Panasonic CU-4E24RBU User manual

© Panasonic Corporation 2015
Order No: PAPAMY1505100CE
Air Conditioner
Outdoor Unit
CU-3E19RBU
CU-4E24RBU
Destination
U.S.A.
Canada
Please file and use this manual together with the service manual for Model No. CS-E9RKUAW CS-E12RKUAW CS-E18RKUAW,
CS-E24RKUAW, CS-ME7RKUA, CS-E12RB4UW, CS-E18RB4UW, CS-ME5RKUA, Order No. PAPAMY1501049CE,
PAPAMY1503094CE, PAPAMY1503095CE, PAPAMY1505112CE.
IMPORT
A
NT S
A
FET
Y
NOTICE
There are special components used in this equipment which are important for safety. These parts are marked by in the Schematic
Diagrams, Circuit Board Diagrams, Exploded Views and Replacement Parts List. It is essential that these critical parts should be replaced
with manufacturer’s specified parts to prevent shock, fire or other hazards. Do not modify the original design without permission of
manufacturer.
!
WARNING
This service information is designed for experienced repair technicians only and is not designed for use by the general public.
It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to
service or repair the product or products dealt with in this service information by anyone else could result in serious injury or death.
PRECAUTION OF LOW TEMPERATURE
In order to avoid frostbite, be assured of no refrigerant leakage during the installation or repairing of refrigerant circuit.

2
TABLE OF CONTENTS
PAGE PAGE
1. Safety Precautions .............................................3
2. Specifications .....................................................5
2.1 CU-3E19RBU ...............................................5
2.2 CU-4E24RBU ...............................................7
3. Dimensions .......................................................16
3.1 CU-3E19RBU .............................................16
3.2 CU-4E24RBU .............................................16
4. Refrigeration Cycle Diagram ...........................17
4.1 CU-3E19RBU .............................................17
4.2 CU-4E24RBU .............................................18
5. Block Diagram ..................................................19
5.1 CU-3E19RBU .............................................19
5.2 CU-4E24RBU .............................................20
6. Wiring Connection Diagram ............................21
6.1 CU-3E19RBU .............................................21
6.2 CU-4E24RBU .............................................22
7. Electronic Circuit Diagram ..............................23
7.1 CU-3E19RBU .............................................23
7.2 CU-4E24RBU .............................................24
8. Printed Circuit Board .......................................25
8.1 Main Printed Circuit Board .........................25
8.2 Noise Filter Printed Circuit Board ...............27
8.3 Display Printed Circuit Board .....................28
9. Installation Information....................................29
9.1 CU-3E19RBU .............................................29
9.2 CU-4E24RBU .............................................30
10. Installation Instruction.....................................31
10.1 CU-3E19RBU .............................................31
10.2 CU-4E24RBU .............................................36
11. Operation Control.............................................41
11.1 Cooling Operation.......................................41
11.2 Heating Operation ......................................42
12. Simultaneous Operation Control ....................43
13. Protection Control............................................44
13.1 Freeze Prevention control (Cool) ...............44
13.2 Dew Prevention control (Cool) ...................44
13.3 Electronic Parts Temperature Rise
Protection 1 (Cool)......................................44
13.4 Electronic Parts Temperature Rise
Protection 2 (Cool)......................................44
13.5 Cooling overload control (Cool)..................45
13.6 Heating overload control (Heat) .................45
13.7 Extreme Low Temperature Compressor
low pressure protection control (Heat) .......46
13.8 Deice Control..............................................46
13.9 Time Delay Safety Control
(Restart Control) .........................................46
13.10 30 seconds Force Operation ......................46
13.11 Total Current Control..................................46
13.12 IPM (power transistor) Protection
Control ........................................................47
13.13 Compressor Protection Control
(Gas leak detection control 1) ....................47
13.14 Compressor Protection Control
(Gas leak detection control 2) ....................47
13.15 Valve close detection control......................48
13.16 Compressor discharge high pressure
protection control ........................................48
14. Servicing Mode .................................................49
14.1 CU-3E19RBU .............................................49
14.2 CU-4E24RBU .............................................51
15. Troubleshooting Guide....................................53
15.1 Self Diagnosis Function..............................53
15.2 Self-diagnosis Method................................55
16. Disassembly and Assembly Instructions ......79
16.1 Outdoor Unit Removal Procedure
(CU-3E19RBU)...........................................79
16.2 Outdoor Unit Removal Procedure
(CU-4E24RBU)...........................................81
17. Technical Data ..................................................84
17.1 CU-3E19RBU .............................................84
17.2 CU-4E24RBU .......................................... 108
18. Exploded View and Replacement Parts
List .................................................................. 191
18.1 CU-3E19RBU .......................................... 191
18.2 CU-4E24RBU .......................................... 194

3
CAUTION
WARNING
WARNING
1. Safety Precautions
Read the following “SAFETY PRECAUTIONS” carefully before perform any servicing.
Electrical work must be installed or serviced by a licensed electrician. Be sure to use the correct rating of the
power plug and main circuit for the model installed.
The caution items stated here must be followed because these important contents are related to safety. The
meaning of each indication used is as below. Incorrect installation or servicing due to ignoring of the instruction
will cause harm or damage, and the seriousness is classified by the following indications.
This indication shows the possibility of causing death or serious injury.
This indication shows the possibility of causing injury or damage to properties.
The items to be followed are classified by the symbols:
Carry out test run to confirm that no abnormality occurs after the servicing. Then, explain to user the operation,
care and maintenance as stated in instructions. Please remind the customer to keep the operating instructions for
future reference.
1. Do not modify the machine, part, material during repairing service.
2. If wiring unit is supplied as repairing part, do not repair or connect the wire even only partial wire break. Exchange the whole wiring unit.
3. Do not wrench the fasten terminal. Pull it out or insert it straightly.
4. Engage dealer or specialist for installation and servicing. If installation or servicing done by the user is defective, it will cause water leakage,
electrical shock or fire.
5. Install according to this installation instructions strictly. If installation is defective, it will cause water leakage, electric shock or fire.
6. Use the attached accessories parts and specified parts for installation and servicing. Otherwise, it will cause the set to fall, water leakage,
fire or electrical shock.
7. Install at a strong and firm location which is able to withstand the set’s weight. If the strength is not enough or installation is not properly done,
the set will drop and cause injury.
8. For electrical work, follow the local national wiring standard, regulation and the installation instruction. An independent circuit and single outlet
must be used. If electrical circuit capacity is not enough or defect found in electrical work, it will cause electrical shock or fire.
9. This equipment is strongly recommended to install with Earth Leakage Circuit Breaker (ELCB) or Residual Current Device (RCD).
Otherwise, it may cause electrical shock and fire in case equipment breakdown or insulation breakdown.
10. Do not use joint cable for indoor/outdoor connection cable. Use the specified indoor/outdoor connection cable, refer to Installation
Instruction CONNECT THE CABLE TO THE INDOOR UNIT and connect tightly for indoor/outdoor connection. Clamp the cable so that no
external force will be acted on the terminal. If connecting or fixing is not perfect, it will cause heat up or fire at the connection.
11. Wire routing must be properly arranged so that control board cover is fixed properly. If control board cover is not fixed perfectly, it will cause
heat-up or fire at the connection point of terminal, fire or electrical shock.
12. When install or relocate air conditioner, do not let any substance other than the specified refrigerant, eg. air etc. mix into refrigeration cycle
(piping). (Mixing of air etc. will cause abnormal high pressure in refrigeration cycle and result in explosion, injury etc.).
13. Do not install outdoor unit near handrail of veranda. When installing air-conditioner unit at veranda of high rise building, child may climb up to
outdoor unit and cross over the handrail and causing accident.
14. This equipment must be properly earthed. Earth line must not be connected to gas pipe, water pipe, earth of lightning rod and
telephone. Otherwise, it may cause electric shock in case equipment breakdown or insulation breakdown.
15. Keep away from small children, the thin film may cling to nose and mouth and prevent breathing.
16. Do not use unspecified cord, modified cord, joint cord or extension cord for power supply cord. Do not share the single outlet
with other electrical appliances. Poor contact, poor insulation or over current will cause electrical shock or fire.
17. Tighten the flare nut with torque wrench according to specified method. If the flare nut is over-tightened, after a long period, the
flare may break and cause refrigerant gas leakage.
This symbol denotes item that is PROHIBITED from doing.

4
CAUTION
WARNING
18. For R410A models, when connecting the piping, do not use any existing (R22) pipes and flare nuts. Using such same may
cause abnormally high pressure in the refrigeration cycle (piping), and possibly result in explosion and injury. Use only R410A
materials.
Thickness of copper pipes used with R410A must be more than 1/32" (0.8mm). Never use copper pipes thinner than 1/32" (0.8mm).
It is desirable that the amount of residual oil is less than 0.0014 oz/32.8 ft (40 mg/10m).
19. During installation, install the refrigerant piping properly before run the compressor. (Operation of compressor without fixing refrigeration
piping and valves at opened condition will cause suck-in of air, abnormal high pressure in refrigeration cycle and result in explosion, injury
etc.).
20. During pump down operation, stop the compressor before remove the refrigeration piping. (Removal of refrigeration piping while
compressor is operating and valves are opened condition will cause suck-in of air, abnormal high pressure in refrigeration cycle and result
in explosion, injury etc.).
21. After completion of installation or service, confirm there is no leakage or refrigerant gas. It may generate toxic gas when the refrigerant
contacts with fire.
22. Ventilate if there is refrigerant gas leakage during operation. It may cause toxic gas when refrigerant contacts with fire.
23. Do not insert your fingers or other objects into the unit, high speed rotating fan may cause injury.
24. Must not use other parts except original parts described in catalog and manual.
25. Using of refrigerant other than the specified type may cause product damage, burst and injury etc.
1. Do not install the unit at place where leakage of flammable gas may occur. In case gas leaks and accumulates at surrounding of the
unit, it may cause fire.
2. Carry out drainage piping as mentioned in installation instructions. If drainage is not perfect, water may enter the room and damage
the furniture.
3. Tighten the flare nut with torque wrench according to specified method. If the flare nut is over-tightened, after a long period, the flare
may break and cause refrigerant gas leakage.
4. Do not touch outdoor unit air inlet and aluminium fin. It may cause injury.
5. Select an installation location which is easy for maintenance.
6. Pb free solder has a higher melting point than standard solder; typically the melting point is 50°F – 70°F (30°C – 40°C) higher. Please use
a high temperature solder iron. In case of the soldering iron with temperature control, please set it to 700 ± 20°F (370 ± 10°C). Pb free solder
will tend to splash when heated too high (about 1100°F / 600°C).
7. Power supply connection to the room air conditioner.
Power supply cord shall be UL listed or CSA approved 3 conductor with minimum AWG12 wires.
Power supply point should be in an easily accessible place for power disconnection in case of emergency.
In some countries, permanent connection of this air conditioner to the power supply is prohibited.
Fix power supply connection to a circuit breaker for permanent connection.
Use NRTL approved fuse or circuit breaker (rating refers to name plate) for permanent connection.
8. Do not release refrigerant during piping work for installation, servicing, reinstallation and during repairing a refrigerant parts.
Take care of the liquid refrigerant, it may cause frostbite.
9. Installation or servicing work: It may need two people to carry out the installation or servicing work.
10. Do not install this appliance in a laundry room or other location where water may drip from the ceiling, etc.
11. Do not sit or step on the unit, you may fall down accidentally.
12. Do not touch the sharp aluminum fins or edges of metal parts.
If you are required to handle sharp parts during installation or servicing, please wear hand glove.
Sharp parts may cause injury.

5
2. Specifications
2.1 CU-3E19RBU
Item Unit OUTDOOR UNIT
Indoor Unit Combination 1.6kW + 2.0kW + 2.0kW
Power Source 1 Phase, 208-230V, 60Hz (Power supply from outdoor unit)
Cooling Operation
Capacity kW 5.58 (1.8 ~ 7.3)
BTU/h 19000 (6100 ~ 24800)
Electrical
Data
Running Current A 7.4 - 6.7
Power Input kW 1.51 (0.36 ~ 2.42)
EER W/W 3.68 (5.00 ~ 3.02)
BTU/hW 12.55 (16.95 ~ 10.25)
Noise Sound Pressure Level dB-A (H/L) 50 / -
Sound Power Level dB (H/L) 66 / -
Heating Operation
Capacity kW 7.65 (1.6 ~ 8.3)
BTU/h 26000 (5500 ~ 28400)
Electrical
Data
Running Current A 10.1 - 9.1
Power Input kW 2.06 (0.32 ~ 2.30)
COP W/W 3.70 (5.00 ~ 3.61)
BTU/hW 12.60 (17.20 ~ 12.35)
Noise Sound Pressure Level dB-A (H/L) 52 / -
Sound Power Level dB (H/L) 68 / -
Maximum Current A 15.0
Starting Current A 10.1
Circuit Breaker Capacity A 30
Dimension
Height mm (inch) 795 (31-5/16)
Width mm (inch) 875 + 95 (34-15/32) + (3-3/4)
Depth mm (inch) 320 (12-5/8)
Net Weight kg (lb) 72 (159)
Connection Cable 3 + 1 (Earth) min AWG16
Pipe Length Range (1 room) m (ft) 3 ~ 25 (9.8 ~ 82.0)
Maximum Pipe Length (Total Room) m (ft) 50 (164.0)
Refrigerant Pipe Diameter Liquid Side mm (inch) 6.35 (1/4)
Gas Side mm (inch) 9.52 (3/8)
Compressor
Type Hermetic Motor / Rotary
Motor Type Brushless (4-poles)
Rated Output W 1.30k
Air Circulation
Type Propeller Fan
Motor Type DC Motor (8-poles)
Rated Output W 60
Fan Speed High (Cooling / Heating) RPM 580 / 650
Heat Exchanger
Type Plate fin configuration forced draft type
Tube Material Copper
Fin Material Aluminum (Blue Coated)
Row / Stage 2 / 36
FPI 19
Air Volume High (Cooling / Heating) m
3
/min
(ft3/min) 41.0 (1447) / 46.3 (1634)
Refrigerant Control Device Expansion Valve
Refrigerant Oil FV50S

6
Item Unit OUTDOOR UNIT
Refrigerant (R410A) g (oz) 2.64k (93.2)
Dry Bulb Wet Bulb
Indoor Operation Range
Cooling
Maximum °C (°F) 32 (89.6) 23 (73.4)
Minimum °C (°F) 16 (60.8) 11 (51.8)
Heating Maximum °C (°F) 30 (86.0) —
Minimum °C (°F) 16 (60.8) —
Outdoor Operation Range
Cooling Maximum °C (°F) 46 (114.8) 26 (78.8)
Minimum °C (°F) -10 (14.0) —
Heating Maximum °C (°F) 24 (75.2) 18 (64.4)
Minimum °C (°F) -15 (5.0) -16 (3.2)
Multi Indoor RPM CS-ME5RKUA CS-ME7RKUA CS-E9RKUAW CS-E12RKUAW CS-E18RKUAW
Mode Fan Tap rpm Airflow
(m3/min) rpm Airflow (m3/min) rpm Airflow (m3/min) rpm Airflow (m3/min) rpm Airflow (m3/min)
COOL
SHi 1080 11.71 1110 12.10 1140 12.21 1280 13.35 1370 18.96
Hi 990 10.70 1020 11.10 1050 11.20 1160 12.00 1330 18.40
Me 820 8.80 840 9.08 850 8.96 940 9.54 1160 16.03
Lo 660 7.00 660 7.06 660 6.83 720 7.08 990 13.65
Lo- 570 6.00 570 6.06 570 5.83 580 5.51 900 12.40
HEAT
SSHi 1210 12.70 1240 13.11 1270 13.21 1370 14.29 1460 20.46
SHi 1120 11.70 1150 12.10 1180 12.20 1300 13.50 1370 19.20
Me 950 9.79 960 9.97 980 9.96 1140 11.71 1210 16.97
Lo 780 7.89 780 7.96 780 7.72 980 9.92 1060 14.87
Lo- 690 6.88 690 6.95 690 6.71 890 8.91 960 13.48
Note
Specifications are subject to change without notice for further improvement.

7
2.2 CU-4E24RBU
Item Unit OUTDOOR UNIT
Indoor Unit Combination 1.6kW + 1.6kW + 2.0kW + 2.0kW
Power Source 1 Phase, 208-230V, 60Hz (Power supply from outdoor unit)
Cooling Operation
Capacity kW 7.02 (3.0 ~ 9.2)
BTU/h 24000 (10200 ~ 31400)
Electrical
Data
Running Current A 9.9 - 8.9
Power Input kW 1.91 (0.53 ~ 2.87)
EER W/W 3.66 (5.66 ~ 3.21)
BTU/hW 12.55 (19.25 ~ 10.95)
Noise Sound Pressure Level dB-A (H/L) 55 / -
Sound Power Level dB (H/L) 71 / -
Heating Operation
Capacity kW 11.1 (4.2 ~ 14.2)
BTU/h 37800 (14300 ~ 48500)
Electrical
Data
Running Current A 15.3 - 13.9
Power Input kW 3.03 (0.70 ~ 4.38)
COP W/W 3.66 (6.00 ~ 3.24)
BTU/hW 12.45 (20.45 ~ 11.05)
Noise Sound Pressure Level dB-A (H/L) 55 / -
Sound Power Level dB (H/L) 71 / -
Maximum Current A 21.1
Starting Current A 15.3
Circuit Breaker Capacity A 45
Dimension
Height mm (inch) 999 (39-11/32)
Width mm (inch) 940 (37-1/32)
Depth mm (inch) 340 (13-13/32)
Net Weight kg (lb) 83 (183)
Connection Cable 3 + 1 (Earth) min AWG16
Pipe Length Range (1 room) m (ft) 3 ~ 25 (9.8 ~ 82.0)
Maximum Pipe Length (Total Room) m (ft) 70 (229.6)
Refrigerant Pipe Diameter Liquid Side mm (inch) 6.35 (1/4)
Gas Side mm (inch) 9.52 (3/8), (E24: 12.70 (1/2))
Compressor
Type Hermetic Motor / Rotary
Motor Type Brushless (4-poles)
Rated Output W 1.30k
Air Circulation
Type Propeller Fan
Motor Type DC Motor (8-poles)
Rated Output W 90
Fan Speed High (Cooling / Heating) RPM 600 / 700
Heat Exchanger
Type Plate fin configuration forced draft type
Tube Material Copper
Fin Material Aluminum (Blue Coated)
Row / Stage 2 / 46
FPI 19
Air Volume High (Cooling / Heating) m
3
/min
(ft3/min) 55.6 (1963) / 66.0 (2330)
Refrigerant Control Device Expansion Valve
Refrigerant Oil FV50S
Refrigerant (R410A) g (oz) 3.40k (120)

8
Item Unit OUTDOOR UNIT
Dry Bulb Wet Bulb
Indoor Operation Range
Cooling Maximum °C (°F) 32 (89.6) 23 (73.4)
Minimum °C (°F) 16 (60.8) 11 (51.8)
Heating Maximum °C (°F) 30 (86.0) —
Minimum °C (°F) 16 (60.8) —
Outdoor Operation Range
Cooling Maximum °C (°F) 46 (114.8) 26 (78.8)
Minimum °C (°F) -10 (14.0) —
Heating Maximum °C (°F) 24 (75.2) 18 (64.4)
Minimum °C (°F) -15 (5.0) -16 (3.2)
Multi Indoor
RPM CS-ME5RKUA CS-ME7RKUA CS-E9RKUAW CS-E12RKUAW CS-E18RKUAW CS-E24RKUAW
Mode Fan
Tap rpm Airflow (m3/min) rpm Airflow (m3/min) rpm Airflow (m3/min) rpm Airflow (m3/min) rpm Airflow (m3/min) rpm Airflow (m3/min)
COOL
SHi 1080 11.71 1110 12.10 1140 12.21 1280 13.35 1370 18.96 1460 19.94
Hi 990 10.70 1020 11.10 1050 11.20 1160 12.00 1330 18.40 1350 18.40
Me 820 8.80 840 9.08 850 8.96 940 9.54 1160 16.03 1180 16.03
Lo 660 7.00 660 7.06 660 6.83 720 7.08 990 13.65 1020 13.79
Lo- 570 6.00 570 6.06 570 5.83 580 5.51 900 12.40 930 12.54
HEAT
SSHi 1210 12.70 1240 13.11 1270 13.21 1370 14.29 1460 20.46 1500 20.35
SHi 1120 11.70 1150 12.10 1180 12.20 1300 13.50 1370 19.20 1460 19.80
Me 950 9.79 960 9.97 980 9.96 1140 11.71 1210 16.97 1310 17.70
Lo 780 7.89 780 7.96 780 7.72 980 9.92 1060 14.87 1160 15.61
Lo- 690 6.88 690 6.95 690 6.71 890 8.91 960 13.48 1050 14.07
Note
Specifications are subject to change without notice for further improvement.

9
Multi Split Combination Possibility:
oA single outdoor unit enables air conditioning of up to three separate rooms for CU-3E19RBU.
oA single outdoor unit enables air conditioning of up to four separate rooms for CU-4E24RBU.
CONNECTABLE INDOOR UNIT
Capacity range of
connectable indoor units
1-room maximum
pipe length (m (ft))
ROOM
Typ e
CU-3E19RBU
OUTDOOR UNIT
Note: “ ” : Available
Remarks for CU-4E24RBU
1. At least two indoor units must be connected.
2. The total nominal cooling capacity of indoor units that will be connected to outdoor unit must be
within connectable capacity range of indoor unit. (as shown in the table above)
Example: The indoor units’ combination below is possible to connect to CU-4E24RBU.
(Total nominal capacity of indoor units is between 4.5kW to 13.6kW)
1) Two CS-E9RKUAW only (Total nominal cooling capacity is 5.0kW)
2) Three CS-E12RKUAW. (Total nominal cooling capacity is 9.6kW)
Wall
Total allowable pipe
length (m (ft))
Total pipe length for
maximum chargeless
length (m (ft))
Additional gas
amount over chargeless
length (g/m (oz/ft))
Allowable elevation (m (ft))
Pipe
length
2.5kW CS-E9RKUAW
3.2kW CS-E12RKUAW,
CS-E12RB4UW
5.0kW CS-E18RKUAW,
CS-E18RB4UW
2.0kW CS-ME7RKUA
7.0kW CS-E24RKUAW
25 (82.0)
50 (164.0)
From 4.5kW
to 9.0kW
A B C
---
30 (98.4)
20 (0.2)
15 (49.2)
25 (82.0)
70 (229.6)
From 4.5kW
to 13.6kW
A B C
CU-4E24RBU
45 (147.6)
20 (0.2)
15 (49.2)
D
1.6kW CS-ME5RKUA

I
n
C

O
n
door Unit :
C
S-E18RB4U
utdoor Unit
:
C
S-ME5RK
U
W
:
CU-3E19R
B
U
A, CS-ME7
R
B
U
R
KUA, CS-
E
10
E
9RKUAW,
C
C
S-E12RKU
A
A
W, CS-E1
8
8
RKUAW, CS-E12RB4U W,

11

I
n
C

O
n
door Unit :
C
S-E12RB4U
utdoor Unit
:
C
S-ME5RK
U
W, CS-E18
R
:
CU-4E24R
B
U
A, CS-ME7
R
R
B4UW
B
U
R
KUA, CS-
E
12
E
9RKUAW,
C
C
S-E12RKU
A
A
W, CS-E1
8
8
RKUAW, C
S
S
-E24RKU
A
A
W,

13

14

15

16
3. Dimensions
3.1 CU-3E19RBU
3.2 CU-4E24RBU
Unit: inch (mm)
Space necessary for
installation
Anchor Bolt Pitch
14-3/16 (360.5) x 24-9/64 (613)
39-3/8 (100 cm)
3-15/16 (10 cm)
3-15/16 (10 cm)
<Top View>
<Front View>
<Side View> <Side View>
24-9/64 (613)
1-5/64
(27.5)
(5-5/32
(131))
5-5/32
(131)
3-3/4
(95)
1-1/2
(38)
5-7/32
(132.5)
1-39/64
(41)
3-17/64
(83)
14-3/16 (360.5)
34-15/32 (875) 12-5/8 (320)
2-21/64
(59)
1-21/32
(42)
31-5/16 (795)
15/16
(23.8)
2-3/64
(52)
63/64
(25)
3-19/32
(91.2) 43/64
(17)
(3-3/16
(81))
(6-37/64
(167))
3-3/8 X 1/8 = 10-1/8
(85.7 x 3 = 257.1)
3-3/8 X 1/8 = 10-1/8
(85.7 x 3 = 257.1)
(8-17/64
(210))
24-13/32 (620) 6-11/16 (170)
13-13/32 (340)
13/64 (5.5)
1-13/32 (36)
37-1/32 (940)
39-11/32 (999)
1-7/16 (36.2)
14-31/32 (380.5)
4-1/8 x 5/32 =
16-17/32
(105 x 4 = 420)
5-3/32
(129.5)
2-15/16
(74.5)
1-1/16
(27)
2-21/32 
(67.7)
4-1/8 x 5/32 =
16-17/32
(105 x 4 = 420)
Space necessary for
installation
Anchor Bolt Pitch
24-13/32 (620) x 14-31/32 (380.5)
39-3/8 (100 cm)
3-15/16 (10 cm)
3-15/16 (10 cm)
<Top View>
<Front View> <Side View><Side View>
Unit: inch (mm)

17
4. Refrigeration Cycle Diagram
4.1 CU-3E19RBU
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE TEMP.
SENSOR (DEF)
INTAKE
TEMP.
SENSOR
HEAT
EXCHANGER
(CONDENSOR)
CONDENSOR
TEMP.
SENSOR
COOLING
HEATING
3-WAY
VALVE
3-WAY
VALVE
ACCUMULATOR
DISCHARGE
MUFFLER
COMPRESSOR
PRESSURE
SWITCH
INDOOR C
INDOOR B
INDOOR A OUTDOOR
HEAT
EXCHANGER
(EVAPORATOR)
INTAKE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
GAS SIDE
HEAT
EXCHANGER
(EVAPORATOR)
INTAKE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
GAS SIDE
HEAT
EXCHANGER
(EVAPORATOR)
INTAKE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
GAS SIDE
3-WAY VALVE
LIQUID SIDE
3-WAY VALVE
LIQUID SIDE
3-WAY VALVE
LIQUID SIDE
3-WAY VALVE
STRAINER
3-WAY
VALVE
STRAINER EXPANSION
VALVE C
STRAINER EXPANSION
VALVE B
STRAINER
EXPANSION
VALVE A
COMPRESSOR
TEMP.
SENSOR
4-WAY
VALVE
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
3-WAY
VALVE

18
4.2 CU-4E24RBU
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE TEMP.
SENSOR (DEF)
INTAKE
TEMP.
SENSOR
HEAT
EXCHANGER
(CONDENSOR)
CONDENSOR
TEMP.
SENSOR
COOLING
HEATING
3-WAY
VALVE
3-WAY
VALVE
ACCUMULATOR
DISCHARGE
MUFFLER
COMPRESSOR
PRESSURE
SWITCH
INDOOR D
INDOOR C
INDOOR B
INDOOR A OUTDOOR
HEAT
EXCHANGER
(EVAPORATOR)
INTAKE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
GAS SIDE
3-WAY
VALVE
HEAT
EXCHANGER
(EVAPORATOR)
INTAKE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
GAS SIDE
HEAT
EXCHANGER
(EVAPORATOR)
INTAKE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
GAS SIDE
HEAT
EXCHANGER
(EVAPORATOR)
INTAKE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
GAS SIDE
3-WAY VALVE
LIQUID SIDE
3-WAY VALVE
LIQUID SIDE
3-WAY VALVE
LIQUID SIDE
3-WAY VALVE
LIQUID SIDE
3-WAY VALVE
STRAINER
STRAINER
3-WAY
VALVE
EXPANSION
VALVE D
STRAINER EXPANSION
VALVE C
STRAINER EXPANSION
VALVE B
STRAINER
EXPANSION
VALV E A
COMPRESSOR
TEMP.
SENSOR
4-WAY
VALVE
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
PIPE
TEMP.
SENSOR
3-WAY
VALVE

19
5. Block Diagram
5.1 CU-3E19RBU
L1 L2
1 2 3
1 2 3
MS
3~
M
FUSE 1
NTC
4-WAY
VALVE
RY-HOT
HEATER
RY-HT
FUSE 2
FUSE 401
SINGLE PHASE POWER SUPPLY
TO INDOOR UNIT A TO INDOOR UNIT B
RY-AC
RY-PWR
(OUTDOOR UNIT)
PTC
PFC CIRCUIT
CAPACITOR CIRCUIT
RECTIFICATION
CIRCUIT
RECTIFICATION
CIRCUIT
REACTOR
NTC
SC
NTC
NOISE FILTER
CIRCUIT
1 2 3
TO INDOOR UNIT C

20
5.2 CU-4E24RBU
L1 L2
1 2 3
1 2 3
MS
3~
M
FUSE 1
NTC
4-WAY
VALVE
RY-HOT
HEATER
RY-HT
FUSE 2
FUSE 401
SINGLE PHASE POWER SUPPLY AC 208/230V 60Hz
TO INDOOR UNIT A TO INDOOR UNIT B
RY-AC
RY-PWR
(OUTDOOR UNIT)
PTC
PFC CIRCUIT
CAPACITOR CIRCUIT
RECTIFICATION
CIRCUIT
RECTIFICATION
CIRCUIT
REACTOR
NTC
SC
NTC
NOISE FILTER
CIRCUIT
1 2 3
TO INDOOR UNIT C
1 2 3
TO INDOOR UNIT D