Panasonic U-72ME2U9, U-120ME2U9, U-96ME2U9, U-144ME2U9, U-72ME2U94 service manual

U-72ME2U9 U-96ME2U9 U-120ME2U9 U-144ME2U9 U-72ME2U94

Order No. SBPAC1404012CE

2WAY VRF System

U-96ME2U94 U-120ME2U94 U-144ME2U94

Model No.

Outdoor Unit

Outdoor Unit TypeType

ME2 2WAY VRF System

 To be connecting Indoor Units

Indoor Units

Indoor Unit TypeType

U2 4-Way Cassette 36"x36"

4-Way Cassette 24"x24"

Y2

D1

1-Way Cassette

Concealed Duct

F2

-Medium Static Concealed Duct

M2

-Low Static Concealed Duct

E1

-High Static

T2

Ceiling

K2

Wall Mounted

P1

Floor Standing

R1

Concealed Floor Standing

S-07MD1U6

S-07MF2U6

S-07MM2U6

S-07MK2U6

S-07MP1U6

S-07MR1U6

Nominal Capacity

72 96 120 144

U-72ME2U9

U-72ME2U94

7 9 12 15 18 24 36 48 54

S-12MU2U6S-09MU2U6S-07MU2U6

S-09MY2U6S-07MY2U6

S-09MD1U6

S-09MF2U6

S-09MM2U6

S-09MK2U6

S-09MP1U6

S-09MR1U6

S-12MY2U6

S-12MD1U6

S-12MF2U6

S-12MM2U6

S-12MT2U6

S-12MK2U6

S-12MP1U6

S-12MR1U6

U-96ME2U9 U-120ME2U9 U-144ME2U9

U-96ME2U94 U-120ME2U94 U-144ME2U94

Nominal Capacity

S-15MF2U6

S-15MM2U6

S-15MP1U6

S-15MR1U6

S-18MY2U6

S-18MF2U6

S-18MM2U6

S-18MT2U6

S-18MK2U6

S-18MP1U6

S-18MR1U6

S-24MU2U6

S-24MF2U6

S-24MT2U6

S-24MK2U6

S-24MP1U6

S-24MR1U6

S-36MU2U6

S-36MF2U6

S-36ME1U6

S-48MF2U6 S-54MF2U6

S-48ME1U6

85464849337007

This air conditioner uses the refrigerant R410A.

REFERENCE NO.

SM830237-07

IMPORTANT!

• 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.

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.

WARNING

• This product must not be modiﬁed or disassembled under any circumstances. Modiﬁed or disassembled unit may cause ﬁre, electric shock or injury.

• 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.

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. Leaked 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 toxic gas.

Others

CAUTION

• Do not sit or step on the unit, you may fall down accidentally.

• Do not touch the air inlet or the sharp aluminum ﬁns of the outdoor unit. You may get injured.

• 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

refrigerant. For additional guidance and precautions related to refrigerant safety, please refer to the following documents:

International Mechanical Code 2012 (IMC-2012) (or more recently revised) ASHRAE 15 ASHRAE 34

400 oz (11.3 kg) per 1,000 ft3 (28.3 m3) for R410A

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.

● This air conditioner shall be installed in accordance with

National Wiring Regulations.

● Pay close attention to all warning and caution notices given in this manual.

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

•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 over-

heating at connection points and a possible ﬁre hazard.

•To prevent possible hazards from insulation failure,

the unit must be grounded.

•This equipment is strongly recommended to be installed

with Earth Leakage Circuit Breaker (ELCB) or Residual Current Device (RCD). Otherwise, it may cause electrical shock and ﬁre in case of equipment breakdown or

insulation breakdown.

WARNING

CAUTION

WARNING

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

This symbol refers to a hazard or 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.

When Wiring

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 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.

…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.

When Connecting Refrigerant Tubing

• Pay particular attention to refrigerant leakages.

•Ventilate the room immediately, 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 toxic gas.

•Keep all tubing runs as short as possible.

•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.

i

CAUTION

Keep the ﬁre alarm and the air outlet at least 5 ft. (1.5 m) away from the unit.

WARNING

•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 refrigerant cycle.

•If the refrigerant comes in contact with a ﬂame, it produces a toxic gas.

•Do not add or replace refrigerant other than speciﬁed type. It may cause product damage, burst and injury, etc.

• 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.

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.

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. Leaked 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 toxic gas.

WARNING

• This product must not be modiﬁed or disassembled under any circumstances. Modiﬁed or disassembled unit may cause ﬁre, electric shock or injury.

• 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.

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.

Others

CAUTION

• Do not sit or step on the unit, you may fall down accidentally.

• Do not touch the air inlet or the sharp aluminum ﬁns of the outdoor unit. You may get injured.

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

If a single unit of the multi air conditioner system is to be installed in a 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 400 oz (11.3 kg) per 1,000 ft3 (28.3 m3) for R410A

For additional guidance and precautions related to refrigerant safety, please refer to the following documents:

International Mechanical Code 2012 (IMC-2012) (or more recently revised) ASHRAE 15 ASHRAE 34

small room, select a suitable model and

refrigerant.

ii

Precautions for Installation Using New Refrigerant

3-2. Use R410A exclusive cylinder only.

Single-outlet valve

(with siphon tube) Liquid refrigerant should be recharged

with the cylinder standing on end as shown.

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.

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)

Valve

Liquid

1. Care regarding tubing

1-1. Process tubing

l

Material: Use clean, dry, free of oil, refrigeration grade, seamless, phosphorous deoxidized copper tube rated for R410A only. Wall thickness shall comply with the applicable legislation. The minimal wall thickness must be in accordance with the table below.

l

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

l

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

l

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

CAUTION

prevent dirt, moisture, or other foreign substances from entering. These substances can result in system malfunction.

Outer diameter Wall thickness Outer diameter Wall thickness

5/8" (15.88) 0.040 (1.016) 1-5/8" (41.28) 0.060 (1.524)

3/4" (19.05) 0.042 (1.0668) Unit: in. (mm)

Material: O Material: O

1/4" (6.35) 0.025 (0.635) 7/8" (22.22) 0.045 (1.143)

3/8" (9.52) 0.030 (0.762) 1-1/8" (28.58) 0.050 (1.27)

1/2" (12.7) 0.035 (0.889) 1-3/8" (34.92) 0.055 (1.397)

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. Since refrigerant composition changes and performance decreases when gas leaks, collect the remaining

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.

Item

Manifold gauge Yes No

Charge hose Yes No To resist higher pressure, material must be changed.

Vacuum pump Yes Yes

Leak detector Yes No

Flaring oil Yes No

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

tools?

New

R407C tools

compatible

with R410A?

Remarks

Types of refrigerant, refrigerating machine oil, and pressure gauge are different.

Use a conventional vacuum pump if it is equipped with a check valve. If it has no check valve, purchase and attach a vacuum pump adapter.

Leak detectors for CFC and HCFC that react to chlorine do not function because R410A contains no chlorine. Leak detector for HFC134a can be used for R410A.

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

Manifold gauge

Vacuum pump

Outlet Inlet

iii

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.

Valve

Single-outlet valve

(with siphon tube) Liquid refrigerant should be recharged

with the cylinder standing on end as shown.

Liquid

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

Completely cleaning out residual refrigerating

machine oil is impossible, even by flushing.

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)

iv

—

1. CONTROL FUNCTIONS

Control Functions

1-3

1-5

1-12

1-18

1-22

7. Oil Control

4-Way Valve Adjustment Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.

Defrost Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.

Upper Current Limitation Mode (Demand control) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10.

Backup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11.

Other Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-27

1-30

1-31

1-34

1-36

1-40

1-4213. Detailed Settings in EEPROM of Outdoor Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-4414. Outdoor Unit Control PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1

2

3

4

5

1 - 1

6

7

8

9

1

2WAY VRF SYSTEM

Control Functions

1. Introduction

2. Selecting Outdoor Unit for Operation

Outdoor Unit Operating Rules

(1) Outdoor Unit Operating Rules

As a result of setting the main outdoor and sub outdoor units due to the O/U.ADD setting, the order of priority for the outdoor units is determined in small values of O/U.ADD sequence. Because in this system all outdoor units contain an inverter compressor, ordinarily there is no absolute order of priority for compressor operation.

(2) Delayed Start of Outdoor Units

1. Delayed start of outdoor unit in the same system

If it is necessary to operate the compressors simultaneously at multiple outdoor units, each outdoor unit will start in order of unit No. every one second, beginning with unit No. 1. *

Operation starts

Main outdoor unit Sub outdoor unit Sub outdoor unit

O/U.ADD = 1 O/U.ADD = 2 O/U.ADD = 3

Starts after 1 second Starts after 2 seconds Starts after 3 seconds

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

2. Delayed start for each system

When systems are linked with one communication cable and multiple systems are required to operate simultaneously by the central control device, all main outdoor units will begin operating simultaneously. In this situation, the load of the power supply equipment increases temporarily. To prevent the overload, the start timing of each system can be delayed. In order to enable this delay time, it must be set in the EEPROM for each system (Main outdoor unit). Those systems (Main outdoor units) where this setting has been made will start after a delay according to their system addresses. To activate this delay start function, it is necessary to set it to EEPROM on main outdoor PCB.

EEPROM setting in main outdoor unit

CODE: 3E

2WAY VRF SYSTEM

Control Functions

Delay timeSetting No.

0

(factory preset mode)

No delay start for each system

1 (System address × 1 × 8) seconds delay

2 (System address × 2 × 8) seconds delay

3 (System address × 3 × 8) seconds delay

2

2WAY VRF SYSTEM

1. Introduction

The ME2U series outdoor units for USA is a system that allows multiple outdoor units to be connected. All the outdoor units do not utilize the sub units that were used in earlier systems. The O/U.ADD of outdoor unit PCB where the unit is set to “1” becomes the main unit and activates as the CCU (command controller unit) functions that controls the entire system.

PCB Setting of Outdoor Unit

In order to determine the outdoor unit to be the main or sub unit, it is necessary to make settings at each PCB.

Main outdoor unit The outdoor unit where the O/U.ADD is set to “1” activates the CCU (command controller unit) functions that controls the entire system. This outdoor unit is the main outdoor unit.

* For the main outdoor unit, perform all the settings in the table (PCB setting of outdoor unit) below.

Sub outdoor unit The outdoor unit where the unit No. is set to other than “1” is a sub outdoor unit. * The system will not operate if outdoor units have been set other than unit No. “1”.

PCB Setting of Outdoor Unit

Control Functions

3

4

5

6

7

Factory

O/U.ADD [SW5] 11Outdoor units address

R.C.ADD [SW1, SW2] 1 Not necessarySystem 1 ~ 30System address

NO.OF I/U [SW3, SW4] 1 Not necessarySystem 1 ~ 64 unitsNo. of indoor units

NO.OF O/U 1 Not necessarySystem 1 ~ 3 unitsNo. of outdoor units[SW6]

* This system can be exteded to connect a maximum of 3 outdoor units.

preset

mode

Main outdoor unit

On-site setting

Sub outdoor unit

On-site setting

Setting other than 1

(Duplication prohibited)

8

9

1 - 2

2WAY VRF SYSTEM

2. Selecting Outdoor Unit for Operation

2WAY VRF SYSTEM

Control Functions

2. Selecting Outdoor Unit for Operation

Outdoor Unit Operating Rules

(1) Outdoor Unit Operating Rules

As a result of setting the main outdoor and sub outdoor units due to the O/U.ADD setting, the order of priority for the outdoor units is determined in small values of O/U.ADD sequence. Because in this system all outdoor units contain an inverter compressor, ordinarily there is no absolute order of priority for compressor operation.

(2) Delayed Start of Outdoor Units

1. Delayed start of outdoor unit in the same system

If it is necessary to operate the compressors simultaneously at multiple outdoor units, each outdoor unit will start in order of unit No. every one second, beginning with unit No. 1. *

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

Operation starts

Control Functions

1

2

Main outdoor unit Sub outdoor unit Sub outdoor unit

O/U.ADD = 1 O/U.ADD = 2 O/U.ADD = 3

Starts after 1 second Starts after 2 seconds Starts after 3 seconds

2. Delayed start for each system

When systems are linked with one communication cable and multiple systems are required to operate simultaneously by the central control device, all main outdoor units will begin operating simultaneously. In this situation, the load of the power supply equipment increases temporarily. To prevent the overload, the start timing of each system can be delayed. In order to enable this delay time, it must be set in the EEPROM for each system (Main outdoor unit). Those systems (Main outdoor units) where this setting has been made will start after a delay according to their system addresses. To activate this delay start function, it is necessary to set it to EEPROM on main outdoor PCB.

EEPROM setting in main outdoor unit

CODE: 3E

Delay timeSetting No.

0

(factory preset mode)

No delay start for each system

3

4

5

6

7

1 (System address × 1 × 8) seconds delay

2 (System address × 2 × 8) seconds delay

3 (System address × 3 × 8) seconds delay

1 - 3

8

9

1

2WAY VRF SYSTEM

Control Functions

2. Selecting Outdoor Unit for Operation

3. Compressor Control

(1) Compressors Mounted in the Outdoor Units

(2) Compressor Selection Rules

Placement of compressor seen from the top

1. Priority order of compressors

A.

A

B

C

D

Decide first priority order of compressor in each outdoor unit.

B. Priority order of compressor trip counter = 0 is higher than that of compressor trip counter = 1.

C. Inverter compressor: Shorter operating time > Longer operating time

D. Compressor that “outdoor unit small address”

installed in outdoor unit

Compressor that “outdoor unit large address” installed in outdoor unit

First priority order of inverter compressor in each outdoor unit > Other inverter compressor

Compressor trip counter =0 > Compressor trip counter =1

Shorter operating time > Longer operating time

“Outdoor unit small address”

installed in outdoor unit

“Outdoor unit large address” installed in outdoor unit

>

*1

*1 Select first priority order of compressor in each outdoor unit by following method.

The compressor that has no trip counter, shorter operating time and smaller number of compressor will be taken first priority. First priority order of inverter compressor in each outdoor unit > Other inverter compressor

2WAY VRF SYSTEM

Control Functions

Type 72, 96 Type 120, 144

Front side

1st compressor

2nd compressor

1st compressor

Front side

Compressor trip counter =0 > Compressor trip counter =1

Shorter operating time > Longer operating time

1st compressor > 2nd compressor

Priority order flow of all compressors

Priority order flow of each outdoor unit

2. Selecting Outdoor Unit for Operation

(3) Outdoor Unit Stop Rules

1. Stopping of all outdoor units

When all outdoor units must stop, all units will stop in order of unit No. every one second.

2. Stopping of individual outdoor units

When it is necessary to reduce the number of operating compressors due to load reduction of indoor units, the outdoor units will stop in order of priority for the compressors. All outdoor units stop when all compressors installed in the outdoor units stop. The outdoor unit which operates continuously until the end installs the highest priority order of compressor in it.

Cooling operation There are two patterns of operation. One is that the operation continues to run until the last one outdoor unit runs due to the detected outdoor temperature and the other is that all outdoor units stop simultaneously.

2WAY VRF SYSTEM

Control Functions

2

3

4

5

All outdoor units stop simultaneously in the operating range of all outdoor units.

Outdoor temperature

118.4°F (48°C)

109.4°F (43°C)

59°F (15°C)

50°F (10°C)

The inverter compressor mounted in the outdoor unit which continues to run until the end is short operating time. The priority order of this inverter compressor is higher than that of other outdoor unit.

Operating range in all outdoor units

*1

Operating range in each inverter compressor

*2

Operating range in all outdoor units

When starting at 109.4°F (43°C) - 118.4°F (48°C),

*1

operation starts from all outdoor operating ranges.

*2

When starting at 50°F (10°C) - 59°F (15°C), operation starts from all outdoor operating ranges.

6

7

8

9

Heating operation Operation continues to run until the last outdoor unit remains in the operating mode.

1 - 4

3. Compressor Control

2WAY VRF SYSTEM

Control Functions

(1) Compressors Mounted in the Outdoor Units

Placement of compressor seen from the top

Type 72, 96 Type 120, 144

2WAY VRF SYSTEM

Control Functions

1st compressor

2nd compressor

Front side

(2) Compressor Selection Rules

1. Priority order of compressors

A.

Decide first priority order of compressor in each outdoor unit. The compressor that has no trip counter, shorter operating time and smaller number of compressor will be taken first priority. First priority order of inverter compressor in each outdoor unit > Other inverter compressor

B. Priority order of compressor trip counter = 0 is higher than that of compressor trip counter = 1.

C. Inverter compressor: Shorter operating time > Longer operating time

D. Compressor that “outdoor unit small address”

installed in outdoor unit

Priority order flow of all compressors

A

First priority order of inverter compressor in each outdoor unit > Other inverter compressor

Compressor that “outdoor unit large address”

>

installed in outdoor unit

Front side

1st compressor

1

2

3

*1

B

C

D

*1 Select first priority order of compressor in each outdoor unit by following method.

Compressor trip counter =0 > Compressor trip counter =1

Shorter operating time > Longer operating time

“Outdoor unit small address”

installed in outdoor unit

Priority order flow of each outdoor unit

Compressor trip counter =0 > Compressor trip counter =1

Shorter operating time > Longer operating time

1st compressor > 2nd compressor

“Outdoor unit large address”

>

installed in outdoor unit

4

5

6

7

8

1 - 5

9

1

2WAY VRF SYSTEM

Control Functions

3. Compressor Control

2

3

2WAY VRF SYSTEM

3. Compressor Control

2. Operating compressors

The compressor with higher priority order starts according to the priority orders described on previous page.

3. Stopping compressors

The compressor with lower priority order stops according to the priority orders described on previous page.

(3) Operation When Starting 2 Compressors Mounted in Outdoor Unit

When necessary capacity gradually increases and one more inverter compressor is additionally started under the present operating compressor, reduce the compressor frequency to 25Hz temporarily and then start an additional compressor. The operation noted above is performed when 1st compressor or 2nd compressor is additionally started. If necessary capacity is initially higher and two compressors are started simultaneously, the operation noted above is not performed and both of them are regarded as the target frequency.

(4) Operating Frequency Range of Inverter Compressor

The inverter compressor can operate within the range in the table below.

1

When the high pressure is over 435psi (3.0MPa), the upper limit frequency is 90Hz. If the high pressure is over 450psi (3.1MPa) and the minimum frequency operation is in progress, the system

2

is stopped. (P25: Pre-trip) If the low pressure is over 213psi (1.47MPa) during operation of the inverter compressor, the system is stopped.

3

(P27: Pre-trip) If 2 inverter compressors are simultaneously operating in the same outdoor unit, the frequency of 1st

4

compressor becomes 5Hz lower than that of the 2nd compressor.

Control Functions

4

5

6

7

8

Type of outdoor unit

Minimum frequency (Hz)

Maximum frequency (Hz) 80

The frequency range in the table above is subject to change without notice.*

(5) Forced Stopping of Compressor

Once a compressor stops, it will not start for a period of 3 minutes (3-minute forced OFF). However, this does not apply when the compressor was forced to stop as the result of a special control operation. (start control, defrost control, refrigerant oil recovery control, etc.)

72 96 120 144

15 15 15

100

15

80

9

1 - 6

2WAY VRF SYSTEM

3. Compressor Control

(6) Capacity Control (Roadmap control)

1 The capacity control by the compressors is performed according to the pressure sensor attached to the outdoor

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

before it is used by microcomputer. This converted temperature is called “pressure sensor temperature”. 2 This control is performed every 30 seconds. 3 Required level of each indoor unit

Required level of indoor unit is calculated by difference between preset temperature in remote controller and

intake temperature of indoor unit (TA), difference between preset discharge air temperature in EEPROM on

indoor unit PCB and discharge air temperature of indoor unit (TF).

Required level has “0” to “30” phases. This level becomes “31” at the test run.

The target temperature of indoor unit heat exchanger is decided according to the maximum required level.

* Target temperature of all indoor units heat exchanger is same value because all indoor units are connected

with the same pressure piping.

4 Denition of evaporation temperature and condensation temperature

● Evaporation temperature (Te): Shows the lowest temperature among the temperature sensors (E1 or E3) when the indoor unit heat exchanger is functioning as an evaporator.

● Condensation temperature (Tc): Shows the highest temperature among the high-pressure saturated temperature in the system.

Control Functions

1

2

6-1. Evaporation temperature adjustment by roadmap control The cooling capacity is adjusted with this control. It prevents freezing of the indoor unit's heat exchanger and the

dew to the outside panel of the indoor unit. The capacity is adjusted according to the following gure.

Evaporation temperature area

deg

Compressor capacity increase possible

43.0 (6.1)

42.8 (6.0)

37.4 (3.0)

37.2 (2.9)

* The evaporation temperature area changes depending on the maximum required level of each indoor unit as

shown above. * Area C is regarded as area B for 6 minutes after compressor starts. * When the system operates in a minimum capacity, the system will continue operating for at least 6 minutes if the

evaporation temperature area is area C. * The evaporation temperature is not adjusted while specially controlling defrosting and the oil recovery, etc. * The evaporation temperature is not adjusted when there are one or more indoor units that select the test run.

If one or more indoor units are selected into test run, the system doesn't stop in all states except alarm appearing.

* The test run will nish automatically in about one hour.

Compressor capacity increase prohibited

Compressor capacity decrease

60.8 (16.0)

55.4 (13.0)

Area A

Area B

Area C

46.4 (8.0)

0

Max. required level

15

51.8 (11.0)

unit: °F (°C)

42.8 (6.0)

37.4 (3.0)

30

3

4

5

6

7

8

1 - 7

9

1

2

3

4

3. Compressor Control

6-2. Condensation temperature adjustment by roadmap control

The area B target temperature is different due to cooling and heating operation.

Target lower temperature

Cooling 127.4°F (53.0°C) 131.0°F (55.0°C)

Heating 118.4°F (48.0°C) 123.8°F (51.0°C)

Cooling mode

1

The purpose of this control at cooling is to prevent abnormal high-pressure.

・Standard setting (at the shipment)

°F (°C) °F (°C)

PX=136.4

(58.0)

136.2

(57.9)

131.2

(55.1)

131.0

(55.0)

127.4

(53.0)

127.2

(52.9)

Thermostat OFF

Compressor capacity decrease

Compressor capacity increase prohibited

Compressor capacity increase possible

Area D

Area C

Area B

Area A

(Tc_tgt_min)

2

PX=136.4

Heating mode Heating capacity is adjusted with this control.

It also prevents abnormal high-pressure simultaneously. The capacity is controlled in the following diagram.

(58.0)

136.2

(57.9)

124.0

(51.1)

123.8

(51.0)

118.4

(48.0)

118.2

(47.9)

Target upper temperature

(Tc_tgt_max)

Thermostat OFF

Compressor capacity decrease

Compressor capacity increase prohibited

Compressor capacity increase possible

Area D

Area C

Area B

Area A

95.0

(35.0)

2WAY VRF SYSTEM

Control Functions

°F (°C)

123.8 (51.0)

118.4

109.4 (43.0)

104.9 (40.5)

(48.0)

5

6

7

8

91.4

(33.0)

15 300

Max. required level

* PX is usually xed to 136.4°F (58°C). If the high pressure goes up rapidly after the compressor starts, the

system experiences urgent stop. The next time the system will start with lower PX. * In the area B, the compressor capacity changes depending on the refrigerant condition. * When the system operates in a minimum capacity, the system will continue operating for at least 6 minutes

if the condensation temperature area is area C.

* The condensation temperature is not adjusted when there are one or more indoor units that select the test run.

Limit pressure adjustment function

Operation pressure is able to be adjusted for existing old piping. If area shift function is set, values below shift. EEPROM setting in main outdoor unit CODE : 4B

Setting No. Limited pressure PX °F (°C) Cooling mode Heating mode

Tc_tgt_min Tc_tgt_max Tc_tgt_min Tc_tgt_max 0 478.5psi (3.3MPa) 126.5 (52.5) 116.6 (47.0) 120.2 (49.0) 116.6 (47.0) 118.4 (48.0) 1 No use - - - - 2 551.1psi (3.8MPa) 136.4 (58.0) 127.4 (53.0) 131.0 (55.0) 118.4 (48.0) 123.8 (51.0) 3 No use - - - - -

9

1 - 8

2WAY VRF SYSTEM

3. Compressor Control

6-3. Protection Control

1

Compressor discharge temperature protection

The compressor capacity is controlled according to the table below. *Discharge temperature that is used for this control is the highest temperature among all compressors.

Discharge temp.

°F (°C)

222.8

(106)

221.0 (105)

219.2 (104)

217.4 (103)

213.8 (101)

2

Abnormal low pressure protection

The compressor capacity is controlled according to the table below.

Low pressure

psi (MPa)

36.3 (0.25)

29.0 (0.20)

24.7 (0.17)

Stop

If this temperature is detected at regular intervals, alarm appears.

Compressor capacity decrease

Compressor capacity increase prohibited

Compressor capacity increase possible

No restriction

Capacity goes up slowly

Capacity increase prohibited

Capacity goes down

Capacity goes down 2.0 hp

Capacity goes down 1.0 hp

Capacity goes down 0.5 hp

Control Functions

hp = horsepower

1

2

3

4

5

6

7

8

1 - 9

9

2WAY VRF SYSTEM

Control Functions

3. Compressor Control

2WAY VRF SYSTEM

Control Functions

3. Compressor Control

Inverter layout

Noise

filter

R

S

T

U

V

W

U

V

W

U

V

W

R S T

Power

supply

Primary CT1

Primary CT2

Secondary CT1

Secondary CT2

Diode bridge

IPM (CM)

1st compressor

Fan motor

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

Use the same values of 1st compressor and 2nd compressor.

unit: Ampere

Current limit 1

Maximum current 1 H

Primary

Maximum current 1 L 15.5

19.5 19.5 19.5 19.5

72 96 120 144

15.5

16.5

15.5

16.5 16.5 16.5

15.5

Current limit 2

Maximum current 2 H

Secondary

Maximum current 2 L 13.1

16.6 23.0 16.6 16.6

19.5

14.1

13.1

14.1 20.5 14.1

13.1

Type of outdoor unit

Noise

filter

Diode bridge

IPM (CM)

IPM (FN)

2nd compressor

3. Compressor Control

3

Current protection This restriction protects the compressor and controls the compressor electric current simultaneously. The current limitation value changes to “normal status” and “overload status” according to the outdoor temperature. The primary and secondary current values of 1st compressor or 2nd compressor are measured.

2WAY VRF SYSTEM

Control Functions

1

2

3

4

Outdoor temperature

U-72ME2U9 / U-96ME2U9 / U-120ME2U9 / U-144ME2U9

A Normal status: Use the same values of 1st compressor and 2nd compressor.

Primary

Secondary

Overload status: Use the same values of 1st compressor and 2nd compressor.

B

114.8°F (46°C)

Type of outdoor unit

Current limit 1

Maximum current 1 H

Maximum current 1 L24

Current limit 2

Maximum current 2 H

Maximum current 2 L24

Current limit 1

B

A

Current table <Overload>

Current table <Normal>

72 96 120 144

30 43 30 30

25 38 22.5

30 44 30 30

25 40 25

72 96 120 144

30 43 30 30

37

39

22.5

21.5

25

24

21.5

24

Outdoor temperature

109.4°F (43°C)

unit: Ampere

5

6

7

8

Primary

Secondary

Inverter layout

Power

supply

R S T

Maximum current 1 H

Maximum current 1 L24

Current limit 2

Maximum current 2 H

Maximum current 2 L24

Noise

R

S

T

Noise

filter

Primary CT1

Primary CT2

filter

25 38 21

30 44 30 30

25 40 23

Diode bridge

37

39

21

20

23

22

20

22

IPM (CM)

U

V

W

IPM (FN)

U

V

W

IPM (CM)

U

V

W

Secondary CT1

1st compressor

Fan motor

Secondary CT2

2nd compressor

9

1 - 10

2WAY VRF SYSTEM

Control Functions

3. Compressor Control

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

Use the same values of 1st compressor and 2nd compressor.

Type of outdoor unit

Current limit 1

72 96 120 144

19.5 19.5 19.5 19.5

2WAY VRF SYSTEM

Control Functions

unit: Ampere

Primary

Secondary

Inverter layout

Power

supply

R S T

Maximum current 1 H

Maximum current 1 L 15.5

Current limit 2

Maximum current 2 H

Maximum current 2 L 13.1

Noise

filter

R

S

T

Primary CT1

Noise

filter

16.5 16.5 16.5

16.6 23.0 16.6 16.6

14.1 20.5 14.1

Diode

bridge

Diode

bridge

15.5

19.5

16.5

15.5

14.1

13.1

15.5

13.1

IPM (CM)

U

V

W

IPM (FN)

U

V

W

IPM (CM)

U

V

W

Secondary CT1

1st compressor

Fan motor

Secondary CT2

2nd compressor

1

2

3

4

Primary CT2

5

6

7

8

1 - 11

9

1

4. Special Control

2WAY VRF SYSTEM

Control Functions

2WAY VRF SYSTEM

Control Functions

4. Special Control

(3) Refrigerant Control Valve [RCV]

The main purpose of this valve is to adjust the flow of refrigerant (refrigerant volume). When the outdoor unit receives a sign of refrigerant shortage, the valve opens and refrigerant is supplied from the receiver tank to the system.

This valve turns ON when the evaporator is refrigerant shortage. The heat exchanger of indoor unit is the evaporator in cooling mode. The heat exchanger of outdoor unit is the evaporator in heating mode.

This valve turns OFF when the excessive amount of refrigerant is in the condenser. The heat exchanger of indoor unit is the condenser in heating operation. The heat exchanger of outdoor unit is the condenser in cooling operation.

This valve turns OFF when the outdoor unit is stopped.

This valve might turn ON when a special control is in progress.

Evaporator

RBV

RCV

LP

HP

Refrigerant shortage in evaporator.

Receiver tank holds refrigerant.

Two-phase

flow

Evaporator

RBV

RCV

LP

HP

Sufficient refrigerant is supplied to evaporator.

High pressure from RCV pushes the liquid refrigerant out of the receiver tank.

ON

Two-phase flow

2

3

4

5

2WAY VRF SYSTEM

4. Output of PCB

Control Functions

Solenoid valve

Expansion valve

Crankcase heater

(1) 4-way Valve [20S]

This valve turns OFF at cooling mode, and turns ON at heating mode. This valve turns OFF at defrosting control. * When the outdoor unit stops, the 4-way valve maintains in the same state as before.

(2) SAVE Valve [SAVE]

● This valve turns ON for 5 seconds before the inverter compressor starts. After the inverter compressor starts, the valve turns ON for 10 seconds. Then it turns OFF.

● This valve turns ON for 30 seconds after the outdoor unit stops. Then it turns OFF.

● This valve turns ON when high pressure sensor detects 496psi (3.42MPa) to prevent abnormal pressure. This valve turns OFF when the high pressure goes down below 481.5psi (3.32MPa).

● This valve might turn ON when the system capacity is excessive although the inverter compressor operates at

Min. frequency.

● This valve turns ON in the following status : (Compressor discharge temperature - High pressure saturation temperature) < 9deg F (5deg C)

● Under control of 4-way valve adjustment control

● This valve turns ON when low pressure sensor goes down 24.7psi (0.17MPa) to prevent abnormal pressure. This valve turns OFF when low pressure sensor increase 29psi (0.20MPa) or over.

Items Remarks Indication on PCB

20S

SAVE

RCV

RBV

ORVR

BPV

ACV

O

2

MOV1

MOV2

MOV4

CH1

CH2

4-way valve

Save valve

Refrigerant control valve

Refrigerant balance valve

Oil recovery valve

By-pass valve

Accumulator valve

O

2 valve

MOV for heat exchanger 1

MOV for heat exchanger 2

SC circuit expansion valve

Crankcase heater for 1st compressor

Crankcase heater for 2nd compressor

6

7

8

9

1 - 12

2WAY VRF SYSTEM

Control Functions

4. Special Control

4. Output of PCB

(3) Refrigerant Control Valve [RCV]

The main purpose of this valve is to adjust the flow of refrigerant (refrigerant volume). When the outdoor unit receives a sign of refrigerant shortage, the valve opens and refrigerant is supplied from the receiver tank to the system.

This valve turns ON when the evaporator is refrigerant shortage. The heat exchanger of indoor unit is the evaporator in cooling mode. The heat exchanger of outdoor unit is the evaporator in heating mode.

This valve turns OFF when the excessive amount of refrigerant is in the condenser. The heat exchanger of indoor unit is the condenser in heating operation. The heat exchanger of outdoor unit is the condenser in cooling operation.

This valve turns OFF when the outdoor unit is stopped.

This valve might turn ON when a special control is in progress.

RCV

HP

Evaporator

Control Functions

1

LP

HP

LP

RBV

RCV

RBV

Two-phase

flow

Refrigerant shortage in evaporator.

Receiver tank holds refrigerant.

ON

Evaporator

Two-phase flow

Sufficient refrigerant is supplied to evaporator.

High pressure from RCV pushes the liquid refrigerant out of the receiver tank.

2

3

4

5

6

1 - 13

7

8

9

1

4. Special Control

2WAY VRF SYSTEM

Control Functions

2WAY VRF SYSTEM

Control Functions

4. Special Control

(5) Oil Recovery Valve [ORVR]

The purpose of this valve is to recover oil from the oil separator of its own outdoor unit or balance tube to the compressor.

This valve turns ON when the oil level of the compressor is “0” or “1”.

This valve turns ON for 2 minutes after the compressor starts.

This valve is always OFF when outdoor unit is stopped.

* For oil level of compressor, see “7. Oil Control”.

This valve turns ON when recovering refrigerant from the stopped outdoor unit.

(6) By-pass Valve [BPV]

This valve is for pushing the oil in the balance piping into other outdoor units.

When the compressor oil level of its own outdoor unit is in the “2” or “1”, this valve turns ON when the oil level “0” is detected in other outdoor units.

When the compressor itself is stopped with a full of refrigerant, this valve turns ON. Then the refrigerant is supplied to the other operating outdoor units.

* This valve turns ON for 10 seconds and turns OFF for 20 seconds.

This operation is repeated while oil is supplied to others.

* For more information on oil level of compressor, see “7. Oil Control”.

(7) Accumulator Valve [ACV]

The purpose of this valve is to recover oil and refrigerant from the accumulator to the compressor.

This valve turns OFF when the compressor operation just started. This valve turns ON when the compressor is warmed up. This valve turns ON while the oil recovery among the systems and defrost control are in progress. This valve turns ON while the MOV4 is operating.

(8) O2 Valve [O2*]

ACV

Accumulator

This valve works when the outdoor unit receives signal of the refrigerant leakage from the indoor unit.

*O

2

valve is the field supply parts.

The indoor unit that transmits the signal of the refrigerant leakage gives “P14”alarm. To activate this function, it is necessary to set it to EEPROM on the main outdoor PCB and indoor PCB.

EEPROM setting in main outdoor unit CODE: C1

Setting No

0

1

2

This function invalid (factory preset mode)

This valve is turned OFF when the system is normal. This valve is turned ON when the outdoor unit receives signal from the indoor unit This valve is turned ON when the system is normal.

This valve is turned OFF when the outdoor unit receives signal from the indoor unit EEPROM setting in indoor unit CODE: 0B

Function of EXCT plug short-circuit

Indoor unit does thermostat OFF

(factory preset mode)

Indoor unit gives “P14”alarm and transmits the refrigerant leakage signal.

2

3

4

5

2WAY VRF SYSTEM

4. Output of PCB

(4) Refrigerant Balance Valve [RBV]

The main purpose of this valve is to adjust the flow of refrigerant (refrigerant volume) in the evaporator. When the outdoor unit receives a sign of overcharged refrigerant, the valve opens and refrigerant is recovered at the receiver tank. This valve also turns ON in order to recover refrigerant at the outdoor unit after heating operation is stopped.

* It is possible to set the RBV to valid or invalid by the outdoor unit EEPROM settings.

Initial setting is invalid.

* This valve is never turned ON with the RCV at the same time.

This valve turns ON for 20 seconds after heating operation is stopped, and then turns OFF.

This valve turns OFF when an abnormal drop in compressor discharge gas temperature is detected.

This valve turns OFF when an abnormal drop in compressor suction gas temperature is detected.

After the valve turns from ON to OFF, it will not turn ON again for 15 minutes.

This valve turns ON when low pressure sensor decreases 24.7psi (0.17MPa) at stopped system. This valve turns OFF when low pressure sensor increases 29psi (0.20MPa).

RCV

HP

RBV

LP

Receiver tank holds a low refrigerant volume.

RCV

HP

RBV

LP

ON

Condenser

Liquid flow

Two-phase flow

Over charge condition

Condenser

Two-phase flow

Liquid flow

Control Functions

6

7

8

9

Appropriate condition

Refrigerant gas in the top of receiver tank is absorbed into low pressure side.

1 - 14

2WAY VRF SYSTEM

Control Functions

4. Special Control

4. Output of PCB

Control Functions

(5) Oil Recovery Valve [ORVR]

The purpose of this valve is to recover oil from the oil separator of its own outdoor unit or balance tube to the compressor.

This valve turns ON when the oil level of the compressor is “0” or “1”.

This valve turns ON for 2 minutes after the compressor starts.

This valve is always OFF when outdoor unit is stopped.

* For oil level of compressor, see “7. Oil Control”.

This valve turns ON when recovering refrigerant from the stopped outdoor unit.

(6) By-pass Valve [BPV]

This valve is for pushing the oil in the balance piping into other outdoor units.

When the compressor oil level of its own outdoor unit is in the “2” or “1”, this valve turns ON when the oil level “0” is detected in other outdoor units.

* This valve turns ON for 10 seconds and turns OFF for 20 seconds.

This operation is repeated while oil is supplied to others.

* For more information on oil level of compressor, see “7. Oil Control”.

When the compressor itself is stopped with a full of refrigerant, this valve turns ON. Then the refrigerant is supplied to the other operating outdoor units.

1

2

(7) Accumulator Valve [ACV]

The purpose of this valve is to recover oil and refrigerant from the accumulator to the compressor.

This valve turns OFF when the compressor operation just started. This valve turns ON when the compressor is warmed up. This valve turns ON while the oil recovery among the systems and defrost control are in progress. This valve turns ON while the MOV4 is operating.

(8) O2 Valve [O2*]

This valve works when the outdoor unit receives signal of the refrigerant leakage from the indoor unit. The indoor unit that transmits the signal of the refrigerant leakage gives “P14”alarm. To activate this function, it is necessary to set it to EEPROM on the main outdoor PCB and indoor PCB.

EEPROM setting in main outdoor unit CODE: C1

Setting No

0 1

2

EEPROM setting in indoor unit CODE: 0B

Setting No

0 1

This function invalid (factory preset mode)

This valve is turned OFF when the system is normal.

This valve is turned ON when the outdoor unit receives signal from the indoor unit

This valve is turned ON when the system is normal.

This valve is turned OFF when the outdoor unit receives signal from the indoor unit

Function of EXCT plug short-circuit

Indoor unit does thermostat OFF

Indoor unit gives “P14”alarm and transmits the refrigerant leakage signal.

valve is the field supply parts.

*O

2

(factory preset mode)

Accumulator

ACV

3

4

5

6

7

8

1 - 15

9

1

4. Special Control

2WAY VRF SYSTEM

Control Functions

2WAY VRF SYSTEM

Control Functions

4. Special Control

(10) SC Circuit Expansion Valve [MOV4]

During cooling operation, the liquid refrigerant which condenses at the outdoor unit heat exchanger flows into the receiver tank, and SC (sub-cooling) approaches 32°F (0°C). When SC is small and the length of the tubing connecting the indoor and outdoor units is long, the refrigerant flow in the indoor unit will be reduced significantly. To prevent this trouble from occurring, MOV4 operates so as to increase super-cooling in the double tube coil.

10-1.

(11) Crankcase Heater Control [CH1, CH2]

When the compressor stops, the crankcase heater of its own compressor is turned ON in the following conditions.

Cooling SC Control

During heating operation, MOV4 operates so as to improve the refrigerant flow of the outdoor unit heat exchanger and the system. MOV4 controls refrigerant flow volume so that it will not flow back to the compressor in the liquid state. MOV4 controls the difference of temperature between the SCG thermistor and low pressure saturated temperature to 5.4deg F (3deg C).

10-2. Heating SC Control

When the discharge temperature increases to 194°F (90°C) or more, MOV 4 opens to 100 pulses to cool down the compressor. Then, the MOV 4 operates according to the state of the discharge temperature between 20 ~ 480 pulses. This operation takes priority over SC control. This operation is continued until discharge temperature decreases to 176°F (80°C) or less.

10-3. Discharge Temperature Control of Compressor

MOV4 controls the difference of temperature between the SCG thermistor and low pressure saturated temperature to 5.4deg F ~ 9deg F (3deg C ~ 5deg C).

Thermistor (SCG)

MOV4 (SH control)

Gas refrigerant returns to accumulator.

Liquid refrigerant

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

Liquid refrigerant

Thermistor (SCG)

MOV4 (Discharge temperature control of compressor)

Liquid refrigerant returns to accumulator.

Liquid refrigerant

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

Liquid refrigerant

When the discharge temperature ≤ the outdoor air temperature + 27deg F (+15deg C) When the outdoor air temperature ≤ 68°F (20°C) When the compressor stops and 30 minutes later.

2WAY VRF SYSTEM

4. Output of PCB

(9) MOV for Heat Exchanger [MOV1, MOV2]

9-1. Type of expansion valves

MOV1 : For upper side heat exchanger MOV2 : For lower side heat exchanger

9-2. Power Initialization

If no indoor units have started (even once) after the power supply to the outdoor unit, the MOV holds the 480 pulses (fully open).

*When the indoor unit receives the signal for operation request from the control equipment, the pulse turns

other than the 480 pulses (regardless of the thermostat ON/OFF or operating ON/OFF). It is necessary to switch ON the power supply again if the 480 pulses are required.

9-3. Control of expansion valves

Expansion valves for heat exchanger control according to the operation mode.

Control Functions

2

3

4

5

6

Stop

0

Cooling HeatingMode of system

Operation

480

Stop

0

Operation

0 ~ 480

Compressor

MOV1 (pulse)

MOV2 (pulse)

* If any one compressor in the outdoor unit is operating at heating mode, expansion valves perform SH

control. SH control adjusts the difference of temperature between the liquid and gas temperature to

-1.8deg F ~ 9deg F (-1deg C ~ 5deg C).

Stop

0

7

8

9

1 - 16

2WAY VRF SYSTEM

Control Functions

4. Special Control

4. Output of PCB

Control Functions

(10) SC Circuit Expansion Valve [MOV4]

10-1.

Cooling SC Control

During cooling operation, the liquid refrigerant which condenses at the outdoor unit heat exchanger flows into the receiver tank, and SC (sub-cooling) approaches 32°F (0°C). When SC is small and the length of the tubing connecting the indoor and outdoor units is long, the refrigerant flow in the indoor unit will be reduced significantly. To prevent this trouble from occurring, MOV4 operates so as to increase super-cooling in the double tube coil.

MOV4 controls the difference of temperature between the SCG thermistor and low pressure saturated temperature to 5.4deg F ~ 9deg F (3deg C ~ 5deg C).

10-2. Heating SC Control

During heating operation, MOV4 operates so as to improve the refrigerant flow of the outdoor unit heat exchanger and the system. MOV4 controls refrigerant flow volume so that it will not flow back to the compressor in the liquid state. MOV4 controls the difference of temperature between the SCG thermistor and low pressure saturated temperature to 5.4deg F (3deg C).

10-3. Discharge Temperature Control of Compressor

When the discharge temperature increases to 194°F (90°C) or more, MOV 4 opens to 100 pulses to cool down the compressor. Then, the MOV 4 operates according to the state of the discharge temperature between 20 ~ 480 pulses. This operation takes priority over SC control. This operation is continued until discharge temperature decreases to 176°F (80°C) or less.

Liquid refrigerant

Thermistor (SCG)

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

MOV4 (SH control)

Thermistor (SCG)

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

1

Gas refrigerant returns to accumulator.

2

Liquid refrigerant

3

4

Liquid refrigerant returns to accumulator.

5

Liquid refrigerant

MOV4 (Discharge temperature control of compressor)

(11) Crankcase Heater Control [CH1, CH2]

When the compressor stops, the crankcase heater of its own compressor is turned ON in the following conditions.

When the discharge temperature ≤ the outdoor air temperature + 27deg F (+15deg C) When the outdoor air temperature ≤ 68°F (20°C) When the compressor stops and 30 minutes later.

1 - 17

6

7

8

9

1

2WAY VRF SYSTEM

Control Functions

5. Outdoor Unit Fan Control

Independent control of outdoor unit This control is intended to prevent snow from accumulating on stopped fans. The fan motor rotates at 500rpm in the below conditions even if the outdoor unit stops.

(1)

Control with snow detection sensor (field supply) If a snow detection sensor (field supply) is available and this function is set in validity, the fan motor of the outdoor unit rotates at 600 rpm when the snow detection sensor detects snow. The judgment of this control performs at 10 minutes interval. One snow detection sensor can control all outdoor units on the communications wiring. The snow detection sensor is only possible to connect to the main outdoor unit (unit No.1) and it can control all outdoor units in communication wiring.

(2)

Fan motor operates for 45 seconds and stops for 2 hours when ambient temperature is 41.18°F (5.1°C) or more. Fan motor operates for 45 seconds and stops for 1.5 hours when ambient temperature is 32.2 - 41.0°F (0.1 - 5.0°C).

Fan motor operates for 45 seconds and stops for 1 hour when ambient temperature is 32.0°F (0.0°C) or less.

EEPROM setting in each main outdoor unit

* All outdoor units are connected with same communication wiring.

To activate this function, it is necessary to set it to the EEPROM on each system’s main outdoor unit PCB.

CODE: 04

System address 1

Snow detection sensor installed

Unit No.1

Unit No.2

Unit No.3

System address 2 System address 3

Function

No snow detection sensor is connected but control is available. (at factory shipment)

Snow detection sensor is connected and control is available.

Setting No.

0

1

No snow detection sensor is connected and control is not available.2

Snow detection sensor is connected but control is not available.3

Setting No.

Fan motor status during snowfall

100000222

ON ON ON ON ON ON OFF OFF OFF

1-2. Snow removal control

2

3

2WAY VRF SYSTEM

5. Outdoor Unit Fan Control

Control Functions

(1) Fan Mode

These outdoor units utilize a DC fan motor that can be controlled in a maximum of 15 steps (15 modes). However, fan modes 14 and 15 can only be used if high static pressure mode has been set.

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

The following table shows the maximum and minimum fan mode and fan forced mode for each unit.

Maximum value

Minimum value * 1 1 1 1

* For the sake of protecting temperature of the electrical parts, the minimum values of the fan mode may sometimes increase in accordance with the ambient temperature or the amount of secondary current.

1-1. High static pressure mode

The outdoor unit allows a high static pressure changing the settings. The maximum permissible static pressure is 0.01psi (80Pa).

Standard

High static

pressure mode

setting

Status of

heat exchanger

Condenser 13 13 12 12

Ambient

Evaporator

Condenser 15 15 12 12

Evaporator

temperature

Ambient

temperature

Ambient

temperature

Ambient

temperature

>

≤

>

≤

50°F

(10°C)

50°F

(10°C)

50°F

(10°C)

50°F

(10°C)

72 96 120 144

13 13 12 12

13 13 13 13

15 15 12 12

15 15 13 13

Type of outdoor unit

4

5

6

7

8

EEPROM setting in each outdoor unit

CODE : 8F

However, maximum fan mode is upper limit.

Setting No.

0 Invalid (factory preset mode) 1 High static pressure mode 2 Never use 3 Never use 4 Never use 5 Never use 6 Never use

9

1 - 18

2WAY VRF SYSTEM

Control Functions

5. Outdoor Unit Fan Control

Control Functions

1-2. Snow removal control

Independent control of outdoor unit

(1)

This control is intended to prevent snow from accumulating on stopped fans. The fan motor rotates at 500rpm in the below conditions even if the outdoor unit stops.

Fan motor operates for 45 seconds and stops for 2 hours when ambient temperature is 41.18°F (5.1°C) or more. Fan motor operates for 45 seconds and stops for 1.5 hours when ambient temperature is 32.2 - 41.0°F (0.1 - 5.0°C).

Fan motor operates for 45 seconds and stops for 1 hour when ambient temperature is 32.0°F (0.0°C) or less.

Control with snow detection sensor (field supply)

(2)

If a snow detection sensor (field supply) is available and this function is set in validity, the fan motor of the outdoor unit rotates at 600 rpm when the snow detection sensor detects snow. The judgment of this control performs at 10 minutes interval. One snow detection sensor can control all outdoor units on the communications wiring. The snow detection sensor is only possible to connect to the main outdoor unit (unit No.1) and it can control all outdoor units in communication wiring.

1

2

To activate this function, it is necessary to set it to the EEPROM on each system’s main outdoor unit PCB.

EEPROM setting in each main outdoor unit

CODE: 04

Setting No.

0

1

No snow detection sensor is connected but control is available. (at factory shipment)

Snow detection sensor is connected and control is available.

No snow detection sensor is connected and control is not available.2

Snow detection sensor is connected but control is not available.3

System address 1

Snow detection sensor installed

Unit No.1

Unit No.2

Unit No.3

Function

System address 2 System address 3

Unit No.1

Unit No.2

Unit No.3

Unit No.1

Unit No.2

3

4

5

6

Unit No.3

Setting No.

Fan motor status during snowfall

* All outdoor units are connected with same communication wiring.

100000222

ON ON ON ON ON ON OFF OFF OFF

1 - 19

7

8

9

1

2WAY VRF SYSTEM

Control Functions

5. Outdoor Unit Fan Control

(2) 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 (compressor capacity) changes dramatically, the initial mode may be recalculated and may be again fixed for 30 seconds.

(3) Operation after Fixed Initial Fan Mode

After the fixed initial fan mode, the fan mode is increased or decreased according to the operating conditions.

3-1. Cooling operation

* The fan mode is always increased when the detected high pressure sensor temperature is 114.8°F (46°C) or

higher.

Fan mode is increased when the detected high pressure saturated temperature is high, and is decreased when the high pressure saturated temperature is low.

The fan mode may be decreased when the system detects refrigerant shortage at an indoor unit.

During cooling operation, if the fan mode becomes “0” and this condition maintains for 3 minutes, the fan mode is changed to “1”.

3-2. When all indoor units are operating in heating mode

If the pressure sensor temperature is low, the fan mode is increased at regular intervals.

If the pressure sensor temperature is high, the fan mode is decreased in order to prevent excessive loads.

The fan mode may be increased when the liquid temperature of outdoor unit heat exchanger drops to

1.8deg F (1deg C) or below.

2

3

4

2WAY VRF SYSTEM

5. Outdoor Unit Fan Control

Control Functions

1-3. Silent mode

This unit includes 2 types of silent modes. See the table under the section “(1) Fan Mode” for maximum fan mode in silent mode. Selecting the silent mode results in operation that gives priority to reducing noise, because these modes involve restrictions on outdoor unit fan modes, the capacity will be somewhat reduced. (It may sometimes become a maximum of -5 hp.)

* Maximum fan mode and frequency in silent mode

Type of outdoor unit 72 96 120 144

Fan mode 9 10 11 11

Frequency (Hz) 48.1 64.4 41.4 54.9

* To activate this function, it is necessary to set it to each outdoor unit.

CODE: 05

Setting No. Mode

0 1 2 3 4 5 6 7 8

* When the setting is "external input to PCB necessary", this function works by short circuiting "SILENT" pins. * When the setting is "external input to PCB unnecessary", this function always works. * When the setting is "silent priority", max. fan mode is decided in the following formula.

Max. fan mode = 13 - ( 35 – Ambient temperature) / 2 However, minimum fan mode is “6”, maximum is “13”. (When high static pressure mode, max is “15”)

* When the setting is "capacity priority", this function works excluding the following conditions.

Condition that silent mode interrupts

Heat exchanger [condenser] of outdoor unit: Ambient temperature ≥ 100.4°F (38°C) Heat exchanger [evaporator] of outdoor unit: Ambient temperature ≤ 35.6°F (2°C)

This function will be useful for nighttime in summer.

Invalidity (Factory preset mode) - -

Silent priority

Capacity priority

External input to PCB Silent mode

Necessary

Unnecessary

Necessary

Unnecessary

Silent mode

-

Silent mode

-

Silent mode

-

Silent mode

-

5

6

7

8

9

1 - 20

2WAY VRF SYSTEM

Control Functions

5. Outdoor Unit Fan Control

(2) 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 (compressor capacity) changes dramatically, the initial mode may be recalculated and may be again fixed for 30 seconds.

(3) Operation after Fixed Initial Fan Mode

After the fixed initial fan mode, the fan mode is increased or decreased according to the operating conditions.

3-1. Cooling operation

Fan mode is increased when the detected high pressure saturated temperature is high, and is decreased when the high pressure saturated temperature is low. * The fan mode is always increased when the detected high pressure sensor temperature is 114.8°F (46°C) or

higher.

The fan mode may be decreased when the system detects refrigerant shortage at an indoor unit.

During cooling operation, if the fan mode becomes “0” and this condition maintains for 3 minutes, the fan mode is changed to “1”.

Control Functions

1

2

3-2. When all indoor units are operating in heating mode

If the pressure sensor temperature is low, the fan mode is increased at regular intervals.

If the pressure sensor temperature is high, the fan mode is decreased in order to prevent excessive loads.

The fan mode may be increased when the liquid temperature of outdoor unit heat exchanger drops to

1.8deg F (1deg C) or below.

3

4

5

6

1 - 21

7

8

9

6. Outdoor Unit CCU (command controller unit) Control

2WAY VRF SYSTEM

Control Functions

2WAY VRF SYSTEM

Control Functions

6. Outdoor Unit CCU (command controller unit) Control

Operating

mode of

indoor unit

Operating

mode of

outdoor unit

Operating

mode of

compressor

Thermostat

ON/OFF

MOV pulse of indoor unit

Stop

Cooling

Stop

Operation

Stop

Operation

Stop

Operation

Stop

OFF

ON

Operation

20

60 ~ 480 (SH control*

1

)

65 - 480 pulses (SC control*

3

)

20

Operation

Fan (only)

Cooling

Heating

Cooling

Heating

1-2. Indoor unit with RAP valve kit

Go to previous page and see the comments with asterisks *1 and *3. In the case of special controls, the MOV performs a special operation. For details, see “4. Output of PCB” under this section.

unit : pulse

Some actuators of indoor unit are controlled by CCU.

(1)

MOV of Indoor Unit

2WAY VRF SYSTEM

Control Functions

1

2

3

4

5

6

1-1. Indoor unit without RAP valve kit

Operating

mode of

indoor unit

Stop

Fan (only)

Cooling

Heating

*1 SH control adjusts the difference between the liquid temperature and gas temperature in indoor unit.

SH = gas temperature (E3) - liquid temperature (E1) Target SH is 37.4deg F (3deg C) when the load level of indoor unit is “30” or “31 (test run)”.

Target SH will be increased up to 63.5deg F (17.5deg C) when the load level of indoor unit is low.

When the refrigerant amount in the system is adjusted, it is necessary to select test run mode that the required level becomes “31”.

*2 MOV pulse changes to 55 for 1 minute when the MOV pulse continues to be 55 or more for 10 minutes.

The purpose of this control is to decrease the flow volume of the refrigerant so that room temperature can be detected with less influence of heat from the refrigerant.

*3 SC control adjusts the difference in temperature between the liquid temperature in indoor unit and

high-pressure saturated temperature in outdoor unit. SC = high-pressure sensor temperature (HPS) - liquid temperature (E1) Target SC is 9deg F ~ 27deg F (5deg C ~ 15deg C) according to the operating condition.

Operating

mode of

outdoor unit

Cooling

Heating

Cooling

Heating

Cooling

Heating

Operating

mode of

compressor

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Thermostat

ON/OFF

OFF

ON

OFF

ON

MOV pulse of indoor unit

20

85

65 ~ 80 20

20

85

65 ~ 80 20

20

1

60 ~ 480 (SH control*

85

55 ~ 80 (prevent remaining refrigerant, suction temperature control*

65 - 480 pulses (SC control*

)

2

)

3

)

unit : pulse

7

8

9

1 - 22

2WAY VRF SYSTEM

Control Functions

6. Outdoor Unit CCU (command controller unit) Control

2WAY VRF SYSTEM

Control Functions

1-2. Indoor unit with RAP valve kit

Operating

mode of

indoor unit

Stop

Fan (only)

Cooling

Heating

Go to previous page and see the comments with asterisks *1 and *3. In the case of special controls, the MOV performs a special operation. For details, see “4. Output of PCB” under this section.

Operating

mode of

outdoor unit

Cooling

Heating

Cooling

Heating

Cooling

Heating

Operating

mode of

compressor

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Thermostat

ON/OFF

OFF

ON

OFF

ON

MOV pulse of indoor unit

20

60 ~ 480 (SH control*

20

20 65 - 480 pulses (SC control*

1

)

3

)

unit : pulse

1

2

3

4

5

6

7

8

1 - 23

9

6. Outdoor Unit CCU (command controller unit) Control

2WAY VRF SYSTEM

Control Functions

2WAY VRF SYSTEM

Control Functions

6. Outdoor Unit CCU (command controller unit) Control

3-2. Heating mode

The indoor unit fan in heating mode is stopped from the CCU in the following condition.

Discharge air temperature of indoor unit ≤ 68°F (20°C) High pressure saturated temperature (HPT) in outdoor unit≤ 77°F (25°C)

Liquid temperature (E1) in indoor unit ≤ 68°F (20°C)

EEPROM setting in main outdoor unit CODE: 0C

Indoor unit

operation mode

Setting No.

0

1

2

4

6

7 (Factory

preset mode)

3

5

Movement of drain pump

Invalid

DP operates for 20 minutes and stops for 2 hours

DP operates for 20 minutes and stops for 20 minutes

DP always operates

DP operates for XX minutes when indoor unit's operation changes; from thermostat ON or thermostat OFF → operation stopped.

DP operates for XX minutes when indoor unit's operation changes; from thermostat ON → thermostat OFF or operation stopped.

All mode

Cooling mode Dry mode Heating mode

Cooling mode Dry mode

Both Setting No. 4 and 5 functions.

DP operates for XX minutes when indoor unit's operation changes from thermostat ON or thermostat OFF → operation stopped.

In the case of special controls, the MOV performs special operation. For details, see “4. Special Control” under this section.

(4) Drain Pump Control

The CCU intervenes in drain pump control of the indoor unit according to the setting in EEPROM in the outdoor unit. The drain pump operates from the CCU control at the following condition.

DP counter ≥ 5

*The DP counter counts each oil recovery control, and 4-way Valve Adjustment Control in cooling operation.

Liquid temperature (E1) in the indoor unit which selected cooling mode < 32°F (0 °C)

* Regardless of operating / stopped mode

*

To activate this function, it is necessary to set EEPROM on the main outdoor unit PCB.

*

When any of setting No. 4 – 7 is selected, this function works only for the type of F2, M2, E1.

Low Silhouette Ducted type indoor unit

In Low Silhouette Ducted types, dirt might be accumulated when water collects in the drain pan for a long term. Therefore, the drain pump works longer to drain water surely.

(2) RAP Valve Kit

2WAY VRF SYSTEM

Control Functions

1

2

3

4

Operating

(3) Indoor Fan Speed Control

mode of

indoor unit

Stop

Fan (only)

Cooling

Heating

RAP valve kit state (ON/OFF) is displayed on "D" in DSBE column when the Checker software is used. 0：OFF 1：ON In the case of special controls, the MOV performs a special operation. For details, see “4. Output of PCB” under this section.

The CCU intervenes in fan control of the indoor unit according to the status of the operating mode. The priority order of fan control by the CCU is higher than that of indoor units.

Operating

mode of

outdoor unit

Cooling

Heating

Cooling

Heating

Cooling

Heating

Operating

mode of

Compressor

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Stop

Operation

Thermostat

ON/OFF

OFF

ON

OFF

ON

RAP valve kit ON/OFF

OFF

OFF ON

5

6

7

8

9

3-1. Dry mode

Indoor unit fan operated in the dry mode is controlled from the CCU as shown in the figure below.

* DTi = ( Air intake temperature of indoor unit) - (Preset temperature by remote controller)

+ 1.8 deg F (+1 deg C)

DTi

Preset fan speed by remote controller

Fan speed

In the case of thermostat ON : “L” In the case of thermostat OFF : “LL”

1 - 24

2WAY VRF SYSTEM

Control Functions

6. Outdoor Unit CCU (command controller unit) Control

Control Functions

3-2. Heating mode

The indoor unit fan in heating mode is stopped from the CCU in the following condition.

Discharge air temperature of indoor unit ≤ 68°F (20°C) High pressure saturated temperature (HPT) in outdoor unit≤ 77°F (25°C)

Liquid temperature (E1) in indoor unit ≤ 68°F (20°C) In the case of special controls, the MOV performs special operation. For details, see “4. Special Control” under this section.

(4) Drain Pump Control

The CCU intervenes in drain pump control of the indoor unit according to the setting in EEPROM in the outdoor unit. The drain pump operates from the CCU control at the following condition.

DP counter ≥ 5

*The DP counter counts each oil recovery control, and 4-way Valve Adjustment Control in cooling operation.

Liquid temperature (E1) in the indoor unit which selected cooling mode < 32°F (0 °C)

* Regardless of operating / stopped mode

Low Silhouette Ducted type indoor unit

In Low Silhouette Ducted types, dirt might be accumulated when water collects in the drain pan for a long term. Therefore, the drain pump works longer to drain water surely. To activate this function, it is necessary to set EEPROM on the main outdoor unit PCB.

*

EEPROM setting in main outdoor unit CODE: 0C

Setting No.

0

1

Invalid

DP operates for 20 minutes and stops for 2 hours

Movement of drain pump

Indoor unit

operation mode

All mode

1

2

3

4

2

3

4

5

6

7 (Factory

preset mode)

*

When any of setting No. 4 – 7 is selected, this function works only for the type of F2, M2, E1.

DP operates for 20 minutes and stops for 20 minutes

DP always operates

DP operates for XX minutes when indoor unit's operation changes; from thermostat ON → thermostat OFF or operation stopped.

DP operates for XX minutes when indoor unit's operation changes; from thermostat ON or thermostat OFF → operation stopped.

Both Setting No. 4 and 5 functions.

DP operates for XX minutes when indoor unit's operation changes from thermostat ON or thermostat OFF → operation stopped.

5

Cooling mode Dry mode Heating mode

6

Cooling mode Dry mode

7

8

1 - 25

9

6. Outdoor Unit CCU (command controller unit) Control

2WAY VRF SYSTEM

Control Functions

2WAY VRF SYSTEM

Control Functions

7. Oil Control

(1) Oil Level

(2) Oil Level Detection

Conditions of oil level in compressor JudgmentOil level

2

1

0

State

Sufficient

Possibility of

shortage

Shortage

The compressor contains sufficient oil. There is no problem.

There will be a risk of oil shortage soon.

Confirm that oil is improved after performing the oil recovery control operation.

The compressor oil is short against required level for normal operation.

Confirm that oil level is improved after performing the oil recovery control among systems.

(4) Inter Outdoor Units Oil Recovery Control – Utilizing Balance Tubes

If the low oil level (1 or 0) continues, that outdoor unit (oil-receiving outdoor unit) receives oil from operating outdoor units where the oil level is not low (oil-supply outdoor units whose all compressor oil levels are 2 or 1).

At the time immediately after the oil level changes from 2 to 1, there is a specified amount of oil in the compressor. Namely, soon after the oil level is changed from 1 to 2, the oil in the compressor is sufficient. After about 1-hour operation, if the oil level “0” indication continues for more than 5 to 10 minutes, it seems to come short of oil in the system. Check valves related to oil recovery operation, the refrigerant tubing and for any oil leakage.

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

(3) Self-separator Oil Recovery Control

When a low oil level (1 or 0) is detected, oil is recovered from the oil separator to the compressor through the ORVR.

Control at the oil-supply outdoor unit begins after an outdoor unit falls into low oil level state. Oil supply is performed for a maximum of 5 minutes from each unit.

When oil supply is ended, oil supply from that outdoor unit will not occur again for a period of [(No. of outdoor units minus 1) × 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 “0”.

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

Solenoid valve control during unit compressor oil recovery

1. Oil-receiving outdoor unit The ORVR turns ON and remains ON during compressor oil recovery.

2. Oil-supply outdoor unit

* The oil recovery might be performed regardless of oil level.

The BPV repeatedly turns ON and OFF according to a constant cycle.

*

Operating time “XX” under the section “(4) Drain Pump Control” described on previous page is able to set in EEPROM of the main outdoor unit.

EEPROM setting in main outdoor unit CODE: 2B

2WAY VRF SYSTEM

Control Functions

Setting No.

1

2

3

4

* *

In the above 2 cases, the drain pump operates by the signal of indoor PCB, not by the CCU.

(5) Discharge Air Temperature Control

For Type F2, M2 and E1 indoor units, discharge air temperature is controlled from the CCU to prevent dew condensation on duct surface in cooling operation. The CCU monitors and adjusts ∆To of indoor unit. The adjustment is made by compressor capacity and MOV operation in the indoor unit.

Situation in which indoor unit stops by discharge air temperature control

20

30

40

50 50 (minutes)

60

The drain pump always operates when the indoor unit is thermostat ON in cooling operation. Once the drain pump operates, it keeps operating for 20 minutes.

∆To : Cooling (Discharge air temperature) - (Preset discharge air temperature)

Heating (Preset discharge air temperature) - (Discharge air temperature)

∆To ≤ -6.3deg F (-3.5deg C), and this condition continues for 7 minutes ∆To ≤ -3.6deg F (-2.0deg C), and this condition continues for (20 + XX) minutes

(factory preset mode)

XX

20 (minutes)

30 (minutes)

40 (minutes)

60 (minutes)

5

6

7

8

9

*

The above mentioned “XX” is able to set in EEPROM of the main outdoor unit.

EEPROM setting in main outdoor unit CODE: E1

Setting No.

-20

-19

-18

...

0

*

...

10

Regarding the preset discharge air temperature that is set in the indoor unit is able to change, see the section “4. REMOTE CONTROLLER FUNCTIONS” for this service manual.

(factory preset mode)

XX

-20 (minutes)

-19 (minutes)

-18 (minutes)

...

0 (minutes)

...

10 (minutes)

1 - 26

7. Oil Control

2WAY VRF SYSTEM

Control Functions

7. Oil Control

(1) Oil Level

2WAY VRF SYSTEM

Control Functions

State

2

1

0

At the time immediately after the oil level changes from 2 to 1, there is a specified amount of oil in the compressor. Namely, soon after the oil level is changed from 1 to 2, the oil in the compressor is sufficient. After about 1-hour operation, if the oil level “0” indication continues for more than 5 to 10 minutes, it seems to come short of oil in the system. Check valves related to oil recovery operation, the refrigerant tubing and for any oil leakage.

(2) Oil Level Detection

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

(3) Self-separator Oil Recovery Control

When a low oil level (1 or 0) is detected, oil is recovered from the oil separator to the compressor through the ORVR.

Sufficient

Possibility of

shortage

Shortage

Conditions of oil level in compressor JudgmentOil level

The compressor contains sufficient oil. There is no problem.

There will be a risk of oil shortage soon.

The compressor oil is short against required level for normal operation.

Confirm that oil is improved after performing the oil recovery control operation.

Confirm that oil level is improved after performing the oil recovery control among systems.

1

2

3

(4) Inter Outdoor Units Oil Recovery Control – Utilizing Balance Tubes

If the low oil level (1 or 0) continues, that outdoor unit (oil-receiving outdoor unit) receives oil from operating outdoor units where the oil level is not low (oil-supply outdoor units whose all compressor oil levels are 2 or 1).

Control at the oil-supply outdoor unit begins after an outdoor unit falls into low oil level state. Oil supply is performed for a maximum of 5 minutes from each unit.

When oil supply is ended, oil supply from that outdoor unit will not occur again for a period of [(No. of outdoor units minus 1) × 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 “0”.

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

Solenoid valve control during unit compressor oil recovery

1. Oil-receiving outdoor unit The ORVR turns ON and remains ON during compressor oil recovery.

2. Oil-supply outdoor unit The BPV repeatedly turns ON and OFF according to a constant cycle.

* The oil recovery might be performed regardless of oil level.

4

5

6

7

8

1 - 27

9

2WAY VRF SYSTEM

Control Functions

7. Oil Control

2WAY VRF SYSTEM

Control Functions

7. Oil Control

For 2 minutes

Indoor units

Control time

Outdoor units

MOV

RAP valve kit

Fan

All outdoor units operate at maximum horsepower.

MOV at all indoor units operate at a fixed pulse according to the indoor unit capacity.

All indoor units operate in Cooling mode (OFF status).

The fan speed depends on the indoor unit operation mode.

In the case of cooling mode

For 2 minutes

Indoor units

Control time

Outdoor units

MOV

RAP valve kit

Fan

All outdoor units operate at more than half horsepower.

MOV at all indoor units operate at 250 pulses.

All indoor units operate in Heating mode (ON status.)

・

As for heating thermostat ON indoor units, follow the indoor unit control system.

・Fan and heating (thermostat OFF) operation of indoor unit will be stopped. ・The fan speed of heating thermostat OFF Concealed Duct - High Static type

indoor unit (Type E1) is changed to LL.

In the case of heating mode

5-2.

The system oil recovery control shall be performed as the flow mentioned below. Normal operation → System oil recovery control → Normal operation

Simplified flow of system oil recovery control

7. Oil Control

(5)

System Oil Recovery Control

The system oil recovery control is performed by operating all the systems. If the stopped outdoor unit exists, the unit starts operating and the system oil recovery control is performed.

5-1.

Start of system oil recovery control

When one of the oil level of compressors is “0”, the system oil recovery control will start. When the accumulated time reaches 60 minutes under the condition of oil level “1” or lower, the system oil recovery control will start. This timer will be cleared when the oil level “2” continues for 5 minutes.

* If any compressor oil level “2” remains in the same outdoor unit even though one compressor oil level “0” exists,

this oil recovery control is not performed.

Control Functions

1

2

3

4

5

6

System oil recovery control is performed. System oil recovery is not performed.

Oil level “2” does NOT exist. Oil level “2” exists.

Outdoor unit

Oil level

12

Outdoor unit

Oil level

01

Outdoor unit

Oil level

12

compressor

When the system oil recovery control is once performed, it will not be resumed for 30 minutes.*

compressor

Outdoor unit

Oil level

02

compressor

7

8

9

1 - 28

7. Oil Control

2WAY VRF SYSTEM

Control Functions

7. Oil Control

3WAY SYSTEM

Control Functions

8. Oil Control

5-2.

Simplified flow of system oil recovery control

The system oil recovery control shall be performed as the flow mentioned below. Normal operation → System oil recovery control → Normal operation

In the case of cooling mode

2WAY VRF SYSTEM

Control Functions

Control time

Outdoor units

Indoor units

RAP valve kit

In the case of heating mode

Control time

Outdoor units

RAP valve kit

Indoor units

MOV

Fan

MOV

Fan

For 2 minutes

All outdoor units operate at maximum horsepower.

MOV at all indoor units operate at a fixed pulse according to the indoor unit capacity.

All indoor units operate in Cooling mode (OFF status).

The fan speed depends on the indoor unit operation mode.

For 2 minutes

All outdoor units operate at more than half horsepower.

MOV at all indoor units operate at 250 pulses.

All indoor units operate in Heating mode (ON status.)

As for heating thermostat ON indoor units, follow the indoor unit control system.

・・Fan and heating (thermostat OFF) operation of indoor unit will be stopped. ・The fan speed of heating thermostat OFF Concealed Duct - High Static type

indoor unit (Type E1) is changed to LL.

1

2

3

4

(6) Oil Rotation Control

The oil rotation control system regularly exchanges oil among the outdoor units regardless of oil level.

Oil rotation control is performed every one hour with accumulated operation time among the connected multiple outdoor units only.

During oil rotation control, ORVR may open in the order of priority of outdoor unit inverter compressor operation every 5 minutes.

(7) Indoor Unit Self Oil Recovery Control

The indoor unit self oil recovery control system can only be performed by the cooling indoor units.

Divided into 8 groups in the order of indoor unit addresses and this oil recovery control is performed every 120 minutes with accumulated operation time per each group for 1 minute.

The indoor unit expansion valve is opened according to the values determined by the indoor unit capacity with thermostat OFF.

20 pulses is opened from the pulse controlling the indoor unit expansion valve with thermostat ON. Then, the fan speed is changed to L.

5

6

7

8

1 - 29

9

2WAY VRF SYSTEM

8. 4-Way Valve Adjustment Control

2WAY VRF SYSTEM

Control Functions

2WAY VRF SYSTEM

Control Functions

9. Defrost Control

(1) Type of Defrost Control

(2) Forced Conditions

This system uses the following 2 defrosting systems.

Defrost does not begin again for 40 minutes of operation after defrost was once completed.

(3) Frost Detection

Frost detection does not occur for 5 minutes after operation starts.

Frost is detected when either condition 1 or 2 below is met.

Condition 1: L2 line shown in the figure below is detected twice for 4 minutes without interruption while the

compressor is operating.

Condition 2:

-13 (-25)

Minimum heat exchanger temperature °F (°C)

50 (10)

Ambient temperature°F (°C)

Frost detection area below the bold lines L1 and L2

L1 L2

59 (15) (Defrosting operation-end temperature)

unit: °F (°C)

30.2 (-1)

26.6 (-3)

17.6 (-8)

14 (-10)

-13.9 (-25.5)

-17.5 (-27.5)

L1 line shown in the figure below is detected for a total of 60 minutes while the compressor is operating.

Even if all indoor units are stopped while defrosting, defrost control continues until it ends.

If the outdoor unit is stopped while defrosting due to protection control or another reason, then defrost control will not start for a minimum of 10 minutes after restart occurs.

System configuration

Only 1 outdoor unit in the refrigerant system

2 or more outdoor units in the refrigerant system

Name of defrost control

Reverse cycle defrost

Outdoor unit cycle defrost

8. 4-Way Valve Adjustment Control

The purpose of this control is to change over the 4-way valve appropriately with big pressure difference. This control is performed at the following conditions.

The first operation after turning on power supply to outdoor unit. The first operation after all outdoor units stopped for 60 minutes.

The mode of the system changes.

Control Functions

1

2

3

4

Cooling operation

Indoor units

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

where thermostats are ON.

Heating operation

Control time

Outdoor units

RAP valve kit

Control time

Outdoor units

MOV

RAP valve kit

Fan

Minimum 1 min - Maximum 20 min [until max. (pressure sensor temp.) 95°F (35°C)]

MOV

All outdoor units operate at the maximum capacity.

MOV at all indoor units operate at 250 pulses.

All indoor units operate in heating mode (ON status).

For 2 minutes

All outdoor units operate at the maximum capacity.

MOV at all indoor units operate at a fixed pulse according to the indoor unit capacity.

All indoor units operate in Cooling mode (OFF status).

・Stop and cooling (thermostat ON/OFF) operation of indoor units will be followed the indoor unit control system. ・Fan operation of indoor unit is changed to LL.

5

6

7

8

・As for heating thermostat ON indoor units, follow the indoor unit control system.

Indoor units

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

where thermostats are ON.

Fan

・Fan and heating (thermostat OFF) operation of indoor unit will be stopped. ・The fan speed of heating thermostat OFF Concealed Duct - High Static type indoor

unit (Type E1) is changed to LL.

9

1 - 30

9. Defrost Control

2WAY VRF SYSTEM

Control Functions

9. Defrost Control

(1) Type of Defrost Control

This system uses the following 2 defrosting systems.

2WAY VRF SYSTEM

Control Functions

System configuration

Only 1 outdoor unit in the refrigerant system

2 or more outdoor units in the refrigerant system

(2) Forced Conditions

Defrost does not begin again for 40 minutes of operation after defrost was once completed. If the outdoor unit is stopped while defrosting due to protection control or another reason, then defrost control will not start for a minimum of 10 minutes after restart occurs. Even if all indoor units are stopped while defrosting, defrost control continues until it ends.

(3) Frost Detection

Frost detection does not occur for 5 minutes after operation starts.

Frost is detected when either condition 1 or 2 below is met.

Condition 1: L2 line shown in the figure below is detected twice for 4 minutes without interruption while the

compressor is operating.

Condition 2:

L1 line shown in the figure below is detected for a total of 60 minutes while the compressor is operating.

Minimum heat exchanger temperature °F (°C)

Name of defrost control

Reverse cycle defrost

Outdoor unit cycle defrost

unit: °F (°C)

1

2

3

-13 (-25)

30.2 (-1)

26.6 (-3)

17.6 (-8)

59 (15) (Defrosting operation-end temperature)

50 (10)

14 (-10)

Frost detection area below the bold lines L1 and L2

-13.9 (-25.5)

-17.5 (-27.5)

Ambient temperature°F (°C)

L1 L2

4

5

6

7

8

1 - 31

9

1

2WAY VRF SYSTEM

Control Functions

(4)

When the heating operation time at system has exceeded “XX” minutes (40 minutes at initial setting), and at least one unit satisfies the decision of defrosting, the defrosting operation is effective.

9. Defrost Control

Heating Operation Set Time (Defrosting Operation Prohibiting Time)

* XX is able to set in EEPROM of main outdoor unit.

* 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).

EEPROM setting in main outdoor unit CODE: A3

Setting No.

25

30

...

XX

25 (minutes)

40 (minutes)

(factory preset code)

30 (minutes)

...

40

85

...

85 (minutes)

90 90 (minutes)

CC

2WAY VRF SYSTEM

Control Functions

(7) Outdoor Unit Cycle Defrost

Outdoor unit cycle defrost is performed in systems where 2 or more outdoor units are connected to the refrigerant system.

In this defrosting, the outdoor units are divided into two groups. When outdoor units in the first defrosting group operate in defrost mode (heat exchanger operating as a condenser), outdoor units in the second defrosting group operates as an evaporator in heating mode. In this way, outdoor units in the second defrosting group supply heat to the unit where defrost is occurring. When outdoor units in the first defrosting group completes defrost, the other outdoor unit performs defrost in the same way.

Outdoor unit cycle defrost is always completed in 2 defrost operations.

7-2. Defrost sequence

7-1. Description of outdoor unit cycle defrost

In the case of 2 outdoor units installed in the refrigerant system:

Switch to

First operation Second operation

In the case of 3 outdoor units installed in the refrigerant system:

Defrost outdoor unit

Evaporator outdoor unit

Defrost outdoor unit

Evaporator outdoor unit

Defrost outdoor unit

Switch to

Heating mode indoor units

Defrost

Preparation

Defrost in

progress

Switch

Defrost in

progress

Defrost end

judgment

Defrost end

judgment

Defrost

end

Thermostat ON Thermostat OFF

Indoor units where fan is operating

Outdoor compressor(s) where defrost occurs first

Stopped indoor unit(s)

Outdoor compressor(s) where defrost follows later

Outdoor unit(s) where defrost follows later

Outdoor unit(s) where defrost occurs first

C

S

C

ON

S

ON

E

C

S

C

OFF

S

ON

E

E → C

C

S

C

OFF

S

OFF

E→C

C → E

C

S

C

ON

S

ON

C

E

Time1 - 7.5 minutes1 minute 1 minute 1 - 7.5 minutes

C

S

C

OFF

S

OFF

C → E or S

E or S

1 minute

Defrost flow E:C:Evaporator operation

Condenser operation S: stop E → C: C → E:

Switching evaporator operation to condenser operation Switching condenser operation to evaporator operation

9. Defrost Control

3WAY SYSTEM

Control Functions

9. Defrost Control

System employs

1 outdoor unit in the refrigerant system

2 or more outdoor units in the refrigerant system

Defrost control method

Reverse cycle defrost

Outdoor unit cycle defrost

This system uses the following 2 defrosting systems.

9-1. Defrost Methods

2

3

4

2WAY VRF SYSTEM

9. Defrost Control

(4) Constraint Conditions

Frost detection does not occur for 10 minutes after operation starts.

Defrost does not begin again for 40 minutes of operation after defrost was once completed.

If all indoor units are stopped while defrosting, or if the outdoor unit is stopped due to protection control or another reason, then defrost control will not start for a minimum of 5 minutes after restart occurs.

Time until next defrost permission when defrost was completed is changed according to the ambient temperature.

Ambient temperature

EEPROM setting in main outdoor unit CODE: A3

(5)

Minute XX + 6 XX + 3 XX

Setting No.

20 21

40 41

90

Defrost End Judgment Conditions

Defrost ends when either of the below defrost end judgment conditions is met.

Condition 1: The temperatures are 59°F (15°C) or higher at all heat exchanger sensors installed on the outdoor

Condition 2: 15 minutes have elapsed. (Reverse cycle defrost)

unit.

18 minutes have elapsed. (Outdoor unit cycle defrost)

To ≤ 14°F (-10°C) 14°F (-10°C) < To ≤ 23°F (-5°C)

40 (factory preset mode)

XX

20 21

Interval of “1”

Never use

Control Functions

23°F (-5°C) < To

5

6

7

8

9

(6)

Reverse Cycle Defrost

If there is only 1 outdoor unit in the refrigerant system, a reverse cycle defrost will be carried out.

Defrost flow E:C:Evaporator operation

Indoor unit

It is possible to change the stopped time according to the setting.

Condenser operation E → C: C → E:

Outdoor unit status CE →

Compressor OperatingStopped Stopped

Cooling mode

Heating mode

Switching evaporator operation to condenser operation Switching condenser operation to evaporator operation

Stopped EC→E

Fan (only) EC→E

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

TimeMaximum 15 minutes1 minute 1 minute

Defrost

preparation

1 - 32

Defrost in

progress

Defrost

end

judgment

Defrost end

→ E

E → C E → C

E → C

2WAY VRF SYSTEM

Control Functions

9. Defrost Control

Control Functions

(7) Outdoor Unit Cycle Defrost

Outdoor unit cycle defrost is performed in systems where 2 or more outdoor units are connected to the refrigerant system.

7-1. Description of outdoor unit cycle defrost

In this defrosting, the outdoor units are divided into two groups. When outdoor units in the first defrosting group operate in defrost mode (heat exchanger operating as a condenser), outdoor units in the second defrosting group operates as an evaporator in heating mode. In this way, outdoor units in the second defrosting group supply heat to the unit where defrost is occurring. When outdoor units in the first defrosting group completes defrost, the other outdoor unit performs defrost in the same way.

7-2. Defrost sequence

Outdoor unit cycle defrost is always completed in 2 defrost operations.

In the case of 2 outdoor units installed in the refrigerant system:

Switch to

Defrost outdoor unit

First operation Second operation

In the case of 3 outdoor units installed in the refrigerant system:

Defrost outdoor unit

Evaporator outdoor unit

Switch to

Evaporator outdoor unit

Defrost outdoor unit

Evaporator outdoor unit

1

2

3

4

Defrost outdoor unit

5

Defrost flow E:C:Evaporator operation

Condenser operation S: stop E → C: C → E:

Outdoor unit(s) where defrost occurs first

Outdoor compressor(s) where defrost occurs first

Outdoor unit(s) where defrost follows later

Outdoor compressor(s) where defrost follows later

Stopped indoor unit(s)

Indoor units where fan is operating

Heating mode indoor units

Time1 - 7.5 minutes1 minute 1 minute 1 - 7.5 minutes

Switching evaporator operation to condenser operation Switching condenser operation to evaporator operation

Thermostat ON Thermostat OFF

Defrost

Preparation

E → C

OFF

E

ON

S

C C

1 - 33

Defrost in

progress

C

ON

E

ON

S

C C

Switch

C → E

OFF

E→C

OFF

S

judgment

Defrost end

S

C C

Defrost in

progress

E

ON

C

ON

S

C C

Defrost

end

E or S

OFF

C → E or S

OFF

S

judgment

Defrost end

S

C C

1 minute

6

7

8

9

10. Upper Current Limitation Mode (Demand control)

3WAY SYSTEM

Control Functions

10. Upper Current Limitation Mode (Demand control)

There are 2 types of control; demand control and infinity limit in the upper current limitation mode. Either of them is controlled by the lower current limitation.

The standard value of the limit current is listed in the table below.

U-72ME2U9 / U-96ME2U9 / U-120ME2U9 / U-144ME2U9

Type of outdoor unit

Cooling mode

72 96 120 144

15.6 A 20.9 A 26.5 A 35.7 A

2WAY VRF SYSTEM

Control Functions

1

2

3

4

Heating mode

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

Type of outdoor unit

Cooling mode

Heating mode

(1) 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 serial-parallel I/O.

Upper current limitation setting

Contact 1

Contact 2

16.8 A 22.2 A 28.9 A 37.5 A

72 96 120 144

7.2 A 9.8 A 12.7 A 16.5 A

7.9 A 10.0 A 13.5 A 16.8 A

Control

No control (Operates to maximum capacity)

Operates to XX% of the upper limit for the rated current.

Operates to YY% of the upper limit for the rated current.

Forced thermostat OFF setting

5

6

7

8

9

: Input present

: Input not present

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

* XX and YY are able to set in EEPROM of main outdoor unit.

EEPROM setting in main outdoor unit

CODE: 1A

Setting No. XX

0 0 40 40 45 45

Interval of “5”

100 100 (factory preset mode)

130 130

-1 No control

CODE: 1B

Setting No. YY

0 0 40 40 45 45

Interval of “5”

70 70 (factory preset mode)

130 130

-1 No control

1 - 34

10. Upper Current Limitation Mode (Demand control)

3WAY SYSTEM

Control Functions

10. Upper Current Limitation Mode (Demand control)

It is able to display the present condition on the remote controller.

EEPROM setting in main outdoor unit

CODE: 1E

Setting No.

0 No display

1 When demand control active, “demand - actived” displayed (factory preset mode).

2 When forced thermostat OFF with demand control active, “demand - actived” displayed.

(2) Upper Current Limitation Mode

Even if the demand control is not performed, upper current limitation is restricted.

2WAY VRF SYSTEM

Control Functions

U-72ME2U9 / U-96ME2U9 / U-120ME2U9 / U-144ME2U9

Type of outdoor Unit

Limited ratio against standard value

Limit value

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

Type of outdoor Unit

Limited ratio against standard value

Limit value

(3) When Using Demand Terminal Block* *Demand Terminal Block is the field supply parts.

Demand terminal block must be connected in order to perform the demand control. (It is also possible to connect the optional Seri-Para I/O unit (optional CZ-CAPDC2) and setup the system.) The current limitation values can be set by changing either contact.

COM short circuit

Non

DRM3

DRM2

DRM1

Cooling mode

Heating mode

Cooling mode

Heating mode

Seri-Para I/O unitDemand terminal block

Contact 1 Contact 2

72 96 120 144

130% 130% 130% 130%

18.3 A 25.2 A 32.5 A 44.4 A

19.8 A 26.9 A 35.6A 45.0 A

72 96 120 144

140% 140% 140% 140%

9.1 A 12.7 A 16.8 A 22.1 A

10.1 A 13.0 A 17.9 A 22.5 A

Control

No control (Operates to maximum capacity.)

Operates to 100% of the upper limit for the rated current

Operates to 70% of the upper limit for the rated current

Forced thermostat OFF setting

1

2

3

4

5

6

: Input present : Input not present

* The rated current indicates the current value that is listed in the catalog or service manual.

**In respect of connection method for demand terminal block and Seri-Para I/O unit, refer to the installation

instructions supplied with the unit.

During setting in DRM1 - DRM3, [CZ-RTC5A] (demand-activated) displays on the

remote controller of the indoor unit.

[CZ-RTC4]

1 - 35

7

8

9

11. Backup Operation

3WAY SYSTEM

Control Functions

12. Backup Operation

2WAY VRF SYSTEM

Control Functions

1

2

(1) Automatic Backup Operation

This system includes a function for automatic backup operation. An alarm is displayed on the remote controller to inform the user that a failure has occurred.

1-1. Alarms that result in automatic backup operation

When the following alarm occurs, automatic backup operation is engaged. Automatic backup operation is not engaged in cases of serious alarm such as communications alarms, etc.

Alarm list 1 (Backup operation continues unless power supply of all outdoor units is turned off.)

Alarm display

H01

H11

H03

H13

H07

Overcurrent in 1st compressor

Overcurrent in 2nd compressor

Current sensor for the 1st compressor is disconnected or shorted

Current sensor for the 2nd compressor is disconnected or shorted

HIC for 1st compressor has failure Overcurrent or overheat of HIC

HIC for 2nd compressor has failure Overcurrent or overheat of HIC

Low on oil or the oil recovery circuit has restriction

A

AH31

AH21

B

3

4

5

6

7

P16

P26

P29

A :

When there is one outdoor unit in the system, only compressor that has sensor failure stops. When there are multiple outdoor units in the system, only the outdoor unit which contains the problem stops but the other outdoor units in the system operate normally.

B :

When there is one outdoor unit in the system, the backup operation does not work. When there are multiple outdoor units in the system, only the outdoor unit which contains the problem stops but the other outdoor units in the system operate normally.

NOTE :

After automatic backup operation caused by alarm listed in alarm list 1, 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 all outdoor unit is reset. Therefore, after repair work is completed, be sure to check whether or not automatic backup mode has been canceled.

Overcurrent of 1st compressor on the secondary side of inverter circuit, or inverter failed to syncronize with rotation

Overcurrent of 2nd compressor on the secondary side of inverter circuit, or inverter failed to syncronize with rotation

Inverter for 1st compressor failed to start or failed to syncronize with rotation

Inverter for 2nd compressor failed to start or failed to syncronize with rotation

Fan motor or inverter drive of outdoor unit has failure BP22

A

AP19

8

9

1 - 36

11. Backup Operation

3WAY SYSTEM

Control Functions

12. Backup Operation

Alarm list 2 (Backup operation continues as long as the problems are not solved.)

Alarm display

2WAY VRF SYSTEM

Control Functions

F04

F05

F06

F07

F08

F12

F14

F16

F17

F23

F24

H05

H08

H15

H27

P03

DISCH1 thermistor at the discharge of 1st compressor reading is abnormal

DISCH2 thermistor at the discharge of 2nd compressor reading is abnormal

EXG1 thermistor at the gas side of 1st heat exchanger of the outdoor unit has failure (EXG1)

EXL1 thermistor at the liquid side of 1st heat exchanger of the outdoor unit has failure (EXL1)

TO thermistor for outdoor ambient air temperature has failure (TO)

SCG thermistor at the outlet of subcooling heat exchanger in outdoor unit has failure (SCG)

High pressure sensor of the outdoor unit has failure (HPS)

Low pressure sensor of the outdoor unit has failure (LPS)

EXG2 thermistor at the gas side of 2nd heat exchanger of the outdoor unit has failure (EXG2)

EXL2 thermistor at the liquid side of 2nd heat exchanger of the outdoor unit has failure (EXL2)

DISCH1 thermistor at the discharge of 1st compressor is disconnected, shorted or misplaced (DISCH1)

OIL1 thermistor for the oil of 1st compressor has failure (OIL1)

DISCH2 thermistor at the discharge of 2nd compressor is disconnected, shorted or misplaced (DISCH2)

OIL2 thermistor for the oil of 2nd compressor has failure (OIL2)

1st compressor discharge temperature too high

B

BSCT thermistor at the suction refrigerant of compressors has failure (SCT)

B

1

2

3

B

4

B

P17

When there is one outdoor unit in the system, only compressor that has sensor failure stops.

A :

When there are multiple outdoor units in the system, only the outdoor unit which contains the problem stops but the other outdoor units in the system operate normally.

B :

When there is one outdoor unit in the system, the backup operation does not work. When there are multiple outdoor units in the system, only the outdoor unit which contains the problem stops but the other outdoor units in the system operate normally.

* Backup operation caused by an alarm listed in “alarm list 2” will finish automatically after 24 hours if the same

alarm does not occur again for 24 hours.

1-2. Start of automatic backup operation

If the above alarms occur, the alarm is displayed on the remote controller, etc. Pressing the remote controller button again starts automatic backup mode.

1-3. Backup operation information display

If a wired remote controller is present,

2nd compressor discharge temperature too high

display blinks during operation.

B

5

6

7

8

1 - 37

9

2WAY VRF SYSTEM

Control Functions

11. Backup Operation

2WAY VRF SYSTEM

Control Functions

11. Backup Operation

All compressors of outdoor unit number 2 are backed up

Unit No. 1

Main unit

CCU function

Unit No. 2

Sub unit

Unit No. 3

Sub unit

Unit No. 1

Main unit

CCU function

Unit No. 2

Sub unit

Unit No. 3

Sub unit

Main outdoor unit Sub outdoor unit Sub outdoor unit Number of setting 2 Not necessary Not necessary Unit No. 123

All compressors in unit No. 2 are backed up. Therefore the setting No. of outdoor units installed on the main outdoor PCB is changed to “2” from “3”.

All compressors of main outdoor unit are backed up

All compressors in unit No. 1 are backed up. Therefore the setting No. of outdoor units installed on the main outdoor PCB is changed to “2” from “3”.

Same setting

Examples:

Combination of 3 outdoor units with 2 compressors

Examples:

Combination of 3 outdoor units with 2 compressors

2-2. Disabling operation of one compressor (Type: 120, 144)

At the SW7 switch on the PCB of the failed outdoor unit, turn ON the switch for the compressor to disable, and turn ON the “BACKUP” switch (SW7).

SW7 switches to turn ON

Type of outdoor unit

In the case of

1st compressor

U-120ME2U9 U-144ME2U9

ON

OFF

BACKUPINV

INV2 / AC

In the case of

2nd compressor

ON

OFF

BACKUPINV

INV2 / AC

U-120ME2U94 U-144ME2U94

ON

OFF

BACKUPINV1

INV2

ON

OFF

BACKUPINV1

INV2

11. Backup Operation

Control Functions

1-4. Check for blinks when automatic backup setting

When operating the automatic backup by setting the outdoor unit EEPROM, blink check on the remote controller and centralized control systems is enabled to change for non-displayed.

1

2

3

4

5

EEPROM setting in main outdoor unit CODE: 49

Setting No.

0 1

(2) Manual Backup Operation

The manual backup can be used when it is necessary to close the service valve for maintenance, etc.

Backup operation procedure

2-1. Disconnecting the failed outdoor unit

(1) Reduce the number of outdoor units set at outdoor unit No.1 by only the number of failed outdoor units. (2) At the SW7 switch on the PCB of the failed outdoor unit, turn ON the switches for all compressor to disable,

and turn ON the “BACKUP” switch (SW7).

Type of outdoor unit

SW7 switches to turn ON

Type of outdoor unit

SW7 switches to turn ON

Display (factory present mode)

Non-displayed

U-72ME2U9 U-96ME2U9

INV1 + BACKUP

INV

INV1 + BACKUP

AC2

AC1

U-72ME2U94 U-96ME2U94

INV1 BACKUP

BACKUP

INV2

INV1 + INV2 + BACKUP

ON

OFF

INV1 + INV2 + BACKUP

ON

OFF

U-120ME2U9 U-144ME2U9

OFF

BACKUPINV

INV2 / AC

U-120ME2U94 U-144ME2U94

OFF

BACKUPINV1

INV2

ON

6

7

8

9

(3) Close all service valves at the failed outdoor units. (4) Reset the power at outdoor unit No. 1.

* The outdoor unit that backed up all compressors is not controlled by CCU (main outdoor unit).

Even if all compressors of the main outdoor unit are backed up, they are not controlled by CCU. However, the CCU function stays active.

1 - 38

2WAY VRF SYSTEM

Control Functions

11. Backup Operation

2-2. Disabling operation of one compressor (Type: 120, 144)

At the SW7 switch on the PCB of the failed outdoor unit, turn ON the switch for the compressor to disable, and turn ON the “BACKUP” switch (SW7).

Control Functions

Type of outdoor unit

In the case of

1st compressor

SW7 switches to turn ON

In the case of

2nd compressor

All compressors of outdoor unit number 2 are backed up

Examples:

Combination of 3 outdoor units with 2 compressors

Unit No. 1

Main unit

CCU function

Main outdoor unit Sub outdoor unit Sub outdoor unit Number of setting 2 Not necessary Not necessary Unit No. 123

All compressors in unit No. 2 are backed up. Therefore the setting No. of outdoor units installed on the main outdoor PCB is changed to “2” from “3”.

Unit No. 2

Sub unit

Same setting

U-120ME2U9 U-144ME2U9

ON

OFF

BACKUPINV

INV2 / AC

ON

OFF

BACKUPINV

INV2 / AC

Unit No. 3

Sub unit

U-120ME2U94 U-144ME2U94

ON

OFF

BACKUPINV1

INV2

ON

OFF

BACKUPINV1

INV2

1

2

3

4

5

All compressors of main outdoor unit are backed up

Examples:

Combination of 3 outdoor units with 2 compressors

Unit No. 1

Main unit

CCU function

Main outdoor unit Sub outdoor unit Sub outdoor unit Number of setting 2 Not necessary Not necessary Unit No. 123

All compressors in unit No. 1 are backed up. Therefore the setting No. of outdoor units installed on the main outdoor PCB is changed to “2” from “3”.

Unit No. 2

Sub unit

Unit No. 3

Sub unit

1 - 39

6

7

8

9

1

2

2WAY VRF SYSTEM

12. Other Functions

(1) Auto Change over Cooling/Heating Function

It is possible to select auto change over cooling/heating mode in each remote controller even in 2WAY VRF system. The system changes to cooling or heating operation according to number of thermostat ON mode. The system selects the mode that has more number of units with thermostat ON. (It is impossible to perform the simultaneous cooling/heating operation.)

The system judges whether to switch the mode in XX minutes intervals. Case 1

Number of thermostat ON indoor units in cooling mode > Number of thermostat ON indoor units in heating mode

→ system selects cooling mode

The heating indoor units will be forced to thermostat OFF.

Case 2

Number of thermostat ON indoor units in cooling mode < Number of thermostat ON indoor units in heating mode

→ system selects heating mode

The cooling indoor units will be forced to thermostat OFF.

* “XX” is able to be set in EEPROM on the outdoor unit’s PCB.

Control Functions

3

4

5

6

EEPROM setting in main outdoor unit CODE: 27

Setting No. XX

0

30 30

40 40

50 50

60 60

90 90

120 120

180 180

240 240

(factory preset mode)

Invalid

7

8

9

1 - 40

2WAY VRF SYSTEM

3WAY SYSTEM

Control Functions

13. Other Functions

12. Other Functions

(2) Maintenance Function for Power Supply Stop of Indoor Unit (E06 ignore)

The system can continue operation even if outdoor unit cannot communicate with some indoor units. It is necessary to set to EEPROM the allowed number of operating indoor units not to be able to communicate. The system will continue operating until the following condition is made to be satisfied.

Value set by the code “23” ≥ No. of indoor units operated until the last moment because of communicative

disorder caused by power supply stop (excluding stopped indoor units). However, the upper limit value set by the code "23" must be less than 25% of the total number of indoor units of the system.

EEPROM setting in main outdoor unit CODE: 23

Allowed number of missing indoor unitSetting No.

-1

0 0

1 1

2 2

This function is invalid

(factory preset mode)

Control Functions

1

2

Interval of “1”

16 16

17

Never use

64

* However, the upper limit value set by the code "23" must be less than 25% of the total number of indoor units of the system.

Examples :

In case of 8 indoor units, setting No. becomes “2”.

Normal operation

Operation continue: Indoor unit failure=2 ≤ Setting No. “2”

ON ON ON ON ON OFF OFF OFF

Error occurs: Indoor unit failure=3 > Setting No. “2”

ON ON ON ON ON OFF OFF OFF

3

4

5

6

Operation continue: Stopped units does not count

ON ON ON ON ON OFF OFF OFF

1 - 41

7

8

9

1

2

3

4

5

6

7

8

2WAY VRF SYSTEM

13. Detailed Settings in EEPROM of Outdoor Unit

Never use the DN code unlisted in the following table. (P) : Factory preset mode

DN Item Setting No.

0=No sensor & control (P)

04 Operation for using snowfall sensor

05 Outdoor fan silent mode

0C Indoor unit drain pump forced operation

Measures against smell when indoor

0D

unit cooling thermostat OFF

1A Demand 1 current (%)

1B Demand 2 current (%)

1E Demand remote controller display

23 E06 ignore function

Auto change over function for 2WAY

27

VRF system

Dew condensation prevention control of

2A

indoor unit

2B DP operation time for slime measures

3E PSccutgt delay-start setting

49 Automatic backup mode setting 0=Display (P) 1=non-displayed

81 Outdoor unit capacity

8F High static pressure setting

The minimum operating time 1 until

A3

defrosting Validity/invalidity of capacity control

A7

when cooling operation

1=Sensor & control 2=No Sensor & no control 3=Sensor & no control 0=Invalid (P) 1=Silent mode 1 2=Silent mode 2 ,,,,, 12=Silent mode 12 0=Invalid 1=stop for 2 hours and drive for 20 min. constantly 2=stop for 20 min. and drive for 20 min. constantly 3=Drive constantly 4-6=delay drive when thermostat OFF 7=delay drive when thermostat OFF (P) 0=Invalid (P) 1=Measures against smell 0=0% ,,,,,40=40% ,,,,,45=45% ,,,,,100=100% (P) ,,,,,130=130%

-1=No control 0=0% ,,,,,40=40% ,,,,,70=70% (P) ,,,,,100=100% ,,,,,130=130%

-1=No control 0=No display 1=When demand control active, “demand - actived” displayed (P) 2=When forced thermostat OFF with demand control active, “demand - actived” displayed

-1=invalid (P),,,,, 0=0,,,,, 1=1,,,,, 13=13 14-52=Never use 0=Invalid (P) 40=40 minutes 60=60 minutes 120=120 minutes 240=240 minutes

(For details, see "12. Other Functions (1)") 0=Invalid (P)

1=30 min, 2=40 min, 3=50 min, 4=60 min 20=20 min, 30=30 min (P), 40=40 min 50=50 min, 60=60 min 0=8 sec delay-start (P) 1=(system address ×1×8) sec delay-start 2=(system address ×2×8) sec delay-start 3=(system address ×3×8) sec delay-start

0=Invalid , 1=22 , 2=25 , 3=28 , 4=32 , 5=36 , 6=40 , 7=45 , 8=50 , 9=56 , 10=63 , 11=71 , 12=80 , 13=90 , 14=100 , 15=112 , 16=125 , 17=140 , 18=160 , 19=180 , 20=210 , 21=224 , 22=250 , 23=280 , 24=335 , 25=355 , 26=420 , 27=450 , 28=500 , 29=560 , 30=600 , 31=630 , 32=670 , 33=710 , 34=800 , 35=840 0=Invalid (P) 1=High static pressure mode 2-6=Never use 20=20min, 21=21min ,,,,, 40=40min (P) 41 - 90=Never use

0=Invalid (P), 1=Valid

30=30 minutes 50=50 minutes 90=90 minutes 180=180 minutes

Control Functions

9

1 - 42

2WAY VRF SYSTEM

13. Detailed Settings in EEPROM of Outdoor Unit

Never use the DN code unlisted in the following table. (P) : Factory preset mode

DN Item Setting No.

Actuation of solenoid valve kit

AC

(EP closed)

C1 O

E1

2

output change

Discharge air temperature control with thermostat OFF additional time

0=Invalid (P), 1=Valid

0=Continuously set OFF (P) 1=Refrigerant leak prevention (normal OFF) 2=Refrigerant leak prevention (normal ON)

-20=-20 min , -19=-19 min ,,,,, 0=0 min (P) ,,,,, 10=10 min

Control Functions

1

2

3

4

5

6

7

1 - 43

8

9

14. Outdoor Unit Control PCB

(1) Outdoor Unit Control PCB A747841

(

U-72ME2U9 / U-96ME2U9

)

2WAY VRF SYSTEM

Control Functions

1

2

3

RC1 plug (

)

CN75

OC plug (

)

CN76

RC plug (

)

CN73

EMG plug (

)

CN69

Terminating resistance pin (

)

CN67

HIC3(CN43

)

Alarm LED (

)

LED1

Alarm LED (

)

LED2

SW5

EEPROM LED (LED3

SW6

)

4

5

6

7

8

HIC4(CN19

HIC2(CN10

HIC1(CN7

Comp. discharge 1 sensor DISCH1(CN55

Suction gas temp. SCG(CN77

)

Outdoor air temp.

Gas temp. sensor at heat exchanger 1, 2 EXG1,2(CN61

TO(CN53)

)

Suction temp. SCT(CN65

)

Oil detection sensor OIL1,2(CN54

Liquid temp.sensor at heat exchanger 1, 2 EXL1,2(CN60

)

Low-pressure sensor LPS(CN49

High-pressure sensor HPS(CN46

)

SW2

SW1

EEPROM memory IC

(

)

IC14

SW7

SW4

TEST(CN22) pin

CHK(CN23) pin

AP(CN24) pin

SW3

Snow sensor (

)

CN34

RUN(CN27) pin

SILENT(CN33

STOP(CN28) pin

A. ADD (

CN30) pin

MODE (

CN40) pin

)

9

1 - 44

14. Outdoor Unit Control PCB

(2) Outdoor Unit Control PCB A747593

(

U-120ME2U9 / U-144ME2U9

)

2WAY VRF SYSTEM

Control Functions

RC1 plug (

)

CN75

OC plug (

)

CN76

RC plug (

CN73

EMG plug

(

)

CN69

EEPROM LED (LED3

Terminating resistance pin (

)

CN67

)

HIC7(CN78

)

HIC3(CN43

)

Alarm LED (

)

LED1

Alarm LED (

)

LED2

1

2

SW5

SW6

3

SW7

EEPROM memory IC

(

)

IC14

HIC8(CN85

HIC6(CN82

HIC5(CN80

HIC4(CN19

HIC2(CN10

HIC1(CN7

Comp. discharge 1 sensor DISCH1(CN55

)

Suction gas temp. SCG(CN77

SW4

SW3

SW2

SW1

Low-pressure sensor LPS(CN49

Snow sensor (

CN34

SILENT(CN33

RUN(CN27) pin

TEST(CN22) pin

CHK(CN23) pin

)

4

5

6

7

STOP(CN28) pin

AP(CN24) pin

A. ADD (



CN30) pin

MODE (

)

CN40) pin

)

High-pressure sensor HPS(CN46

)

Oil detection sensor OIL1,2(CN54

Comp. discharge 2 sensor DISCH2(CN56

)

Gas temp.sensor at heat exchanger 1, 2 EXG1,2(CN61

)

Outdoor air temp. TO(CN53)

Suction temp. SCT(CN65

1 - 45

Liquid temp.sensor at heat exchanger 1, 2

)

EXL1,2(CN60

8

9

PCB and Functions

1. Outdoor Unit Control PCB

VWNPU

V WUNP

14. Outdoor Unit Control PCB

(3) Outdoor Unit Control PCB ACXA73-03280

(

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

2WAY VRF SYSTEM

Control Functions

)

1

2

3

LPS(CN49)

HPS(CN46)

CN34 SW3

LED2

LED1

SW7

SW6

SW5

CN33

SW4

OIL1,2(CN54)

SW1SW2

DISCH1(CN55)

CN25

DISCH2(CN56)

CN24CN23CN22

TO(CN53)

EXL1,2(CN60)

EXG1,2(CN61)

SCT(CN65)

SCG(CN77)

CN40

CN30

CN28

CN27

4

5

6

7

8

9

1 - 46

CN67 CN69

CN82

14. Outdoor Unit Control PCB

(4) Outdoor Unit HIC PCB A747843

(U-72ME2U9 / U-120ME2U9 / U-144ME2U9)

2WAY VRF SYSTEM

Control Functions

1

2

(5) Outdoor Unit HIC PCB A747846

(U-96ME2U9)

3

VWNPU

4

5

6

7

1 - 47

8

V WUNP

9

1. Outdoor Unit Control PCB

PCB and Functions

1. Outdoor Unit Control PCB

PCB and Functions

A747842

ACXA73-02080

A747845

(U-72ME2U9 / U-120ME2U9 / U-144ME2U9)

(U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94)

(U-96ME2U9)

(7) Outdoor Unit Filter PCB

14. Outdoor Unit Control PCB

(6) Outdoor Unit HIC PCB ACXA73-02090

(U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94)

2WAY VRF SYSTEM

Control Functions

1

2

3

4

5

6

7

8

W NUVUP

NV NW

9

1 - 48

1. Outdoor Unit Control PCB

PCB and Functions

14. Outdoor Unit Control PCB

(7) Outdoor Unit Filter PCB

2WAY VRF SYSTEM

Control Functions

A747842

(U-72ME2U9 / U-120ME2U9 / U-144ME2U9)

ACXA73-02080

(U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94)

A747845

(U-96ME2U9)

1

2

3

4

5

6

7

8

1 - 49

9

1. Outdoor Unit Control PCB

PCB and Functions

1. Outdoor Unit Control PCB

PCB and Functions

(U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94)

(9) Outdoor Unit Relay PCB ACXA73-02110

1

2

14. Outdoor Unit Control PCB

(8) Outdoor Unit FAN PCB A747844

A747844

(U-72ME2U9 / U-96ME2U9 / U-120ME2U9 / U-144ME2U9)

2WAY VRF SYSTEM

Control Functions

3

4

5

6

7

P W V U N

ACXA73-02100

(U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94)

P

U

V

W

NU

NV

8

9

NW

1 - 50

1. Outdoor Unit Control PCB

PCB and Functions

14. Outdoor Unit Control PCB

(9) Outdoor Unit Relay PCB ACXA73-02110

(U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94)

2WAY VRF SYSTEM

Control Functions

1

2

3

4

5

6

7

1 - 51

8

9

1. Outdoor Unit Control PCB

PCB and Functions

1. Outdoor Unit Control PCB

PCB and Functions

(3P, Black) (CN67)

For communications circuit impedance matching

A connecting socket (2P, White) is attached to the terminating resistance pin at the time of

In the case of link wiring which combines the inter-unit control wiring for multiple systems into a single communications circuit, when using, see the item “5. Auto Address Setting” under the section “6. TEST RUN”.

•

LED1, 2

LED 1 and 2 blink alternately while auto address setting is in progress. Display the alarm contents for alarms which were detected by the outdoor unit.

•

RUN pin (2P, White) (CN27)

Start pin

Short-circuit this pin and apply a pulse signal to start all indoor units in that refrigerant system.

STOP pin (2P, White) (CN28)

Stop pin

CHK pin (2P, White) When set to short-circuit, changes to test run mode.

(Test run mode is automatically cancelled after an hour.) When short-circuit is cancelled, test run mode is cancelled.

Short-circuit this pin and apply a pulse signal to stop all indoor units in that refrigerant system.

AP pin (2P, White) (CN24)

Vacuuming pin

To perform vacuuming of the outdoor unit, short-circuit this pin and then turn the power ON. All solenoid valves turn ON and vacuuming begins smoothly. (Do not perform auto address setting at this time.) Release the short-circuit to return the unit to normal status.

•

MODE pin (3P, Black) (CN40)

Indoor unit Heating / Cooling mode change pin

During the summer season, short-circuit this pin in the cooling mode. Then, perform auto address setting. When auto address setting is completed, release the short-circuit to return the unit to normal status.

When cooling mode is short-circuited, cooling operation can be used.

•

When heating mode is short-circuited, heating operation can be used.•

TEST pin (2P, White) (CN22)

(CN23)

This pin is used to test the PCB at the factory. When the power is turned ON after this pin has been short-circuited, all output signals will be output in sequence

DEF pin (2P, White) When the pin of the main unit is short-circuit in heating mode, defrosting operation is started.

Even if short circuited, defrosting will not be activated immediately.

(CN25)

SNOW plug (3P, Red)

Can be used when installing a snowfall sensor device.

(CN34)

SILENT plug (2P, White)

Can be used when setting the outdoor unit fan is sound absorbing mode.

(CN33)

. (Sequential output does not occur if this pin is short-circuited when

the power is already ON.) Releasing this pin returns the unit to normal control.

•

OC EMG terminal (3P, Black) (CN69)

RC1 EMG terminal (3P, Black) (CN82)

If “TO INDOOR UNIT” accidently connected to high voltage, use the terminal base TM1. Method: 1. Replace the pins 1 and 2 of CN69 with the pins 2 and 3.

2. Disconnect JP11.

If “TO OUTDOOR UNIT” accidently connected to high voltage, use the terminal base TM1. Method: 1. Replace the pins 1 and 2 of CN82 with the pins 2 and 3.

2. Disconnect JP12.

Terminating resistance pin

shipment from the factory.

14. Outdoor Unit Control PCB

(10) Functions

2WAY VRF SYSTEM

Control Functions

1

2

3

4

5

6

A. ADD pin (2P, White) (CN30)

Rotary switch (10 positions, Black)

DIP switch (2P, Black)

Rotary switch (10 positions, Red)

DIP switch (3P, Black) (For details concerning SW3 and SW4, see Table 2.)

SW5 DIP switch (3P, Black)

SW6 DIP switch (3P, Black)

Auto address setting pin

Short-circuit this pin for 1 second or longer to automatically set the addresses at the indoor units that are connected to that outdoor unit and are within the same system. The system address is "1" at the time of shipment. Auto address setting is necessary even for communications lines in a single system where the inter-unit control wiring does not cross to any other systems. While auto address setting is in progress, the 2 LEDs (LED1, 2: Red) on the outdoor unit control PCB blink alternately. (Short-circuiting this pin while auto address setting is in progress will stop the auto address setting operation.)

Outdoor system address setting switchSW1

The setting is "1" at the time of shipment. It is not necessary to change the setting if wiring is connected only to an outdoor unit and indoor units in a single system and the inter-unit control wiring does not cross multiple systems. If wiring links the inter-unit control wiring for multiple systems to the same communications lines, then a different address must be set for each refrigerant tubing system. If wiring links multiple systems, a maximum of 30 systems (up to 64 indoor units) can be connected. This setting can be set up to "39," however control will be for 30 systems even if the setting is set to higher than 30. An alarm will be displayed if system addresses are duplicated. (For details, see Table 1.)

Switches for setting system address 10s digit and 20s digitSW2

If 10 systems or more are set, the setting is made by a combination of this DIP switch and SW1. If 10 - 19 systems are set, set switch 1 (10s digit) to ON. If 20 - 29 systems are set, set switch 2 (20s digit) to ON, and set switch 1 (10s digit) to OFF. If 30 systems are set, set both switch 1 (10s digit) and switch 2 (20s digit) to ON. (For details concerning SW1 and SW2, see Tabl

Switch for setting the number of connected indoor units. In order to allow the outdoor unit to SW3

manage indoor units in the same refrigerant system, set the number of connected indoor units.

(For details, see Table 2.)

Switches for setting the 10s, 20s, and 30s digit for the number of connected indoor units SW4

Unit No. setting switch

The setting is "1" at the time of shipment. (For details, see Table 3.)

Switch for setting the number of outdoor units

Turn the switches ON according to the number of outdoor units (1 - 3). (For details, see Table 4.)

e 1.

)

7

8

9

DIP switch (4P, Black or 3P, Black)

Backup operation switchSW7 If 1st compressor has malfunctioned, turn INV or INV1 ON and BACKUP SW ON to operate the outdoor unit using only 2nd compressor. If 2nd compressor has malfunctioned, turn INV2 / AC or INV2 ON and BACKUP SW ON to operate the outdoor unit using only 1st compressor.

1 - 52

1. Outdoor Unit Control PCB

PCB and Functions

14. Outdoor Unit Control PCB

Terminating resistance pin (3P, Black) (CN67)

For communications circuit impedance matching

A connecting socket (2P, White) is attached to the terminating resistance pin at the time of

•

shipment from the factory. In the case of link wiring which combines the inter-unit control wiring for multiple systems

•

into a single communications circuit, when using, see the item “5. Auto Address Setting” under the section “6. TEST RUN”.

2WAY VRF SYSTEM

Control Functions

LED1, 2

RUN pin (2P, White) (CN27)

STOP pin (2P, White) (CN28)

AP pin (2P, White) (CN24)

MODE pin (3P, Black) (CN40)

TEST pin (2P, White) (CN22)

LED 1 and 2 blink alternately while auto address setting is in progress.

•

Display the alarm contents for alarms which were detected by the outdoor unit.

•

Start pin

Short-circuit this pin and apply a pulse signal to start all indoor units in that refrigerant system.

Stop pin

Short-circuit this pin and apply a pulse signal to stop all indoor units in that refrigerant system.

Vacuuming pin

To perform vacuuming of the outdoor unit, short-circuit this pin and then turn the power ON.

•

All solenoid valves turn ON and vacuuming begins smoothly. (Do not perform auto address setting at this time.) Release the short-circuit to return the unit to normal status.

•

Indoor unit Heating / Cooling mode change pin

During the summer season, short-circuit this pin in the cooling mode.

•

Then, perform auto address setting. When auto address setting is completed, release the short-circuit to return the unit to normal status.

When heating mode is short-circuited, heating operation can be used.• When cooling mode is short-circuited, cooling operation can be used.

•

This pin is used to test the PCB at the factory.

•

When the power is turned ON after this pin has been short-circuited, all output signals will be output in sequence the power is already ON.) Releasing this pin returns the unit to normal control.

. (Sequential output does not occur if this pin is short-circuited when

1

2

3

4

CHK pin (2P, White) When set to short-circuit, changes to test run mode. (CN23)

DEF pin (2P, White) When the pin of the main unit is short-circuit in heating mode, defrosting operation is started. (CN25)

SNOW plug (3P, Red) (CN34)

SILENT plug (2P, White) (CN33)

OC EMG terminal (3P, Black) (CN69)

RC1 EMG terminal (3P, Black) (CN82)

(Test run mode is automatically cancelled after an hour.) When short-circuit is cancelled, test run mode is cancelled.

Even if short circuited, defrosting will not be activated immediately.

Can be used when installing a snowfall sensor device.

Can be used when setting the outdoor unit fan is sound absorbing mode.

If “TO INDOOR UNIT” accidently connected to high voltage, use the terminal base TM1. Method: 1. Replace the pins 1 and 2 of CN69 with the pins 2 and 3.

2. Disconnect JP11.

If “TO OUTDOOR UNIT” accidently connected to high voltage, use the terminal base TM1. Method: 1. Replace the pins 1 and 2 of CN82 with the pins 2 and 3.

2. Disconnect JP12.

1 - 53

5

6

7

8

9

PCB and Functions

1. Outdoor Unit Control PCB

Table 1.

14. Outdoor Unit Control PCB

Setting the System Address

1

2

3

4

[SW1: Rotary switch (black), SW2: 2P DIP (black)]

Outdoor system address

1 refrigerant system only

Link wiring

Table 2. Setting the Number of Indoor Units

[SW3: Rotary switch (red), SW4: 3P DIP (black)]

Number of Indoor Units

1 2 3

1

1 2 3 4 5 6 7 8

9 10 11 12 13 14 15 16 17 18 19

SW3 Setting

SW1 setting

0

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9

1 2 3

SW2 setting

1P

(10s digit)

OFF

OFF OFF OFF OFF OFF OFF OFF OFF OFF

ON ON ON ON ON ON ON ON ON ON

SW4 Setting

1 2 3 OFF OFF OFF

(20s digit)

OFF OFF OFF

2P

OFF

OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF

OFF OFF OFF

Outdoor system address

20 21 22 23 24

Link wiring

Table 3. Setting the Outdoor Unit address [SW5: DIP switch (black)]

Outdoor Unit

Address

1 2 3

25 26 27 28 29 30

ON

OFF

ON

SW1 setting

0 1 2 3 4 5 6 7 8 9 0

SW5 Setting

1 2 3

2WAY VRF SYSTEM

Control Functions

SW2 setting

1P

(10s digit)

OFF OFF OFF OFF OFF OFF OFF OFF OFF OFF

ON

OFF

ON ON

2P

(20s digit)

ON ON ON ON ON ON ON ON ON ON ON

OFF OFF OFF

5

6

7

8

9

10 11

19 20 21

29 30 31

39 40 41

49 50 51

59 60 61 62 63 64

9

9 0 1

9 0 1 2 3 4

OFF

ON ON

ON OFF OFF

OFF OFF OFF

OFF

ON

ON OFF OFF

OFF

ON

OFF OFF OFF

OFF

ON ON

ON OFF OFF

OFF OFF OFF

OFF

ON

OFF OFF OFF

OFF

ON ON

ON ON ON

ON ON ON ON ON ON

Table 4. Setting the Number of Outdoor Units

[SW6: DIP switch (black)]

Number of Outdoor Units

1 2 3

1 - 54

1 2 3

ON

OFF

ON

SW6 Setting

OFF

ON ON

OFF OFF OFF

Contents

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

2. OUTDOOR UNIT REPAIR PROCEDURES

2WAY VRF SYSTEM

1. -2

Removing Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. -4

Discharging Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. -7

Backup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.

Recovering Refrigerant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. -14

Checking for Leakage After Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6. -15

Evacuating System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7.

Charging Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8. -22

Pumping Out Refrigerant from Outdoor Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9. -26

Compressor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10. 2

Replacing Peripheral Parts of Fusible Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

High and Low Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11. -37

2

-9

-16

-36

1

2

3

4

5

6

7

8

2 - 1

9

1. Removing Panels

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

1. Removing Panels

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

1. Removing Panels

Fig. 1-c

Fig. 1-d

Type: 72, 96

Type: 120, 144

Upper side front panel

Lower side front panel

Power outlet panel

Tubing cover

Mounting Plate

Power outlet panel

Tubing cover

Lower side front panel

Upper side front panel

Mounting Plate

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

(1) Front panels removal

• Remove 2 front (upper and lower) panels.

(2) Power outlet panel & tubing cover removal

• Remove the power outlet panel.

• Remove the tubing cover.

U-72ME2U9 / U-96ME2U9 / U-120ME2U9 / U-144ME2U9

CAUTION

Be sure to turn off the power before maintenance work. Then start working when 5 minutes or longer has passed after turning off the power.

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

1

2

3

4

5

Type: 72, 96

Type: 120, 144

Upper side front panel

Lower side front panel

Mounting Plate

Tubing cover

Power outlet panel

Fig. 1-a

6

7

8

9

Upper side front panel

2 - 2

Lower side front panel

Tubing cover

Power outlet panel

Mounting Plate

Fig. 1-b

1. Removing Panels

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

1. Removing Panels

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

Type: 72, 96

Upper side front panel

Lower side front panel

Mounting Plate

1

Tubing cover

Power outlet panel

2

Fig. 1-c

Type: 120, 144

Upper side front panel

Lower side front panel

Power outlet panel

Mounting Plate

3

4

5

Tubing cover

6

Fig. 1-d

7

2 - 3

8

9

1

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

2. Discharging Compressor Oil

Type: 72, 96

Type: 120, 144

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

Fig. 2-c

Fig. 2-d

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

2. Discharging Compressor Oil

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Nitrogen gas

Manifold gauge

Lo Hi

Oil balance tube service port (For ø5/16” (ø7.94mm)-dia connector)

Packless valve or the like

Container

Nitrogen gas

Manifold gauge

Lo Hi

Packless valve or the like

Container

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Oil balance tube service port (For ø5/16” (ø7.94mm)-dia connector)

2

2WAY VRF SYSTEM

2. Discharging Compressor Oil

Outdoor Unit Repair Procedures

Sampling of 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.

2-1. Discharging Oil from Oil Separator

Recover the refrigerant from the outdoor unit following the procedure given in “4. Recovering Refrigerant”.

In the case of 1 outdoor unit in a system Open the balance tube using the flathead screwdriver.

In the case of more than 2 outdoor units in a system Close other outdoor unit balance valves.

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. (Figs. 2-a, 2-b, 2-c and 2-d)

The low-pressure outlet port is nearly at the center area in the unit. For the model

CAUTION

U-72ME2U94/U-96ME2U94, the low-pressure outlet port is located at the rear of the box containing the trans. A faulty outdoor unit may remain pressurized. The oil outlet port employs a Schrader-type push-to-release valve. Be careful to avoid accidental oil release when using the port.

U-72ME2U9 / U-96ME2U9 / U-120ME2U9 / U-144ME2U9

Type: 72, 96

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

3

4

5

6

7

8

Nitrogen gas

Manifold gauge

Lo Hi

Container

Type: 120, 144

Manifold gauge

Lo Hi

Container

Packless valve or the like

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Oil balance tube service port (For ø5/16” (ø7.94mm)-dia connector)

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Oil balance tube service port (For ø5/16” (ø7.94mm)-dia connector)

Fig. 2-a

9

2 - 4

Fig. 2-b

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

2. Discharging Compressor Oil

U-72ME2U94 / U-96ME2U94 / U-120ME2U94 / U-144ME2U94

Type: 72, 96

Manifold gauge

Lo Hi

Packless valve or the like

Nitrogen gas

Container

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Oil balance tube service port (For ø5/16” (ø7.94mm)-dia connector)

Fig. 2-c

1

2

Nitrogen gas

Type: 120, 144

Manifold gauge

Lo Hi

Container

Packless valve or the like

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Oil balance tube service port (For ø5/16” (ø7.94mm)-dia connector)

Fig. 2-d

3

4

5

6

7

2 - 5

8

9

1

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

2. Discharging Compressor Oil

3-1. Automatic Backup

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

For details, see the item “11. Backup Operation” under the section 1.

3-2. Manual Backup

3-2-1. Backup operation by disconnecting the outdoor unit (1) Changing the outdoor unit control PCB settings

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. For details, see “(2) Manual Backup Operation” of “11. Backup Operation” under the section 1.

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, “ ” blinks 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.

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

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

3. Backup Operation

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.

In order to cancel automatic backup mode, it is necessary to reset the power of all the outdoor units in the system.

Settings at No. 1 unit (main unit)

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 (gas tubes, liquid tube, and balance tube) at the failed outdoor unit, and disconnect the communication wiring between the outdoor units.

Action

No change

Subtract the number of failed units from the current setting.

Switch on outdoor unit control PCB

System address (SW2, SW1)

No. of indoor units (SW4, SW3)

No. of outdoor units (SW6)

Outdoor unit No. (SW5) No change

CAUTION

2

2WAY VRF SYSTEM

2. Discharging Compressor Oil

2-2. Discharging Oil in Compressor

Recover the refrigerant in the outdoor unit following the procedures in “4. Recovering Refrigerant.” Remove the compressor and discharge the oil in it. See “9. Compressor” for detailed procedures.

2-3. Checking the Oil

Acceptance/rejection criteria for the oil

Condition of

refrigeration cycle

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.

Normal Yellowish None 0.02 or less 3.5 or less

Abnormal overheat-

operation

Motor burnout

Color Odor Total acid value Hue

Brownish

Brownish /

blackish

Condition of oil

Smells somewhat

(not as strong as below)

Pungent / burnt odor

Outdoor Unit Repair Procedures

Judgment criteria for changing oil*

0.06 or over 4.0 or over

Changing the oil and system cleaning with dry-cores are necessary.

3

4

5

6

7

8

9

2 - 6

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

3. Backup Operation

Outdoor Unit Repair Procedures

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

3-1. Automatic Backup

For details, see the item “11. Backup Operation” under the section 1.

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, “ ” blinks 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 of all the outdoor units in the system.

CAUTION

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

3-2. 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. For details, see “(2) Manual Backup Operation” of “11. Backup Operation” under the section 1.

3-2-1. Backup operation by disconnecting the outdoor unit (1) Changing the outdoor unit control PCB settings

Settings at No. 1 unit (main unit)

Switch on outdoor unit control PCB

System address (SW2, SW1)

No. of indoor units (SW4, SW3)

No. of outdoor units (SW6)

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.

Action

No change

Subtract the number of failed units from the current setting.

1

2

3

4

5

Outdoor unit No. (SW5) 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 (gas tubes, liquid tube, and balance tube) at the failed outdoor unit, and disconnect the communication wiring between the outdoor units.

2 - 7

6

7

8

9

1

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

3. Backup Operation

4-1. Refrigerant Recovery Procedures (from Outdoor Units)

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.

(1) Turn off the power of the outdoor unit beforehand (at power mains).

(2) Fully close each service valve on the liquid tube, gas tubes, 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. (Figs. 3-a, 3-b)

(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. (Figs. 3-a, 3-b)

(5) Locate the AP pin (CN24) 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.

(6) Carry out refrigerant recovery.

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

4. Recovering Refrigerant

The remaining refrigerant in the faulty outdoor unit may create internal pressure. Before connecting hoses, be sure to confirm that each of the manifold gauge valves is tightly closed. Note that the connection ports employ Schrader-type push-to-release valves.

CAUTION

For detailed procedures such as connecting the refrigerant recovery unit with the recovery cylinder and methods used for recovery, follow the specific instructions that came with the refrigerant recovery unit.

CAUTION

By short-circuiting the AP pin (CN24), each solenoid valve in the outdoor unit is 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.

CAUTION

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

CAUTION

Type: 72, 96

Fig. 3-a

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Lo Hi

Refrigerant recovery unit

Manifold

gauge

Refrigerant recovery cylinder

2

3

4

2WAY VRF SYSTEM

3. Backup Operation

(2) Adjusting the refrigerant for backup operation

CAUTION

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 gas 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 gas tube valve at the failed outdoor unit.

Collecting refrigerant in the failed outdoor unit

Short-circuit the AP pin (CN24) 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.

After adjusting the amount of refrigerant, turn OFF the power at the failed outdoor unit, release the shortcircuit at the AP pin (CN24), 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.

After recovery work is completed, wire the communication lines between indoor and outdoor units again. If it not finished yet, an alarm is emitted immediately.

Outdoor Unit Repair Procedures

5

6

7

8

9

2 - 8

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

4. 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.

4-1. Refrigerant Recovery Procedures (from Outdoor Units)

(1) Turn off the power of the outdoor unit beforehand (at power mains).

(2) Fully close each service valve on the liquid tube, gas tubes, 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. (Figs. 3-a, 3-b)

The remaining refrigerant in the faulty outdoor unit may create internal pressure.

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. (Figs. 3-a, 3-b)

CAUTION

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

For detailed procedures such as connecting the refrigerant recovery unit with the recovery cylinder and methods used for recovery, follow the specific instructions that came with the refrigerant recovery unit.

1

2

(5) Locate the AP pin (CN24) 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 pin (CN24), each solenoid valve in the outdoor unit

CAUTION

(6) Carry out refrigerant recovery.

CAUTION

is 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.

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

Type: 72, 96

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Manifold

gauge

Lo Hi

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

3

4

5

6

7

Refrigerant recovery unit

Refrigerant recovery cylinder

2 - 9

8

Fig. 3-a

9

4. Recovering Refrigerant

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

4. Recovering Refrigerant

4-2-1. Cooling operation (for all units)

(CHECK)

button for 4 seconds or longer.)

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

4-2-2. 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. 4, follow the instructions

given in (2) through (6) below. If the service port is instead located in the outdoor side, follow the instructions in “4-2-3. Refrigerant recovery procedures (2).”

(2) After running the unit in Cooling mode for about 5 minutes as described in “4-2-1. Cooling operation (for all

units),” fully close the liquid tube ball valve.

(3) Run the unit in Cooling mode for 10 to 20 minutes more.

(6) Recover the remaining refrigerant from the

indoor unit using the refrigerant recovery unit.

(4) Fully close the gas tube 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. 4) Do each connection quickly to prevent air from entering the tubing.

(2) If the remote controller is not available for maintenance of the outdoor unit.

1. Connect the outdoor unit maintenance remote controller to the RC connector (3P) (BLU) (CN73) on any one of the outdoor unit control PCBs. Then start a test run of all units. (Press and hold the

1. Determine the outdoor unit where the unit No. setting (SW5) (3P DIP switch) (Blue) on the outdoor unit control PCB is set to No. 1.

3. Short-circuit the CHK pin (CHK)(CN23) on the PCB to start test run operation.

2. Short-circuit the MODE pin (“COOL” side of CN40) on the main outdoor unit control PCB.

2. Press the See the section 3 for the detail of the outdoor maintenance remote controller operation. It may be possible to determine whether operation is cooling or heating by touching the gas tubing. Cooling : low temperature (68 °F (20 °C) or lower) Heating : high temperature (140 °F (60 °C) or higher)

(MODE) button and change to cooling operation and ensure that the cooling is performed.

The gas tubing becomes hot (140 °F (60 °C) or higher) in heating mode. Be careful so as not to be burnt when touching the tubing.

CAUTION

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

CAUTION

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

4. Recovering Refrigerant

NOTE

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

Lo Hi

Refrigerant recovery unit

Ball valve (field supply)

Indoor

unit

Outdoor unit side

M

Ball valve (field supply)

Service port

Manifold

gauge

Refrigerant recovery cylinder

Gas tube

Liquid tube

M

Fig. 4

Type: 120, 144

2WAY VRF SYSTEM

Outdoor Unit Repair Procedures

1

2

3

4

5

6

7

8

9

Low-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

High-pressure outlet port (for ø5/16” (ø7.94mm)-dia connector)

Manifold

gauge

Lo Hi

Liquid tube service port (for ø5/16” (ø7.94mm)-dia connector)

Refrigerant recovery unit

Gas tube service port (for ø5/16” (ø7.94mm)-dia connector)

Refrigerant recovery cylinder

4-2. 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.

4-2-1. Cooling operation (for all units)

4-2-2. Refrigerant recovery procedures (1)

Turn off all equipment in system

a faulty unit, let other normal indoor

units run (excluding indoor unit where

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

Charge refrigerant in repaired unit H* (Amount of charge

should equal that recovered by refrigerant recovery unit)

Change controllable number of indoor units (including

changes in group control and integrated-control settings)

Replace or repair faulty unit

Check for leakage in repaired unit H*

Evacuate air from repaired unit H*

Ready for normal operation

START

Ball valve is provided

in the indoor unit

YES

When

replacing or repairing

refrigerant is

recovered)

YES

Power

recovered

YES

Open ball valve

END

4-2-3. Refrigerant

recovery procedures (2)

NO

Figs. 2-a, 2-b,

NO

*

2-c and 2-d

Modify power to permit

turning off power to

refrigerant-recovered

indoor units independently

Service work performed on indoor units is done simultaneously using the service ports at the liquid tube side and the gas tube side ball valves. Refer to each section in the “Installation Instructions” on refrigerant charging, leak checking, and evacuation procedures.

2 - 10

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

Replace or repair faulty unit

Check for leakage in repaired unit H*

Evacuate air in repaired unit H*

Charge refrigerant in repaired unit H* (Amount of charge should equal that

recovered by refrigerant recovery unit)

Ready for normal operation

Fig. 3-b

END

Open the ball valve

END