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