Mitsubishi Electric MXZ-2HJ40VA User manual

Models
MXZ-2HJ40VA -E1 ,ER1 ,ET1
MXZ-3HJ50VA -E1 ,ER1 ,ET1
HFC
utilized
R410A
INDOOR UNIT
SERVICE MANUAL No. OBH709
REVISED EDITION-A
OUTDOOR UNIT
CONTENTS
1. TECHNICAL CHANGES ··································· 2
2. PART NAMES AND FUNCTIONS····················· 3
3. SPECIFICATION················································ 4
4. NOISE CRITERIA CURVES······························ 6
5. OUTLINES AND DIMENSIONS ························ 7
6. WIRING DIAGRAM············································ 9
7. REFRIGERANT SYSTEM DIAGRAM············· 10
8. PERFORMANCE CURVES····························· 13
9. ACTUATOR CONTROL··································· 19
10. SERVICE FUNCTIONS···································· 20
11. TROUBLESHOOTING····································· 24
12. DISASSEMBLY INSTRUCTIONS···················· 50
INDOOR UNITS COMBINATION SHEETS
NOTE:
RoHS compliant products have <G> mark
on the spec name plate.
PARTS CATALOG (OBB709)
MXZ-2HJ40VA
Indoor unit service manual
MSZ-HJ•VA Series (OBH647C)
Please void OBH709.
Revision A:
• Additional refrigerant charge for MXZ-
3HJ50- E1 ,ER1 ,ET1 has been corrected.

2
<Preparation before the repair service>
Prepare the proper tools.
Prepare the proper protectors.
Provide adequate ventilation.
After stopping the operation of the air conditioner, turn off the power-supply breaker and remove the power plug.
Discharge the capacitor before the work involving the electric parts.
<Precautions during the repair service>
Do not perform the work involving the electric parts with wet hands.
Do not pour water into the electric parts.
Do not touch the refrigerant.
Do not touch the hot or cold areas in the refrigeration cycle.
When the repair or the inspection of the circuit needs to be done without turning off the power, exercise great caution not to
touch the live parts.
Use the specified refrigerant only
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the spec labels provided with our products.
We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused by
failure to follow the instructions.
TECHNICAL CHANGES
1
MXZ-2HJ40VA - E1 , ER1 , ET1
MXZ-3HJ50VA - E1 , ER1 , ET1
1. New model
Revision A:
• Additional refrigerant charge for MXZ-3HJ50- E1 ,ER1 ,ET1 has been corrected.
(Refer to 7. REFRIGERANT SYSTEM DIAGRAM.)
OBH709A

3
PART NAMES AND FUNCTIONS
2
ACCESSORIES
MXZ-2HJ40VA
Air inlet
Air outlet
Drain outlet
Piping
Drain hose
(Back and side)
Model MXZ-2HJ40VA MXZ-3HJ50VA
Drain socket 1 1
Drain cap 2
Air outlet
Drain outlet
Air inlet
(Back and side)
MXZ-3HJ50VA
OBH709A

4
SPECIFICATION
3
Outdoor model MXZ-2HJ40VA
Outdoor unit power supply Single phase
230 V, 50 Hz
System
Indoor units number 2
Piping total length m Max. 30
Connecting pipe length m Max. 20
Height difference (Indoor ~ Outdoor) m Refer to 7 REFRIGERANT SYSTEM DIAGRAM.
Height difference (Indoor ~ Indoor) m Refer to 7 REFRIGERANT SYSTEM DIAGRAM.
Function Cooling Heating
Capacity Rated frequency (Min.-Max.) 2 kW 4.0 (1.1 - 4.3) 4.3 (1.0 - 4.7)
Breaker capacity A 15
Electrical
data
Power input (Total) 1, 2 W 1,050 1,160
Running current (Total) 1, 2 A 5.1 5.6
Power factor (Total) 1, 2% 90
Starting current (Total) 1, 2 A 5.6
Coefficient of performance (C.O.P) (Total) 1, 2 3.81 3.71
Compressor
Model KNB092FFDHC
Output W 1,100
Current 1, 2 A 4.7 5.2
Refrigeration oil (Model) L 0.32 (NEO22)
Fan motor
Model RC0J50-FA
Current 1, 2 A 0.19 0.23
Dimensions W x H x D mm 800 x 550 x 285
Weight kg 32
Special
remarks
Air flow (Rated) m3/h 1,752 1,914
Sound level (Rated) dB(A) 48 52
Fan speed (Rated) rpm 840 910
Refrigerant filling capacity (R410A) kg 0.95
1 Measured under rated operating frequency.
2 When connected with below indoor units.
MSZ-HJ25VA + MSZ-HJ25VA
NOTE: Test conditions are based on ISO 5151. (Refrigerant piping length (one way): 5 m)
COOLING INDOOR Dry-bulb temperature 27.0 °C Wet-bulb temperature 19.0 °C
OUTDOOR Dry-bulb temperature 35.0 °C Wet-bulb temperature 24.0 °C
HEATING INDOOR Dry-bulb temperature 20.0 °C
OUTDOOR Dry-bulb temperature 7.0 °C Wet-bulb temperature 6.0 °C
OBH709A

5
Outdoor model MXZ-3HJ50VA
Outdoor unit power supply Single phase
230 V, 50 Hz
System
Indoor units number 2 to 3
Piping total length m Max. 50
Connecting pipe length m Max. 25
Height difference (Indoor ~ Outdoor) m Refer to 7 REFRIGERANT SYSTEM DIAGRAM.
Height difference (Indoor ~ Indoor) m Refer to 7 REFRIGERANT SYSTEM DIAGRAM.
Function Cooling Heating
Capacity Rated frequency (Min.-Max.) 2 kW 5.0 (2.7 - 6.5) 6.0 (2.4 - 7.5)
Breaker capacity A 25
Electrical
data
Power input (Total) 1, 2 W 1,130 1,310
Running current (Total) 1, 2 A 5.0 5.8
Power factor (Total) 1, 2% 99
Starting current (Total) 1, 2 A 5.8
Coefficient of performance (C.O.P) (Total) 1, 2 4.42 4.58
Compressor
Model SNB130FGBH1T
Output W 1,300
Current 1, 2 A 4.5 5.3
Refrigeration oil (Model) L 0.7 (NEO22)
Fan motor
Model SIC-71FW-F764-1
Current 1, 2 A 0.20 0.23
Dimensions W x H x D mm 840 x 710 x 330
Weight kg 57
Special
remarks
Air flow (Rated) m3/h 2,252 2,379
Sound level (Rated) dB(A) 50 53
Fan speed (Rated) rpm 630 660
Refrigerant filling capacity (R410A) kg 2.7
1 Measured under rated operating frequency.
2 When connected with below indoor units.
MSZ-HJ25VA + MSZ-HJ25VA + MSZ-HJ25VA
NOTE: Test conditions are based on ISO 5151. (Refrigerant piping length (one way): 5 m)
COOLING INDOOR Dry-bulb temperature 27.0 °C Wet-bulb temperature 19.0 °C
OUTDOOR Dry-bulb temperature 35.0 °C Wet-bulb temperature 24.0 °C
HEATING INDOOR Dry-bulb temperature 20.0 °C
OUTDOOR Dry-bulb temperature 7.0 °C Wet-bulb temperature 6.0 °C
OBH709A

6
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
CoolingHigh
FUNCTION
FAN SPEED
HeatingHigh
48
SPL(dB(A))
52
LINE
NOISE CRITERIA CURVES
4
MXZ-2HJ40VA
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
CoolingHigh
FUNCTION FAN SPEED
HeatingHigh
50
SPL(dB(A))
53
LINE
MXZ-3HJ50VA
OUTDOOR UNIT
MICROPHONE
1m
Test conditions
Cooling :Dry-bulb temperature 35°C Wet-bulb temperature 24°C
Heating :Dry-bulb temperature 7°C Wet-bulb temperature 6°C
OBH709A

7
OUTLINES AND DIMENSIONS
5
MXZ-2HJ40VA Unit: mm
OBH709A

8
1.Installation space
Note : Leave front and both sides
free of obstruction.
Note : Leave rear, overhead and
both sides free of obstruction.
500 or more
100 or more
Note : Leave front and overhead
free of obstruction.
100 or more 350 or more
200 or more
500 or more
2.Service space
100 or more
500 or more
350 or more
350 or more
100 or more Service space
Liquid pipe : Ø6.35(flared)1/4 C unit connection
B unit connection
A unit connection
Gas pipe : Ø9.52(flared)3/8
Liquid pipe : Ø6.35(flared)1/4
Gas pipe : Ø9.52(flared)3/8
Liquid pipe : Ø6.35(flared)1/4
Gas pipe : Ø9.52(flared)3/8
MXZ-3HJ50VA Unit: mm
OBH709A

9
WIRING DIAGRAM
6
MXZ-2HJ40VA - E1 , ER1 , ET1
MXZ-3HJ50VA - E1 , ER1 , ET1
OBH709A

10
UNIT: mm (inch)
Piping length each indoor unit (a, b) 20 m
Total piping length (a+b) 30 m
Bending point for each unit 20
Total bending point 30
MXZ-2HJ40VA
MAX REFRIGERANT PIPING LENGTH
a
b
Outdoor
unit
Indoor
units
15 m
10 m
15 m
Refrigerant piping length (one way, 2 unit total)
Calculation : Xg = 20 g/m x (Refrigerant piping length (m) - 20)
Outdoor unit
precharged
(g) 30 m
200
20 m
0
950
Max.
Height
difference
Outdoor unit union diameter
For
Indoor unit A Liquid 6.35(1/4)
Gas 9.52(3/8)
Indoor unit B Liquid 6.35(1/4)
Gas 9.52(3/8)
Stop valve
(with strainer #100) LEV A
LEV B
Compressor
Muffler
4-way valve
Indoor unit
B
Indoor unit
A
Indoor unit
A
Indoor unit
B
Capillary tube
Capillary tube
Stop valve
(with strainer #100)
Refrigerant flow in cooling
Refrigerant flow in heating
Discharge
temperature
thermistor RT62
Stop valve
(with service port)
Stop valve
(with service port)
Strainer
#100
Sub muffler
Defrost
thermistor
RT61
Ambient
temperature
thermistor
RT65
Outdoor heat
exchanger
temperature
thermistor
RT68 FAN-OUT
HEX-OUT
It is irrelevant which unit is higher.
ADDITIONAL REFRIGERANT CHARGE
UNIT: mm
REFRIGERANT SYSTEM DIAGRAM
7
Refrigerant pipe diameter is different according to indoor unit to be
connected. When using extension pipes, refer to the right table.
When diameter of refrigerant pipe is different from that of outdoor
unit union, use optional Different-diameter pipe.
For further information on Different-diameter pipe, refer to "PARTS
CATALOG".
OBH709A

11
Strainer
#100
Power
receiver
LEV A
LEV B
LEV C
Oil separator
Compressor
Defrost
thermistor
RT61
Distributor
Muffler
4-way valve
LEV E
Indoor unit
C
Indoor unit
B
Indoor unit
A
Indoor unit
A
Indoor unit
B
Indoor unit
C
Capillary tube
Capillary tube
Capillary tube
Capillary tube
Capillary tube
Discharge
temperature
thermistor RT62
Strainer
#100
Strainer
#100
Strainer
#100
R.V. coil
OFF
ON Refrigerant flow in cooling Refrigerant flow in heating
Ambient
temperature
thermistor
RT65
Outdoor heat
exchanger
temperature
thermistor
RT68
FAN-OUT
HEX-OUT
Strainer
#100
Stop valve with
service port
Stop valve
High-pressure switch
UNIT: mm (inch)
UNIT: mm
MXZ-3HJ50VA
MAX REFRIGERANT PIPING LENGTH
Outdoor unit union diameter
For
Indoor unit A Liquid 6.35(1/4)
Gas 9.52(3/8)
Indoor unit B Liquid 6.35(1/4)
Gas 9.52(3/8)
Indoor unit C Liquid 6.35(1/4)
Gas 9.52(3/8)
a
b
c
Outdoor
unit
Indoor
units
15 m
10 m
15 m
Max.
Height
difference
Piping length each indoor unit (a, b, c) 25 m
Total piping length (a+b+c) 50 m
Bending point for each unit 25
Total bending point 50
It is irrelevant which unit is higher.
Refrigerant pipe diameter is different according to indoor unit to be
connected. When using extension pipes, refer to the right table.
When diameter of refrigerant pipe is different from that of outdoor
unit union, use optional Different-diameter pipe.
For further information on Different-diameter pipe, refer to "PARTS
CATALOG".
ADDITIONAL REFRIGERANT CHARGE
Outdoor unit
precharged
(g)
Refrigerant piping length (one way, 3 unit total)
40 m 50 m
2,700 0 200
Calculation : Xg = 20 g/m x (Refrigerant piping length (m) - 40)
OBH709A

12
When relocating or disposing of the air conditioner, pump down the system following the procedure below so that no refriger-
ant is released into the atmosphere.
1) Turn off the breaker.
2) Connect the gauge manifold valve to the service port of the stop valve on the gas pipe side of the outdoor unit.
3) Fully close the stop valve on the liquid pipe side of the outdoor unit.
4) Turn on the breaker.
5) Start the emergency COOL operation on all the indoor units.
6) When the pressure gauge shows 0.05 to 0 MPa [Gauge] (approximately 0.5 to 0 kgf/cm²), fully close the stop valve
on the gas pipe side of the outdoor unit and stop the operation. (Refer to the indoor unit installation manual about the
method for stopping the operation.)
* If too much refrigerant has been added to the air conditioner system, the pressure may not drop to 0.05 MPa [Gauge]
(approximately 0.5 kgf/cm²)
, or the protection function may operate due to the pressure increase in the high-pressure
refrigerant circuit. If this occurs, use a refrigerant collecting device to collect all of the refrigerant in the system, and then
recharge the system with the correct amount of refrigerant after the indoor and outdoor units have been relocated.
7) Turn off the breaker. Remove the pressure gauge and the refrigerant piping.
When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes.
The compressor may burst and cause injury if any foreign substance, such as air, enters the pipes.
WARNING
PUMPING DOWN
OBH709A

13
PERFORMANCE CURVES
8
The standard specifications apply only to the operation of the air conditioner under normal conditions.
Since operating conditions vary according to the areas where these units are installed, the following information has been pro-
vided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.
(1) GUARANTEED VOLTAGE
198 - 264 V 50 Hz
(2) AIR FLOW
Air flow should be set at MAX.
(3) MAIN READINGS
(1) Indoor intake air wet-bulb temperature : °CWB
(2) Indoor outlet air wet-bulb temperature : °CWB
(3) Outdoor intake air dry-bulb temperature : °CDB
(4) Total input: W
(5) Indoor intake air dry-bulb temperature : °CDB
(6) Outdoor intake air wet-bulb temperature : °CWB
(7) Total input : W
Indoor air wet and dry bulb temperature difference on the left side of the following chart shows the difference between the
indoor intake air wet and dry bulb temperature and the indoor outlet air wet and dry bulb temperature for your reference at
service.
How to measure the indoor air wet and dry bulb temperature difference
1. Attach at least 2 sets of wet and dry bulb thermometers to the indoor air intake as shown in the figure, and at least 2 sets
of wet and dry bulb thermometers to the indoor air outlet. The thermometers must be attached to the position where air
speed is high.
2. Attach at least 2 sets of wet and dry bulb thermometers to the outdoor air intake.
Cover the thermometers to prevent direct rays of the sun.
3. Check that the air filter is cleaned.
4. Open windows and doors of room.
5. Press the EMERGENCY OPERATION switch once (twice) to start the EMERGENCY COOL (HEAT) MODE.
6. When system stabilizes after more than 15 minutes, measure temperature and take an average temperature.
7. 10 minutes later, measure temperature again and check that the temperature does not change.
INDOOR UNIT OUTDOOR UNIT
}
}
Cooling
Heating
Wet and dry bulb
thermometers
BACK VIEW
Wet and dry bulb
thermometers
FRONT VIEW
MXZ-2HJ40VA MXZ-3HJ50VA
OBH709A

14
8-1. CAPACITY AND THE INPUT CURVES
MXZ-2HJ40VA
Outdoor intake air Dry-bulb temperature (°C)
46454645
Outdoor intake air Dry-bulb temperature (°C)
Indoor intake air Wet-bulb temperature (°C)
Indoor intake air Wet-bulb temperature (°C)
6.7
6.1
5.6
5.1
4.6
4.1
25 class
7.4
6.8
6.2
5.6
5.1
4.5
35 class
Indoor air Wet-bulb temperature
difference (°C)
Outdoor intake air Wet-bulb temperature (°C) Outdoor intake air Wet-bulb temperature (°C)
Indoor intake air Dry-bulb temperature (°C)
Indoor intake air Dry-bulb temperature (°C)
20.6
19.0
17.4
15.8
14.3
12.7
11.1
9.5
25 class
22.9
21.1
19.3
17.6
15.8
14.1
12.3
10.5
35 class
Indoor air Dry-bulb temperature
difference (°C)
Indoor air Wet-bulb temperature
difference (°C)
Outdoor intake air Dry-bulb temperature (°C)
46454645
Outdoor intake air Dry-bulb temperature (°C)
Indoor intake air Wet-bulb temperature (°C)
Indoor intake air Wet-bulb temperature (°C)
50 class
7.4
6.8
6.2
5.6
5.1
4.5
6.7
6.1
5.6
5.1
4.6
4.1
10.5
9.6
8.7
7.9
7.1
6.3
35 class
25 class
MXZ-3HJ50VA
50 class
24.7
22.8
20.9
19.0
17.1
15.2
13.3
11.4
35 class
20.6
19.0
17.4
15.8
14.3
12.7
11.1
9.5
25 class
22.9
21.1
19.3
17.6
15.8
14.1
12.3
10.5
Indoor air Dry-bulb temperature
difference (°C)
Outdoor intake air Wet-bulb temperature (°C) Outdoor intake air Wet-bulb temperature (°C)
Indoor intake air Dry-bulb temperature (°C)
Indoor intake air Dry-bulb temperature (°C)
OBH709A

15
<COOL>Capacity
Frequency Hz
<COOL>Total input
0 50 100 150
0.5
1.0
1.5
Frequency Hz
0 50 100 150
0.5
1.0
1.5
<COOL>Capacity
Frequency Hz
<COOL>Total input
0 50 100 150
0.5
1.0
1.5
Frequency Hz
0 50 100 150
0.5
1.0
1.5
<HEAT>Capacity <HEAT>Total input
Frequency Hz
0 50 100 150
0.5
1.0
1.5
Frequency Hz
0 50 100 150
0.5
1.0
1.5
2.0
<HEAT>Capacity <HEAT>Total input
Frequency Hz
0 50 100 150
0.5
1.0
1.5
Frequency Hz
0 50 100 150
0.5
1.0
1.5
25-class unit
MXZ-2HJ40VA
35-class unit
8-2.
CAPACITY AND INPUT CORRECTION BY INVERTER OUTPUT FREQUENCY (single operation)
OBH709A

16
25-class unit
<COOL>Capacity
Frequency Hz
<COOL>Total input
0 50 100 150
0.5
1.0
1.5
Frequency Hz
0 50 100 150
0.5
1.0
1.5
<COOL>Capacity
Frequency Hz
<COOL>Total input
0 50 100 150
0.5
1.0
1.5
Frequency Hz
0 50 100 150
0.5
1.0
1.5
<COOL>Capacity
Frequency Hz
<COOL>Total input
0 50 100 150
0.5
1.0
1.5
Frequency Hz
0 50 100 150
0.5
1.0
1.5
<HEAT>Capacity <HEAT>Total input
Frequency Hz
0 50 100 150
0.5
1.0
1.5
Frequency Hz
050100150
0.5
1.0
1.5
<HEAT>Capacity <HEAT>Total input
Frequency Hz
0 50 100 150
0.5
1.0
1.5
Frequency Hz
050100150
0.5
1.0
1.5
<HEAT>Capacity <HEAT>Total input
Frequency Hz
0 50 100 150
0.5
1.0
1.5
2.0
Frequency Hz
0 50 100 150
0.5
1.0
1.5
2.0
MXZ-3HJ50VA
35-class unit
50-class unit
OBH709A

17
1. Press EMERGENCY OPERATION switch to start COOL or HEAT mode (COOL : Press once, HEAT : Press twice).
2. Test run operation starts and continues to operate for 30 minutes.
3. Compressor operates at rated frequency.
4. Indoor fan operates at High speed.
5. After 30 minutes, test run operation finishes and EMERGENCY OPERATION starts (Operation frequency of compressor
varies).
6. To cancel test run operation or EMERGENCY OPERATION, press EMERGENCY OPERATION switch or any button on
remote controller.
8-3. HOW TO OPERATE FIXED-FREQUENCY OPERATION <Test run operation>
Both indoor and outdoor units are under the
same temperature/humidity condition.
Operation : TEST RUN OPERATION (Refer to 8-3.)
Dry-bulb temperature ( )Relative humidity (%)
20 50
25 60
30 70
8-4. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT CURVE
(single operation)
NOTE: The unit of pressure has been changed to MPa on the international system of units (SI unit system).
The conversion factor is : 1 (MPa [Gauge]) = 10.2 (kgf/cm2 [Gauge])
(1) COOL operation
MXZ-2HJ40VA
25-class unit
Outdoor low pressure
(MPa[Gauge])
Outdoor unit current (A)
Ambient temperature ( )
Ambient humidity (%) Ambient temperature ( )
Ambient humidity (%)
50 60 70 (%) (%)
50 60 70
42Hz
42Hz
15
14
13
12
11
10
9
8
715 20 25 30 35
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
15 20 25 30 35
0
1
2
3
4
5
Outdoor low pressure
(MPa[Gauge])
Outdoor unit current (A)
Ambient temperature ( )
Ambient humidity (%) Ambient temperature ( )
Ambient humidity (%)
50 60 70 (%) (%)
50 60 70
42Hz
42Hz
15
14
13
12
11
10
9
8
715 20 25 30 35
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
15 20 25 30 35
0
1
2
3
4
5
35-class unit
MXZ-3HJ50VA
25-class unit
Outdoor low pressure
(MPa[Gauge])
Outdoor unit current (A)
Ambient temperature ( )
Ambient humidity (%) Ambient temperature ( )
Ambient humidity (%)
50 60 70 (%) (%)
50 60 70
40Hz
40Hz
15
14
13
12
11
10
9
8
715 20 25 30 35
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
15 20 25 30 35
0
1
2
3
4
5
35-class unit
Outdoor low pressure
(MPa[Gauge])
Outdoor unit current (A)
Ambient temperature ( )
Ambient humidity (%) Ambient temperature ( )
Ambient humidity (%)
50 60 70 (%) (%)
50 60 70
40Hz
40Hz
15
14
13
12
11
10
9
8
715 20 25 30 35
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
15 20 25 30 35
0
1
2
3
4
5
50-class unit
Outdoor low pressure
(MPa[Gauge])
Outdoor unit current (A)
Ambient temperature ( )
Ambient humidity (%) Ambient temperature ( )
Ambient humidity (%)
50 60 70 (%) 50 60 70
40Hz 40Hz
15
14
13
12
11
10
9
8
7
(%)
15 20 25 30 35
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
15 20 25 30 35
0
1
2
3
4
5
OBH709A

18
Condition :
Operation : TEST RUN OPERATION (Refer to 8-3.)
(2) HEAT operation
Dry bulb temperature (°C) Indoor
20.0
14.5 2 1
Outdoor
7
615 12 20.0 14.5
Wet bulb temperature (°C)
MXZ-2HJ40VA
25-class unit
0 5 10 15 20 25
0
1
2
3
4
5
Ambient temperature ( )
48Hz
Outdoor unit current (A)
0 5 10 15 20 25
0
1
2
3
4
5
Ambient temperature ( )
48Hz
Outdoor unit current (A)
35-class unit
25-class unit 35-class unit
MXZ-3HJ50VA 50-class unit
0 5 10 15 20 25
3
4
5
6
7
8
Ambient temperature ( )
47Hz
Outdoor unit current (A)
0 5 10 15 20 25
3
4
5
6
7
8
Ambient temperature ( )
47Hz
Outdoor unit current (A)
0 5 10 15 20 25
3
4
5
6
7
8
Ambient temperature ( )
47Hz
Outdoor unit current (A)
OBH709A

19
ACTUATOR CONTROL
9
Relation between main sensor and actuator
Sensor Purpose Actuator
Compressor LEV Outdoor
fan motor R.V. coil
Discharge temperature thermistor Protection
Indoor coil temperature thermistor Cooling: Coil frost prevention
Heating: High pressure protection
Defrost thermistor Heating: Defrosting
Fin temperature thermistor Protection
Ambient temperature thermistor Control/Protection
Outdoor heat exchanger
temperature thermistor Cooling: Control/Protection
Capacity code Control
MXZ-2HJ40VA MXZ-3HJ50VA
OBH709A

20
OutdoordisplayP.C.board
SW1 SW2
ON
123456
ON
SERVICE FUNCTIONS
10
10-1. THE POSITION OF SWITCH
MXZ-2HJ40VA MXZ-3HJ50VA
MXZ-2HJ40VA
ON
SW1
ON
SW1
Cool/Dry Heat
With this function, you can lock the operation mode of the outdoor unit.
Once the operation mode is locked to either COOL/DRY mode or HEAT mode, the air conditioner operates in that mode
only.
Default setting is required to activate this function.
Please explain this function to your customers and ask them whether they want to use it.
[How to lock the operation mode]
(1) Turn OFF the breaker and make sure that the LED goes off.
(2) Set SW1 or SW2 as shown in the figure below.
(3) Turn ON the breaker.
10-2. LOCKING THE OPERATION MODE OF THE AIR CONDITIONER (COOL, DRY, HEAT)
MXZ-2HJ40VA
SW1 on the outdoor display P.C. board
ON
56
SW2
ON
56
SW2
Cool/Dry Heat
MXZ-3HJ50VA
SW2 on the outdoor control P.C. board
MXZ-3HJ50VA
Oudoorcontrol P.C. board
ON
SW2
SW871
123456
OBH709A