Service manual

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SERVICE MANUAL

CONTENTS

1. TECHNICAL CHANGES ··································· 3

2. PART NAMES AND FUNCTIONS ····················· 4

3. SPECIFICATION ················································ 5

4. NOISE CRITERIA CURVES ······························ 8

5. OUTLINES AND DIMENSIONS ························ 9

6. WIRING DIAGRAM ·········································· 10

7. REFRIGERANT SYSTEM DIAGRAM ············· 13

8. PERFORMANCE CURVES ····························· 15

9. ACTUATOR CONTROL ··································· 29

10. SERVICE FUNCTIONS ···································· 30

11. TROUBLESHOOTING ····································· 31

12. DISASSEMBLY INSTRUCTIONS ···················· 55

Models

SPLIT-TYPE AIR CONDITIONERS

MUZ-FD25VA -

MUZ-FD25VAH -

MUZ-FD35VA -

MUZ-FD35VAH -

MUZ-FD50VA -

NOTE:

RoHS compliant products have <G> mark on the spec name plate.

HFC

utilized

R410A

No. OBH489

REVISED EDITION-C

OUTDOOR UNIT

Indoor unit service manual

MSZ-FD•VA Series (OBH488)

PARTS CATALOG (OBB489)

Please void OBH489 REVISED EDITION-B.

MUZ-FD25/35

Revision C:

• Errors in TROUBLESHOOTING have been

corrected.

Summary of content (62 pages)

PAGE 1
Revision C: • Errors in TROUBLESHOOTING have been corrected. Please void OBH489 REVISED EDITION-B. SPLIT-TYPE AIR CONDITIONERS OUTDOOR UNIT SERVICE MANUAL HFC utilized No. OBH489 REVISED EDITION-C R410A Models MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH MUZ-FD50VA - E1 E1 , E2 E1 E1 E1 Indoor unit service manual MSZ-FD•VA Series (OBH488) CONTENTS MUZ-FD25/35 1. TECHNICAL CHANGES ··································· 3 2. PART NAMES AND FUNCTIONS ····················· 4 3.
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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. Revision A: • MUZ-FD25VAH- E2 has been added.
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1 TECHNICAL CHANGES MUZ-FD25VA - E1 MUZ-FD25VAH - E1 MUZ-FD35VA - E1 MUZ-FD35VAH - E1 MUZ-FD50VA - E1 1. New model MUZ-FD25VAH - E1 → MUZ-FD25VAH - E2 1.
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2 PART NAMES AND FUNCTIONS MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH Air inlet (back and side) Piping Drain hose Air outlet Drain outlet MUZ-FD50VA Air inlet (back and side) Piping Drain hose Air outlet Drain outlet ACCESSORIES Drain socket Drain cap MUZ-FD25/35VA 1 - MUZ-FD50VA 1 2 4
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3 SPECIFICATION Outdoor model MUZ-FD25VA Power supply Cooling Capacity Rated frequency (Min.-Max.
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MUZ-FD50VA Power supply Cooling Capacity kW Rated frequency (Min.-Max.
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Specifications and rated conditions of main electric parts Item Current transformer Smoothing capacitor Diode module Fuse Defrost heater Intelligent power module Expansion valve coil Reactor Current-detecting resistor Current-limiting PTC thermistor Terminal block Relay R.V.
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4 NOISE CRITERIA CURVES MUZ-FD35VA MUZ-FD35VAH MUZ-FD25VA MUZ-FD25VAH SPL(dB(A)) FUNCTION COOLING 46 HEATING 90 80 70 NC-70 60 NC-60 50 NC-50 40 NC-40 30 NC-30 20 NC-20 NC-10 10 FUNCTION SPL(dB(A)) COOLING 47 HEATING 50 63 125 250 500 1000 2000 4000 8000 BAND CENTER FREQUENCIES, Hz 80 70 NC-70 60 NC-60 50 NC-50 40 NC-40 30 NC-30 20 10 63 125 250 500 1000 OCTAVE BAND SOUND PRESSURE LEVEL, 0dB re 0.
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5 OUTLINES AND DIMENSIONS MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH Unit: mm REQUIRED SPACE Drain hole ø42 (25/35VA) Drain hole ø33 (25/35VAH) 100 re r mo mo m 0 10 mm or m Bolt pitch for installation 304-325 ore 44 Air in Open two sides of left, right, or rear side. 17.5 40 2 holes 10 × 21 Air out 22.3 350 mm or m ore re r mo mo m 200 Service panel 23 Liquid refrigerant pipe joint Refrigerant pipe (flared) ø6.35 150 69 Gas refrigerant pipe joint Refrigerant pipe (flared) ø9.
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6 WIRING DIAGRAM MUZ-FD25VA MUZ-FD35VA 10
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MUZ-FD25VAH MUZ-FD35VAH 11
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MUZ-FD50VA 12
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7 REFRIGERANT SYSTEM DIAGRAM MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH Refrigerant pipe ø9.52 (with heat insulator) Unit: mm 4-way valve Muffler Stop valve (with service port) Discharge temperature thermistor RT62 Flared connection Outdoor heat exchanger Muffler Outdoor heat exchanger temperature thermistor RT68 Ambient temperature thermistor RT65 Compressor Defrost thermistor RT61 Capillary tube ø3.0×ø1.8×600(×2) Flared connection Refrigerant pipe ø6.
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MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE Refrigerant piping: m Piping size O.D: mm Max. Length A Max. Height difference B Gas MUZ-FD25 MUZ-FD35 20 12 9.52 MUZ-FD50 30 15 12.7 Liquid 6.35 Indoor unit Max. Height difference B Max.
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8 PERFORMANCE CURVES MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH MUZ-FD50VA The standard 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.
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7.0 7.7 4.6 6.3 7.0 4.1 5.7 6.3 3.7 5.1 5.6 3.3 4.5 4.9 1.3 Input correction factors 5.1 1.2 22 20 18 24 26 1.1 1.0 0.9 Indoor intake air Wet-bulb temperature(°C) 0.8 -10 MUZ-FD50VA MUZ-FD35VAH MUZ-FD35VA 8.5 MUZ-FD25VAH 7.7 MUZ-FD25VA Indoor air Wet-bulb temperature difference (°C) Total input (Cooling : at Rated frequency) 5.5 -5 0 5 10 15 20 25 30 35 40 45 Outdoor intake air Dry-bulb temperature (°C) 19.3 23.7 1.2 14.6 17.7 21.7 13.3 16.1 19.7 12.0 14.
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8-2. CAPACITY AND INPUT CORRECTION BY OPERATIONAL FREQUENCY OF COMPRESSOR MUZ-FD25VA MUZ-FD25VAH 1.5 1.0 0.5 4 Input correction factors 0.5 Capacity correction factors 1.0 2.0 Correction of Heating input Correction of Heating capacity 2.0 2.5 Input correction factors Capacity correction factors Correction of Cooling input Correction of Cooling capacity 1.5 1.5 1.0 0.5 0.0 0.0 0.
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8-3. TEST RUN OPERATION (How to operate fixed-frequency operation) 1. Press EMERGENCY OPERATION switch to start COOL or HEAT mode (COOL: Press once, HEAT: Press twice). 2. Test run operation starts and continues to operate for 30 minutes. 3. Compressor operates at rated frequency in COOL mode or 58 Hz in HEAT mode. 4. Indoor fan operates at High speed. 5. After 30 minutes, test run operation finishes and EMERGENCY OPERATION starts (operation frequency of compressor varies). 6.
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Outdoor unit current MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VAH MUZ-FD35VA (A) 2.4 (A) 4.0 (A) 4.0 2.2 3.5 3.5 2.0 3.0 3.0 1.8 15 2.5 15 30 35(°C) 20 25 70 (%) 50 60 Ambient temperature(°C) Ambient humidity(%) 30 35(°C) 20 25 70 (%) 50 60 Ambient temperature(°C) Ambient humidity(%) 2.5 15 30 35(°C) 20 25 70 (%) 50 60 Ambient temperature(°C) Ambient humidity(%) MUZ-FD50VA (A) 6.5 6.0 5.5 5.0 4.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD25VA MUZ-FD25VAH CAPACITY: 2.5 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.85 INPUT: 485 W OUTDOOR DB (°C) 21 25 27 30 SHF INPUT 21 18 2.94 1.97 0.67 388 2.81 1.88 0.67 407 2.70 1.81 0.67 427 2.60 1.74 0.67 446 21 20 3.06 1.68 0.55 407 2.94 1.62 0.55 432 2.85 1.57 0.55 441 2.75 1.51 0.55 461 22 18 2.94 2.09 0.71 388 2.81 2.00 0.71 407 2.70 1.92 0.71 427 2.60 1.85 0.71 446 22 20 3.06 1.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD25VA MUZ-FD25VAH CAPACITY: 2.5 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.85 INPUT: 485 W OUTDOOR DB (°C) 35 40 46 SHF INPUT 21 18 2.45 1.64 0.67 475 2.25 1.51 0.67 504 2.08 1.39 0.67 524 21 20 2.58 1.42 0.55 495 2.40 1.32 0.55 519 2.23 1.22 0.55 548 22 18 2.45 1.74 0.71 475 2.25 1.60 0.71 504 2.08 1.47 0.71 524 22 20 2.58 1.52 0.59 495 2.40 1.42 0.59 519 2.23 1.31 0.59 548 22 22 2.73 1.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD35VA CAPACITY: 3.5 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.85 INPUT: 850 W OUTDOOR DB (°C) 21 25 27 30 SHF INPUT 21 18 4.11 2.76 0.67 680 3.94 2.64 0.67 714 3.78 2.53 0.67 748 3.64 2.44 0.67 782 21 20 4.29 2.36 0.55 714 4.11 2.26 0.55 757 3.99 2.19 0.55 774 3.85 2.12 0.55 808 22 18 4.11 2.92 0.71 680 3.94 2.80 0.71 714 3.78 2.68 0.71 748 3.64 2.58 0.71 782 22 20 4.29 2.53 0.59 714 4.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD35VA CAPACITY: 3.5 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.85 INPUT: 850 W OUTDOOR DB (°C) 35 40 46 Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT 21 18 3.43 2.30 0.67 833 3.15 2.11 0.67 884 2.91 1.95 0.67 918 21 20 3.61 1.98 0.55 867 3.36 1.85 0.55 910 3.12 1.71 0.55 961 22 18 3.43 2.44 0.71 833 3.15 2.24 0.71 884 2.91 2.06 0.71 918 22 20 3.61 2.13 0.59 867 3.36 1.98 0.59 910 3.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD35VAH CAPACITY: 3.5 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.85 INPUT: 835 W OUTDOOR DB (°C) 21 25 27 30 SHF INPUT 21 18 4.11 2.76 0.67 668 3.94 2.64 0.67 701 3.78 2.53 0.67 735 3.64 2.44 0.67 768 21 20 4.29 2.36 0.55 701 4.11 2.26 0.55 743 3.99 2.19 0.55 760 3.85 2.12 0.55 793 22 18 4.11 2.92 0.71 668 3.94 2.80 0.71 701 3.78 2.68 0.71 735 3.64 2.58 0.71 768 22 20 4.29 2.53 0.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD35VAH CAPACITY: 3.5 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.85 INPUT: 835 W OUTDOOR DB (°C) 35 40 46 Q SHC SHF INPUT Q SHC SHF INPUT Q SHC SHF INPUT 21 18 3.43 2.30 0.67 818 3.15 2.11 0.67 868 2.91 1.95 0.67 902 21 20 3.61 1.98 0.55 852 3.36 1.85 0.55 893 3.12 1.71 0.55 944 22 18 3.43 2.44 0.71 818 3.15 2.24 0.71 868 2.91 2.06 0.71 902 22 20 3.61 2.13 0.59 852 3.36 1.98 0.59 893 3.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD50VA CAPACITY: 5.0 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.77 INPUT: 1500 W OUTDOOR DB (°C) 21 25 27 30 SHF INPUT 21 18 5.88 3.47 0.59 1200 5.63 3.32 0.59 1260 5.40 3.19 0.59 1320 5.20 3.07 0.59 1380 21 20 6.13 2.88 0.47 1260 5.88 2.76 0.47 1335 5.70 2.68 0.47 1365 5.50 2.59 0.47 1425 22 18 5.88 3.70 0.63 1200 5.63 3.54 0.63 1260 5.40 3.40 0.63 1320 5.20 3.28 0.63 1380 22 20 6.13 3.
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PERFORMANCE DATA COOL operation at Rated frequency MUZ-FD50VA CAPACITY: 5.0 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.77 INPUT: 1500 W OUTDOOR DB (°C) 35 40 46 SHF INPUT 21 18 4.90 2.89 0.59 1470 4.50 2.66 0.59 1560 4.15 2.45 0.59 1620 21 20 5.15 2.42 0.47 1530 4.80 2.26 0.47 1605 4.45 2.09 0.47 1695 22 18 4.90 3.09 0.63 1470 4.50 2.84 0.63 1560 4.15 2.61 0.63 1620 22 20 5.15 2.63 0.51 1530 4.80 2.45 0.51 1605 4.45 2.27 0.51 1695 22 22 5.45 2.
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PERFORMANCE DATA HEAT operation at Rated frequency MUZ-FD25VA MUZ-FD25VAH CAPACITY: 3.2 kW INDOOR DB (°C) INPUT: 610 W OUTDOOR WB (°C) -10 -5 0 5 10 15 20 Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT 15 2.02 397 2.43 476 2.85 537 3.26 580 3.68 616 4.06 634 4.48 647 21 1.92 427 2.30 506 2.72 561 3.10 604 3.52 634 3.90 653 4.30 677 26 1.73 458 2.14 537 2.53 592 2.94 634 3.36 665 3.74 683 4.16 702 MUZ-FD35VA CAPACITY: 4.
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9 ACTUATOR CONTROL MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH MUZ-FD50VA 9-1. OUTDOOR FAN MOTOR CONTROL The fan motor turns ON/OFF, interlocking with the compressor. [ON] The fan motor turns ON 5 seconds before the compressor starts up. [OFF] The fan motor turns OFF 15 seconds after the compressor has stopped running. 5 seconds 15 seconds ON Compressor OFF ON Outdoor fan motor OFF 9-2. R.V. COIL CONTROL Heating . . . . . . . . . . . . . . . . . ON Cooling . . . . . . . . . . . . . . . . . OFF Dry .
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MUZ-FD50 Sensor Purpose Discharge temperature thermistor Indoor coil temperature thermistor Defrost thermistor Fin temperature thermistor Ambient temperature thermistor Outdoor heat exchanger temperature thermistor 10 Protection Cooling: Coil frost prevention Heating: High pressure protection Heating: Defrosting Protection Cooling: Low ambient temperature operation Cooling: Low ambient temperature operation Cooling: High pressure protection Compressor LEV ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ Actuator Outdoor fa
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11 TROUBLESHOOTING MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH MUZ-FD50VA 11-1. CAUTIONS ON TROUBLESHOOTING 1. Before troubleshooting, check the following 1) Check the power supply voltage. 2) Check the indoor/outdoor connecting wire for miswiring. 2.
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11-2. FAILURE MODE RECALL FUNCTION Outline of the function This air conditioner can memorize the abnormal condition which has occurred once. Even though LED indication listed on the troubleshooting check table (11-3.) disappears, the memorized failure details can be recalled. This mode is very useful when the unit needs to be repaired for the abnormality which does not recur. 1.
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2. Flow chart of the detailed outdoor unit failure mode recall function Operational procedure The outdoor unit might be abnormal. Confirm if outdoor unit is abnormal according to the following procedures. Confirm that the remote controller is in the failure mode recall function. With the remote controller headed towards the indoor unit, press TOO COOL or TOO WARM button to adjust the set temperature to 25°C. 1 Does POWER lamp on the indoor unit blink at the interval of 0.
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3. Outdoor unit failure mode table MUZ-FD25/35 POWER lamp (Indoor unit) Abnormal point (Failure mode / protection) LED indication (Outdoor P.C. board) OFF None (Normal) 2-time flash 2.5 seconds OFF Outdoor power system 3-time flash 2.5 seconds OFF Discharge temperature thermistor Defrost thermistor 1-time flash every 2.5 seconds Fin temperature thermistor 3-time flash 2.5 seconds OFF P.C. board temperature thermistor 4-time flash 2.5 seconds OFF Ambient temperature thermistor 2-time flash 2.
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MUZ-FD50VA POWER lamp (Indoor unit) Abnormal point (Failure mode / protection) LED indication (Outdoor P.C. board) LED1 LED2 OFF None (Normal) Lighting Lighting 2-time flash Outdoor power system Lighting Lighting Overcurrent protection stop is continuously performed 3 times within 1 minute after the compressor gets started, or when converter protection stop or bus-bar voltage protection stop is continuously performed 3 times within 3 minutes after start-up.
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11-3. TROUBLESHOOTING CHECK TABLE MUZ-FD25/35 No. 1 Symptom Outdoor unit does not operate. Abnormal point/ Condition 1-time flash every Outdoor power sys2.5 seconds tem LED indication 3 6-time flash 2.5 seconds OFF 11-time flash 2.5 seconds OFF 14-time flash 2.5 seconds OFF 5 6 7 8 Outdoor control sys- Nonvolatile memory data cannot be read properly. tem (POWER lamp of the indoor unit lights up or flashes 7-time.
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MUZ-FD50VA No. 1 2 LED indication Abnormal point/ ConCondition dition LED1(Red) LED2(Yellow) Outdoor unit Outdoor power system Overcurrent protection stop is continuously performed 3 times does not operwithin 1 minute after the compressor gets started, or when ate. converter protection stop or bus-bar voltage protection stop is Lightning Twice continuously performed three times within 3 minutes after startup.
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No. 20 Symptom Outdoor unit operates. 21 LED indication Abnormal point/ Condition LED1(Red) LED2(Yellow) Primary current protection Once Lighting Secondary current protection High-Pressure protection Twice Lighting Defrosting in cooling 22 3 times 23 4 times 24 25 26 5 times Outdoor unit operates 9 times Lighting Condition Remedy These symptoms do not mean any abnormality of the product, but check the following points. The current of the compressor exceeds 13 A.
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11-4. TROUBLE CRITERION OF MAIN PARTS MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH MUZ-FD50VA Part name Defrost thermistor (RT61) Check method and criterion Figure Ambient temperature thermistor (RT65) Measure the resistance with a tester. Fin temperature thermistor (RT64) Refer to 11-6. "Test point diagram and voltage," 1. "Inverter P.C. board", or 2. "Outdoor electronic control P.C. board", the chart of thermistor.
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11-5. TROUBLESHOOTING FLOW A How to check inverter/compressor MUZ-FD25/35 Disconnect the connector (CN61) between compressor and the intelligent power module (IPM). See 11-5. Check the voltage between terminals. Are the voltages balanced? Yes No Replace the inverter P.C. board. See 11-5. Check the compressor. “Check of open phase”. “Check of compressor”. MUZ-FD50 Disconnect the terminal of the compressor. 3 minutes after turning on the power supply, start EMERGENCY OPERATION.
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B Check of open phase MUZ-FD25/35 ● With the connector between the compressor and the intelligent power module disconnected, activate the inverter and check if the inverter is normal by measuring the balance of voltage between the terminals. Output voltage is 50 - 130 V. (The voltage may differ according to the tester.) << Operation method>> Start cooling or heating operation by pressing EMERGENCY OPERATION switch on the indoor unit. (TEST RUN OPERATION: Refer to 8-3.
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D Check of compressor winding MUZ-FD25/35 ● Disconnect the connector (CN61) between the compressor and intelligent power module, and measure the resistance between the compressor terminals. <> at 3 points BLK-WHT Measure the resistance between the lead wires at 3 points. BLK-RED WHT-RED <> Refer to 11-4. 0 [Ω] ················Abnormal [short] Infinite [Ω] ·······Abnormal [open] NOTE: Be sure to zero the ohmmeter before measurement.
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G Check of outdoor thermistors Disconnect the connector of thermistor in the outdoor P.C. board (see below table), and measure the resistance of thermistor. Is the resistance of thermistor normal? (Refer to 11-6.1. or 11-6.2.) Yes No Replace the thermistor except RT64. When RT64 is abnormal, replace the inverter P.C. board or the outdoor power board. Reconnect the connector of thermistor. Turn ON the power supply and press EMERGENCY OPERATION switch.
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MUZ-FD50 • Heating operation does not work. 1. Disconnect the lead wire leading to the compressor. 2. 3 minutes after turning on the power supply, start EMERGENCY OPERATION in HEAT mode. Is there voltage of 230 VAC between pin1 and pin 2 at connector CN912? Yes No Turn OFF power supply of indoor and outdoor unit. Disconnect the connector CN912 in noise filter P.C. board. Is there normal resistance to R.V. coil? No Replace the R.V. coil. 1.
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I Check of outdoor fan motor MUZ-FD25/35 Disconnect CN932 from the inverter P.C. board, and measure the resistance of the outdoor fan motor. Is the resistance of outdoor fan motor normal? (Refer to 11-4.) Yes No Replace the outdoor fan motor. Replace the inverter P.C. board. MUZ-FD50 Disconnect CN932 from the outdoor electronic control P.C. board, and measure the resistance of the outdoor fan motor. Is the resistance of outdoor fan motor Yes normal? (Refer to 11-4.) No Turn on the power supply.
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J Check of power supply MUZ-FD25/35 Disconnect the connector (CN61) between compressor and intelligent power module. Turn ON power supply and press EMERGENCY OPERATION switch. Does POWER lamp on the indoor unit light up? Yes Is there voltage 260 - 300 VDC between DB61 (+) and DB61 (–) on the inverter P.C. board? (Refer to 11-6.1.) No Rectify indoor/outdoor connecting wire. No Yes Check the electric parts in main circuit.
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K Check of LEV (Expansion valve) Turn ON the power supply. While pressing both OPERATION SELECT button and TOO COOL button on the remote controller at the same time, press RESET button. First, release RESET button. Hold down the other two buttons for another 3 seconds. Confirm that the indicators on the LCD screen shown in the right figure are all displayed. Then release the buttons.
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L Check of inverter P.C. board MUZ-FD25/35 Check the outdoor fan motor. (Refer to 11-5. .) Is the fuse (F901) blown on the inverter P.C. board? Yes No Inverter P.C. board (Solder side) Check the connection of the connectors (CN932) of the outdoor fan motor. If the connection is poor, make it correct. CN932 Operate the outdoor unit by starting EMERGENCY OPERATION. Check the LED indication on the inverter P.C. board.
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M How to check miswiring and serial signal error Turn OFF the power supply. Is there rated voltage in the power supply? Yes Check the power supply. No Turn ON the power supply. Is there rated voltage between outdoor terminal block S1 and S2? Yes No Check the wiring. Press EMERGENCY OPERATION switch once.
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N Electromagnetic noise enters into TV sets or radios Is the unit earthed? Yes Is the distance between the antennas and the indoor unit within 3 m, or is the distance between the antennas and the outdoor unit within 3 m? No Earth the unit. No Yes Extend the distance between the antennas and the indoor unit, and/or the antennas and the outdoor unit.
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O Check of defrost heater MUZ-FD25VAH MUZ-FD35VAH Check the following points before checking electric continuity. 1. Does the resistance of ambient temperature thermistor have the characteristics? Refer to 11-6.1. 2. Is the resistance of defrost heater normal? Refer to 11-4. 3. Does the heater protector remain conducted (not open)? 4.
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11-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUZ-FD25VA MUZ-FD25VAH MUZ-FD35VA MUZ-FD35VAH C62 C63 Smoothing Smoothing capacitor capacitor DB61 Bus-bar voltage 260 - 300 VDC (-) (+) Back side of unit CN722 C61 Heater Smoothing F701 Fuse capacitor T3.15AL250VAC connector MUZ-FD•VAH F801 Fuse T3.15AL250VAC 230 VAC CN721 R.V.coil 230 VAC F901 Fuse T3.
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2. Outdoor electronic control P.C. board Defrost thermistor (RT61) Ambient temperature thermistor (RT65) Fin temperature thermistor (RT64) Outdoor heat exchanger temperature thermistor (RT68) 200 500 400 140 120 100 80 60 300 40 200 20 0 100 10 20 30 40 50 60 70 80 90 70 60 50 40 30 0 20 10 20 30 40 50 60 70 80 Temperature (°C) 0 80 10 100 110 120 0 -20 10 20 30 40 CN781 12 VDC GND (power board) (–)Rush current relay (–)R.V.
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3. Noise filter P.C. board MUZ-FD50VA CN901 To electronic control P.C. board CN902 To power board CN903 To power board 230 VAC Input CN912 R.V. coil 230 VAC 230 VAC Output CN61 230 VAC Output F64 FUSE T2AL250V NR64 VARISTOR 4. Outdoor power board MUZ-FD50VA Connect to the compressor Voltage among phases: 5 to 180 V Connect to the earth 325-370 VDC Output (Red) (+) 1 CN2 Connect to the controller board (+)1-5(–): Signal transmission (To electronic control P.C.
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12 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 (1) 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. (1) Slide the sleeve and check if there is a locking lever or not.
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OPERATING PROCEDURE PHOTOS 2. Removing the inverter assembly, inverter P.C. board (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors: CN721 (R.V. coil) CN722 (Defrost heater) CN932 (Fan motor) CN641 (Defrost thermistor and discharge temperature thermistor) CN643 (Ambient temperature thermistor) CN644 (Outdoor heat exchanger temperature thermistor) CN724 (LEV) (3) Remove the compressor connector (CN61).
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OPERATING PROCEDURE PHOTOS 5. Removing outdoor fan motor Photo 6 (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the following connectors: CN932 (Fan motor) (3) Remove the propeller nut. (4) Remove the propeller. (5) Remove the screws fixing the fan motor. (6) Remove the fan motor. Outdoor heat exchanger temperature thermistor 6. Removing the compressor and 4-way valve (1) Remove the cabinet and panels. (Refer to 1.) (2) Remove the inverter assembly. (Refer to 2.
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12-2. MUZ-FD50VA NOTE: Turn OFF power supply before disassembly. OPERATING PROCEDURE PHOTOS 1. Removing the cabinet Photo 1 (1) (2) (3) (4) (5) (6) (7) Remove the screws of the service panel. Remove the screws of the top panel. Remove the screw of the valve cover. Remove the service panel. Remove the top panel. Remove the valve cover. Disconnect the power supply and indoor/outdoor connecting wire. (8) Remove the screws of the cabinet. (9) Remove the cabinet. (10) Remove the screws of the back panel.
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OPERATING PROCEDURE PHOTOS 2. Removing the inverter assembly, outdoor electric control P.C. board, power board, noise filter P.C. board and reactor. (1) Remove the top panel, cabinet and service panel. (Refer to 1.) (2) Remove the back panel. (Refer to 1.) (3) Disconnect the following connectors:
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OPERATING PROCEDURE PHOTOS 3. Removing the defrost thermistor, discharge temperature thermistor, outdoor heat exchanger temperature thermistor and ambient temperature thermistor Photo 5 Outdoor heat exchanger temperature thermistor (1) Remove the top panel, cabinet and service panel. (Refer to 1.) (2) Remove the back panel. (Refer to 1.) (3) Disconnect the following connectors:
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OPERATING PROCEDURE PHOTOS 5. Removing the compressor and 4-way valve Photo 7 (1) Remove the top panel, cabinet and service panel. (Refer to 1.) (2) Remove the back panel. (Refer to 1.) (3) Remove the inverter assembly. (Refer to 2.) (4) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 MPa. (5) Detach the brazed part of the suction and the discharge pipe connected with compressor. (6) Remove the compressor nuts. (7) Remove the compressor.
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HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2007 MITSUBISHI ELECTRIC CO.,LTD Distributed in Jul. 2011. No. OBH489 REVISED EDITION-C Distributed in Nov. 2008. No. OBH489 REVISED EDITION-B 5 Distributed in Oct. 2007. No. OBH489 REVISED EDITION-A 6 Distributed in Aug. 2007. No. OBH489 6 Made in Japan New publication, effective Jul. 2011 Specifications subject to change without notice.