Mitsubishi Electric MUFZ-KJ25VEHZ User manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ··································· 3
2. PART NAMES AND FUNCTIONS····················· 3
3. SPECIFICATION················································ 4
4. NOISE CRITERIA CURVES ······························ 6
5. OUTLINES AND DIMENSIONS ························ 7
6. WIRING DIAGRAM············································ 8
7. REFRIGERANT SYSTEM DIAGRAM ··············· 9
8. PERFORMANCE CURVES ····························· 10
9. ACTUATOR CONTROL··································· 19
10. SERVICE FUNCTIONS···································· 20
11. TROUBLESHOOTING ····································· 21
12. DISASSEMBLY INSTRUCTIONS···················· 39
Models
SPLIT-TYPE AIR CONDITIONERS
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
HFC
utilized
R410A
No. OBH668
OUTDOOR UNIT
Indoor unit service manual
MFZ-KJ•VE Series (OBH666)
PARTS CATALOG (OBB668)
MUFZ-KJ25VEHZ -E1
MUFZ-KJ35VEHZ -E1

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.
OBH668

3
MUFZ-KJ25VEHZ - E1
MUFZ-KJ35VEHZ - E1
1. New model
TECHNICAL CHANGES
1
Air outlet
Drain outlet
Piping
Drain hose
Air inlet
(back and side)
MUFZ-KJ25VEHZ
MUFZ-KJ35VEHZ
PART NAMES AND FUNCTIONS
2
OBH668

4
Outdoor model MUFZ-KJ25VEHZ MUFZ-KJ35VEHZ
Power supply Single phase, 230 V, 50 Hz
Capacity
Rated frequency (Min.-Max.)
Cooling kW 2.5 (0.5 - 3.4) 3.5 (0.5 - 3.7)
Heating 3.4 (1.2 - 5.1) 4.3 (1.2 - 5.8)
Breaker Capacity A 10 12
Electrical data
Power input 1 (Total) Cooling W540 940
Heating 770 1,110
Running current 1
(Total)
Cooling A2.7 4.2
Heating 3.6 5.1
Power factor 1 (Total) Cooling %87 98
Heating 91 93
Starting current 1 (Total) A 3.6 5.1
Coefficient of performance
(COP) 1 (Total)
Cooling 4.63 3.72
Heating 4.42 3.91
Compressor
Model SNB140FRUMT
Output W 950
Current 1 Cooling A2.19 3.69
Heating 3.16 4.61
Refrigeration oil (Model) L 0.35 (FV50S)
Fan motor
Model RC0J50-CI
Current 1Cooling A0.31
Heating 0.31
Dimensions W × H × D mm 800 × 550 × 285
Weight kg 37
Special remarks
Dehumidification Cooling L/h 0.6 1.4
Air flow 1
Cooling Med.
m3/h
1,806
Low 1,038
Heating
High 2,016
Med. 1,710
Low 1,326
Sound
level 1
Cooling dB(A) 46 47
Heating 51
Fan speed
Cooling Med.
rpm
810
Low 490
Heating
High 900
Med. 770
Low 610
Fan speed regulator 3
Refrigerant filling capacity (R410A) kg 1.10
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.
SPECIFICATION
3
OBH668

5
Specifications and rated conditions of main electric parts
Model
Item MUFZ-KJ25VEHZ MUFZ-KJ35VEHZ
Smoothing
capacitor (C61, C62) 600 μF/ 620 μF 420 V
Diode module (DB61) 15 A 600 V
Fuse (F61) T20AL250V
(F701, F801, F901) T3.15AL250V
Defrost heater (H) 230 V 130 W
Power module (IC700) 15 A 600 V
(IC932) 8A600V
Expansion valve
coil (LEV) 12 V DC
Reactor (L61) 23 mH
Power factor
controller (IC820) 20A 600V
Circuit
protection (PTC64, PTC65) 33 Ω
Terminal block (TB) 5 P
Relay
(X63) 3 A 250 V
(X64) 20 A 250 V
(X66) 3 A 250 V
(X69) 10A 250V
R.V. coil (21S4) 220 - 240 V AC
Heater protector (26H) Open 45°C
OBH668

6
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, 0dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION SPL(dB(A)) LINE
HEATING
46
51
NC-10
MUFZ-KJ25VEHZ
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
COOLING
FUNCTION SPL(dB(A)) LINE
HEATING
47
51
NC-10
MUFZ-KJ35VEHZ
NOISE CRITERIA CURVES
4
Test conditions
Cooling: Dry-bulb temperature 35°C
Heating: Dry-bulb temperature 7°C Wet-bulb temperature 6°C
OUTDOOR UNIT
MICROPHONE
1 m
OBH668

7
Unit: mm
MUFZ-KJ25VEHZ
MUFZ-KJ35VEHZ
10
69
800
302.5
500 Bolt pitch for installation
150
22.3
Handle
550
280
164.5
99.5
170.5
23
Service panel
Service port
285
344.5
44
400
Air in
Air out
Air in
17.5
Bolt pitch for
installation
304~325
40
Liquid refrigerant pipe joint
Refrigerant pipe (flared) ø6.35
Gas refrigerant pipe joint
Refrigerant pipe (flared) ø9.52
43
35
2 holes 10 X 21
REQUIRED SPACE
100 mm or more
350 mm or more
200 mm or more
100 mm or more
100 mm or more
Drain hole ø33
OUTLINES AND DIMENSIONS
5
OBH668

8
WIRING DIAGRAM
6
MUFZ-KJ25VEHZ
MUFZ-KJ35VEHZ
OBH668

9
Unit: mm
MUFZ-KJ25VEHZ
MUFZ-KJ35VEHZ
Outdoor
heat
exchanger
Flared connection
Defrost
thermistor
RT61
Discharge
temperature
thermistor
RT62
Flared connection
Stop valve
(with strainar)
Stop valve
Refrigerant flow in cooling
Compressor
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 ON
cooling OFF
Strainer
#100
LEV
Ambient
temperature
thermistor
RT65
Muffler
Capillary tube
ø4.0×ø2.4×240
Outdoor heat
exchanger
temperature
thermistor
RT68
Capillary tube
ø3.0×ø2.0×210
Muffler
REFRIGERANT SYSTEM DIAGRAM
7
Max. Length
A
Max. Height
difference
B
Indoor
unit
Outdoor unit
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE
Model Refrigerant piping: m Piping size O.D: mm
Max. Length A Max. Height difference B Gas Liquid
MUFZ-KJ25/35 20 12 9.52 6.35
ADDITIONAL REFRIGERANT CHARGE (R410A: g)
Model Outdoor unit
precharged
Refrigerant piping length (one way)
7 m 8 m 9 m 10 m 11 m 12 m 13 m 14 m 15 m 20 m
MUFZ-KJ25/35 1,100 0 30 60 90 120 150 180 210 240 390
Calculation: X g = 30 g/m × (Refrigerant piping length (m) - 7)
OBH668

10
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]
}
Cooling
(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]
}
Heating(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.
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.
MUFZ-KJ25VEHZ
MUFZ-KJ35VEHZ
INDOOR UNIT OUTDOOR UNIT
Wet and dry bulb
thermometers
FRONT VIEW
Wet and dry bulb
thermometers
BACK VIEW
Cooling capacity ( at Rated frequency)
0.9
1.0
1.1
1.2
1.3
1.4
1.5
-10-5 0 5 1015202530354045
Outdoor intake air Dry-bulb temperature(°C)
Capacity correction factors
26
24
20
18
22
Indoor intake air Wet-bulb
temperature( )
MUFZ-KJ35VEHZ
MUFZ-KJ25VEHZ
Indoor air Wet-bulb temperature
difference (°C)
8.5
7.9
7.2
6.6
6.0
5.4
4.8
12.9
11.8
10.8
9.8
8.8
7.9
7.0
8-1. CAPACITY AND INPUT CURVES
PERFORMANCE CURVES8
OBH668