Mitsubishi MSC-GA20VB Service Manual

CONTENTS1. TECHNICAL CHANGES ····································22. PART NAMES AND FUNCTIONS······················33. SPECIFICATION··················

10MSC-GA20VB MUH-GA20VB MUH-GA35VB MSC-GA35VBMUH-GA25VB MSC-GA25VB8.57.87.16.45.85.110.09.28.37.56.86.011.010.09.18.27.46.520.018.516.915.413.912.310.

118-2.OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENTCOOL operation① Both indoor and outdoor unit are under the same temperature/humidity condition.➁ Ai

12HEAT operationCondition indoor:Dry bulb temperature 20.0°CWet bulb temperature 14.5°COutdoor:Dry bulb temperature 7,15,20°CWet bulb temperature 6,12

13MSC-GA20VB : MUH-GA20VBPERFORMANCE DATACOOL operation (230V)21 18 2.70 1.51 0.56 572 2.59 1.45 0.56 601 2.48 1.39 0.56 629 2.39 1.34 0.56 65821 2

14MSC-GA20VB : MUH-GA20VB PERFORMANCE DATACOOL operation (230V)21 18 2.25 1.26 0.56 701 2.07 1.16 0.56 744 1.99 1.11 0.56 75821 20 2.37 1.04 0.44

15MSC-GA25VB : MUH-GA25VB PERFORMANCE DATACOOL operation (230V)21 18 3.11 1.62 0.52 656 2.98 1.55 0.52 689 2.86 1.49 0.52 722 2.76 1.43 0.52 75421

16MSC-GA25VB : MUH-GA25VB PERFORMANCE DATACOOL operation (230V)21 18 2.60 1.35 0.52 804 2.39 1.24 0.52 853 2.29 1.19 0.52 86921 20 2.73 1.09 0.40

17MSC-GA35VB : MUH-GA35VB PERFORMANCE DATACOOL operation (230V)21 18 4.11 1.97 0.48 872 3.94 1.89 0.48 916 3.78 1.81 0.48 959 3.64 1.75 0.48 10032

18MSC-GA35VB : MUH-GA35VB PERFORMANCE DATACOOL operation (230V)21 18 3.43 1.65 0.48 1068 3.15 1.51 0.48 1134 3.03 1.45 0.48 115521 20 3.61 1.30 0.

19MSC-GA20VB : MUH-GA20VB PERFORMANCE DATAHEAT operation (230V)MSC-GA25VB : MUH-GA25VB OUTDOOR WB(:)INDOOR-10 -5 0 5 10 15 20DB(:)Q INPUT Q

TECHNICAL CHANGES21MUH-A07YV- ➔MUH-GA20VB-1. Indication of capacity has been changed. (BTU base ➔ kw)2. Dimension of outdoor unit has been changed. (W

20TROUBLESHOOTING113. Troubleshooting procedure1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate a

2111-2. Instruction of troubleshootingStartIndoor unit operates.Outdoor unit doesn't operate.Indoor unit doesn't receive the signal from re

22AACheck of outdoor unitCompressor and/or outdoor fan motor doesn’t operate.YesCompressor doesn't operate.YesYesIs there 230V AC between 3 on th

23BB Check of outdoor unitDoes compressor stop?NoYesIs there 230V AC between 3 on thecompressor contactor (52C) and N on the outdoor terminal block (

24DDHow to check mis-wiring and serial signal errorSerial signal error is indicated.(0.5-sec. ON, 0.5-sec. OFF)1. Turn OFF the power supply(indoor/out

25EE Check of outdoor thermistorMeasure resistance between CN 661 1 and 2.NoYe sReplace the thermistor.Defrost thermistor (RT61)Reconnect CN661.Turn

26MUH-GA20VB MUH-GA25VBMUH-GA35VB Outdoor deicer P.C. boardCN711Outdoor fan motor 230V ACCN721R.V. coil230V ACF61Fuse2A/250V}}CN661 1-2Defrost thermis

27DISASSEMBLY INSTRUCTIONS12MUH-GA20VB MUH-GA25VB MUH-GA35VB OUTDOOR UNITOPERATING PROCEDURE PHOTOS1. Removing the cabinet(1) Remove the screws of

283. Removing the propeller and the outdoor fan motor(1) Remove the cabinet. (Refer to 1.)(2) Remove the propeller nut.(3) Remove the propeller.NOTE :

29OPERATING PROCEDURE PHOTOS4. Removing the compressor(1) Remove the cabinet. (Refer to 1.)(2) Remove the relay panel.(3) Remove the soundproof felt.(

3PART NAMES AND FUNCTIONS2( )Air inletAir outletDrain outletPipingDrain hoseback : MUH-GA20VBback and side : MUH-GA2

30PARTS LIST (non-RoHS compliant)132235221115MUH-GA20VB MUH-GA25VB MUH-GA35VB 417 14192018136 78910 11121623This figure shows MUH-GA20VB.2413

31Part numbers that are circled are not shown in the illustration.123456789101112131415161718192021222324252627282930313233E02 904 630E02 905 630E

RoHS PARTS LIST (RoHS compliant)32142235221115417 14192018136 78910 11121623This figure shows MUH-GA20VB.24MUH-GA20VB MUH-GA25VB MUH-GA35VB 14

331234567891011121314151617181920212223242526272829E12 904 630E12 905 630E12 906 630E12 A86 630E12 904 301E12 905 301E12 899 232E12 903

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CCCopyright 2005 MITSUBISHI ELECTRIC ENGINEERING CO.,LTDDistributed in May 2007. No.OB387 REVISED EDITION-B 6Distributed in May 2006. No.OB387 REVISED

4CapacityDehumidificationOutdoor air flowPower outletRunning currentPower inputAuxiliary heaterPower factorStarting currentCompressor motor currentFan

5NOISE CRITERIA CURVES490807060504030201063 125 250 500 1000 2000 4000 8000APPROXIMATETHRESHOLD OFHEARING FORCONTINUOUSNOISENC-60NC-50NC-40NC-30NC-20N

6OUTLINES AND DIMENSIONS51069800302.5500 Bolt pitch for installation15022.3Handle550280164.599.5170.523Service panelService port285344.544400Air inAir

7WIRING DIAGRAM6SYMBOLT61TB1,TB221S452CSYMBOLMFNR61RT61SR61,SR62SYMBOLC1C65DSARF61MCNAMENAME NAMECOMPRESSOR CAPACITOROUTDOOR FAN CAPACITORSURGE ABSORB

8REFRIGERANT SYSTEM DIAGRAM7OUTDOOR UNIT(with heat insulator)Refrigerant pipe [ 9.524-way valveDefrostthermistorRT61MufflerOutdoorheatexchangerCapilla

9Length of connecting pipe : mIndoor unitGas 0.43Liquid 0.5 Piping size O.D : mmLiquid6.35Gas9.52Outdoor unitGas 0Liquid 0ModelMUH-GA20VBMUH-GA2