even once) after the power was turned ON, the outdoor unit electronic control valve operates at 480 pulses.

7-3. Heat Exchanger Controlled by Each Electronic Control Valve

The configuration of the heat exchangers is different depending on the capacity of the outdoor unit.

Heat exchanger 1

Heat exchanger 2

Front

Type 72, 96

Operation of electronic control valves during normal unit operation

Heat exchanger status

All indoor units in Cooling mode

All indoor units in Heating mode

Mixed heating/ cooling operation

●

When all indoor units are operating in Cooling mode or Heating mode, all outdoor unit heat exchangers are used

Outdoor heat exchanger condenser

Outdoor heat exchanger evaporator

Condensor 480 480 Maximum ﬂ ow control Stopped 0 0 Refrigerant shut-off Evaporator 45~480 15~480 SH control Stopped 0 0 Refrigerant shut-off Condensor 50~480 50~480 Heat exchanger capacity control Stopped 0 0 Refrigerant shut-off Evaporator 45~480 15~480 SH control Stopped 0 0 Refrigerant shut-off

MOV1 MOV2 Remarks

if even one of the compressors in that outdoor unit is operating.

●

During mixed heating/cooling operation, the number of heat exchangers used varies according the conditions of

the indoor units. However, heat exchanger 1 at the outdoor unit which contains the inverter compressor with the lowest amount of operating time is always used.

●

SH control controls the difference between the liquid temperature and gas temperature to 2 ~ 10°F.

●

During heating mode SH operation, refrigerant may not flow to the heat exchanger.

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3-WAY VRF SYSTEM

7. Outdoor Unit Electronic Control Valves [MOV1, MOV2, MOV4]

Control Functions

7-4. SC Circuit Electronic Control Valve [MOV4]

(1) Operation to increase SC During cooling operation, or mixed heating/cooling operation when the outdoor unit heat exchanger is

functioning as a condenser, the liquid refrigerant which condenses at the outdoor unit heat exchanger flows into the receiver tank, and SC (sub-cool = supercooling) approaches 0°F. When SC is small and the length of the tubing connecting the indoor and outdoor units is long, the pressure loss increases, possibly resulting in lower capacities. Therefore, MOV4 operates at the double tube near the discharge port of the outdoor unit in order to increase SC.

MOV4 uses the receiver tank detection sensor and low-pressure sensor located near the accumulator to

perform control in order to prevent liquid back-up.

Liquid refrigerant (SC = 0˚F)

Gas refrigerant returns to the accumulator.

Refrigerant on the outer side evaporates, cooling the liquid refrigerant on the inner side.

Liquid refrigerant (large SC)

Electronic control valve 4 (expansion valve) controls the flow.

(2) Operation when discharge temperature is high When the discharge temperature increases, the SC circuit electronic control valve opens to 480 pulses. This

intentionally causes a mild liquid back-up, cooling the compressor. This operation takes priority over operation intended to increase SC. It is performed at top priority in all operating modes.

Liquid refrigerant returns to the accumulator.

Liquid refrigerant

Does not fully evaporate, resulting in liquid back-up.

Electronic control valve 4 opens to 480 pulses.

Liquid refrigerant

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Page 29

3-WAY VRF SYSTEM

8. Outdoor Fan Control

Control Functions

8-1. Fan mode

These outdoor units utilize a DC fan motor that can be controlled in a maximum of 16 steps (16 modes). However, fan modes 15 and 16 can only be used if high static-pressure mode has been set. * For information concerning EEPROM settings, refer to the field application functions.

8-2. Outdoor Fan Min. Fan Mode and Max. Fan Mode

Min. fan mode Max. fan mode

Cooling operation

Heating operation 1 14

* Even if the fan mode is 0 during cooling operation, the fan mode may change to 1 at regular intervals for

temperature protection of the inverter hybrid IC.

Outdoor air temp. > 59°F: 1 Outdoor air temp. ≤ 59°F: 0

8-3. Fixed Initial Fan Mode

For the first 30 seconds after operation starts, the mode is fixed at the initial mode which was calculated from the relationship between the outdoor air temperature and the outdoor unit horsepower. If the outdoor unit horsepower changes dramatically, the initial mode may be recalculated and may be again fixed for 30 seconds.

8-4. Operation after Fixed Initial Fan Mode

After the fixed initial fan mode, the fan mode is increased or decreased according to the operating conditions. (1) Cooling mode at all indoor units, or else mixed heating/cooling operation when the outdoor unit is functioning

as a condenser (A) Fan mode is increased when the pressure sensor temperature is high, and is decreased when the pressure

sensor temperature is low. * The fan mode is always increased when the pressure sensor temperature is 122°F or higher.

(B) The fan mode may be decreased when symptoms of insufficient gas are detected at an indoor unit.

(2) Heating mode at all indoor units, or else mixed heating/cooling operation when the outdoor unit is functioning

as an evaporator (A) If the condensation temperature is low, the fan mode is increased at regular intervals. (B) If the condensation temperature is high, the fan mode is decreased in order to prevent excessive loads. (C) The fan mode may be increased when the outdoor liquid temperature drops to 44°F or below.

8-5. Snow Removal Control

(1) When the outdoor air temperature is 50°F or below, the fan operates for 30 seconds every 2 hours in fan mode

8, even when the outdoor unit is stopped or the heat exchanger is not in use. This control is intended to prevent snow from accumulating on stopped fans. (Because the outdoor air temperature cannot be accurately detected when the unit is stopped, a higher outdoor air temperature is used for the control condition, in order to ensure correct operation.)

(2) If the fan mode becomes 0 during cooling operation, the fan mode is changed to 1.

* This control is predictive control. Use a snowfall sensor as necessary according to the installation conditions.

8-6. When the Compressor Magnet Switch Seizing Alarm Occurs

Because there is the possibility that the high pressure has increased, the fan operates in Max. fan mode.

8-7. Other

This unit includes settings for high static-pressure and for Quiet mode. For information about these settings, refer to the field application functions.

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3-WAY VRF SYSTEM

9. Demand Control

Serial-parallel I/O must be connected in order to perform demand control. The below input is received by serial-parallel I/O, and demand control is performed.

The demand values can be set as needed with this device. For more information, refer to the field application functions.

Control Functions

Demand setting

Contact 1 Contact 2

¯¯ {¯ ¯{ {{

: Input present

{

No control Operates to maximum capacity. Rated current — Operates at up to 70% of rated current — Shutdown state —

: Input not present

Control Demand meaning

* The rated current indicates the current value that is listed in the catalog or similar material. If the capacity of this

device is insufficient, the inverter compressor raises its operating frequency in order to maintain capacity. For this reason, it is capable of operating at a current which exceeds the rated current (up to approximately 130%).

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3-WAY VRF SYSTEM

10. Indoor Unit Control of the Electronic Control Valve

Control Functions

10-1. Normal Control

(1) Cooling operation

Position of electronic control valve

Outdoor unit operating

Stopped 20 20

Fan 20 20

Thermostat

Cooling

The SH target value is controlled so that the difference [E3 – E1] is 4 – 12°F, depending on the operating conditions.

OFF

Thermostat ONPerforms SH control in the range of 55 – 480

pulses.

20 20

However, a decline in the required level may cause the SH target value to increase. Be aware that in this case, the electronic control valve closes slightly. This can be easily identified incorrectly as insufficient gas.

(2) Heating operation

(A) Except Type E1

Position of electronic control valve

Outdoor unit operating

Stopped Shuts off refrigerant at 20 pulses. 85

Fan Shuts off refrigerant at 20 pulses. 85

Heating

Thermostat

OFF

Thermostat ONPerforms SC distribution control within the range of 55 –

Shuts off refrigerant at 20 pulses. 85

480 pulses.

Outdoor unit

stopped

–

Outdoor unit

stopped

–

* The SC target value is controlled so that the difference [Pressure temp. sensor – E1] is 10 – 40°F, depending

on the operating conditions.

(B) Type E1

Position of electronic control valve

Outdoor unit

stopped

–

Heating

Outdoor unit operating

Stopped 20 20

Fan 20 20

Thermostat

OFF

Thermostat ONPerforms SC distribution control within the range of 55 –

480 pulses.

20 20

* The SC target value is controlled so that the difference [Pressure temp. sensor – E1] is 10 – 40°F, depending

on the operating conditions. However, if installation is combined with except type E1, the value is controlled so that the difference [Pressure temp. sensor – E1] is 10 – 80°F.

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Page 32

10. Indoor Unit Control of the Electronic Control Valve

10-2. Special Control

Control

Tube refrigerant oil

recovery control

Reverse cycle defrost control

Outdoor cycle defrost control

System refrigerant

oil recovery control

Operating

mode

Cooling All indoor units

Heating All indoor units 480

Heating

Cooling/

heating

Cooling All indoor units

Heating All indoor units 250

Subject indoor units Position of electronic control valve

Stopped Cooling control, according to indoor unit capacity

Fan Cooling control, according to indoor unit capacity

Thermostat

Cooling

Heating

Cooling

Heating

OFF

Thermostat ONFixed pulse for heating, according to indoor unit

Thermostat

OFF

Stopped 20

Fan 20

Thermostat

OFF

Thermostat

OFF

Fixed pulse for cooling, according to indoor unit capacity

Cooling control, according to indoor unit capacity

Cooling control, according to indoor unit capacity However, position is 20 pulses for type E1.

capacity Heating control, according to indoor unit capacity

However, position is 20 pulses for type E1.

Cooling control, according to indoor unit capacity

Heating control, according to indoor unit capacity

Fixed pulse for cooling, according to indoor unit capacity

3-WAY VRF SYSTEM

Control Functions

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3-WAY VRF SYSTEM

11. Solenoid Valve Kit Control

This device connects the solenoid valve kit which is used to switch between indoor unit cooling/heating for 3-WAY types.

Operation of the except type E1 solenoid valve kit

Discharge

valve

Stopped OFF OFF ON OFF

Fan OFF OFF ON OFF

Thermostat

Cooling

Thermostat

Heating

OFF

OFF ON ON ON

ON OFF OFF OFF

Operation of the type E1 solenoid valve kit

Discharge

valve

Stopped OFF OFF ON OFF

Fan OFF OFF ON OFF

Thermostat

Cooling

Thermostat

Heating

OFF

OFF ON ON ON

OFF OFF OFF OFF

ON OFF OFF OFF

Intake

valve

Intake

valve

Balance

valve

Balance

valve

EP valve (evaporation

temp. control valve)

EP valve (evaporation

temp. control valve)

Control Functions

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3-WAY VRF SYSTEM

12. Indoor Special Control

Control Functions

12-1. Switching Control (EC control)

If the settings indicate that an RAP valve kit is present (for type E1, the setting on initial shipment from the factory is “present”), then the thermostat does not turn ON for 3 minutes after the indoor unit operating mode is changed from any mode other than heating (including stopped) to heating with thermostat ON. This is done in order to balance the pressure within the heat exchanger.

* With type E1, this control is activated after defrost control is completed, turning the thermostat OFF for 3 minutes.

12-2. Indoor Unit Thermostat ON/OFF Delay Timer

(1) After the thermostat turns ON at an indoor unit, the thermostat will not be turned OFF by the room temperature

thermostat or discharge temperature thermostat for a period of 3 minutes.

However, if the condensation temperature reaches or exceeds the PX temperature, the thermostat turns off in

order to prevent overload.

(2) After the thermostat turns OFF at an indoor unit, the thermostat will not turn ON again for a minimum of 3 minutes.

12-3. Indoor Unit Refrigerant Oil Self-Recovery Control

This control is performed periodically only during cooling operation. (1) At indoor units which are stopped, operating in fan mode, or where the thermostat is OFF, the electronic control

valve is opened for 1 – 2 minutes.

(2) At indoor units where the thermostat is ON, the electronic control valve position is opened by 10 pulses from

the current position.

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3-WAY VRF SYSTEM

13. Discharge Temperature

Control Functions

(1) Discharge temperature protection alarm This device sets an upper limit discharge temperature of 222°F for all compressors. When the discharge tem-

perature reaches 222°F, that compressor is stopped and restarted. If the same high discharge condition occurs 4 times, then an alarm occurs.

After a compressor has stopped, that compressor will not operate until the temperature has dropped to or below

the start-prohibit temperature.

Discharge temperature protection list

Compressor No. Compressor 1 Compressor 2

Type Inverter Constant-speed

Stop temp. 222 222

Start-prohibit temp. 194 194

Alarm display P03 P17

(2) Discharge sensor trouble detection control

An alarm occurs if the discharge temperature remains abnormally high when the system has been stopped for

60 minutes.

* In this case, possible causes include sensor failure and compressor overheating caused by an insufficient

level of refrigerant.

The alarm also occurs if the sensor temperature is at or above the abnormal temperature (176°F) when 20 min-

utes have passed after the compressor stopped.

* In this case, it is possible that the discharge temperature from a different outdoor unit is being detected, due to

an error in the installation of the discharge thermistor.

Discharge sensor failure list

Compressor No. Compressor 1 Compressor 2

Type Inverter Constant-speed

Stop temp. F04 F05

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3-WAY VRF SYSTEM

14. Current Protection

(1) Fan motor

Alarm Description

P22 Occurs when the fan motor detects overcurrent, or when the motor is locked and does

not turn.

(2) Inverter compressor

Alarm Description

P16 Occurs during ordinary operation when overcurrent (27 A) is detected. P26 Occurs under the same conditions as P16 when the inverter compressor is operating

at or above 80 Hz.

P29 Occurs when missing phase or overcurrent (48 A) is detected at inverter compressor

start. (The alarm at frequencies below 25 Hz)

H31 Occurs when HIC detects overcurrent (75 A), or when an abnormal high temperature

(302 °F) is reached.

The inverter current includes a primary current and secondary current. The alarm judgment utilizes both

currents. Generally, the secondary current is larger that the primary current.

(3) Constant-speed compressor

An alarm occurs when overcurrent or lock current is detected.

List of overcurrent and lock currents

Control Functions

Outdoor unit

type

96 Compressor 2 23.1 27.3

Constant-speed

compressor

Overload

current [A]

Lock current

[A]

List of Alarms

Compressor

No.

Detected

current

Alarm display H11 H12

Compressor 2

Overcurrent

Lock

current

(4) CT circuit detection trouble

Alarm Description

Compressor 1 (inverter compressor)

Compressor 2 (constantspeed compressor)

H03 Occurs when an open CT circuit is detected in the inverter

compressor.

H13 Occurs when a current value of 1.5 A or less is detected

when the constant-speed compressor is operating.

If the inverter compressor operating frequency is low, the current value is also low. Therefore this alarm is

detected only when the compressor is stopped.

The operating current of the constant-speed compressors is always higher than 1.5 A. Therefore, this alarm

occurs as the result of an open circuit or failure.

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3-WAY VRF SYSTEM

15. Low Oil Alarm

Ordinary operation is resumed after system oil recovery control is completed. If a stop occurs again as a result of a low oil level, this alarm occurs. This alarm will not occur if system oil recovery control has not already been performed.

However, the alarm may not occur if the outdoor unit where the system oil recovery conditions were met is not the same as the outdoor unit which stopped due to low oil level. In this case, system oil recovery control may be performed again.

Low oil alarm

Alarm display H07

Control Functions

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3-WAY VRF SYSTEM

16. Pressure Sensor Failure

This system contains 2 types of pressure sensors: a high-pressure sensor and a low-pressure sensor. (1) High-pressure sensor failure Identification of a failure caused by a loose or displaced connector is based on the relationship between the pres-

sure detected by the high-pressure sensor and the operation of the high-pressure switch, and on the relationship between the temperature detected by the high-pressure sensor and the various temperature thermistors.

However, when the pressure increases suddenly, the judgment for the high-pressure sensor failure alarm may

occur before operation of the high-pressure switch. Therefore, before concluding that there is a failure in the pressure sensor, first verify that the service valve was not accidentally left closed, that there are no blocked circuits, and that there is no leakage of refrigerant into stopped outdoor units. Also check for a difference between

the high pressure measured by the manifold gauge and the pressure detected by the pressure sensor. (2) Low-pressure sensor failure Identification of a failure caused by a loose or displaced connector is based on the relationship between the

temperature detected by the low-pressure sensor and the various temperature thermistors. Before concluding that a failure has occurred, check for a difference between the low pressure measured by the

manifold gauge and the pressure detected by the low-pressure sensor.

High-pressure sensor failure Low-pressure sensor failure

Alarm display F16 F17

Control Functions

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3-WAY VRF SYSTEM

17. Backup Operation

Control Functions

17-1. Automatic Backup Operation

This system includes a function for automatic backup operation. An alarm is also displayed to inform the operator that a failure has occurred.

(1) Alarms that result in automatic backup operation When compressor trouble or fan motor trouble makes emergency continued operation impossible, automatic

backup operation mode is engaged. Automatic backup mode is not engaged in cases of communications alarms, automatic reset alarms, and other instances when emergency operation is possible by pressing the

remote controller buttons or changing other conditions. The alarms that result in automatic backup mode are P16, P22, P26, P29, H11, H12, and H31. (2) Start of automatic backup operation If the above alarms occur, the alarm is displayed on the control device. Pressing the control device button again

starts automatic backup mode. (3) Operation [1] When 1 outdoor unit is installed When 1 compressor has failed, backup operation is possible using the other compressors. However, operation

does not occur when the outdoor fan is unable to operate as a result of alarm P22. [2] When multiple outdoor units are installed When automatic backup mode is engaged, the outdoor unit where the above alarm occurred stops operating.

However, if one or more of the compressors is able to operate, then this outdoor unit operates only when the

operation of all outdoor units is required for special control or other system purposes. (4) Alarm display If a wired remote controller is present, the (5) Canceling automatic backup operation Repair the outdoor unit where the failure occurred. When repairs are completed, reset the power on outdoor

unit No.1.

After automatic backup mode has been engaged, it will not be canceled automatically when the repair of the

failed outdoor unit is completed. Automatic backup mode will be canceled only when the power on outdoor

unit No.1 is reset. Therefore, after repair work is completed, be sure to check whether or not automatic backup

mode has been canceled. How to check: [1] Use test run or other means to verify that all outdoor units operate continuously. [2] If a wired remote controller is present, check that the display has disappeared.

display blinks during operation.

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3-WAY VRF SYSTEM

17. Backup Operation

Control Functions

17-2. Manual Backup

If an alarm that does not result in automatic backup occurs frequently, possible causes include failure (such as refrigerant leakage) of a functional part at an outdoor unit other than the unit where the alarm occurs.

In this case, because the outdoor unit service valve must be closed, backup operation must be performed manually. (1) Backup operation procedure [1] Disconnecting the failed outdoor unit (A) Reduce the number of outdoor units set at outdoor unit No.1 by the number of failed outdoor units. Then

turn OFF the power or disconnect the inter-unit communications line at the failed outdoor units. (B) Close all service valves at the failed outdoor units. (C) Reset the power at outdoor unit No.1. [2] Disabling operation of 1 compressor At the S010 switch on the PCB of the failed outdoor unit, turn ON the switch for the compressor to disable, and

turn ON the “backup” switch.

INV AC2AC1 Backup

OFF

(A) Compressor 1 backup

(B) Compressor 2 backup

• In order to perform simultaneous backup operation for 2 or more compressors, use a combination of the switch

settings shown above.

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3-WAY VRF SYSTEM

18. Service Maintenance Functions

The outdoor unit EEPROM settings can be used for the following functions.

Control Functions

18-1. Outdoor Unit Noise Countermeasure: EEPROM 05 (set at each outdoor unit)

This unit includes 3 types of Quiet modes. (However, when they are engaged, operation is in Quiet mode 24 hours a day.) Selecting a Quiet mode results in operation that gives priority to reducing noise. Because these modes involve restrictions on outdoor unit fan modes and the operation frequency, the capacity will be somewhat reduced.

Setting Max. fan mode Effect Amount of capacity reduction

014

112

211

310

Normal operation (setting at time of factory shipment)

Noise reduced by approx. 1 – 2 dB from the catalog value.

Noise reduced by approx. 2 – 3 dB from the catalog value.

Noise reduced by approx. 5 dB from the catalog value.

Approx. 0.5 hp

Approx. 1.2 hp

Approx. 1.8 hp

* If Quiet mode is set, the capacity will begin to decrease during heating operation at low outdoor temperatures,

when the outdoor air temperature is below standard conditions.

* It is possible to set Quiet mode only for nighttime by using the snowfall sensor input terminal and a timer for quiet

operation. In this case, operation is the Quiet mode determined by the above setting.

18-2. Slime Countermeasure: EEPROM 0C (set only on the main unit)

This setting controls the operation of the drain pump.

Setting Description

0 Normal control (setting at time of factory shipment)

1 The drain pump operates for 20 minutes at 2-hour intervals.

2 The drain pump operates for 20 minutes at 20-minute intervals.

3 The drain pump operates constantly.

18-3. Delayed Start for Each System: Outdoor EEPROM 3E (set only on outdoor unit No. 1)

The operation start time can be delayed according to the set system addresses. This setting reduces the voltage drop by preventing multiple systems from starting at the same time when operation

is restarted after multiple operating systems were stopped due to a power outage or other cause.

Setting Effect

0 No delayed start (setting at time of factory shipment)

1 Start begins after [1 second × System address]

2 Start begins after [2 seconds × System address]

3 Start begins after [3 seconds × System address]

18-4. Automatic Backup: Outdoor EEPROM 48 (set only on outdoor unit No. 1)

Automatic backup is set to occur at the time the unit is shipped from the factory. However, the automatic backup function can be disabled by changing this setting to 1.

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3-WAY VRF SYSTEM

18. Service Maintenance Functions

Control Functions

18-5. Automatic Backup Mode: Outdoor EEPROM 49 (set only on outdoor unit No. 1)

Two types of automatic backup modes (when multiple outdoor units are installed) can be selected.

Setting Operation Condition

0 Backup outdoor units operate only during special control. Setting at time of factory

shipment

1 Only the backup compressors remain stopped. Other OK

compressors installed in the same outdoor unit operate as normal.

* Even when “1” is set, the outdoor unit will remain stopped if all of the compressors in the outdoor unit have failed. * If only 1 outdoor unit is installed, the operation is according to setting “1” even if “0” is set.

18-6. Snowfall Input Switching: Outdoor EEPROM 4A (set at each outdoor unit)

The snowfall sensor input terminal on the outdoor unit PCB is used for input from the snowfall sensor. It is also possible to connect an external timer and use it to enable nighttime Quiet mode operation.

Setting Operation

0 Used for snowfall sensor input (setting at

time of factory shipment).

1 Used for Quiet mode input.

18-7. Optional Solenoid Valve Control Operation Setting:

Outdoor EEPROM C0 (set at each outdoor unit)

Setting Operation

0 No output (setting at time of factory shipment)

1 Refrigerant shut-off valve control (for cooling when the outdoor air temperature is

below standard conditions)

2—

External liquid valve control (used in special cases when the discharge gas temperature is likely to especially rise)

18-8. High Static Pressure Mode: Outdoor EEPROM 8F (set at each outdoor unit)

This product can be made compatible with high static pressure by changing the settings. By changing the setting item 8F to “6,” this product can be made compatible with outdoor unit static pressure of

approximately 0.0085 psi (10 hp).

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3-WAY VRF SYSTEM

18. Service Maintenance Functions

Control Functions

18-9. Compressor operating sequence: Outdoor EEPROM 46

(set at outdoor units which include CCU functions)

When this setting is set to “1,” the compressors start in sequence beginning from the No. 1 outdoor unit. (The setting is “0” at the time of shipment. With this setting, compressors with lower operating time are started

first in order to balance the compressor operating times.)

18-10. Demand value setting: Outdoor EEPROM 1A, 1B

(set at outdoor units that include CCU functions)

Demand setting

Contact 1 Contact 2

¯¯

No limit

Control Demand meaning

Operates to maximum capacity.

{¯

¯{

{{

Demand can be set from 40 – 130% at EEPROM 1A.

Demand can be set from 40 – 130% at EEPROM 1B.

Remains stopped.

Current is limited to the set values.

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3-WAY VRF SYSTEM

19. Other Functions

Control Functions

19-1. Snowfall Sensor Functions: Outdoor EEPROM 04

A unit identified as having a snowfall sensor attached will periodically send a signal indicating the snowfall sensor input status to all outdoor units in the same system (or all wired outdoor units in the case of linked systems). It is therefore unnecessary to install and wire multiple snowfall sensors.

(1) Snowfall sensor settings

* If the snowfall sensor is used, then depending on the circumstances it is necessary to make the correct setting at

* If “control is not performed” is set, control by the above signal is ignored. This setting is used in order to conserve

(2) Control operation [1] Outdoor units where “sensor input present” is set send the snowfall sensor input information every 10

[2] At systems where “control is performed” is set, the above information is used to control operation of the

[3] At systems where “control is not performed” is set, the snowfall sensor input and above information ignored,

[4] In the case of a W-Multi system, control can be performed when snowfall sensor input is connected to any

Snowfall sensor input information is detected once every 10 minutes. Therefore, the outdoor fan may continue

In addition, the outdoor fan may remain stopped for up to 10 minutes when snowfall sensor input is present.

Setting Operation

2 3

all outdoor units in the system.

energy at outdoor units that include a snowfall-protection hood. Recommended: If a low-speed fan mode is required (for all-year cooling or other reasons), install a snowfall-

minutes to all linked systems if the system wiring is linked.

outdoor fan.

and the outdoor fan does not operate.

outdoor unit.

operating for up to 10 minutes even when there is no snowfall sensor input.

Sensor input not present. Control is performed. (Setting at time of factory shipment)

Sensor input present. Control is performed.

Sensor input not present. Control is not performed. Sensor input present. Control is not performed.

protection hood and set this setting to ON.

19-2. Function for Automatic Judgment of Insufficient Refrigerant Gas and Overcharge

This system includes a simple function for judging the level of refrigerant. However, be aware that false judgments may occur if the control elements of the outdoor unit or indoor unit fail.

(1) Starting refrigerant level judgment mode Short-circuit the CHECK pin on the No. 1 outdoor for 4 seconds or longer to engage this mode. (The LED on

the outdoor unit PCB begins blinking.)

(2) Conditions for refrigerant level judgment After judgment mode starts, judgment occurs when all outdoor units in the system have been operating

continuously for 30 minutes or longer.

* Refrigerant level judgment requires that all outdoor units operate continuously for 30 minutes or longer. This is

in order to prevent incorrect adjustment of the refrigerant level based on false detection caused by refrigerant accumulation or recovery at stopped outdoor units (stopped due to failures of functional elements). After the judgment is displayed, repeated judgment will occur under new operating conditions if all outdoor units continue operating. Therefore, the judgment display may change when later judgments occur.

* Judgment mode is automatically canceled after 4 hours.

1 - 36

Page 45

19. Other Functions

(3) Outdoor unit PCB LED indications in judgment mode

LED1 LED2 Recommended response

Judgment mode Blinking Blinking

Normal ON ON

Insufﬁ cient gas Blinking OFF Charge with refrigerant a little at a time.

3-WAY VRF SYSTEM

Control Functions

Overcharge OFF Blinking Recover refrigerant a little at a time.

Judgment not possible

Blinking

alternately

When judgment mode is not engaged, the LED indicates the normal display (OFF), or else indicates alarms or

other information.

If the insufficient gas or overcharge judgment is not stable, then recover refrigerant a little at a time when the

overcharge display appears. End refrigerant adjustment when the normal or insufficient gas display appears.

(4) Canceling judgment mode When judgment mode is cancelled, the LED returns to the standard status display (OFF unless an alarm or

other event has occurred). [1] Automatic cancel Judgment mode is canceled automatically when 4 hours have passed after it was started. [2] Forced cancel Short-circuit the CHECK pin while the judgment mode display is active in order to cancel judgment mode. <Reference> General Guidelines for Insufficient Gas and Overcharge Judgment in automatic judgment mode can be problematic in some cases. Therefore, the following guidelines

are provided for general judgment of the refrigerant amount.

• Symptoms of insufficient gas

Cooling operation

There is an indoor unit where the position of the electronic control valve is much higher (open by 300 pulses or more) than it was at start, and the difference [E3 – E1] at that indoor unit is large (30°F or more).

Heating operation

There is an outdoor unit where the position of the electronic control valve is much higher (open by 300 pulses or more) than it was at start, and the difference [Liquid temp. – Gas temp.] at that outdoor unit is large (30°F or more).

• Symptoms of overcharge

Cooling operation

Heating operation

The high-pressure sensor temperature is 134°F or higher, and the difference [Pressure sensor temp. – Liquid temp.] at that outdoor unit is large (30°F or more).

There is an indoor unit where the position of the electronic control valve is much higher (open by 300 pulses or more) than it was at start, and the difference [Pressure sensor temp. – E3] at that indoor unit is large (50°F or more).

These are only guidelines, therefore the judgment may vary depending on the installation conditions, load

characteristics, and other elements.

1 - 37

Page 46

– MEMO –

1 - 38

Page 47

3-WAY VRF SYSTEM

Contents

Outdoor Unit Repair Procedures

2. OUTDOOR UNIT REPAIR PROCEDURES

1. Removing Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2. Removing Electrical Component Box and Duct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

3. Discharging Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

4. Backup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

5. Recovering Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

6. Checking for Leakage After Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

7. Evacuating System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

8. Charging Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16

9. Pumping Out Refrigerant from Outdoor Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20

10. Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

11. High and Low Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35

12. Replacing 4-way valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36

2 - 1

Page 48

3-WAY VRF SYSTEM

1. Removing Panels

Outdoor Unit Repair Procedures

Procedures:

1. Removing Panels

2. Removing Electrical Component Box and Duct

3. Discharging Compressor Oil

4. Backup Operation

5. Recovering Refrigerant

6. Checking for Leakage After Repair

7. Evacuating System

8. Charging Compressor Oil

9. Pumping Out Refrigerant from Outdoor Unit (when repairing parts other than compressor)

10. Compressor

11. High and Low Pressure Sensors

12. Replacing 4-way valve

(1) Front panel removal (Fig. 2-1)

• Remove the front panel (remove 11 screws).

(2) Power outlet panel & valve cover removal (Fig. 2-2)

• Remove the power outlet panel (remove 2 screws).

• Remove the valve cover (remove 2 screws).

Front panel

Fig. 2-1

Power outlet panel

2 - 2

Valve cover

Fig. 2-2

Page 49

3-WAY VRF SYSTEM

2. Removing Electrical Component Box and Duct

Be sure to turn off the power before removing the electrical component box. Then check that the power LED (D53) on the control PCB of the outdoor unit is not lit.

(1) Remove the electrical component box cover

(remove 6 screws). (Fig. 2-3)

Outdoor Unit Repair Procedures

(2) Remove power and control wires from terminals.

(3) Remove internal wires with extended connectors

on the outdoor control PCB. (Solenoid valves, thermistors, crankcase heaters and others)

(4) Disconnect power lines connected to the

secondary terminals of the magnetic contactor for the compressor.

Electrical component box cove

Fig. 2-3

(5) Remove the electrical component box (remove 2

screws). (Fig. 2-4)

CAUTION

Be sure to release the locking mechanism

before disconnecting each connector.

(6) Remove the center duct. (Fig. 2-5)

The center duct is fitted into the upper and

lower ducts and held in place by the electrical component box, an arrangement that makes possible independent removal of the center duct.

Electrical

component box

Fig. 2-4

Upper duct

Center duct

Lower duct

Fig. 2-5

2 - 3

Page 50

2. Removing Electrical Component Box and Duct

(7) Remove the lower duct. (2 screws, 1 tab) (Fig. 2-6)

Lower duct

3-WAY VRF SYSTEM

Outdoor Unit Repair Procedures

Fig. 2-6

(8) Remove the upper duct. (3 screws) (Fig. 2-7)

Upper duct

Fig. 2-7

2 - 4

Page 51

3-WAY VRF SYSTEM

3. Discharging Compressor Oil

Discharged oil can be used for checking the condition of the system. Based on the appearance and color of the discharged oil, a judgment can be made on whether the system is operating normally or not.

Outdoor Unit Repair Procedures

3-1. Discharging Oil from Oil Separator

Recover the refrigerant from the outdoor unit following the procedure given in “5. Recovering Refrigerant.” Install hoses as indicated on the equipment and feed nitrogen gas gradually to provide pressure to the system from the low-pressure outlet and collect oil in a pan or container. (Fig. 2-8)

• The low-pressure outlet port is at the Lo side of the right side.

CAUTION

Packless valve or the like

• A faulty outdoor unit may remain pressurized. The oil delivery port employs a Schrader-type push-to-release valve. Be careful to avoid accidental oil release when using the port.

Container

Oil delivery port (For 1/4" (6.35mm)-dia. connector)

Manifold gauge

Lo Hi

Nitrogen gas

Low-pressure outlet port (For 5/16" (7.94mm)-dia.

Fig. 2-8

connector)

3-2. Discharging Oil in Compressor

Recover the refrigerant in the outdoor unit following the procedures in “5. Recovering Refrigerant.” Remove the compressor and discharge the oil in it. Refer to “10. Compressor” for detailed procedures.

3-3. Checking the Oil

Acceptance/rejection criteria for the oil

Condition of

refrigeration cycle

Normal Yellowish None 0.02 or less 3.5 or less

Abnormal

overheat operation

Motor burnout

Brownish

Brownish /

blackish

Condition of oil Judgment criteria for changing oil*

Color Odor Total acid value Hue

Smells somewhat

(not as strong as below)

Pungent / burnt odor

0.06 or over 4.0 or over

Changing the oil and system cleaning

with dry-cores are necessary.

Changing the oil and system cleaning

with dry-cores are necessary.

* It is difficult to measure the total acid value in the field, therefore oil hue and odor are the rule of thumb. Checking

for carbon deposits and abrasive metal powder can additionally be used to assess the system condition.

2 - 5

Page 52

3-WAY VRF SYSTEM

4. Backup Operation

This system includes an emergency automatic backup function that allows the A/C to operate during the period after trouble occurs until repairs are made. However, during repair and at other times, use manual backup operation.

Outdoor Unit Repair Procedures

4-1. Automatic Backup

For details, refer to the control functions section. After the alarm details are sent to the control device, control for automatic backup operation begins when the

ON/OFF button of the wired remote controller is pressed again (operation is started after the alarm is cleared). During this operating mode, “CHECK” flashes on the wired remote controller only to inform the user that operation is in backup mode. However this is not displayed on any other control devices.

• In order to cancel automatic backup mode, it is necessary to reset the power on the control PCB of the outdoor unit where the outdoor unit No. setting (S007) on the control PCB is set to No. 1 (main unit).

CAUTION

Backup operation is intended as emergency operation until repairs are made. Have repairs made as soon as possible.

If the power is not reset on the control PCB of the No. 1 outdoor unit (main unit), backup mode operation will continue after the repairs are completed.

4-2. Manual Backup

This backup operation is the conventional method of backup operation. It involves disconnecting the failed outdoor unit from the system, and operating only the normal outdoor units.

4-2-1. Backup operation by disconnecting the outdoor unit

(1) Changing the outdoor unit control PCB settings

< If the failed outdoor unit is not the No. 1 unit>

• Settings at No. 1 unit (main unit)

Switch on outdoor unit control PCB Action

System address (S003, S002) No change

No. of indoor units (S005, S004) No change

No. of outdoor units (S006) Subtract the number of failed units from the current setting.

Outdoor unit No. (S007) No change

• Settings at normal outdoor units other than the No. 1 unit

No particular changes

• Settings at the failed outdoor unit

No particular changes However, close all service valves (suction tube, discharge tube, liquid tube, balance tube) at the failed outdoor unit, and disconnect the wiring between the outdoor units.

2 - 6

Page 53

3-WAY VRF SYSTEM

4. Backup Operation

If the No. 1 unit (main unit) has failed, a different outdoor unit must be set as the No. 1 unit (main unit).

• Settings at the failed No. 1 outdoor unit

– No particular changes –

• Settings at No. 1 unit (main unit)

However, close all service valves (suction tube, discharge tube, liquid tube, balance tube) at the failed outdoor unit, and disconnect the wiring between the outdoor units (main-sub unit wiring).

Switch on outdoor unit control PCB Action

System address (S003, S002) Make the same settings as on the failed No. 1 unit.

No. of indoor units (S005, S004) Make the same settings as on the failed No. 1 unit.

No. of outdoor units (S006) Subtract the number of failed units from the current setting.

Outdoor Unit Repair Procedures

Outdoor unit No. (S007) Change to “1.”

To this outdoor unit, connect the inter-unit communication line which was previously connected to the No. 1 unit (main unit).

After recovery work is completed, return the outdoor unit No. setting (now =

1) to the value it was before the failure and repair. If this is not done, there will

CAUTION

• Settings at other outdoor units

No particular changes.

(2) Adjusting the refrigerant for backup operation

During backup operation, all of the service valves on the failed unit are closed. However, if a check of the backup operating conditions shows that the level of gas is low, recover the refrigerant from the failed outdoor unit. If the level of gas is too high, collect refrigerant at the failed outdoor unit.

Recovering refrigerant

●

With the normal outdoor units operating, monitor the operating condition and open/close the suction tube

service valve on the failed outdoor unit where all the service valves were closed. In this way, recover refrigerant from the failed outdoor unit in order to adjust the amount of refrigerant in the system. After adjusting the amount of refrigerant, close the suction tube valve at the failed outdoor unit.

Collecting refrigerant in the failed outdoor unit

●

• Short-circuit the vacuum application pin (CN102) on the control PCB of the failed outdoor unit where the

service valves are closed, then turn the power ON. Also disconnect the wiring between the outdoor units.

• With the normal outdoor units operating, monitor the operating condition and open/close the liquid tube

service valve on the failed outdoor unit where all the service valves were closed. In this way, collect refrigerant in the failed outdoor unit in order to adjust the amount of refrigerant in the system.

be duplicated outdoor unit No. settings. In this case an alarm does not occur immediately, however operation may be unstable. Reconnect the inter-unit communications line to the No. 1 unit.

2 - 7

Page 54

3-WAY VRF SYSTEM

4. Backup Operation

• After adjusting the amount of refrigerant, turn OFF the power at the failed outdoor unit, release the

short-circuit at the vacuum application pin, and close the liquid tube valve at the failed outdoor unit. * Refrigerant recovery is not affected by the power status of the failed outdoor unit. However, collecting

refrigerant in the failed outdoor unit is affected by whether the power at that outdoor unit can be turned ON. If the power cannot be turned ON, use a refrigerant recovery device and recover the refrigerant into a recovery cylinder in order to adjust the amount of refrigerant in the system.

4-2-2. Backup operation by setting the failed compressor not to operate

Backup operation settings for each compressor

INV compressor AC1 compressor Setting for backup operation

OK Failed DIP switch S010:

Turn BACK UP and AC1 ON.

Failed OK DIP switch S010:

Turn BACK UP and INV ON.

Outdoor Unit Repair Procedures

2 - 8

Page 55

3-WAY VRF SYSTEM

5. Recovering Refrigerant

Outdoor Unit Repair Procedures

The following equipment and tools are required:

Jumper wire with clips, adjustable wrench, set of manifold gauge valves specially designed for refrigerant R410A only, vacuum pump, refrigerant recovery unit, pre-purged refrigerant cylinder for recovery, flathead screwdriver, and outdoor unit maintenance remote controller.

5-1. Refrigerant Recovery Procedures (from outdoor unit)

(1) Turn off the power of the outdoor unit beforehand (at power mains). (2) Fully close each service valve on the suction tube, discharge tube, liquid tube, and the balance tube of the

outdoor unit.

(3) Connect the outdoor unit’s high-pressure and low-pressure outlet ports with the Hi and Lo sides of the manifold

gauge valves using hoses. (Fig. 2-9)

The remaining refrigerant in the faulty outdoor unit may create internal

CAUTION

(4) Connect the manifold gauge valves, refrigerant recovery unit, and recovery cylinder using hoses. To avoid the

entry of air into the refrigerant tubing, carry out this connection work carefully. (Fig. 2-9)

pressure. Before connecting hoses, be sure to confirm that each of the manifold gauge valves is tightly closed. Note that the connection ports employ Schradertype push-to-release valves.

For detailed procedures such as connecting the refrigerant recovery unit

CAUTION

with the recovery cylinder and methods used for recovery, follow the specific instructions that came with the refrigerant recovery unit.

(5) Locate the AP (Air Purge) pins on the control PCB in the faulty outdoor unit and short them using the clips of

the jumper wire. Then restore electrical power to the outdoor unit.

By short-circuiting the AP pins, each solenoid valve in the outdoor unit is

CAUTION

forcibly opened as soon as power comes on, which releases all remaining refrigerant into the recovery cylinder. Since neglecting this procedure may leave some refrigerant in the system, it is important that you carry out this step.

(6) Carry out refrigerant recovery.

CAUTION

To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.

Manifold

gauge

Refrigerant recovery unit

Refrigerant recovery cylinder

High-pressure outlet port (For 5/16" (7.94mm)-dia. connector)

Fig. 2-9

2 - 9

Low-pressure outlet port (For 5/16" (7.94mm)-dia. connector)

Page 56

3-WAY VRF SYSTEM

5. Recovering Refrigerant

Outdoor Unit Repair Procedures

5-2. Refrigerant Recovery Procedures (Indoor Unit)

The flowchart below shows the refrigerant recovery procedures you must follow when replacing or repairing the indoor unit due to trouble in the refrigerant circuit.

START

5-2-1. Cooling operation (for all units)

Ball valve is provided in the indoor unit

YES

5-2-2.

Refrigerant recovery procedures (1)

Turn off all equipment in system

When replacing or repairing a faulty

unit, let other normal indoor units run

(excluding indoor unit where refrigerant

Power can independently be turned

off for indoor unit where refrigerant is

Change controllable number of indoor

units (including changes in group

control and integrated-control settings)

Other indoor units can operate normally

Check for leakage in repaired unit

Evacuate air from repaired unit

Charge refrigerant in repaired unit

(Amount of charge should equal that

recovered by refrigerant recovery unit)

is recovered)

YES

recovered

YES

Replace or repair faulty unit

Refrigerant recovery

5-2-3.

procedures (2)

Modify power to permit turning off

power to refrigerant-recovered

indoor units independently

Turn off all equipment in system

Replace or repair faulty unit

Check for leakage in repaired unit

Evacuate air from repaired unit

Charge refrigerant in repaired unit

(Amount of charge should equal that

recovered by refrigerant recovery unit)

Ready for operation

END

Replace or repair faulty unit

Check for leakage in repaired unit

Evacuate air in repaired unit

Change controllable number of indoor

units (including changes in group

control and integrated-control settings)

Open ball valve

Ready for normal operation

END

Service work performed on indoor units is done simultaneously using the service ports at the liquid (narrow tube) side

★

and the gas (wide tube) side ball valves. Refer to each section in the “Installation Instructions” on refrigerant charging,

Charge refrigerant in repaired unit

(Amount of charge should equal that

recovered by refrigerant recovery unit)

Open the ball valve

Ready for normal operation

END

leak checking, and evacuation procedures.

2 - 10

Page 57

3-WAY VRF SYSTEM

5. Recovering Refrigerant

Outdoor Unit Repair Procedures

5-2-1. Cooling operation (for all units)

(1) If the remote controller (CZ-RTC2) is used for maintenance of the outdoor unit

Connect the outdoor unit maintenance remote controller to the RC connector (CN006) (3P) (BLU) on any

➀

one of the outdoor unit control PCBs. Then start a test run of all units. (Press and hold the button for 4 seconds.)

Press the

➁

CAUTION

Use the remote controller (CZ-RTC2) to check the operating status of the indoor units. Check that all units

➂

are operating in Cooling mode.

(MODE) button and change to cooling operation.

Even if the mode that is originally displayed is “Cool,” be sure to press the (MODE) button once or more to change to cooling operation. (Pressing the (MODE) button ensures that heating/cooling operation is not mixed and that all units are operating in either Heating or Cooling mode.)

(CHECK)

CAUTION

(2) If the remote controller (CZ-RTC2) is not available for maintenance of the outdoor unit

Determine the outdoor unit where the unit No. setting (S007) (3P DIP switch) (BLU) on the outdoor unit

➀

control PCB is set to No. 1.

Short-circuit the mode-change pin (CN101) on the outdoor unit control PCB of the No. 1 unit. Then

➁

short-circuit the test-run pin (CN023) to start operation. (Short-circuiting the mode-change pin ensures that heating/cooling operation is not mixed and that all units are operating in either Heating or Cooling mode.)

Check the displays of the indoor unit remote controllers. Check that all units are operating in Cooling mode.

➂

If all units are operating in Heating mode, perform the steps listed below.

CAUTION

Release the short-circuit at the test-run pin (CN023) on the outdoor unit control PCB of the No. 1 unit. Then

➃

short-circuit the stop pin (CN104) to stop operation.

Short-circuit the mode-change pin (CN101) on the outdoor unit control PCB of the No. 1 unit.

➄

* Switching of the 4-way valve occurs immediately before operation starts. Therefore it does not change at

this time. (Mode change cannot be judged from the sound.)

Short-circuit the test-run pin (CN023) on the outdoor unit control PCB of the No. 1 unit. Then check the

➅

displays of the indoor unit remote controllers. Check that all units are operating in Cooling mode.

With the 3-way valve, it is difficult to determine whether operation is heating or cooling by touching the tubing.

5-2-2. Refrigerant recovery procedures (1) (using indoor unit ball valve)

(1) If a ball valve with a service port has been provided in the indoor unit as shown in Fig. 2-10, follow the

instructions given in (2) through (6) below. If the service port is instead located in the outdoor side, follow the instructions in “5-2-3. Refrigerant recovery procedures (2).”

(2) After running the unit in Cooling mode for about 5 minutes as described in “5-2-1. Cooling operation (for all

units),” fully close the discharge line, the liquid line ball valve, and indoor unit ball valve. (3) Run the unit in Cooling mode for 10 to 20 minutes more. (4) Fully close the suction line ball valve, and stop the operation of all units. (5) Use hoses to connect the manifold gauge valves, refrigerant recovery unit, and refrigerant recovery cylinder

with each other. (Fig. 2-10) Do each connection quickly to prevent air from entering the tubing.

CAUTION

Remaining refrigerant may create internal pressure, therefore care should be taken when connecting the hoses.

2 - 11

Page 58

5. Recovering Refrigerant

Outdoor Unit Repair Procedures

(6) Recover the remaining refrigerant from the indoor unit using the refrigerant recovery unit.

3-WAY VRF SYSTEM

NOTE

To determine completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.

Ball valve (separately purchased) Service port

Outdoor

unit side

Refrigerant

recovery

Refrigerant recovery cylinder

Discharge tube

unit

Suction tube

Liquid tube

Manifold

gauge

Solenoid valve kit

Fig. 2-10

Solenoid

valve kit

Indoor unit

5-2-3. Refrigerant recovery procedures (2): for indoor unit with no ball valve

Refrigerant in all indoor units and the refrigerant tubing circuit must be pumped into the outdoor unit. The maximum refrigerant storage capacity per a single outdoor unit is approx. 529 oz. Thus, in order to collect all refrigerant from the system, a separate refrigerant recovery unit is necessary. Follow these procedures to correctly perform pump down. Perform work correctly, according to the work procedures given below.

Connect the manifold gauge to the high- and low-pressure outlet ports on the outdoor unit where pump down

➀

will be performed. Be sure that no air enters the tubing at this time.

Fully close the discharge tube valve on the outdoor unit where pump down will be performed.

➁

Follow the instructions in “5-2-1. Cooling operation (for all units)” and operate all units in Cooling mode for

➂

approximately 5 minutes. Then fully close the liquid tube valve on the outdoor unit where pump down will be performed.

When the high-pressure gauge reaches 406.1 psi or higher, or the low-pressure gauge reaches 72.5 psi or

➃

below, at the outdoor unit where pump down is being performed, press the ON/OFF button on the outdoor unit maintenance remote controller to stop operation at all units. Then immediately fully close the suction tube valve on the outdoor unit where pump down is being performed.

* If the outdoor unit maintenance remote controller is unavailable, follow the procedure below to stop all of the

units.

Pull out the SCT connector (2P) (YEL) (CN231) on the outdoor unit control PCB of the unit where pump

down is being performed. When the SCT connector is pulled out, immediately alarm F12 (sensor trouble) occurs and all outdoor units stop operating. Be sure that you do NOT grasp the lead wire when pulling out the connector. Removing any other connector may not cause the units to stop. Therefore be sure to pull out the SCT connector only.

CAUTION

Turn off power to all equipment in the system. Then pull out the RC1 connector (4P) (BLU) (CN106) on the

➄

It is not necessary to recover the refrigerant from the balance tube. Therefore do not operate the balance tube valve.

outdoor control PCB in the outdoor unit for which pump down has been completed. * By pulling out the RC1 connector, communication between the main and the sub outdoor units will be isolated.

Change the setting of controllable outdoor unit numbers (reduce by 1 unit).

➅

* If the setting is incorrect, the E30 alarm (outdoor unit serial communication signal error) occurs and the unit

will not operate.

Turn on power for all equipment in the system and let the remaining outdoor units run in Cooling mode.

➆

Repeat steps (1) through (7) and complete pump down for all outdoor units.

➇

2 - 12

Page 59

3-WAY VRF SYSTEM

5. Recovering Refrigerant

Using hoses with Schrader-type push-to-release valves, connect the manifold gauge valves to the suction line

➈

service port, the discharge line service port and the liquid line service port in the next outdoor unit to undergo pump down. (Fig. 2-11)

Remaining refrigerant in the system may cause internal pressure. Check that each

CAUTION

Use hoses to connect the manifold gauge valves, refrigerant recovery unit, and refrigerant recovery cylinder.

➉

Quickly connect each part to prevent air from entering the tubing.

Recover remaining refrigerant from the inter-unit tubing and indoor units using the refrigerant recovery unit.

NOTE

To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.

valve on the manifold gauge is tightly closed. A Schrader-type push-to-release valve is provided for each connection port.

Discharge tube service port (For 5/16" (7.94mm)-dia. connector)

Liquid tube service port (For 5/16" (7.94mm)-dia. connector)

Outdoor Unit Repair Procedures

Manifold gauge

Lo Hi

Refrigerant recover unit

Refrigerant recovery cylinder

Suction tube service port (For 5/16" (7.94mm)-dia. connector)

Fig. 2-11

5-3. Recovery of Refrigerant from Entire System

(1) Turn off power to the entire outdoor system. (2) Short-circuit the AP (Air Purge) pins (CN102) on the outdoor control PCB of all outdoor units, then supply power

to the outdoor units. * By short-circuiting the AP pins and supplying power to the outdoor units, the solenoid valve in each unit is

forcibly opened and all remaining refrigerant can be recovered.

(3) If any unit has encountered a power failure, follow the instructions in “5-1. Refrigerant Recovery Procedures

(from Outdoor Units)” and perform refrigerant recovery for the faulty outdoor unit.

(4) Connect the manifold gauge to the high- and low-pressure outlet ports (Schrader-type valves) on any outdoor

unit. (Fig. 2-11)

CAUTION

(5) Connect the manifold gauge valves, refrigerant recovery unit, and refrigerant recovery cylinder. Quickly connect

each part to prevent air from entering the tubing.

(6) Check that each service valve of the suction line, discharge line, liquid line, and the balance tube for the outdoor

unit has opened, then perform refrigerant recovery.

* If only a single outdoor unit is installed, the balance tube is not used. Therefore, leave this valve closed.

Remaining refrigerant may cause internal pressure. Check that each valve on the manifold gauge valves is tightly closed. The connection port uses a Schrader-type push-to-release valve.

NOTE

To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.

2 - 13

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3-WAY VRF SYSTEM

6. Checking for Leakage After Repair

Outdoor Unit Repair Procedures

6-1. Pressure Check for Leakage of Outdoor Unit

After completing repair of the outdoor unit, carry out the following leakage check. (1) Check that all service valves for suction tube, discharge tube, liquid tube, and balance tube in the repaired

outdoor unit are fully closed. (2) Connect the manifold gauge valves to the high- and low-pressure outlet ports of the outdoor unit. (3) Feed nitrogen gas into the circuit until 522.1 psi pressure is reached. If it is apparent that the nitrogen gas is not

entering the repaired section, interrupt the feeding. Short-circuit the AP pins (CN102) on the outdoor unit control

PCB, turn on power to run the outdoor unit, then resume feeding nitrogen. (4) Apply soapy water to the repaired part (such as a newly welded part), and briefly inspect for any leakage. If

there are any leaks, bubbles will show on the tubing surface.

* To continue the air-tight check after the brief leak inspection, turn on power while short-circuiting the AP pins.

Again feed nitrogen gas to obtain a system pressure of 522.1 psi. Then measure both the outdoor ambient temperature and the pressure in the system. Leave the system in this state for 1 full day and night, and again measure the outdoor ambient temperature and pressure (to determine any reduced values). During the inspection, it is recommended that an awning or cover be used to shield the unit in case of rain. If no problem is found, purge all nitrogen from the system.

Manifold gauge

Lo Hi

Nitrogen gas

High-pressure outlet port (For 5/16" (7.94mm)dia. connector)

Low-pressure outlet port (For 5/16" (7.94mm)-dia. connector)

Fig. 2-12

6-2. Checking for Leakage in Refrigerant Tubing Between Indoor and Outdoor Units

Refer to the “Installation Instructions” that came with the outdoor unit.

2 - 14

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3-WAY VRF SYSTEM

7. Evacuating System

This procedure is carried out to ensure there is no remaining refrigerant or other gases (nitrogen, etc.) in the repaired outdoor unit and tubing.

Outdoor Unit Repair Procedures

7-1. Evacuating Repaired Outdoor Unit

(1) Check that each service valve of the suction tube, discharge tube, liquid tube, and balance tube in the outdoor

unit are fully closed. (2) Connect the manifold gauge valves to the high-pressure and low-pressure sensor outlets of the outdoor unit.

(Fig. 2-13) (3) Connect the manifold gauge valves to the vacuum pump.

* If the AP pins (CN102) on the outdoor control PCB have already been short-circuited, step (4) is not

necessary.

(4) Turn off power to the repaired outdoor unit and short-circuit the AP (Air Purge) pins on the outdoor control PCB.

CAUTION

By short-circuiting the AP pins and turning on power to the outdoor unit, all electronic valves in the outdoor unit are forcibly opened and any remaining nitrogen gas can be recovered. Failure to perform this procedure may result in nitrogen gas remaining in the refrigerant circuit and causing operating problems. Therefore, never skip this step.

(5) Turn the power ON at the outdoor unit where vacuum will be applied. Then run the vacuum pump and continue

evacuation until the vacuum condition falls to less than –14.7 psig (5 Torr).

CAUTION

Vacuum pump

To ensure proper evacuation, refer to the operating instructions that came with the vacuum pump.

Manifold gauge

Lo Hi

High-pressure outlet port (For 5/16" (7.94mm)

-dia. connector)

Low-pressure outlet port

Fig. 2-13

(For 5/16" (7.94mm)-dia. connector)

7-2. Evacuating Refrigerant Tubing Between Indoor and Outdoor Units

Refer to the “Installation Instructions” that came with the outdoor unit.

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3-WAY VRF SYSTEM

8. Charging Compressor Oil

Outdoor Unit Repair Procedures

8-1. If Refrigerant Has Already Been Charged to Outdoor Unit

Be sure to use an exclusive oil-charging tank for charging compressor oil. Prior to charging, carry out vacuum drying inside the tank and take care that no air (in the form of bubbles) is permitted to enter the tank.

The oil charging procedures are given below.

* The receiver tank used for maintenance may be used as an exclusive oil-charging tank.

When installing the oil-charging

(DPR : CV6230817937)

tank to the refrigerant system to serve as a safety bypass circuit for refrigerant, connect it to the

Nipple

suction line service port carefully to avoid releasing refrigerant into the atmosphere.

CAUTION

Perform oil charging work carefully so that no

Packless valve

(Receiver-tank: CV6380152988)

liquid refrigerant enters the charging tank.

Fig. 2-14

(1) Evacuation drying in oil-charging tank With the lower side valve fully closed, open the upper side valve and connect it to the vacuum pump via the

manifold gauge valves as shown below. Run the vacuum pump and evacuate the tank until the pressure falls to

below –14.7 psig (5 Torr) for the evacuation drying. After the evacuation drying is finished, fully close the upper

valve. Next, fully close the manifold gauge valves and stop the vacuum pump.

CAUTION

To ensure proper evacuation, refer to the operating instructions that came with the vacuum pump.

Vacuum pump

Manifold gauge

Lo Hi

Open to run, then close to stop

Upper side valve

Close to stop

Lower side valve

Fig. 2-15

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3-WAY VRF SYSTEM

8. Charging Compressor Oil

(2) Charging compressor oil into oil-charging tank Connect a piece of pipe to the lower valve and then insert the other end deeply into the bottom of the oil

container. Make sure you avoid letting any air be sucked into the tube. Next, run the vacuum pump and open the

manifold gauge valves, then open the upper and lower valves to begin charging oil into the charging tank.

First close the lower and then, this one before stopping.

Manifold gauge

Lo Hi

Upper valve

Close this valve before stopping.

Outdoor Unit Repair Procedures

Lower valve

Vacuum pump

Oil

Fig. 2-16

When the predetermined amount of oil has been charged into the oil-charging tank, immediately close the lower valve and start the vacuum pump to reduce the pressure below –14.7 psig (5 Torr). Then close the upper valve and stop the vacuum pump.

CAUTION

Do this operation quickly because compressor oil easily absorbs moisture from the air.

(3) Charging compressor oil into outdoor unit Connect the lower valve to the low-pressure sensor outlet (with Schrader-type push-to-release valve) in the

outdoor unit to be oil-charged, and then connect the high-pressure sensor outlet (with push-to-release valve) to

the upper valve via the manifold gauge valves (at Hi-pressure gauge side). In addition, connect the suction line

service port (with push-to-release valve) to the DPR (Discharge Pressure Regulator). Carry out the connection

work quickly to avoid letting air enter.

• The hoses may be subject to internal pressure from the refrigerant inside the

CAUTION

outdoor unit. A Schrader-type push-to-release valve is provided at each connection port.

• Since the DPR valve opens at pressures of 362.6 psi and above, be sure to connect the DPR to the suction line service port (low-pressure side).

High-pressure outlet port (For 5/16" (7.94mm)-dia. connector)

Low-pressure

outlet port (For 5/16" (7.94mm)-dia. connector)

Suction tube service port (For 5/16" (7.94mm)-dia. connector)

DPR

Upper valve

Manifold gauge

Lo Hi

Close to stop

Lower valve

Close to stop

Fig. 2-17

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3-WAY VRF SYSTEM

8. Charging Compressor Oil

Next follow the instructions in “5-2-1. Cooling operation (for all units)” at the outdoor unit where oil will be charged, and start cooling operation at all units. When the operating conditions have stabilized, perform steps 1, 2, and 3 in sequence and open the valves. When this is done, the refrigerant pressure from operation forces the oil out of the oil charge tank, and oil is charged into the outdoor unit from the low-pressure outlet port. From time to time close the upper valve on the top of the oil charge tank (only this valve) and shake the tank to check the amount of remaining oil.

High-pressure outlet port (For 5/16" (7.94mm)-dia. connector)

Upper valve

Low-pressure outlet port

5/16"

(For

(7.94mm)-dia.

connector)

Manifold gauge

HiLo

Procedure 1: Open the Hi-side manifold gauge valve

Lower valve

Outdoor Unit Repair Procedures

DPR

Procedure 2: Open the upper valve

Suction tube service port (For 5/16"

(7.94mm)

-dia. connector)

Connect from here to refrigerant recovery unit

Procedure 3: Open the lower valve

Fig. 2-18

To terminate the oil charging work, do as follows: To end the charge process, first close the valve on the high-pressure side of the manifold gauge. Then wait

several tens of seconds after the pressure display on the manifold gauge low-pressure gauge stabilizes (in order to equalize the pressure with the low-pressure outlet port and to vaporize the refrigerant in the charge tank). Then perform steps 1 and 3 in sequence and fully close the valves. Finally, connect the refrigerant recovery unit to the Lo-gauge side, shut down all indoor and outdoor units, and then recover the remaining refrigerant in the oil-charging tank, manifold gauge valves, and connecting hoses. Perform these procedures quickly and securely so that no air can enter. After, charge the necessary amount of new refrigerant by referring to the “Installation Instructions” that came with the outdoor unit.

NOTE

To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.

8-2. If Outdoor Unit Has Not Been Charged with Refrigerant

When a compressor has been replaced or in any other case where the outdoor unit has not been charged with refrigerant, first charge with refrigerant then follow the instructions in “8-1. If Refrigerant Has Already Been Charged to Outdoor Unit” and charge with oil.

Or, alternatively, follow the procedure below. (1) Connect a tube to the oil outlet port on the outdoor unit to be charged with oil. Insert the other end of the tube

into the oil container.

(2) Follow the instructions in “7. Evacuating System,” and apply vacuum to the outdoor unit to be charged with oil.

When this is done, oil is charged into the outdoor unit through the oil outlet port.

(3) When the unit has been charged with the designated amount of oil, stop the vacuum pump.

CAUTION

Because oil absorbs moisture readily, this work must be completed quickly.

2 - 18

Page 65

8. Charging Compressor Oil

3-WAY VRF SYSTEM

Outdoor Unit Repair Procedures

High-pressure outlet port (For 5/16" (7.94mm)-dia. connector)

Vacuum pump

Manifold gauge

HiLo

Oil tube service port (For 1/4" (6.35mm)-dia. connector)

Low-pressure outlet port (For 5/16" (7.94mm)

-dia. connector)

Oil

Fig. 2-19

8-3. Charging Additional Compressor Oil (after replacing compressor)

The rated amount of oil is pre-charged in the compressors as given below:

Model name Compressor model Q’ty Pre-charged amount of oil (gal)

U-72MF1U9

U-72MF1U9E

U-96MF1U9

U-96MF1U9E

C-9RVN273H0U (Inverter-controlled rotary compressor)

JT160G-KTTJ (Constant-speed scroll compressor)

1 0.50

1 0.55

When replacing a faulty compressor, be sure to first measure the amount of remaining oil in the compressor. Charge additional new oil equal to the difference in the remaining oil and the rated amount as listed above.

For example: Type of replaced compressor: JT160G-KTTJ

Remaining oil in the removed compressor: 0.58 gal

Additional oil to be charged: 0.58 gal (remaining oil in the removed compressor) – 0.55 gal (rated oil amount) =

0.026 gal * If the result is a negative amount (remaining oil in the removed compressor is less than the rated amount), it is

not necessary to discharge the extra oil from the system.

For the method used for additional oil charging after compressor replacement, refer to “8-1. If Refrigerant Has Already Been Charged to Outdoor Unit.”

Required equipment and tools: Jumper wire with clips, adjustable wrench, set of manifold gauge valves, refrigerant

recovery unit, pre-purged refrigerant cylinder for recovery, flat-head screwdriver, and outdoor unit maintenance remote controller.

This work is performed in order to collect the refrigerant from an outdoor unit where repairs (other than compressor replacement) will be performed into other outdoor units and indoor units, and the refrigerant tubing.

2 - 19

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3-WAY VRF SYSTEM

9. Pumping Out Refrigerant from Outdoor Unit

Outdoor Unit Repair Procedures

9-1. If Remote Controller (CZ-RTC2) is Used for Maintenance of Outdoor Unit

(1) Refer to “4. Backup Operation” and perform backup operation.

(2) Connect the manifold gauge valves at the Lo side to the low-pressure outlet port of the outdoor unit to be

repaired. Also connect the refrigerant recovery cylinder to any one of the normal outdoor units at the liquid line service port (Schrader-type push-to-release valve). Perform the connection work quickly so that no air is allowed to enter. (Fig. 2-20)

* Connecting the refrigerant recovery cylinder is done to prevent pressure from rising excessively during

backup operation by recovering the refrigerant from the outdoor unit to be repaired. (Measure the weight of the refrigerant and cylinder itself beforehand and provide sufficient safety measures, such as installing a high-pressure cutout in the circuit.)

CAUTION

(3) Connect the outdoor unit maintenance remote controller to the RC connector (CN006) (3P) (BLU) on the

outdoor unit control PCB of the outdoor unit to be repaired. Then start a test run of all units. (Press and hold the

(CHECK) button for 4 seconds.)

(4) Press the

CAUTION

(5) Use the outdoor unit maintenance remote controller to check the operating status of the indoor units. Check

that all units are operating in Heating mode. For details concerning operation of the outdoor unit maintenance remote controller, refer to the “Outdoor unit maintenance remote controller” item.

The hoses may be subject to internal pressure from the refrigerant inside the outdoor unit. Check that the manifold gauge valves are fully closed beforehand. A Schrader-type push-to-release valve is provided at each connection port.

(MODE) button and change to heating operation.

Even if the mode that is originally displayed is “Heat,” be sure to press the (MODE) button once or more to change to heating operation. (Pressing the (MODE) button ensures that heating/cooling operation is not mixed and that all units are operating in either Heating or Cooling mode.)

CAUTION

With the 3-way valve, it is difficult to determine whether operation is heating or cooling by touching the tubing.

(6) Close the suction tube and balance tube on the outdoor unit to be repaired. Then slowly close the liquid tube

service valve.

(7) When the low pressure at the outdoor unit to be repaired reaches 72.5 psi or below, press the ON/OFF button

on the outdoor unit maintenance remote controller to stop all the units. Then immediately fully close the discharge tube valve on that outdoor unit.

While closing the valves, the rise in discharge temperature or another factor may

CAUTION

cause a protective device to activate, stopping the operation of the outdoor unit. If this occurs, immediately fully close the discharge tube valve on the outdoor unit to be repaired.

(8) Connect the high-pressure gauge side of the manifold gauge to the high-pressure outlet port on the outdoor

unit to be repaired, and connect the manifold gauge to the refrigerant recovery device. Be sure that no air enters the tubing at this time.

(9) Short-circuit the vacuum application pin on the outdoor unit control PCB of the unit to be repaired. Then turn ON

the outdoor unit power.

CAUTION

When the vacuum application pin is short-circuited and the power is turned ON, all solenoid valves in the outdoor unit are forced open, allowing the refrigerant to be recovered from all tubes which are separated by solenoid valves. If this work is not performed, it will not be possible to recover all of the refrigerant at the refrigerant recovery device. Be sure to perform this step.

(10) Open both Hi- and Lo-side valves on the manifold gauge valves, and recover the refrigerant remaining in the

outdoor unit. After that, measure the amount of recovered refrigerant.

NOTE

To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.

2 - 20

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3-WAY VRF SYSTEM

9. Pumping Out Refrigerant from Outdoor Unit

Outdoor Unit Repair Procedures

9-2. If Remote Controller (CZ-RTC2) is Not Available for Maintenance of the Outdoor Unit

(1) Refer to “4. Backup Operation” and perform backup operation. (2) Connect the manifold gauge valves at the Lo side to the low-pressure outlet port of the outdoor unit to be

* Connecting the refrigerant recovery cylinder is done to prevent pressure from rising excessively during the

CAUTION

(3) Determine the outdoor unit where the unit No. setting (S007) (3P DIP switch) (BLU) on the outdoor unit control

PCB is set to No. 1.

(4) Short-circuit the mode-change pin (CN101) on the outdoor unit control PCB of the No. 1 unit. Then short-circuit

the test-run pin (CN023) to start operation. (Short-circuiting the mode change pin ensures that heating/cooling operation is not mixed and that all units are operating in either Heating or Cooling mode.)

(5) Check the displays of the indoor unit remote controllers. Check that all units are operating in Heating mode. If all

units are operating in Cooling mode, perform the steps listed below.

CAUTION

With the 3-way valve, it is difficult to determine whether operation is heating or cooling by touching the tubing.

(6) Release the short-circuit at the test-run pin on the outdoor unit control PCB of the No. 1 unit. Then short-circuit

the stop pin (CN104) to stop operation.

(7) Short-circuit the mode-change pin (CN101) on the outdoor unit control PCB of the No. 1 unit.

* Switching of the 4-way valve occurs immediately before operation starts. Therefore it does not change at this

time. (Mode change cannot be judged from the sound.)

(8) Short-circuit the test-run pin (CN023) on the outdoor unit control PCB of the No. 1 unit. Then check the displays

of the indoor unit remote controllers. Check that all units are operating in Cooling mode.

(9) Close the suction tube and balance tube on the outdoor unit to be repaired. Then slowly close the liquid tube

service valve.

(10) When the low pressure at the outdoor unit to be repaired reaches 72.5 psi or below, pull out the SCT

connector (2P) (YEL) (CN231) from the outdoor unit control PCB of that outdoor unit. Then immediately fully close the discharge tube valve on that outdoor unit. * Pulling out the SCT connector immediately stops all of the outdoor units.

While closing the valves, the rise in discharge temperature or another factor may cause

CAUTION

(11) Connect the high-pressure gauge side of the manifold gauge to the high-pressure outlet port on the outdoor

unit to be repaired, and connect the manifold gauge to the refrigerant recovery device. Be sure that no air enters the tubing at this time.

(12) Open both Hi- and Lo-side valves on the manifold gauge valves, and recover the refrigerant remaining in the

outdoor unit. After that, measure the amount of recovered refrigerant.

NOTE

To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.

a protective device to activate, stopping the operation of the outdoor unit. If this occurs, immediately fully close the discharge tube valve on the outdoor unit to be repaired.

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9. Pumping Out Refrigerant from Outdoor Unit

Faulty outdoor unit Other outdoor unit

Manifold gauge

Lo Hi

High-pressure outlet port

(For 5/16" (7.94mm-dia.

connector)

Low-pressure outlet port (For 5/16" (7.94mm-dia. connector)

3-WAY VRF SYSTEM

Outdoor Unit Repair Procedures

Liquid tube service port (For 5/16" (7.94mm-dia. connector)

Refrigerant

recovery

cylinder

Measuring scale

Connect from here to refrigerant recovery unit

Fig. 2-20

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3-WAY VRF SYSTEM

10. Compressor

Outdoor Unit Repair Procedures

10-1. Compressor Trouble Diagnosis and Check Methods

Generally, compressor failures can be classified into the following categories. (1) Mechanical trouble → (A) Locking (intrusion of foreign objects, galling, etc.) (B) Pressure rise failure (damaged valve, seal, bearing, or other component) (C) Noise (damaged stator rotor, valve, or other component)

(2) Electrical trouble

(A) Coil burning

→

(B) Open circuit (C) Insulation failure (D) Short circuit Trouble diagnosis is based on the following remote controller displays: [H03] (Compressor 1: INV compressor,

center), [H11] [H12] [H13] (Compressor 2: constant-speed compressor 1, left side when viewed from front). A judgment is made based on factors that include the following: coil resistance (varies depending on the compressor), insulation resistance, current, leakage breaker operation, oil and refrigerant fouling, odor, pressure, and noise.

Reference: Insulation resistance (Use a DC 500 V insulation resistance meter and measure the insulation

resistance between the electrified and non-electrified parts.)

(a) Motor

Min. 300 M

→

Ω

(b) Compressor → Min. 100 MΩ (servicing part) (c) Unit

Min. 10 MΩ (This is due to the presence of refrigerant, which decreases the

→

insulation resistance.)

* Minimum insulation resistance as required by generally accepted requirements is 1 MΩ.

JUDGMENT START

Is there

Is there burning of the failed

compressor motor?

YES

Follow the instructions in

“3. Discharging Compressor Oil” and

drain the oil from all compressors in the

same system. Then inspect.

Follow the instructions in

“3. Discharging Compressor Oil”

and drain the oil from the failed

compressor. Then inspect.

Is the color phase 4.0 or above, or is a

YES

sharp odor present?

Are there 2 or more outdoor units where

the compressor oil color phase is 4.0 or

higher or where a sharp odor is present?

YES

Go to “10-2-3. Replacing all compressors in a system.”

Follow the instructions in “10-2-4. Dry

core cleaning” and perform dry core

cleaning of all outdoor units.

Go to “10-2-2. Replacing all compressors in a failed unit.”

Follow the instructions in

“10-2-4. Dry core cleaning” and

perform dry core cleaning of the

failed outdoor unit.

Reference: Symptoms of motor burning

1. Ground fault results in breaker operation.

2. Short circuit results in different coil resistance at different phases.

3. Open circuit

2 - 23

Go to “10-2-1. Replacing only the

failed compressor.”

Page 70

3-WAY VRF SYSTEM

10. Compressor

Outdoor Unit Repair Procedures

10-2. Replacing the Compressor(s)

10-2-1. Replacing only the failed compressor

(1) If backup operation is required, follow the instructions in “4. Backup Operation” and engage backup operation. (2) Follow the instructions in “10-3. Removing and Installing Compressors” and replace the failed compressor. (3) Fully close the high- and low-pressure gauge valves on the manifold gauge, then stop the vacuum pump. (4) Disconnect the manifold gauge from vacuum pump. Connect the manifold gauge to the cylinder where the

refrigerant was recovered. At this time, be careful that air does not enter the tubing.

(5) Open the valve on the refrigerant recovery cylinder and the high-pressure gauge valve on the manifold gauge

to charge with refrigerant. At this time, the low-pressure gauge valve on the manifold gauge remains fully closed.

If the recovered refrigerant becomes mixed with another refrigerant or another gas

CAUTION

(6) When charging has been completed with an amount of new refrigerant equal to the amount of recovered

refrigerant, or when charging with the same amount of new refrigerant has not been completed but no more refrigerant will enter the unit, fully close the high-pressure gauge valve on the manifold gauge. Next, turn the power OFF at the repaired outdoor unit, then remove the short circuit at the AP pin (CN102). Finally, fully open all valves on the suction tube, discharge tube, liquid tube, and balance tube.

(7) If backup operation was engaged, follow the instructions in “4. Backup Operation” and perform backup

operation recovery.

(8) If charging with an amount of new refrigerant equal to the amount of recovered refrigerant was not possible,

fully close the high-pressure gauge valve on the manifold gauge. Then, while the unit is operating in “5-2-1. Cooling operation (for all units)”, open the low-pressure gauge valve on the manifold gauge and charge with the designated amount of refrigerant.

When charging with liquid refrigerant, add refrigerant a little at a time in order to

CAUTION

(such as nitrogen or air), do not use the recovered refrigerant for charging. Charge with the designated amount of new refrigerant.

prevent liquid back-flow.

(9) Fully close the low-pressure gauge valves on the manifold gauge, follow the instructions in “8. Charging

Compressor Oil,” and charge with oil if necessary.

(10) Remove the manifold gauge.

CAUTION

The connecting port employs a Schrader-type push-to-release valve. When disconnecting the hose, pressure will be applied from the refrigerant in the outdoor unit.

2 - 24

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3-WAY VRF SYSTEM

10. Compressor

Outdoor Unit Repair Procedures

10-2-2. Replacing all compressors in a failed unit

(1) Follow the instructions in “3. Discharging Compressor Oil” and drain the oil from the oil separator in the failed

unit. Measure the amount of drained oil. (2) If backup operation is required, follow the instructions in “4. Backup Operation” and engage backup operation. (3) Follow the instructions in “10-3. Removing and Installing Compressors” and replace all compressors in the

failed unit. (4) Fully close the high- and low-pressure gauge valves on the manifold gauge, then stop the vacuum pump. (5) Disconnect the manifold gauge from the vacuum pump. Connect the manifold gauge to the refrigerant

cylinder. At this time, be careful that air does not enter the tubing.

CAUTION

(6) Open the valve on the refrigerant cylinder, and open the high-pressure gauge valve on the manifold gauge

(with the low-pressure gauge valve closed). When charging has been completed with an amount of new

refrigerant equal to the amount of recovered refrigerant, or when charging with the same amount of new

refrigerant has not been completed but no more refrigerant will enter the unit, fully close the high-pressure

gauge valve on the manifold gauge. Next, turn the power OFF at the repaired outdoor unit, then remove the

short circuit at the AP pin (CN102). Finally, fully open all valves on the suction tube, discharge tube, liquid

tube, and balance tube. However, leave the balance tube fully closed if only a single outdoor unit is installed. (7) If backup operation was engaged, follow the instructions in “4. Backup Operation” and perform backup

operation recovery. (8) If charging with an amount of new refrigerant equal to the amount of recovered refrigerant was not possible,

fully close the high-pressure gauge valve on the manifold gauge. Then, while the unit is operating according

to “5-2-1. Cooling operation (for all units),” open the low-pressure gauge valve on the manifold gauge and

charge with the designated amount of refrigerant.

CAUTION

(9) Fully close the low-pressure gauge valves on the manifold gauge, follow the instructions in “8. Charging

Compressor Oil,” and charge with the necessary amount of oil. Also add an amount of oil that is equivalent to

the amount that was drained from the oil separator. (10) Remove the manifold gauge.

Do not reuse the recovered refrigerant. Use a refrigerant cylinder that contains new refrigerant.

When charging with liquid refrigerant, add refrigerant a little at a time in order to prevent liquid back-flow.

CAUTION

(11) Follow the instructions in “10-2-4. Dry core cleaning” and perform dry core cleaning of the outdoor unit that

failed.

The connecting port employs a Schrader-type push-to-release valve. When disconnecting the hose, pressure will be applied from the refrigerant in the outdoor unit.

2 - 25

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3-WAY VRF SYSTEM

10. Compressor

Outdoor Unit Repair Procedures

10-2-3. Replacing all compressors in a system

(1) Follow the instructions in “3. Discharging Compressor Oil” and drain the oil from the oil separators in all

outdoor units. Measure the amount of drained oil.

(2) Follow the instructions in “10-3. Removing and Installing Compressors” and replace all compressors in the

system.

(3) Follow the instructions in “6. Checking for Leakage After Repair” and check for leaks at all outdoor units and

in the tubing. (4) Follow the instructions in “7. Evacuating System” and apply vacuum to all outdoor units and tubing. (5) Fully close the high- and low-pressure gauge valves on the manifold gauge, then stop the vacuum pump. (6) Disconnect the manifold gauge from vacuum pump. Connect the manifold gauge to the refrigerant cylinder.

Be especially careful that air does not enter the tubing.

CAUTION

(7) Open the valve on the refrigerant cylinder, and open the high-pressure gauge valve on the manifold gauge.

When charging has been completed with an amount of new refrigerant equal to the amount of recovered

refrigerant, or when charging with the same amount of new refrigerant has not been completed but no more

refrigerant will enter the unit, first turn the power OFF at the repaired outdoor unit, then remove the short circuit

at the AP pin (CN102). Then fully open all valves on the suction tube, discharge tube, liquid tube, and balance

tube. However, leave the balance tube fully closed if only a single outdoor unit is installed. (8) If backup operation was engaged, follow the instructions in “4. Backup Operation” and perform backup

operation recovery. (9) If charging with an amount of new refrigerant equal to the amount of recovered refrigerant was not possible,

fully close the high-pressure gauge valve on the manifold gauge. Then, while the unit is operating in Cooling

mode, open the low-pressure gauge valve on the manifold gauge and charge with the designated amount of

refrigerant.

CAUTION

Do not reuse the recovered refrigerant. Use a refrigerant cylinder that contains unused refrigerant.

When charging with liquid refrigerant, add refrigerant a little at a time in order to prevent liquid back-flow.

(10) Fully close the low-pressure gauge valves on the manifold gauge, follow the instructions in “8. Charging

Compressor Oil,” and charge with the necessary amount of oil. Also add an amount of oil that is equivalent to

the amount that was drained from the oil separators. (11) Remove the manifold gauge.

CAUTION

(12) Follow the instructions in “10-2-4. Dry core cleaning” and perform dry core cleaning of all outdoor units.

The connecting port employs a Schrader-type valve. When disconnecting the hose, pressure will be applied from the refrigerant in the outdoor unit.

2 - 26

Page 73

3-WAY VRF SYSTEM

10. Compressor

Outdoor Unit Repair Procedures

10-2-4. Dry core cleaning

If burning or other failures occur repeatedly at compressors within the same system, in many cases the cause is acid, sludge, carbon, or other substances that remain in the refrigeration cycle as the result of insufficient cleaning.

If, when the oil is inspected, there is an outdoor unit where the oil color phase is 4.0 or higher, or where a sharp odor is present, carry out all steps below to perform dry core cleaning.

(A) If a ball valve is installed on the outdoor unit

(1) Refer to “5-2-1. Cooling operation (for all units)” and operate all outdoor units in either Heating or Cooling mode. (2) If all units are operated in Cooling mode, close first the liquid tube service valve then the ball valve on all

outdoor units where dry cores will be attached.

If all units are operated in Heating mode, close first the ball valve then the liquid tube service valve on all

outdoor units where dry cores will be attached.

* This step is performed in order to expel refrigerant from the tubing between the liquid tube service valve and

the ball valve. Approximately 4 – 5 seconds is a sufficient interval between closing each of the 2 valves. (3) Press the ON/OFF button on the outdoor unit maintenance remote controller to stop the operation of all units. * If the outdoor unit maintenance remote controller is not available, use the following method to stop the

operation of all units: Pull out the SCT connector (2P) (YEL) (CN231) from the outdoor unit control PCB of the unit where

pump-down is being performed. When the SCT connector is pulled out, alarm F12 (sensor trouble) immediately occurs and all outdoor units stop operating. Be sure that you do NOT grasp the lead wire when pulling out the connector. Removing any other connector may not cause the units to stop. Therefore be sure to pull out only the SCT connector.

(4) Connect a refrigerant recovery device to the liquid tube service port (Schrader-type valve) of all outdoor units

where dry cores will be attached, then recover the refrigerant from the tubing. Be sure that no air enters the tubing at this time.

CAUTION

When the hose is connected, internal pressure is applied by the remaining refrigerant in the inter-unit tubing. The connection port employs a Schrader-type valve. To determine when refrigerant recovery is compete, follow the instructions in the instruction manual of the refrigerant recovery device.

(5) As shown in Fig. 2-21, disconnect the tube that runs from the liquid tube valve to the ball valve on all outdoor

units where dry cores will be attached. Then attach the dry cores.

(6) At all outdoor units where dry cores are attached, pressurize with 522.1 psi of nitrogen from the liquid tube

service port and check for leaks.

(7) After evacuating all nitrogen gas from the tubing, apply vacuum from the liquid tube service port to all outdoor

units where dry cores are attached until the pressure is –14.7 psig (5 Torr) or less. (8) Fully open the liquid tube valve and ball valve on all outdoor units where dry cores are attached. (9) Operate all outdoor units for approximately 3 hours (in either Heating or Cooling mode or mixed Cooling and

Heating mode). (10) Follow the above procedure, and replace all dry cores with new dry cores. (11) Operate all outdoor units for approximately 20 minutes (in either Heating or Cooling mode or mixed Cooling

and Heating mode). (12) Follow the instructions in “3. Discharging Compressor Oil” and drain a small amount of the oil from the

oil separators of all outdoor units where dry cores are attached. Check the color phase, odor, and other

characteristics. (13) If the results show that dry core cleaning is still necessary (for example, a color phase of 4.0 or higher), return

to Step 11 and repeat until the results are normal (including a color phase of 3.5 or less).

(14) Perform steps (1) – (4), and remove all dry cores. Then connect the tubing between the liquid (narrow) tube

valves and the ball valves.

CAUTION

Perform another dry core replacement after approximately 30 hours of system operation.

2 - 27

Page 74

3-WAY VRF SYSTEM

10. Compressor

(15) At all outdoor units where dry cores were removed, pressurize with 522.1 psi of nitrogen from the liquid tube

service port and check for leaks. (16) After evacuating all nitrogen gas from the tubing, apply vacuum to all outdoor units where dry cores were

removed until the pressure is –14.7 psig (5 Torr) or less. (17) INSTALLATION: Refer to the “Information for the Person in Charge of Installation” items. Charge with an

amount of refrigerant equal to the amount that was recovered.

Outdoor Unit Repair Procedures

(B) If a ball valve is not installed on the outdoor unit

(1) Refer to “Refrigerant recovery procedures (2) for indoor unit with no ball valve” under “5-2. Refrigerant

Recovery Procedures (Indoor Unit).” Perform pump down of the refrigerant from all indoor units and inter-unit

tubing to the outdoor unit side. (2) Cut the liquid (narrow) tube at all outdoor units where dry cores will be attached, then attach the dry cores

and ball valves as shown in Fig. 2-21. (3) For the next steps, refer to (6) – (17) in (A) on the previous page.

Cleaning dry core

Liquid tube service valve

Normal unitOutdoor unit

(Bidirectional type for R410A)

Dry core

Ball valve

Balance tube

Liquid tube

Discharge tube

Suction tube

Fig. 2-21

2 - 28

Page 75

3-WAY VRF SYSTEM

10. Compressor

Outdoor Unit Repair Procedures

10-3. Removing and Installing Compressors

When removing and installing compressors, use sufficient caution to ensure that moisture or other substances do not enter the refrigerant tubing system.

10-3-1. Replacing compressors

* For all types 72 and 96, follow the replacement procedure below.

(A) Replacing the inverter compressor (Compressor 1 on remote controller alarm display)

Removal

■

1) Connect a manifold gauge to the high- and low-pressure outlet ports at the outdoor unit where the

compressor will be replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas replacement in the outdoor unit tubings.

(2) Follow the instructions in “1. Removing Panels” and “2. Removing Electrical Component Box and Duct” and

remove the corresponding parts from the outdoor unit where the compressor will be replaced. (3) Remove the cap at the compressor terminal plate. Disconnect the power terminal. (4) Remove the crankcase heater. (5) Remove the 3 bolts, and remove the washers and rubber washers (quantities indicated in the figure below). (6) Disconnect the tube-with-flare-nut using two adjustable wrenches. At this time, cover the tube in place with

waste cloth while watching out for oil leaks. Then cap the disconnected tube and mount the flare nut on the

compressor. Tighten the flare nut with a seal bonnet (1/4") in it.

NOTE

If oil remaining in the compressor reaches the equalized oil level, oil will come pouring out when the tube-with-flare-nut is removed.

(7) Prepare to disconnect the 2 brazed locations shown in the figure.

CAUTION

Protect the sensors and the surrounding plates, rubber, lead wires, clamps, and other items. Remove the discharge sensor shown in the figure 2-22.

(8) Disconnect the 2 brazed locations shown in the figure below.

(9) Pull the compressor toward you.

CAUTION

Brazed locations (2)

Tube-with-flare-nut

Washer (1)

Rubber washer (1)

When pulling the compressor toward you, be careful not to cause any abnormal deformation of the tube-with-flare-nut.

Bolt

Remove the discharge sensor

Inverter compressor

Bolt Washer (1) Rubber washer (1)

Crankcase heater

Bolt Washer (1) Rubber washer (1)

Front view

Fig. 2-22

2 - 29

Page 76

10. Compressor

Installation

■

Outdoor Unit Repair Procedures

(1) Remove the rubber stopper and tube cap (brazed) from the new compressor. (2) Install the crankcase heater onto the new compressor. (3) Place the 2 pieces of cushioning rubber in the designated positions on the compressor. (4) Place the 2 pieces of cushioning rubber onto the legs of the new compressor.

3-WAY VRF SYSTEM

CAUTION

When setting the compressor into the unit, be careful not to cause any abnormal deformation of the tube-with-flare-nut.

(5) Place the remaining cushioning rubber onto the new compressor, at the position shown in the figure below. (6) Remove the bolts that are temporarily fastening the pieces of cushioning rubber (inner 2 legs), and anchor

the 3 compressor legs using the bolts, washers, and rubber washers. (7) Remove the flare nut from the new compressor, and connect the tube-with-flare-nut. (8) Shape the tubes and insert them at the 2 welding locations. (9) Connect a manifold gauge to the high- and low-pressure outlet ports at the outdoor unit where the

compressor was replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas

replacement. (10) Perform copper brazing at the 2 welding locations. (11) Follow the instructions in “6. Checking for Leakage After Repair” and check for leaks at the outdoor unit where

the compressor was replaced.

CAUTION

At this time, also check for leaks at the flare nut connection on the tube-with-flare-nut.

(12) Re-install all components that were removed. Re-install the electrical component box in the same position as

it was before.

Be sure to check for looseness of the power terminal connections at the compressor

CAUTION

terminal plate, and to check by pulling vertically on the connections. If the terminals become disconnected easily, replace the wiring Assy.

(13) Follow the instructions in “7. Evacuating System” and apply vacuum to the outdoor unit where the compressor

was replaced.

Brazed

locations (2)

Bolt Washer (1) Rubber washer (1)

Cushioning rubber (Temporary fastening bolts-2 inner legs)

Tube-with-flare-nut

Front view

Crankcase heater

Fig. 2-23

Front view

Cushioning rubber (Inner 1 leg)

Fig. 2-24

2 - 30

Page 77

3-WAY VRF SYSTEM

10. Compressor

Outdoor Unit Repair Procedures

(B) Replacing the constant-speed compressor

(Compressor 2 on remote controller alarm display)

Removal

■

(1) Connect the manifold gauge to the high- and low-pressure outlet ports at the outdoor unit where the compres-

sor will be replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas replacement.

(2) Follow the instructions in “1. Removing Panels” and “2. Removing Electrical Component Box and Duct” and

remove the corresponding parts from the outdoor unit where the compressor will be replaced. (3) Remove the cap at the compressor terminal plate. Disconnect the power terminal. (4) Remove the crankcase heater. (5) Remove the bolts(3 locations), washers, and spacers (1 each at the 3 locations shown in the figure). * The compressor rear leg is not anchored. (6) Prepare to disconnect the 3 brazed locations shown in the figure.

Constant-speed

compressor

(left side)

discharge sensor

Bolt Washer: 1 Rubber washer: 1 (1 each at the 3 locations)

Crankcase heater

CAUTION

Remove

• Protect the sensors and surrounding plates, rubber, lead wires, clamps, and

Brazed locations (3)

Protect the oil equalizer tube connectors

Front view

Fig. 2-25

other items. Pay particular attention to protection of the oil equalizer tube connector parts, and removal of the discharge sensor. An O-ring is mounted inside the oil equalizer tube connector parts. It must be protected and do not lose it.

(7) Disconnect the 3 brazed locations shown in the figure 2-25.

* First disconnect the ø1/4" (ø6.35 mm) tube, then disconnect the ø1/2" (ø12.7 mm) and ø7/8" (ø22.22 mm)

tubes.

(8) Pull the compressor toward you.

2 - 31

Page 78

3-WAY VRF SYSTEM

10. Compressor

Installation

■

(1) Remove the 2 brazed tube caps (2 pieces) from the compressor. (2) Remove hexagonal caps from the compressor. * When removing the hexagonal caps, hold the fixing nut at the main unit side so as not to loose it with a

wrench or spanner. And then, loosen and remove the hexagonal cap.

Hexagonal cap

Outdoor Unit Repair Procedures

Oil equalizer tube connector parts

Fixing nut at the main unit side

O-ring

Fig. 2-26

(3) Remove the oil equalizer tube connector parts along with the O-ring from the removed compressor and

mount them on the replaced new compressor. (4) Install the crankcase heater onto the new compressor. (5) Temporary mount 2 cushion rubbers with bolts at the position as shown in the figure 2-27. Set up the leg of the new compressor onto the 2 cushion rubbers.

Cushion rubbers

Bolts

(Temporary mounting: 2 locations

at back side, each 1 piece)

Front view

Fig. 2-27

2 - 32

Page 79

3-WAY VRF SYSTEM

10. Compressor

Front view

Fig. 2-28

(6) Set the remaining cushioning rubber beneath the new compressor leg at the locations shown in the figure 2-28. (7) Remove the bolts which are temporarily fastening the 2 pieces of cushioning rubber, and anchor the 3

compressor legs using the bolts, washers, and rubber washers. (8) Insert the pre-shaped tube assembly at the 3 brazing locations indicated. (9) Connect the manifold gauge to the high- and low-pressure outlet ports at the outdoor unit where the

compressor was replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas

replacement. (10) Perform copper brazing at the 3 brazing locations.

CAUTION

In the same way as during removal, pay particular attention to protection of the oil equalizing tube connector parts shown in the figure 2-28. An O-ring is mounted inside the oil equalizer tube connector parts. It must be protected and do not lose it.

Outdoor Unit Repair Procedures

Brazing locations (3)

Bolt Washer: 1 Rubber washer: 1 (1 each at the 3 locations)

Protect the oil equalizer tube connectors

Cushioning rubber guide

(11) Follow the instructions in “6. Checking for Leakage After Repair” and check for leaks at the outdoor unit where

the compressor was replaced. (12) Re-install all components that were removed. Re-install the electrical component box in the same position as it

was before.

CAUTION

Be sure to check for looseness of the power terminal connection at the compress or terminal plate, and to check by pulling vertically on the connections. If the terminals become disconnected easily, replace the wiring Assy.

(13) Follow the instructions in “7. Evacuating System” and apply vacuum to the outdoor unit where the compressor

was replaced.

2 - 33

Page 80

3-WAY VRF SYSTEM

10. Compressor

Removal

■

(1) Follow the instructions in “(A) Replacing the inverter compressor,” “(B) Replacing the constant-speed

compressor,” and remove the compressors.

* There is no predetermined sequence for removal; any compressor may be removed first.

Installation

■

(1) Follow the instructions in “(A) Replacing the inverter compressor,” “(B) Replacing the constant-speed

compressor,” and remove the compressors.

* There is no predetermined sequence for installation; any compressor may be installed first.

Outdoor Unit Repair Procedures

2 - 34

Page 81

3-WAY VRF SYSTEM

11. High and Low Pressure Sensors

The outdoor unit connection ports for the high and low pressure sensors employ Schrader-type push-to-release valves. Therefore it is not necessary to recover refrigerant when removing and installing them.

Outdoor Unit Repair Procedures

11-1. Removing the High Pressure Sensor

(1) Follow the instructions in “1. Removing Panels” and “2. Removing Electrical Component Box and Duct”

and remove the corresponding components from the outdoor unit where the high pressure sensor will be

removed. (2) Disconnect the high pressure sensor connector (3P) (BLK) from terminal CN009 on the outdoor unit control

PCB of the outdoor unit where the high pressure sensor will be removed. (3) Use 2 adjustable wrenches in combination to remove the high pressure sensor.

CAUTION

When removing the high pressure sensor, internal pressure will be applied by the refrigerant in the outdoor unit. The high pressure sensor connection port on the outdoor unit employs a Schrader-type valve.

11-2. Removing the Low Pressure Sensor

(1) Follow the instructions in “1. Removing Panels” and “2. Removing Electrical Component Box and Duct ” and

remove the corresponding components from the outdoor unit where the low pressure sensor will be removed. * If there is sufficient space to allow removal of the left-side panel, then it is possible to remove the low

pressure sensor without removing the electrical component box and duct.

(2) Disconnect the low pressure sensor connector (3P) (WHT) from terminal CN024 on the outdoor unit control

PCB of the outdoor unit where the low pressure sensor will be removed. (3) Use 2 adjustable wrenches in combination to remove the low pressure sensor.

CAUTION

When removing the low pressure sensor, internal pressure will be applied by the refrigerant in the outdoor unit. The low pressure sensor connection port on the outdoor unit employs a Schrader-type valve.

11-3. Installing the High and Low Pressure Sensors

(1) Use 2 adjustable wrenches in combination to install the high and low pressure sensors.

Low pressure

sensor

Fig. 2-29

High pressure sensor

2 - 35

Page 82

3-WAY VRF SYSTEM

12. Replacing 4-way valve

When replacing 4-way valve of type 72 (for type with the inverter compressor), be sure to protect check valves, which are located adjacent to the 4-way valve, while performing replacement work. Type 96 (for type with 1 or 2 compressor) is not located near to the check valves, therefore no protection is necessary.

Outdoor Unit Repair Procedures

12-1. When the replacement is available from the right side of the unit

(1) Remove the front panel of the outdoor unit, then remove the right side panel of the unit. (2) Follow the instructions in “9. Pumping Out Refrigerant from Outdoor Unit”, recover the refrigerant of the

outdoor unit where the 4-way valve is located. (3) Connect the manifold gauge to the high and low-pressure outlet ports at the outdoor unit where the

4-way valve will be replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas

replacement. (4) Prepare the brazing kit to disconnect the brazed parts (4 locations).

CAUTION

(5) After replacing the 4-way valve, follow the instructions in “6. Checking for Leakage After Repair”, and “7.

Evacuating System”. The outdoor unit after replaced 4-way valve shall be checked for gas leakage and

perform system evacuation. (6) Fully open service valves on the outdoor unit. However, if only one outdoor unit is installed, leave the balance tube kept closed. (7) Charge the recovered refrigerant with the Refrigerant Recovery Unit by referring to the Installation

Instructions that came with the outdoor unit and the refrigerant recovery unit.

Protect the check valves as shown in the figure 2-30.

Fig. 2-30

Check valve

4-way valve

Brazed parts (4 locations)

2 - 36

Page 83

3-WAY VRF SYSTEM

12. Replacing 4-way valve

Outdoor Unit Repair Procedures

12-2. When the replacement is not available from the right side of the unit

(1) Follow the instructions of “10. Compressor” and remove the constant-speed compressor. (2) Connect the manifold gauge to the high and low-pressure outlet ports at the outdoor unit where the

4-way valve will be replaced. Connect the manifold gauge to a nitrogen cylinder and perform nitrogen gas

replacement. (3) Prepare the brazing kit to disconnect the brazed parts (4 locations).

CAUTION

Protect the check valves as shown in the figure 2-31.

Check valve

4-way valve

Brazed parts (4 locations)

Fig. 2-31

(4) After replacing the 4-way valve, follow the instructions in “10. Compressor”, and reinstall the removed

constant-speed compressor in the outdoor unit.

2 - 37

Page 84

– MEMO –

2 - 38

Page 85

3-WAY VRF SYSTEM

Contents

Outdoor Unit Maintenance Remote Controller

3. OUTDOOR UNIT MAINTENANCE REMOTE CONTROLLER

1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

2. Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3. Ordinary Display Controls and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

4. Monitoring Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

5. Outdoor Unit Alarm History Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11

6. Mode Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

3 - 1

Page 86

1. Overview

3-WAY VRF SYSTEM

Outdoor Unit Maintenance Remote Controller

OUTDOOR UNIT MAINTENANCE REMOTE CONTROLLER (CZ-RTC2) for 3-WAY VRF

About the outdoor unit maintenance remote controller

■

The outdoor unit utilizes nonvolatile memory (EEPROM) on its PCB. This allows EEPROM data to replace the setting switches that were present on previous PCBs. The outdoor unit maintenance remote controller is used to set and change these EEPROM data. In addition to setting and checking the outdoor unit EEPROM data, this remote controller can also be used to monitor the outdoor unit alarm history, monitor the various indoor and outdoor temperatures, and check the indoor unit connection status (number of units, operating mode, etc.).

NOTE

Outdoor unit maintenance remote controller does not function as an ordinary remote controller. It is therefore only used for test runs and during servicing.

System diagram

Outdoor unit maintenance

remote controller

Special service checker wiring

(Servicing No.: CV6231785082)

Outdoor unit

[Service Checker Section]

CZ-RTC2

Inter-unit control wiring

Outdoor unit control PCB

Remote controller Ass’y

Operation manual included in package.

●

The special service checker wiring is required in order to connect the outdoor unit maintenance remote controller

Indoor

unit

Remote

controller

Indoor

unit

Remote

controller

to the outdoor unit PCB.

●

Ordinary remote controllers or other controller are still required for the indoor units, even when the outdoor unit

maintenance remote controller is connected.

3 - 2

Page 87

3-WAY VRF SYSTEM

2. Functions

Functions on the ordinary display

■

(1) Functions: Button operations can be used to perform the following functions.

• Start/stop of all indoor units

• Switching between cooling and heating

• Test run of all indoor units

• Double-speed operation of indoor units (Do not use for actual operation. Doing so may damage the devices.)

(2) Display: The following can be displayed.

• Alarm details display

• No. of indoor/outdoor units

• Unit Nos. of connected indoor/outdoor units

• Indoor/outdoor unit operating status (blinks when an alarm occurs)

• Indoor unit thermostat ON

• Display of individual outdoor unit alarms

• Total operating time of outdoor unit compressors

• Oil level of the outdoor unit oil sensor

• Total outdoor unit power ON time

• Outdoor unit microcomputer version, other information

Outdoor Unit Maintenance Remote Controller

Temperature monitor

■

• Displays the indoor/outdoor unit sensor temperatures.

Outdoor unit alarm history monitor

■

• Displays the outdoor unit alarm history.

Mode settings

■

• Setting mode 1 and setting mode 2 are used to make the outdoor EEPROM setting.

3 - 3

Page 88

3. Ordinary Display Controls and Functions

Functions on the ordinary display

■

•

Connect the special service checker wiring to the outdoor unit PCB. The connection is shown in the figure below.

PCB connector (3P, BLU)

Special service checker wiring

Relay connector (2P, WHT)

Remote controller Ass’y

3-WAY VRF SYSTEM

Outdoor Unit Maintenance Remote Controller

Outdoor unit PCB

RC (3P, BLU)

●

If the communications line in the inter-unit control wiring is connected, it can be left as-is.

●

In case of an independent outdoor unit (1 maintenance remote controller connected to 1 outdoor unit, automatic

address setting for indoor units not completed), both setting mode 1 and setting mode 2 can be used.

●

The overall system status for that refrigerant system is displayed.

3 - 4

Page 89

3. Ordinary Display Controls and Functions

●

All units start/stop (Fig. 3-1) <Operation> The (ON/OFF operation) button can be used to

start and stop all the indoor units.

• The LED turns ON when 1 or more indoor units is

operating.

• The LED blinks when an alarm has occurred at 1 or

more indoor units during operation.

●

Switching between cooling/heating (Fig. 3-1) <Operation> The (MODE) button switches between heating and

cooling modes.

• The specifications are equivalent to the heating/cooling

inputs on the previous outdoor unit PCBs.

• The display shows the operating mode of the indoor unit

with the lowest unit No.

3-WAY VRF SYSTEM

Outdoor Unit Maintenance Remote Controller

LED

Fig. 3-1

●

All units test run (Fig. 3-2) <Operation> The (CHECK) button switches test run ON/OFF for

all indoor units.

• Press and hold for 4 seconds to turn ON.

“TEST” is displayed while the test run is in progress.

• The status of test runs that are started from the indoor

unit remote controller are not displayed on the outdoor unit maintenance remote controller.

●

Double-speed

• Do not use for actual operation.

(Doing so may damage the devices.)

<Operation> The timer button is used to switch between double-

speed and normal operation.

Fig. 3-2

• During double-speed operation, the SLEEPING MODE

mark is displayed.

3 - 5

Page 90

3. Ordinary Display Controls and Functions

Display (functions)

■

•

Use the temperature setting and buttons to change the item code.

Item code Item Remarks

Outdoor unit alarm

➀

No. of connected indoor units Quantity

Unit Nos. of connected indoor unit 7-segment display

Operating status of indoor unit 7-segment display

Thermostat ON status of indoor unit 7-segment display

No. of connected outdoor units 1 – 2

Unit Nos. of connected outdoor units 7-segment display

Operating status of outdoor unit compressor 7-segment display

➁

Outdoor Unit Maintenance Remote Controller

Alarm code display

3-WAY VRF SYSTEM

Compressor 1 operating time 0 – 99999999 hrs

Compressor 2 operating time 0 – 99999999 hrs

Compressor 3 operating time 0 – 99999999 hrs

Compressor 1 oil level 0 = Empty 1 = Insufﬁ cient 2 = Sufﬁ cient

Compressor 2 oil level 0 = Empty 1 = Insufﬁ cient 2 = Sufﬁ cient

Compressor 3 oil level 0 = Empty 1 = Insufﬁ cient 2 = Sufﬁ cient

Outdoor unit power ON time 0 – 99999999 hrs

Compressor 1 operation count 0 – 65535 times

Compressor 2 operation count 0 – 65535 times

Compressor 3 operation count 0 – 65535 times

Alarm history 1 (most recent)

Alarm history 2

Alarm history 3

Alarm history 4

Alarm history 5

Alarm history 6

Alarm history 7

Display only. Alarm code and unit No. of unit where alarm occurred are displayed alternately. 0 = CCU 1 – 2 = Outdoor unit

Alarm history 8 (oldest)

Firmware version Display the version No. × 100.

Program version Display the version No. × 100.

3 - 6

Page 91

3. Ordinary Display Controls and Functions

3-WAY VRF SYSTEM

Outdoor Unit Maintenance Remote Controller

(3) XX-YY R.C.

Displays the outdoor unit sub-bus address which is currently selected. XX = Outdoor system address on main bus line (1 – 30) YY = Outdoor unit sub-bus address (1 – 8). “1” appears when there is only 1 outdoor unit.

Locations where ➀, ➁, and ➂ are displayed as shown in Fig. 3-3.

Fig. 3-3

LED

01: <No. of connected indoor units>

4 units connected

Fig. 3-4 Fig. 3-5

02: <Unit Nos. 1, 2, 3, and 4 are

connected>

3 - 7

Page 92

3. Ordinary Display Controls and Functions

Concerning the 7-segment, 4-digit display remote controller timer display

■

Outdoor Unit Maintenance Remote Controller

The connected unit Nos. are displayed as shown below, using the 7-segment 4-digit (

the colon.

●

Display for unit Nos. 1 − 20

OFF OFF

313188

21217

ON ON

61116

414199

510 1520

ON ON

OFFOFF

Meaning of display colon

1 ~ 20 21 ~ 40

is not displayed.

●

Display for unit Nos. 21 − 40

OFF OFF OFF OFF

23 33 3828

22 27 32 37

26 31 36

24 34 3929

25 30 35 40

Meaning of display colon

1 ~ 20

21 ~ 40

ON ON ON ON

3-WAY VRF SYSTEM

) display and

61 ~ 8041 ~ 60

●

The meaning of the colon display changes in the same way, allowing unit Nos. up to 80 to be displayed.

●

Sample displays of the unit Nos. of connected indoor units

•

Display of unit No. 1

•

Display of unit Nos. 1 and 2

•

Display of unit Nos. 1, 2, and 3

•

Display of unit Nos. 1, 2, 3, and 4

NOTE

The colon display (Unit Nos. 1 – 20, 21 – 40) changes automatically every 10 seconds. (The display does not change if higher unit numbers do not exist.) Pressing the

button switches the display immediately to the next higher level, even if 10 seconds have

not passed.

The total compressor operating time is displayed

■

(in 1-hour units) using 8 digits.

• When the ﬁ rst 4 digits are displayed, the bottom dot of the colon is lit. (Figure (A))

• When the last 4 digits are displayed, the colon points are not lit. (Figure (B))

• The display of the ﬁ rst 4 and last 4 digits changes automatically every 10 seconds. It can

also be changed by pressing the button.

(B)(A)

10: <Total compressor operating time>

NOTE

(A) and (B) are displayed alternately. (The example here (0000, 0062) indicates 62 hours.)

With the outdoor unit maintenance remote controller (when connected to the outdoor unit), the unit remote controller check functions will not operate.

3 - 8

Page 93

4. Monitoring Operations

Display the indoor unit and outdoor unit sensor temperatures.

Press and hold the (CHECK) button and

➀

buttons simultaneously for 4 seconds or longer to switch to temperature monitor mode.

During temperature monitoring, is lit.

(The display and operations are the same as

when monitor mode is started from the unit remote controller.)

Press the button and select the indoor unit

➁

to monitor.

Use the temperature setting and

➂

buttons to select the item code of the temperature to monitor.

The selected indoor unit No. and the temperature

data are displayed.

3-WAY VRF SYSTEM

Outdoor Unit Maintenance Remote Controller

To end monitoring, press the (CHECK) button.

➃

The display returns to the normal display.

NOTE

The display does not blink.

3 - 9

Page 94

4. Monitoring Operations

Display of unit No. 1 (main unit)

■

DN Description Remarks

Intake temp. °F

E1 °F

E2 °F

E3 °F Indoor unit

Discharge temp. °F

Discharge temp. setting °F

Indoor unit electronic control valve position STEP

Discharge temp. 1 °F

Discharge temp. 2 °F

High-pressure sensor temp. °F

Heat exchanger gas 1 °F

Heat exchanger liquid 1 °F

Heat exchanger gas 2 °F

Heat exchanger liquid 2 °F

Outdoor air temp. °F

Not used

Inverter primary current A

CT2 A Outdoor unit

MOV1 pulse STEP

MOV2 pulse STEP

Discharge temp. 3 °F

CT3 A

MOV3 pulse STEP

MOV4 pulse STEP

Heat exchanger gas 3 °F

Heat exchanger liquid 3 °F

Low-pressure sensor temp. °F

Receiver temp. °F

Oil 1 °F

Oil 2 °F

Oil 3 °F

Actual operating frequency Hz

Outdoor Unit Maintenance Remote Controller

3-WAY VRF SYSTEM

NOTE

0A and subsequent items are outdoor unit data. 0A – 22 are for unit No. 1. 2A – 42 are for unit No. 2.

3 - 10

Page 95

5. Outdoor Unit Alarm History Monitor

•

Displays outdoor unit alarms only. Does not display indoor unit alarms.

•

Check the indoor unit alarm histories separately using the

indoor unit remote controllers or other control device.

Press and hold the (CHECK) button and button

➀

simultaneously for 4 seconds or longer to change to outdoor unit alarm history mode.

During temperature monitoring, displays.

The display and operations are the same as the

monitoring of the alarm device history that is performed using the unit remote controller. However, the outdoor unit address appears instead of the unit No.

Press the button and select the outdoor unit for

➁

alarm history monitoring.

Use the temperature setting and buttons

➂

to select the item code for the alarm history.

3-WAY VRF SYSTEM

Outdoor Unit Maintenance Remote Controller

The display shows the address of the selected outdoor

unit, the item code, and the alarm history (alarm data).

The outdoor unit address is displayed as R.C. XX-YY.

System XX = Outdoor unit system address R.C. XX = Outdoor unit system address YY = Outdoor unit sub-bus address (always “1” for

3-WAY VRF units)

Unit code is displayed as 01 – 08. 01 indicates the most

recent alarm.

The alarm history is indicated by the alarm code. (If there

have been no alarm codes, “-- --” is displayed.)

To clear the alarm history, press the button. (The

➃

outdoor unit alarm history will be cleared.)

To exit, press the (CHECK) button. The display

➄

returns to the normal remote controller display.

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Page 96

6. Mode Settings

Setting mode 1

■

Press and hold the (CHECK) button and

➀

(VENTILATION) button simultaneously for 4

seconds or longer.

Use the temperature setting and

➁

buttons to change the item code. The item codes and setting data are shown in the table below.

Use the timer time and buttons to change

➂

the setting data.

To confirm the changed setting data, press the

button.

(At this time, “

lit.)

During this mode, “

➃

The outdoor unit address display section displays “ALL,” the item code number (DN value in the table), and the setting data (8 digits).

(The setting data is displayed in 8 digits. The

display changes between the first 4 digits (Fig. A ) and the last 4 digits (Fig. B ). When the first 4 digits are displayed, the bottom dot of the colon is lit.)

” stops blinking and remains

” is displayed, blinking.

3-WAY VRF SYSTEM

Outdoor Unit Maintenance Remote Controller

Display of first 4 digits

Display of last 4 digits

To exit the setting mode, press the (CHECK)

➄

button.

A and B are displayed alternately.

(Example shows display of 0000 0001.)

DN Parameter Description

0 = Sensor input not present. Control is performed.

Snowfall sensor usage

Outdoor unit fan Quiet mode

Energy saving mode

Energy saving operation plug

Demand 1 current

Demand 2 current

1 = Sensor input present. Control is performed. 2 = Sensor input not present. Control is not performed. 3 = Sensor input present. Control is not performed.

0 = Disabled 1 = Quiet mode 1 2 = Quiet mode 2 3 = Quiet mode 3 4 = Quiet mode 4

0 = None 1 = Discharge temp. control only (Mode 3) 2 = Demand only (Mode 2) 3 = Discharge temp. control + Demand (Mode 1)

0 = Independent 1 = All indoor units linked

0 = 0% 1 = 40 … 4 = 70 7 = 100 8 = 120 9 = 140 10 = 160 11 = 200 12 = –1 (no limit)

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Page 97

3-WAY VRF SYSTEM

6. Mode Settings

Setting mode 2

■

Press and hold the (CHECK) button, button, and button

➀

simultaneously for 4 seconds or longer.

Use the temperature setting and buttons to change the item

➁

code. The item codes and setting data are shown in the table below.

Use the timer time and buttons to change the setting data.

➂

To confirm the changed setting data, press the button.

(At this time, “

During this mode, “

➃

outdoor unit address “System XX-YY” (System XX = System address, YY = Address at outdoor unit sub-bus), item code number (DN value in the table below), and the setting data (8 digits).

(The setting data is displayed in 8 digits. The display changes between the first 4 digits (Fig. A ) and the last 4

digits (Fig. B ). When the first 4 digits are displayed, the bottom dot of the colon is lit.)

To end the setting mode, press the (CHECK) button. The display returns to the normal display mode.

➄

” stops blinking and remains lit.)

” is displayed, blinking. The display shows the set

Outdoor Unit Maintenance Remote Controller

Fig. 3-6

Display of first 4 digits Display of last 4 digits

A and B are displayed alternately. (Example shows 0000 0410 (R410A).)

List of Item Codes

DN Parameter Description

81 Outdoor unit capacity 0 = Disabled 224 = 72 Type 280 = 96 Type

3 - 13

Page 98

– MEMO –

3 - 14

Page 99

3-WAY VRF SYSTEM

Contents

Remote Controller Functions

4. REMOTE CONTROLLER FUNCTIONS

1. Simple Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

2. Detailed Settings Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

3. Remote Controller Servicing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

4 - 1

Page 100

1. Simple Settings Function

3-WAY VRF SYSTEM

Remote Controller Functions

•

This allows the filter lifetime, operating mode priority change, central control address, and other settings to be made for an individual or groupcontrol indoor unit to which the remote controller used for simple settings is connected.

When simple settings mode is engaged, operation stops at the individual or group-control indoor unit to which the remote controller for simple settings is connected.

Press and hold the

➀

simultaneously for 4 seconds or longer.

“ ,” unit No. “ ” (or “ ” in the case of

➁

group control), item code “ ,” and settings data “ ” are displayed blinking on the remote controller LCD display (Fig. 4-1). At this time, the indoor unit fan (or all indoor unit fans in the case of group control) begins operating.

If group control is in effect, press the

➂

button and select the address (unit No.) of the indoor unit to set. At this time, the fan at the indoor unit begins operating.

and buttons

[Remote Controller Functions Section]

Fig. 7-1

Fig. 4-1

CZ-RTC2

* If unit No. “ ” is displayed, the same setting

will be made for all indoor units.

Press the temperature setting /

➃

buttons to select the item code to change.

Press the timer time / buttons to select the

➄

desired setting data.

* For item codes and setting data, refer to the

following page.

Press the button. (The display stops blinking

➅

and remains lit, and setting is completed.)

Press the button to return to normal remote

➆

controller display.

4 - 2

Panasonic 3-Way Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

SERVICE MANUAL

CONTENTS

1. CONTROL FUNCTIONS

1. Introduction

2. Selecting an Outdoor Unit for Operation

3. Compressor Control

4. Special Controls

5. Other Controls

6. Operation of Solenoid Valves

7. Outdoor Unit Electronic Control Valves [MOV1, MOV2, MOV4]

8. Outdoor Fan Control

9. Demand Control

10. Indoor Unit Control of the Electronic Control Valve

11. Solenoid Valve Kit Control

12. Indoor Special Control

13. Discharge Temperature

14. Current Protection

15. Low Oil Alarm

16. Pressure Sensor Failure

17. Backup Operation

18. Service Maintenance Functions

19. Other Functions

2. OUTDOOR UNIT REPAIR PROCEDURES

1. Removing Panels

2. Removing Electrical Component Box and Duct

3. Discharging Compressor Oil

4. Backup Operation

5. Recovering Refrigerant

6. Checking for Leakage After Repair

7. Evacuating System

8. Charging Compressor Oil

9. Pumping Out Refrigerant from Outdoor Unit

10. Compressor

11. High and Low Pressure Sensors

12. Replacing 4-way valve

3. OUTDOOR UNIT MAINTENANCE REMOTE CONTROLLER

1. Overview

2. Functions

3. Ordinary Display Controls and Functions

4. Monitoring Operations

5. Outdoor Unit Alarm History Monitor

6. Mode Settings

4. REMOTE CONTROLLER FUNCTIONS

1. Simple Settings Function