Mitsubishi Electric MUZ-HJ25VA-E1 User manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ··································· 3
2. PART NAMES AND FUNCTIONS····················· 3
3. SPECIFICATION················································ 4
4. NOISE CRITERIA CURVES ······························ 5
5. OUTLINES AND DIMENSIONS ························ 6
6. WIRING DIAGRAM············································ 7
7. REFRIGERANT SYSTEM DIAGRAM ··············· 8
8. PERFORMANCE CURVES ······························· 9
9. ACTUATOR CONTROL··································· 18
10. SERVICE FUNCTIONS···································· 19
11. TROUBLESHOOTING ····································· 19
12. DISASSEMBLY INSTRUCTIONS···················· 33
Models
SPLIT-TYPE AIR CONDITIONERS
MUZ-HJ25VA -E1
MUZ-HJ35VA -E1
HFC
utilized
R410A
No. OBH648
OUTDOOR UNIT
Indoor unit service manual
MSZ-HJ•VA Series (OBH647)
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
PARTS CATALOG (OBB648)
MUZ-HJ25VA
MUZ-HJ35VA

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.
OBH648

3
MUZ-HJ25VA - E1
MUZ-HJ35VA - E1
1. New model
1TECHNICAL CHANGES
ACCESSORIES
Air outlet
Drain outlet
Piping
Drain hose
Air inlet
(Back and side)
MUZ-HJ25VA MUZ-HJ35VA
Drain socket 1
2PART NAMES AND FUNCTIONS
OBH648

4
3SPECIFICATION
Outdoor model MUZ-HJ25VA MUZ-HJ35VA
Power supply Single phase, 230 V, 50 Hz
Capacity
Rated frequency (Min.-Max.)
Cooling kW 2.5 (1.3 - 3.0) 3.15 (1.4 - 3.5)
Heating 3.15 (0.9 - 3.5) 3.6 (1.1 - 4.1)
Breaker Capacity A 10
Electrical data
Power input 1 (Total) Cooling W730 1,040
Heating 870 995
Running current 1
(Total)
Cooling A3.7 4.9
Heating 4.2 4.8
Power factor 1 (Total) Cooling %85 92
Heating 90 90
Starting current 1 (Total) A 4.2 4.9
Coefficient of performance
(COP) 1 (Total)
Cooling 3.42 3.03
Heating 3.62 3.62
Compressor
Model KNB065FUJHC KNB073FUVHC
Output W 500 550
Current 1Cooling A3.3 4.4
Heating 3.8 4.4
Refrigeration oil (Model) L 0.32 (NEO22)
Fan motor Model RA6V21-BD
Current 1 A 0.23
Dimensions W × H × D mm 699 × 538 × 249
Weight kg 24 25
Special remarks
Dehumidification Cooling /h 0.4 0.6
Air flow 1 m3/h 1,890 1,890
Sound level 1 Cooling dB(A) 50 50
Heating 50 50
Fan speed rpm 840 840
Fan speed regulator 1 1
Refrigerant filling capacity (R410A) kg 0.70 0.72
NOTE: Test conditions are based on ISO 5151.
Cooling: Indoor Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Outdoor Dry-bulb temperature 35°C
Heating: Indoor Dry-bulb temperature 20°C
Outdoor Dry-bulb temperature 7°C Wet-bulb temperature 6°C
Refrigerant piping length (one way): 5 m
1 Measured under rated operating frequency.
Specifications and rated conditions of main electric parts
Model
Item MUZ-HJ25VA MUZ-HJ35VA
Smoothing capacitor (C61) 800 μF 420 V
Diode module (DB61) 15 A 600 V
(DB65) 10 A 600 V
Fuse (F701, F801) T3.15AL250V
Power module (IC700) 8 A 600 V 10 A 600 V
Expansion valve coil (LEV) 12 VDC
Reactor (L61) 18 mH
Switching power transistor (IC821) 30 A 600 V
Circuit protection (PTC64) 33 Ω
Terminal block (TB) 3 P
Relay
(X61) 3 A 250 V
(X63) 3 A 250 V
(X64) 20 A 250 V
R.V. coil (21S4) 220 - 240 VAC
OBH648

5
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
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
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
COOLING
FUNCTION SPL(dB(A)) LINE
HEATING
50
50
MUZ-HJ25VA
90
80
70
60
50
40
30
20
10 63 125 250 500 1000 2000 4000 8000
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
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
COOLING
FUNCTION SPL(dB(A)) LINE
HEATING
50
50
Test conditions
Cooling : Dry-bulb temperature 35°C
Heating : Dry-bulb temperature 7°C Wet-bulb temperature 6°C
OUTDOOR UNIT
MICROPHONE
1m
MUZ-HJ35VA
4NOISE CRITERIA CURVES
OBH648

6
Unit : mm
MUZ-HJ25VA MUZ-HJ35VA
5OUTLINES AND DIMENSIONS
REQUIRED SPACE
100 mm
or more
100 mm
or more
100 mm
or more
350 mm
or more
200 mm
or more
41.5
270.3
157.7
43°
40°
102.7
13.5
538
Air in
Air in
Air out
349.5
55.7
121.4
249
17.9
699
500121
259
Bolt pitch for
installation
294~267
285
19.6
Liquid refrigerant pipe joint
Refrigerant pipe (flared) ø6.35
Gas refrigerant pipe joint
Refrigerant pipe (flared) ø9.52
Drain hole ø33
2 - 10.3 X 19.3 Oval hole
OBH648

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MUZ-HJ25VA
6WIRING DIAGRAM
MUZ-HJ35VA
OBH648

8
Unit : mm
MUZ-HJ25VA MUZ-HJ35VA
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
(with strainer)
Stop valve
(with service port)
Refrigerant flow in cooling
Compressor
Muffler
4-way valve
Refrigerant flow in heating
Refrigerant pipe ø9.52
(with heat insulator)
Refrigerant pipe ø6.35
(with heat insulator)
R.V. coil
heating OFF
cooling ON
Strainer
#100
Capillary tube
ø 3.0 × ø 1.4 × 260
LEV
Muffler
(HJ35 only)
7REFRIGERANT SYSTEM DIAGRAM
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE
Refrigerant piping: m Piping size O.D: mm
Max. Length
A
Max. Height difference
BGas Liquid
MUZ-HJ25VA
MUZ-HJ35VA 20 12 9.52 6.35
Max. Length
A
Max. Height
difference
B
Indoor
unit
Outdoor unit
ADDITIONAL REFRIGERANT CHARGE (R410A : g)
Model Outdoor unit
precharged
Refrigerant piping length (one way)
5 m 6 m 7 m 8 m 9 m 10 m 11 m 12 m 13 m 14 m 15 m 20 m
MUZ-HJ25VA 700 0 0 0 20 40 60 80 100 120 140 160 260
MUZ-HJ35VA 720
Calculation: X g = 20 g/m (Refrigerant piping length (m) - 7)
NOTE : Refrigerant piping exceeding 7 m requires additional refrigerant charge according to the calculation.
OBH648

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The standard specifications apply only to the operation of the air conditioner under normal conditions. Since operating condi-
tions vary according to the areas where these units are installed, the following information has been provided 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 : °C WB
(2) Indoor outlet air wet-bulb temperature : °C WB
(3) Outdoor intake air dry-bulb temperature : °C DB
(4) Total input: W
(5) Indoor intake air dry-bulb temperature : °C DB
(6) Outdoor intake air wet-bulb temperature : °C WB
(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.
}
}
Cooling
Heating
MUZ-HJ25VA MUZ-HJ35VA
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.
PERFORMANCE CURVES8
INDOOR UNIT OUTDOOR UNIT
Wet and dry bulb
thermometers
FRONT VIEW
Wet and dry bulb
thermometers
BACK VIEW
OBH648

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Indoor intake air Dry-bulb temperature (°C)
Outdoor intake air Wet-bulb temperature (°C) Outdoor intake air Wet-bulb temperature (°C)
Indoor intake air Dry-bulb temperature (°C)
Indoor air Wet-bulb temperature
difference (°C)
MUZ-HJ25VA
at Rated frequency
MUZ-HJ35VA
at Rated frequency
20.6
19.0
17.4
15.8
14.3
12.7
11.1
9.5
22.9
21.1
19.3
17.6
15.8
14.1
12.3
10.5
NOTE: The above broken lines are for the heating operation without any frost and
defrost operation.
Indoor air Wet-bulb temperature
difference (°C)
Outdoor intake air Dry-bulb temperature (°C)
MUZ-HJ25VA
at Rated frequency
MUZ-HJ35VA
at Rated frequency
6.1
5.6
5.1
4.6
4.1
3.6
6.8
6.2
5.6
5.1
4.5
4.0
18 20 25 30 35 464540
0.8
0.9
1.0
1.1
1.2
1.3 Total input (cooling)
Input correction factor
22
20
18
Indoor intake air Wet-bulb temperature (°C)
26 24
8-1. CAPACITY AND INPUT CURVES
Indoor air Wet-bulb temperature
difference (°C)
Outdoor intake air Dry-bulb temperature (°C)
MUZ-HJ25VA
at Rated frequency
MUZ-HJ35VA
at Rated frequency
7.2
6.7
6.1
5.6
5.1
4.6
4.1
8.0
7.4
6.8
6.2
5.6
5.1
4.5
18 20 25 30 35 40 4645
0.9
1.0
1.1
1.2
1.3
1.4
1.5
Indoor intake air Wet-bulb temperature (°C)
Cooling capacity
Capacity correction factor
22
20
18
26
24
OBH648