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

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

CONTENTS

1. CONTROL FUNCTIONS

1. Introduction

2. Selecting Outdoor Unit for Operation

3. Compressor Control

4. Output of PCB

5. Outdoor Unit Fan Control

6. Outdoor Unit CCU (command controller unit) Control