SERVICE MANUAL MUH-GA20VB- MUH-GA20VB- MUH-GA25VB- MUH-GA25VB- MUH-GA35VB- E1 OUTDOOR UNIT. No. OB387. Wireless type Models HFC

Transcription

1 SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS Revision A: MUH-A20VB- E2 and MUH-A25VB - have been added. Please void OB87. E2 OUTDOOR UNIT SERVICE MANUAL HFC utilized R40A. OB87 REVISED EDITION-A Wireless type Models MUH-A20VB- E MUH-A20VB- E2 MUH-A25VB- E MUH-A25VB- E2 MUH-A5VB- E Indoor unit service manual MSC-A VB Series (OB85) MSC-CA VB Series (OB9) MSC-CB VB Series (OB49) CONTENTS MUH-A20VB MUH-A25VB MUH-A5VB. TECHNICAL CHANES 2 2. PART NAMES AND FUNCTIONS. SPECIFICATION 4. NOISE CRITERIA CURVES 5 5. OUTLINES AND DIMENSIONS 6 6. WIRIN DIARAM 7 7. REFRIERANT SYSTEM DIARAM 8 8. PERFORMANCE CURVES 9 9. ACTUATOR CONTROL 9 0. SERVICE FUNCTIONS 20. TROUBLESHOOTIN DISASSEMBLY INSTRUCTIONS 27. PARTS LIST 0 4. RoHS PARTS LIST 2 NOTE: This service manual describes technical data of outdoor units. RoHS compliant products have <> mark on the spec name plate. For servicing of RoHS compliant products, refer to the RoHS Parts List.

2 Revision A: MUH-A20VB- E2 and MUH-A25VB- E2 have been added. TECHNICAL CHANES MUH-A07YV-. Indication of capacity has been changed. (BTU base kw) 2. Dimension of outdoor unit has been changed. (W780mm x H540mm x D255mm W800mm x H550mm x D285mm). Stop valve cover has been added. 4. Outdoor fan motor has been changed. (RC6V20-AB RA6V2-AD) 5. Outdoor fan motor capacitor has been changed. 6. Compressor capacitor has been changed. 7. Outdoor heat exchanger has been changed. (L-BEND FLAT) MUH-A09YV-. Indication of capacity has been changed. (BTU base kw) 2. Dimension of outdoor unit has been changed. (W780mm x H540mm x D255mm W800mm x H550mm x D285mm). Stop valve cover has been added. 4. Outdoor fan motor has been changed. (RA6V-FB RA6V-KB) 5. Outdoor fan motor capacitor has been changed. 6. Compressor capacitor has been changed. 7. Outdoor heat exchanger has been changed. (2 Row Row) MUH-A2YV- E E E. Indication of capacity has been changed. (BTU base kw) 2. Dimension of outdoor unit has been changed. (W780mm x H540mm x D255mm W800mm x H550mm x D285mm). Stop valve cover has been added. 4. Outdoor fan motor has been changed. (RA6V-FB RA6V-KB) 5. Outdoor fan motor capacitor has been changed. 6. Compressor capacitor has been changed. 7. Size of stop valve (gas) has been changed.([2.7 [9.52) 8. Outdoor heat exchanger has been changed. (2 Row Row) MUH-A20VB-. Compressor has been changed. (BN092VHST KN092VDMHC) 2. Compressor capacitor has been changed.. Capillary tube has been changed. 4. Refrigerant filling capacity has been changed. 5. Deicer P.C. board has been changed. MUH-A25VB- E E MUH-A20VB- MUH-A25VB- MUH-A5VB- MUH-A20VB- MUH-A25VB-. Compressor has been changed. (RN04VHSHT KN04VTMHC) 2. Compressor capacitor has been changed.. Capillary tube has been changed. 4. Refrigerant filling capacity has been changed. 5. Deicer P.C. board has been changed. E E E E2 E2 2

3 2 PART NAMES AND FUNCTIONS OUTDOOR UNIT MUH-A20VB MUH-A25VB MUH-A5VB Air inlet back : MUH-A20VB ( ) back and side : MUH-A25VB Piping Drain hose Air outlet MUH-A5VB ACCESSORIES MUH-A20VB MUH-A25VB MUH-A5VB <Outdoor unit: MUH type> Drain socket Drain outlet SPECIFICATION Capacity Electrical data Compressor Fan motor Special remarks Outdoor model Outdoor unit power supply Function Capacity Dehumidification Outdoor air flow Power outlet Running current Power input Auxiliary heater Power factor Starting current Compressor motor current Fan motor current kw R/h K /h A A W A(kW) % A A A Coefficient of performance (C.O.P) Model Output W Winding " resistance (at 20:) Model Winding " resistance (at 20:) Dimensions WOHOD mm Weight kg Sound level db Fan speed rpm Fan speed regulator Refrigerant filling kg capacity (R40A) Refrigeration oil (Model) cc Cooling MUH-A20VB - E Single phase 20V,50Hz, RN092VHSHT 600 C-R.87 C-S 6.4 RA6V2-AD WHT-BLK 66 BLK-RED o550o (NEO22) Heating Cooling MUH-A20VB - E2 Single phase 20V,50Hz, KN092VDMHC 650 C-R.62 C-S 5.40 RA6V2-AD WHT-BLK 66 BLK-RED o550o (NEO22) Heating NOTE: Test conditions are based on ISO 55. Cooling : Indoor DB27 C WB9 C Heating : Indoor DB20 C Outdoor DB5 C WB24 C Outdoor DB 7 C/WB 6 C Indoor-Outdoor piping length : 5m

4 Outdoor model MUH-A25VB - E MUH-A25VB - E2 MUH-A5VB - E Capacity Electrical data Compressor Fan motor Special remarks Outdoor unit power supply Function Capacity Dehumidification Outdoor air flow Power outlet Running current Power input Auxiliary heater Power factor Starting current Compressor motor current Fan motor current kw R/h K /h A A W A(kW) % A A A Coefficient of performance (C.O.P) Model Output W Winding " resistance (at 20:) Model Winding " resistance (at 20:) Dimensions WOHOD mm Weight kg Sound level db Fan speed rpm Fan speed regulator Refrigerant filling kg capacity (R40A) Refrigeration oil (Model) cc Cooling Single phase 20V,50Hz,902 0 Heating RN04VHSHT 700 C-R.40 C-S 4.56 RA6V-KB WHT-BLK 25 BLK-RED o550o (NEO22) Cooling Single phase 20V,50Hz,902 0 Heating KN04VTMHC 700 C-R.62 C-S 5.40 RA6V-KB WHT-BLK 25 BLK-RED o550o (NEO22) Cooling ,050 Single phase 20V,50Hz, RN5VHSHT 900 C-R 2.79 C-S.6 RA6V-KB WHT-BLK 25 BLK-RED o550o (NEO22) Heating NOTE: Test conditions are based on ISO 55. Cooling : Indoor DB27 C WB9 C Heating : Indoor DB20 C Outdoor DB5 C WB24 C Outdoor DB 7 C/WB 6 C Indoor-Outdoor piping length : 5m 4

5 4 NOISE CRITERIA CURVES MUH-A20VB FUNCTION COOLIN HEATIN SPL(dB(A)) 47 LINE MUH-A25VB MUH-A5VB FUNCTION COOLIN HEATIN SPL(dB(A)) 49 LINE 90 Test conditions, Cooling :DB5: WB24: Heating :DB 7: WB 6: 90 Test conditions, Cooling :DB5: WB24: Heating :DB 7: WB 6: OCTAVE BAND SOUND PRESSURE LEVEL, db re MICRO BAR NC-70 NC-60 NC-50 NC-40 NC-0 OCTAVE BAND SOUND PRESSURE LEVEL, db re MICRO BAR NC-70 NC-60 NC-50 NC-40 NC APPROXIMATE THRESHOLD OF HEARIN FOR CONTINUOUS NOISE NC APPROXIMATE THRESHOLD OF HEARIN FOR CONTINUOUS NOISE NC-20 BAND CENTER FREQUENCIES, Hz BAND CENTER FREQUENCIES, Hz OUTDOOR UNIT m MICROPHONE 5

6 5 OUTLINES AND DIMENSIONS MUH-A20VB MUH-A25VB MUH-A5VB OUTDOOR UNIT 400 Air in Drain hole [42 REQUIRED SPACE 00mm or more Basically open 00mm or more without any obstruction in front and on both sides of the unit. 00mm or more Unit: mm Air in (MUH-A25 /A5VB) Bolt pitch for installation 04~25 200mm or more 50mm or more holes 0X2 Air out Service panel Open two sides of left, right, or rear side. Handle Liquid refrigerant pipe joint Refrigerant pipe (flared) [ Service port as refrigerant pipe joint Refrigerant pipe (flared) [ Bolt pitch for installation 800 6

7 6 WIRIN DIARAM MUH-A20VB MUH-A25VB MUH-A5VB OUTDOOR UNIT TO INDOOR UNIT POWER SUPPLY ~/N 20V 50Hz CONNECTIN 2V TB2 N CIRCUIT BREAKER TB L N PE RN/YLW RED BLK BRN BLU DSAR BLU BRN RT6 F6 2 CN70 TAB20 CN66 T6 4 SR62 NR6 52C 2S4 CN72 SR6 C CN7 C65 2 RED BLK S WHT BLK RED WHT C MC MF R SYMBOL NAME SYMBOL NAME SYMBOL NAME C COMPRESSOR CAPACITOR OUTDOOR FAN MOTOR T6 TRANSFORMER MF C65 OUTDOOR FAN CAPACITOR (INNER FUSE) TB,TB2 TERMINAL BLOCK DSAR F6 SURE ABSORBER FUSE(T2AL250V) NR6 RT6 VARISTOR DEFROST THERMISTOR 2S4 52C R.V. COIL COMPRESSOR CONTACTOR MC COMPRESSOR(INNER PROTECTOR) SR6,SR62 SOLID STATE RELAY NOTE:. About the indoor side electric wiring refer to the indoor unit electric wiring diagram for servicing. 2. Use copper conductors only. (For field wiring). Symbols below indicate. /: Terminal block, : Connector 7

8 7 REFRIERANT SYSTEM DIARAM MUH-A20VB MUH-A25VB MUH-A5VB OUTDOOR UNIT Refrigerant pipe [ 9.52 (with heat insulator) 4-way valve Unit:mm Flared connection Stop valve (with service port) Muffler Defrost thermistor RT6 Outdoor heat exchanger Flared connection Refrigerant pipe [6.5 (with heat insulator) Compressor Capillary tube [.0x[.4x700 (MUH-A20VB - E ) [.0x[.4x900 (MUH-A20VB - E2 ) [.0x[.4x000(MUH-A25VB - E ) [.0x[.6x500(MUH-A25VB - E2 ) [.0x[.4x500 (MUH-A5VB) Check valve Strainer #00 Stop valve R.V. coil heating ON cooling OFF Capillary tube [.0x[.4x500 (MUH-A20VB - E ) [.0x[.4x00 (MUH-A20VB - E2, MUH-A5VB) [.0x[.4x600 (MUH-A25VB - E ) [.0x[.6x750 (MUH-A25VB - E2 ) Refrigerant flow in cooling Refrigerant flow in heating 8

9 MAX. REFRIERANT PIPIN LENTH Model Refrigerant piping : m Max. length A Max. height B Piping size O.D : mm as Liquid Length of connecting pipe : m Indoor unit Outdoor unit MUH-A20VB MUH-A25VB MUH-A5VB as 0.4 Liquid 0.5 as 0 Liquid 0 MAX. HEIHT DIFFERENCE Indoor unit Max. height B Refrigerant Piping Max. length A Outdoor unit ADDITIONAL REFRIERANT CHARE(R40A : g) Model MUH-A20VB - MUH-A20VB - MUH-A25VB - MUH-A25VB - MUH-A5VB - E E2 E E2 E Outdoor unit precharged m 0 Refrigerant piping length (one way) 0m 5m 20m 25m Calculation : Xg = 20g/m x (A-7)m 8 PERFORMANCE CURVES MUH-A20VB MUH-A25VB MUH-A5VB The standard data contained in these 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 provided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve. () UARANTEED VOLTAE 98~264V (2) AIR FLOW Air flow should be set at MAX. () MAIN READINS () Indoor intake air wet-bulb temperature : CWB (2) Indoor outlet air wet-bulb temperature : CWB () 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/dry-bulb temperature difference on the left side of the chart on page 0 shows the difference between the indoor intake air wet/dry-bulb temperature and the indoor outlet air wet/dry-bulb temperature for your reference at service. 9 } } Cooling Heating

10 How to measure the indoor air wet-bulb/dry-bulb temperature difference. 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.. Check that the air filter is cleaned. 4. Open windows and doors of room. 5. Press the EMERENCY OPERATION switch once(twice) to start the EMERENCY COOL (HEAT) MODE. 6. When system stabilizes after more than 5 minutes, measure temperature and take an average temperature minutes later, measure temperature again and check that the temperature does not change. INDOOR UNIT OUTDOOR UNIT Wet-and dry-bulb thermometers Wet-and dry-bulb thermometers 8-.CAPACITY AND THE INPUT CURVES MSC-A20VB MUH-A20VB MSC-A25VB MUH-A25VB MSC-A5VB MUH-A5VB MSC-A20VB MUH-A20VB MSC-A25VB MUH-A25VB MSC-A5VB MUH-A5VB NOTE:The above curves are for the heating operation without any frost. 0

11 8-2.OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT COOL operation Both indoor and outdoor unit are under the same temperature/humidity condition. Dry-bulb temperature Relative humidity(%) ➁ Air flow should be set at MAX. The unit of pressure has been changed to MPa on the international system of units(si unit system). The conversion factor is : (MPa[auge]) =0.2(kgf/f[auge] ) (kgf/f[auge])(mpa[auge]). Outdoor low pressure MUH-A20VB 20V Outdoor unit current (A) 4 2 MUH-A20VB 20V (kgf/f[auge])(mpa[auge]). Outdoor low pressure (:) (%) Ambient temperature( C) Ambient humidity(%) MUH-A25VB 20V Outdoor unit current (A) (%) Ambient temperature( C) Ambient humidity(%) 4 2 MUH-A25VB 20V 5(:) (%) Ambient temperature( C) Ambient humidity(%) 5(:) (%) Ambient temperature( C) Ambient humidity(%) 5(:) (kgf/f[auge])(mpa[auge]) MUH-A5VB MUH-A5VB Outdoor low pressure. 20V Outdoor unit current (A) 6 20V (%) Ambient temperature( C) Ambient humidity(%) 5(:) (%) Ambient temperature( C) Ambient humidity(%) 5(:)

12 HEAT operation Condition indoor:dry bulb temperature 20.0 C Wet bulb temperature 4.5 C Outdoor:Dry bulb temperature 7,5,20 C Wet bulb temperature 6,2,4.5 C 5 MUH-A20VB 5 MUH-A25VB Outdoor unit current (A) Outdoor unit current (A) 4 20V (:) Ambient temperature( C) MUH-A5VB 6 20V 5 4 Outdoor unit current (A) 20V (:) Ambient temperature( C) (:) Ambient temperature( C) 2

13 PERFORMANCE DATA COOL operation (20V) MSC-A20VB : MUH-A20VB CAPACITY : 2.(kW) SHF : 0.74 INPUT : 75(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT NOTE Q :Total capacity (kw) SHF :Sensible heat factor DB :Dry-bulb temperature SHC :Sensible heat capacity (kw) INPUT :Total power input (W) WB :Wet-bulb temperature

14 PERFORMANCE DATA COOL operation (20V) MSC-A20VB : MUH-A20VB CAPACITY : 2.(kW) SHF : 0.74 INPUT : 75(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT NOTE Q :Total capacity (kw) SHF :Sensible heat factor DB :Dry-bulb temperature SHC :Sensible heat capacity (kw) INPUT :Total power input (W) WB :Wet-bulb temperature 4

15 PERFORMANCE DATA COOL operation (20V) MSC-A25VB : MUH-A25VB CAPACITY : 2.65(kW) SHF : 0.70 INDOOR DB(:) INDOOR WB(:) INPUT : 820(W) OUTDOOR DB(:) Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT 0 SHC SHF INPUT NOTE Q :Total capacity (kw) SHF :Sensible heat factor DB :Dry-bulb temperature SHC :Sensible heat capacity (kw) INPUT :Total power input (W) WB :Wet-bulb temperature 5 Q

16 PERFORMANCE DATA COOL operation (20V) MSC-A25VB : MUH-A25VB CAPACITY : 2.65(kW) SHF : 0.70 INDOOR DB(:) INDOOR WB(:) INPUT : 820(W) OUTDOOR DB(:) Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT NOTE Q :Total capacity (kw) SHF :Sensible heat factor DB :Dry-bulb temperature SHC :Sensible heat capacity (kw) INPUT :Total power input (W) WB :Wet-bulb temperature 6

17 PERFORMANCE DATA COOL operation (20V) MSC-A5VB : MUH-A5VB CAPACITY :.5(kW) SHF : 0.66 INPUT : 090(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT NOTE Q :Total capacity (kw) SHF :Sensible heat factor DB :Dry-bulb temperature SHC :Sensible heat capacity (kw) INPUT :Total power input (W) WB :Wet-bulb temperature 7

18 PERFORMANCE DATA COOL operation (20V) MSC-A5VB : MUH-A5VB CAPACITY :.5(kW) SHF : 0.66 INPUT : 090(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT NOTE Q :Total capacity (kw) SHF :Sensible heat factor DB :Dry-bulb temperature SHC :Sensible heat capacity (kw) INPUT :Total power input (W) WB :Wet-bulb temperature 8

19 PERFORMANCE DATA HEAT operation (20V) MSC-A20VB : MUH-A20VB CAPACITY : 2.5(kW) INPUT : 690(W) OUTDOOR WB(:) INDOOR DB(:) Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT MSC-A25VB : MUH-A25VB CAPACITY :.0(kW) INPUT : 820(W) OUTDOOR WB(:) INDOOR DB(:) Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT MSC-A5VB : MUH-A5VB CAPACITY :.7(kW) INPUT : 020(W) OUTDOOR WB(:) INDOOR DB(:) Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT NOTE Q:Total capacity (kw) INPUT:Total power input (W) DB:Dry-bulb temperature WB:Wet-bulb temperature ACTUATOR CONTROL R.V. coil control Heating ON Cooling OFF Dry OFF NOTE: The 4-way valve reverses for 5 seconds right before start-up of the compressor. (COOL / DRY) (HEAT) 5 seconds 5 seconds Compressor R.V. coil Outdoor fan ON OFF ON OFF ON OFF ON OFF ON OFF ON OFF 9

20 0 SERVICE FUNCTIONS MUH-A20VB MUH-A25VB MUH-A5VB 0-. COMPULSORY DEFROSTIN MODE FOR SERVICE By short circuit of the connector JPDS and JPS on the outdoor deicer P.C. board, defrosting mode can be accomplished regardless of the defrost interval restriction. (Refer to -5.) Defrost thermistor RT6 must read below - C CHANE IN DEFROST SETTIN <JRF> When the JRF wire of the deicer P.C. board is cut, the defrost interval time will be changed. <JR> When the JR wire of the deicer P.C. board is cut, the defrost temperature will be changed.(refer to -5.) MODEL MUH-A20VB MUH-A25VB MUH-A5VB Jumper wire JRF JR Change point Defrost interval time changes from 40 minutes to 5 minutes. Defrost start temperature changes from -: to 0:. TROUBLESHOOTIN MUH-A20VB MUH-A25VB MUH-A5VB -. Cautions on troubleshooting. Before troubleshooting, check the following: ) Check the power supply voltage. 2) Check the indoor/outdoor connecting wire for mis-wiring. 2. Take care the following during servicing. ) Before servicing the air conditioner, be sure to turn off the main unit first with the remote controller, and then after confirming the horizontal vane is closed, turn off the breaker and/or disconnect the power plug. 2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic control P.C. board. ) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the components. 4) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires. Lead wiring Housing point. Troubleshooting procedure ) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality. To make sure, check how many times the abnormality indication is flashing on and off before starting service work. 2) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the components for bursting and discoloration. ) When troubleshooting, refer to -2. Instruction of troubleshooting. 20

21 -2. Instruction of troubleshooting MUH-A20VB MUH-A25VB MUH-A5VB Start Indoor unit operates. Outdoor unit doesn't operate. Indoor unit operates. Outdoor unit doesn't operate normally. Indoor unit doesn't receive the signal from remote controller. OPERATION INDICATOR lamp on the indoor unit is flashing on and off. Outdoor unit operates in only Test Run operation. W Outdoor unit doesn't operate even in Test Run operation. W Outdoor unit doesn't stop even if indoor unit stops. Unit doesn't operate normal operation in COOL or HEAT mode. Indoor unit operates, when the EMERENCY OPERATION switch is pressed. Indoor unit doesn't operate, when the EMERENCY OPERATION switch is pressed. Check room temperature thermistor. Refer to -5. "Test point diagram and voltage". Refer to -4. A "Check of outdoor unit". Refer to -4. B "Check of outdoor unit". Refer to -4. C "Check of R.V. coil". Refer to "Check of remote controller and receiver P.C. board".. Check indoor / outdoor connecting wire. 2. Refer to "Check of indoor electronic control P.C. board". Refer to indoor unit service manual. W "Test run operation" means the operation within 0 minutes after EMERENCY OPERATION switch is pressed. Flash on and off at 0.5-second intervals Cause: Indoor/Outdoor unit Mis-wiring or trouble of serial signal 2-time flash Cause: Indoor unit Trouble of room temperature/ indoor coil thermistor -time flash Cause: Indoor unit Trouble of indoor fan motor 4-time flash Cause: Indoor unit Trouble of indoor unit control system 6-time flash Cause: Outdoor unit Trouble of thermistor in outdoor unit 7-time flash Cause: Outdoor unit Trouble of outdoor control system Refer to -4. D "How to check mis-wiring and serial signal error (When outdoor unit doesn't work)". W Check room temperature thermistor and indoor coil thermistor. Refer to -5. "Test point diagram and voltage". Refer to "Check of indoor fan motor". Replace the indoor electronic control P.C. board. Refer to -4. E"Check of outdoor thermistor". Replace the deicer P.C. board. W.<The case of the trouble of the serial signal> When the power is turned off and then turned on again, the indication shows the trouble of mis-wiring. 2

22 -. Trouble criterion of main parts MUH-A20VB MUH-A25VB MUH-A5VB Part name Defrost thermistor (RT6) Check method and criterion Measure the resistance with a tester. (Part temperature 0 C ~ 40 C) Refer to 0-5. Test point diagram and voltage, Outdoor deicer P.C. board, the chart of thermistor. Figure Compressor (MC) INNER PROTECTOR MUH- A20/A25VB- E 50i 5 C OPEN 90i0 C CLOSE MUH- A20/A25VB- E2 60i 5 C OPEN 90i0 C CLOSE MUH-A5VB 55i 5 C OPEN 90i0 C CLOSE C-R C-S Measure the resistance between the terminals with a tester. (Coil wiring temperature 0 C ~ 40 C) MUH-A20VB- E.4~4.8Ω 5.4~6.6Ω MUH-A20VB- E2.9~.9Ω 4.76~5.8Ω rmal MUH-A25VB- E 2.99~.67Ω 4.02~4.92Ω MUH-A25VB- E2.9~.9Ω 4.76~5.8Ω MUH-A5VB 2.46~.0Ω 2.96~.6Ω WHT C P AUX. MAIN S R BLK RED Outdoor fan motor (MF) INNER FUSE 45i 2 C CUT OFF Measure the resistance between the terminals with a tester. (Coil wiring temperature 0 C ~ 40 C) Color of lead wire WHT-BLK BLK-RED MUH-A20VB 2 ~ 96 Ω 24 ~ 296 Ω rmal MUH-A25/A5VB 89 ~ 2 Ω 270 ~ 2 Ω MAIN AUX. FUSE BLK REDWHT -4. Troubleshooting flow Compressor and/or outdoor fan motor doesn t operate. P INNER PROTECTOR A Check of outdoor unit Start Is the switch SW2-2 on the indoor electronic control P.C. board set to MUH type? Change the switch SW-2-2 on the indoor electronic control P.C. board to MUH type. Operate the unit in COOL or HEAT mode by pressing the EMERENCY OPERATION switch. -minute time delay works. Test run operation operates for 0 minutes. Compressor doesn't operate. Is there 5V DC between J205 + J0 on the deicer P.C. board? Is there 20V AC between on the compressor contactor (52C) and N on the outdoor terminal block (TB)? Check the compressor and compressor capacitor, and rectify the connecting wire. Replace the deicer P.C. board. Is there 20V AC between 4 on the compressor contactor (52C) and TAB20 on the deicer P.C. board? Replace the deicer P.C. board. Rectify the indoor and outdoor connecting wire. Is there 20V AC between L N on the outdoor terminal block (TB)? Rectify the connecting wire. Outdoor fan motor doesn't operate. Rectify the indoor and outdoor connecting wire. Is there 5V DC between J205 + J0 on the deicer P.C. board? Check the outdoor fan motor and rectify the connecting wire. Is there 20V AC between 4 on the compressor contactor (52C) and TAB 20 on the deicer P.C. board? Replace the deicer P.C. board. 22 Is there 20V AC between L N on the outdoor terminal block (TB)? Rectify the connecting wire.

23 Compressor and/or outdoor fan motor doesn t stop. B Check of outdoor unit Start Turn OFF the power supply. After minute, turn ON power supply again. Does compressor stop? OK Is there 20V AC between on the compressor contactor (52C) and N on the outdoor terminal block (TB)? Replace the deicer P.C. board. Rectify the connecting wire. Does outdoor fan motor stop? Replace the deicer P.C. board. OK Unit operates COOL mode even if it is set to HEAT mode. w First, measure the resistance of R.V. coil to confirm it is disconnected or is not short-circuit. C Check of R.V. coil Turn ON the power supply and operate the indoor unit in HEAT mode by pressing the EMERENCY OPERATION switch. After minutes, does the unit operate in COOL mode? Is there 20V AC between CN72 2 on the deicer P.C. board? OK Replace the deicer P.C. board Replace the R.V. coil. Unit operates HEAT mode even if it is set to COOL mode. w First, measure the resistance of R.V. coil to confirm it is disconnected or is not short-circuit. C Check of R.V. coil Turn ON the power supply and operate the indoor unit in COOL mode by pressing the EMERENCY OPERATION switch. After minutes, does the unit operate in HEAT mode? Ok Is there 20V AC between CN72 2 on the deicer P.C. board? Replace the R.V. coil. Replace the deicer P.C. board. 2

24 When OPERATION INDICATOR lamp flashes 0.5-second intervals. Outdoor unit does not operate. D How to check mis-wiring and serial signal error Start Turn OFF the power supply(indoor/outdoor unit). w Set the switch(sw2-2) on indoor electronic control P.C. board to MU or MUX type, when the outdoor unit is MU or MUX type. If the setting is MUH or MXZ type, the unit does not work. w 2 Short circuit of JP and JPS on the indoor electronic control P.C. board enables self-check to be displayed in seconds. Is the outdoor unit "MUH" type? Set the switch(sw2-2) on the indoor electronic control P.C. board to MU or MUX type. w Make them sure. Turn ON the power supply(indoor/outdoor unit). Press once EMERENCY OPERATION switch. min. later, check the self-check result displayed on OPERATION INDICATOR lamp on indoor unit. w 2 Is this mis-wiring, poor contact, or disconnection of wire? Serial signal error is indicated. (0.5-sec. ON, 0.5-sec. OFF) Does the unit operate? Refer to the "Instruction of troubleshooting." OK. Turn OFF the power supply(indoor/outdoor unit) and disconnect indoor and outdoor connecting wire on indoor side. 2. Short-circuit between indoor terminal block N and.. Turn ON the power supply(indoor unit) and press once EMERENCY OPERATION switch. Is there 20V DC between both ends of R2 on indoor electronic control P.C. board? ( By tester, the stylus is between 0 ~ 20V. ) Turn OFF the power supply(indoor unit). Connect ON indoor and outdoor connecting wire. Replace the indoor electronic control P.C. board. Turn ON the power supply(outdoor unit). Is there 20V AC between outdoor terminal block L-N (TB)? Check the outdoor power supply, power supply cord and connection. Is there 5V DC between J205 + J0 - on the deicer P.C. board? Turn ON the power supply(indoor unit). Replace the deicer P.C. board. During EMERENCY OPERATION, is there 0V DC between both ends of R60? (By tester, the stylus is between 5 ~0V) Make the wiring between CN70 on the deicer P.C. board and outdoor terminal block correct. Replace the deicer P.C. board. Refer to indoor unit service manual. 24

25 When OPERATION INDICATOR lamp flashes 6-time. Thermistors in the outdoor unit are abnormal. E Check of outdoor thermistor Start Turn OFF the power supply. Defrost thermistor (RT6) Measure resistance between CN 66 and 2. Is the resistance of thermistor normal? Reconnect CN66. Turn ON the power supply and press the EMERENCY OPERATION switch. Replace the deicer P.C. board. Does the unit operate 0 minutes or more? Replace the thermistor. OK Defective contact of the connector is considered. 25

26 20V AC} -5. Test point diagram and voltage MUH-A20VB MUH-A25VB MUH-A5VB Outdoor deicer P.C. board CN7 Outdoor fan motor 20V AC } CN72 R.V. coil 20V AC } Power supply input NR6 Varistor F6 Fuse 2A/250V 5V DC J205 J } CN66-2 Defrost thermistor RT R60 } 5~0VDC Defrost interval time short pin (JPDS, JPS) (Refer to 0-.) } Jumper wire for change in defrost setting (JRF,JR) (Refer to 0-2.) 2V DC J204 J

27 2 DISASSEMBLY INSTRUCTIONS <"Terminal with locking mechanism" Detaching points> The terminal which has the locking mechanism can be detached as shown below. There are two types ( Refer to () and (2)) of the terminal with locking mechanism. The terminal without locking mechanism can be detached by pulling it out. Check the shape of the terminal before detaching. () Slide the sleeve and check if there is a locking lever or not. (2) The terminal with this connector has the locking mechanism. Sleeve Locking lever Slide the sleeve. 2Pull the terminal while pushing the locking lever. Connector Hold the sleeve, and pull out the terminal slowly. MUH-A20VB MUH-A25VB MUH-A5VB OUTDOOR UNIT OPERATIN PROCEDURE. Removing the cabinet () Remove the screws of the top panel. (2) Remove the screw of the service panel. () Remove the screws of the cabinet. (4) Remove the screws of the front panel and motor support. (5) Remove the service panel, and remove the screw from the insides. (6) Remove the top panel. (7) Remove the cabinet. Photo PHOTOS Screw of the front panel and motor support Photo Screws of the top panel Photo 2 MUH-A20VB Screws of the cabinet Screw of the Service panel Screws of the top panel Screw of the cabinet Screws of the cabinet 27

28 OPERATIN PROCEDURE PHOTOS 2. Removing the deicer P.C. board () Remove the service panel and the cabinet. (2) Disconnect all the connectors and the terminals on the deicer P.C. board. () Remove the deicer P.C. board. Photo 4 Screw of the relay panel Deicer P.C. board Relay panel Terminal block Surge absorber. Removing the propeller and the outdoor fan motor () Remove the cabinet. (Refer to.) (2) Remove the propeller nut. () Remove the propeller. NOTE : Loose the propeller in the rotating direction for removal. When attaching the propeller, align the mark on the propeller and the motor shaft cut section. Set the propeller in position by using the cut on the shaft and the mark on the propeller. (4) Disconnect the outdoor fan motor connector. (5) Remove screws fixing the fan motor. (6) Remove the outdoor fan motor. Photo 5 MUH-A20VB Propeller Screw of the outdoor fan motor Terminal cover Screws of the relay panel Propeller nut Sound proof felt R.V. coil 28

29 OPERATIN PROCEDURE PHOTOS 4. Removing the compressor () Remove the cabinet. (Refer to.) (2) Remove the relay panel. () Remove the soundproof felt. (4) Remove the terminal cover on the compressor. (5) Disconnect lead wires from the glass terminal of the compressor. (6) Recover gas from the refrigerant circuit. NOTE : Recover gas from the pipes until the pressure gauge shows 0 kg/cm 2 (0 MPa). (7) Disconnect the welded part of the discharge pipe. (8) Disconnect the welded part of the suction pipe. (9) Remove nuts fixing the compressor. (0) Remove the compressor. Photo 6 lass terminal Discharge pipe 4-Way valve Suction pipe Compressor Compressor nuts 29

30 PARTS LIST (non-rohs compliant) MUH-A20VB MUH-A25VB MUH-A5VB -. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS This figure shows MUH-A20VB. 0

31 PARTS LIST (non-rohs compliant) MUH-A20VB MUH-A25VB MUH-A5VB -. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS Part numbers that are circled are not shown in the illustration. Symbol Q'ty/unit. in Wiring Part. Part name MUH-A20VB MUH-A25VB MUH-A5VB Remarks Diagram - E - E - E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E OUTDOOR HEAT EXCHANER OUTDOOR HEAT EXCHANER OUTDOOR HEAT EXCHANER OUTDOOR FAN MOTOR OUTDOOR FAN MOTOR CABINET CABINET RILLE PROPELLER BASE BASE COMPRESSOR RUBBER SET COMPRESSOR COMPRESSOR COMPRESSOR STOP VALVE (AS) STOP VALVE (LIQUID) BACK PANEL BACK PANEL SERVICE PANEL DRAIN SOCKET TERMINAL BLOCK TERMINAL BLOCK 4-WAY VALVE 4-WAY VALVE COMPRESSOR CAPACITOR COMPRESSOR CAPACITOR COMPRESSOR CAPACITOR SURE ABSORBER DEICER P.C. BOARD DEICER P.C. BOARD DEFROST THERMISTOR CONDENSER NET CONDENSER NET TOP PANEL SEPARATOR MOTOR SUPPORT R. V. COIL R. V. COIL FUSE VARISTOR CHECK VALVE CAPILLARY TUBE CAPILLARY TUBE CAPILLARY TUBE CAPILLARY TUBE CAPILLARY TUBE MF MF MC MC MC TB TB2 C C C DSAR RT6 2S4 2S4 F6 NR6 RA6V2- RA6V- RUBBERS/SET RN092VHSHT RN04VHSHT RN5VHSHT [9.52 [6.5 P 2P 20+ /440V AC 25+ /440V AC 0+ /440V AC T2AL250V [.0O[.4O700 [.0O[.4O500 [.0O[.4O000 [.0O[.4O600 [.0O[.4O00

32 4 RoHS PARTS LIST (RoHS compliant) MUH-A20VB MUH-A25VB MUH-A5VB 4-. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS This figure shows MUH-A20VB. 2