Mitsubishi Electric MUZ-LN25VG-E1 Service Manual
  1. Manuals
  2. Brands
  3. Mitsubishi Electric Manuals
  4. Air Conditioner
  5. MUZ-LN25VG-E1
  6. Service manual

Mitsubishi Electric MUZ-LN25VG-E1 Service Manual

Hide thumbs Also See for MUZ-LN25VG-E1:
Table of Contents

Advertisement

Quick Links

Download this manual
OUTDOOR UNIT
SERVICE MANUAL
Models
MUZ-LN25VG
-
,
,
E1
ER1
ET1
-
,
,
E1
ER1
ET1
-
,
,
E1
ER1
ET1
-
,
,
,
E1
ER1
ET1
E2
-
,
,
,
E1
ER1
ET1
E2
-
,
,
,
E1
ER1
ET1
E2
-
,
,
,
E1
ER1
ET1
E2
-
,
,
E1
ET1
ER1
Revision G:
• TROUBLESHOOTING CRITERION OF
MAIN PARTS has been corrected.
[Expansion valve coil (LEV) in 12-4.]
• Some descriptions have been modified.
OBH767 REVISED EDITION-F is void.
HFC
utilized
R32
,
,
,
ET2
ER2
E3
,
,
,
ET2
ER2
E3
,
,
,
ET2
ER2
E3
Indoor unit service manual
MSZ-LN•VGW/V/B/R Series (OBH766)
CONTENTS
1. TECHNICAL CHANGES ······························3
USING REFRIGERANT R32 ·························4
3. PART NAMES AND FUNCTIONS ··················6
4. SPECIFICATION ········································7
5. NOISE CRITERIA CURVES ························ 10
6. OUTLINES AND DIMENSIONS ··················· 12
7. WIRING DIAGRAM ··································· 16
8. REFRIGERANT SYSTEM DIAGRAM ··········· 24
9. PERFORMANCE CURVES ························ 28
10. ACTUATOR CONTROL ····························· 49
11. SERVICE FUNCTIONS ······························ 50
12. TROUBLESHOOTING ······························· 51
13. DISASSEMBLY INSTRUCTIONS ················· 76
PARTS CATALOG (OBB767)
No. OBH767
REVISED EDITION-G

Advertisement

Table of Contents
loading

Related Manuals for Mitsubishi Electric MUZ-LN25VG-E1

Summary of Contents for Mitsubishi Electric MUZ-LN25VG-E1

  • Page 1: Table Of Contents

    Revision G: • TROUBLESHOOTING CRITERION OF MAIN PARTS has been corrected. [Expansion valve coil (LEV) in 12-4.] • Some descriptions have been modified. OBH767 REVISED EDITION-F is void. OUTDOOR UNIT No. OBH767 SERVICE MANUAL REVISED EDITION-G utilized Models MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG MUZ-LN60VG MUZ-LN25VG2...
  • Page 2 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.

  • Page 3: Muz-Ln35Vg

    TECHNICAL CHANGES MUZ-LN25VG - MUZ-LN35VG - MUZ-LN50VG - MUZ-LN60VG - 1. New model MUZ-LN25VG - MUZ-LN25VG2 - MUZ-LN35VG - MUZ-LN35VG2 - MUZ-LN50VG - MUZ-LN50VG2 - 1. The heat exchanger has been changed. 2. The refrigerant amount has been changed. MUZ-LN25VG - MUZ-LN25VG2 - MUZ-LN35VG - MUZ-LN35VG2 -...

  • Page 4: Servicing Precautions For Units Using Refrigerant R32

    SERVICING PRECAUTIONS FOR UNITS USING REFRIGERANT R32 Servicing precautions for units using refrigerant R32 WARNING This unit uses a flammable refrigerant. If refrigerant leaks and comes in contact with fire or heating part, it will create harmful gas and there is risk of fire. Do not use means to accelerate the defrosting process or to clean, other than those recommended by the manufacturer.
  • Page 5 5. Detection of Flammable Refrigerants Under no circumstances shall potential sources of ignition be used in the searching for or detection of refrigerant leaks. A halide torch (or any other detector using a naked flame) shall not be used. 6. Leak Detection Methods Electronic leak detectors may be used to detect refrigerant leaks but, in the case of flammable refrigerants, the sensitivity may not be adequate, or may need recalibration.

  • Page 6: Part Names And Functions

    PART NAMES AND FUNCTIONS MUZ-LN25VG MUZ-LN25VG2 MUZ-LN35VG MUZ-LN35VG2 Air inlet (Back and side) Piping Air outlet Drain hose Drain outlet MUZ-LN50VG MUZ-LN50VG2 MUZ-LN60VG Air inlet Air inlet (Back and side) (back and side) Piping Piping Drain hose Air outlet Drain hose Air outlet Drain outlet Drain outlet...

  • Page 7: Specification

    SPECIFICATION MUZ-LN25VG MUZ-LN25VG2 MUZ-LN35VG MUZ-LN35VG2 Outdoor model Power supply Single phase, 230 V, 50 Hz Cooling 2.5 (1.0 - 3.5) 2.5 (1.0 - 3.5) 3.5 (0.8 - 4.0) 3.5 (0.8 - 4.0) Capacity Rated (Min.-Max.) Heating 3.2 (0.8 - 5.4) 3.2 (0.7 - 5.4) 4.0 (1.0 - 6.3) 4.0 (0.9 - 6.3)
  • Page 8 MUZ-LN50VG MUZ-LN50VG2 MUZ-LN60VG MUZ-LN60VG2 Outdoor model Power supply Single phase, 230 V, 50 Hz Cooling 5.0 (1.0 - 6.0) 5.0 (1.0 - 6.0) 6.1 (1.4 - 6.9) 6.1 (1.4 - 6.9) Capacity Rated (Min. - Max.) Heating 6.0 (1.0 - 8.2) 6.0 (1.0 - 8.2) 6.8 (1.8 - 9.3) 6.8 (1.8 - 9.3)
  • Page 9 Specifications and rated conditions of main electric parts Model MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG Item (C62, C63) 600 µF/ 620 µF 420 V Smoothing capacitor (C61, C62, C63) 600 µF/ 620 µF 420 V (DB61) 15 A 600 V 25 A 600 V Diode module (DB65) 25A 600V...

  • Page 10: Noise Criteria Curves

    NOISE CRITERIA CURVES MUZ-LN25VG MUZ-LN25VG2 FUNCTION SPL(dB(A)) LINE FUNCTION SPL(dB(A)) LINE COOLING COOLING HEATING HEATING NC-70 NC-70 NC-60 NC-60 NC-50 NC-50 NC-40 NC-40 NC-30 NC-30 NC-20 NC-20 NC-10 NC-10 1000 2000 4000 8000 1000 2000 4000 8000 BAND CENTER FREQUENCIES, Hz BAND CENTER FREQUENCIES, Hz MUZ-LN35VG MUZ-LN35VG2...
  • Page 11 MUZ-LN50VG MUZ-LN50VG2 FUNCTION SPL(dB(A)) LINE FUNCTION SPL(dB(A)) LINE COOLING COOLING HEATING HEATING NC-70 NC-70 NC-60 NC-60 NC-50 NC-50 NC-40 NC-40 NC-30 NC-30 NC-20 NC-20 NC-10 NC-10 1000 2000 4000 8000 1000 2000 4000 8000 BAND CENTER FREQUENCIES, Hz BAND CENTER FREQUENCIES, Hz MUZ-LN60VG MUZ-LN60VG2 FUNCTION SPL(dB(A))

  • Page 12: Outlines And Dimensions

    OUTLINES AND DIMENSIONS MUZ-LN25VG MUZ-LN35VG Unit: mm MUZ-LN25VG2 MUZ-LN35VG2 OBH767G...
  • Page 13 MUZ-LN50VG Unit: mm MUZ-LN50VG2 OBH767G...
  • Page 14 MUZ-LN60VG Unit: mm REQUIRED SPACE *1. 500 mm or more when front and sides of the unit are clear 417.5 Air in Air in Air out 2-holes 10 21 *2. When any 2 sides of left, right and rear of the unit are clear Service panel Liquid refrigerant pipe joint Refrigerant pipe (flared)
  • Page 15 MUZ-LN60VG2 REQUIRED SPACE FLARED ø6.35 (1/4”) FLARED ø12.7 (1/2”) OBH767G...

  • Page 16: Wiring Diagram

    WIRING DIAGRAM MUZ-LN25VG MUZ-LN35VG OBH767G...
  • Page 17 MUZ-LN25VG2- MUZ-LN35VG2- MUZ-LN25VG2- MUZ-LN35VG2- OBH767G...
  • Page 18 MUZ-LN25VG2- MUZ-LN35VG2- MUZ-LN25VG2- MUZ-LN35VG2- OBH767G...
  • Page 19 MUZ-LN50VG OBH767G...
  • Page 20 MUZ-LN50VG2- MUZ-LN50VG2- OBH767G...
  • Page 21 MUZ-LN50VG2- MUZ-LN50VG2- OBH767G...
  • Page 22 MUZ-LN60VG- MUZ-LN60VG- OBH767G...
  • Page 23 MUZ-LN60VG2- MUZ-LN60VG2- OBH767G...

  • Page 24: Refrigerant System Diagram

    REFRIGERANT SYSTEM DIAGRAM MUZ-LN25VG MUZ-LN35VG Unit: mm MUZ-LN25VG2 MUZ-LN35VG2 Refrigerant pipe ø9.52 4-way valve (with heat insulator) Muffler Outdoor heat exchanger Stop valve temperature thermistor Outdoor Muffler RT68 Discharge heat Flared connection exchanger temperature thermistor RT62 Ambient Compressor temperature thermistor RT65 Defrost thermistor...
  • Page 25 MUZ-LN60VG Unit: mm Refrigerant pipe ø 12.7 (with heat insulator) 4-way valve Stop valve Outdoor Flared connection Discharge heat Ambient temperature exchanger temperature thermistor Defrost thermistor RT62 thermistor RT65 RT61 Compressor Outdoor heat exchanger temperature thermistor RT68 Flared connection Capillary tube Strainer Strainer R.V.
  • Page 26 MUZ-LN60VG2 Refrigerant pipe ø12.7 (with heat insulator) 4-way valve Stop valve Outdoor Flared connection Discharge heat Ambient temperature exchanger temperature thermistor Defrost thermistor RT62 thermistor RT65 RT61 Compressor Outdoor heat exchanger temperature thermistor Flared connection RT68 Strainer Strainer #100 Muffler #100 R.V.
  • Page 27 Indoor unit Max. Height difference Max. Length Outdoor unit ADDITIONAL REFRIGERANT CHARGE (R32: g) Refrigerant piping length (one way) Outdoor unit Model precharged 9 m 10 m 11 m 12 m 13 m 14 m 15 m 16 m 17 m 18 m 19 m 20 m MUZ-LN25VG 1,000 MUZ-LN35VG...

  • Page 28: Performance Curves

    PERFORMANCE CURVES MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG MUZ-LN60VG MUZ-LN25VG2 MUZ-LN35VG2 MUZ-LN50VG2 MUZ-LN60VG2 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.
  • Page 29 9-1. CAPACITY AND INPUT CURVES Cooling capacity (at Rated frequency) 10.4 11.4 11.2 Indoor intake air Wet-bulb 10.5 10.3 temperature( ) Outdoor intake air Dry-bulb temperature(°C) Total input (Cooling : at Rated frequency Indoor intake air Wet-bulb temperature( ) Outdoor intake air Dry-bulb temperature (°C) Heating capacity (at Rated frequency) 14.5...
  • Page 30 9-2. CAPACITY AND INPUT CORRECTION BY OPERATIONAL FREQUENCY OF COMPRESSOR MUZ-LN25VG Correction of Cooling capacity Correction of Cooling input Correction of Heating capacity Correction of Heating input The operational frequency The operational frequency The operational frequency The operational frequency of compressor (Hz) of compressor (Hz) of compressor (Hz) of compressor (Hz)
  • Page 31 MUZ-LN50VG Correction of Heating capacity Correction of Heating input Correction of Cooling capacity Correction of Cooling input The operational frequency The operational frequency The operational frequency The operational frequency of compressor (Hz) of compressor (Hz) of compressor (Hz) of compressor (Hz) MUZ-LN50VG2 Correction of Heating capacity Correction of Heating input...
  • Page 32 9-4. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT COOL operation Dry-bulb temperature (°C) Relative humidity (%) Both indoor and outdoor unit are under the same temperature/ humidity condition. Operation: TEST RUN OPERATION (Refer to 8-3.) Outdoor low pressure MUZ-LN25VG MUZ-LN25VG2 (kgf/cm [Gauge])(MPa [Gauge]) (kgf/cm...
  • Page 33 Outdoor unit current MUZ-LN25VG2 MUZ-LN35VG2 MUZ-LN25VG MUZ-LN35VG Ambient temperature(°C) Ambient temperature(°C) Ambient temperature(°C) Ambient temperature(°C) Ambient humidity(%) Ambient humidity(%) Ambient humidity(%) Ambient humidity(%) MUZ-LN50VG MUZ-LN60VG MUZ-LN50VG2 MUZ-LN60VG2 Ambient temperature(°C) Ambient temperature(°C) Ambient humidity(%) Ambient humidity(%) HEAT operation Condition: Indoor Outdoor Dry bulb temperature (°C) 20.0 20.0...
  • Page 34 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN25VG CAPACITY: 2.5 kW SHF: 0.97 INPUT: 485 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 2.94 2.32 0.79 2.81 2.22 0.79 2.70 2.13 0.79 2.60 2.05 0.79 3.06...
  • Page 35 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN25VG CAPACITY: 2.5 kW SHF: 0.97 INPUT: 485 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 2.45 1.94 0.79 2.25 1.78 0.79 2.08 1.64 0.79 2.58 1.73 0.67 2.40 1.61...
  • Page 36 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN25VG2 CAPACITY: 2.5 kW SHF: 0.97 INPUT: 485 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 2.94 2.32 0.79 2.81 2.22 0.79 2.70 2.13 0.79 2.60 2.05 0.79 3.06...
  • Page 37 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN25VG2 CAPACITY: 2.5 kW SHF: 0.97 INPUT: 485 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 2.45 1.94 0.79 2.25 1.78 0.79 2.08 1.64 0.79 2.58 1.73 0.67 2.40 1.61...
  • Page 38 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN35VG CAPACITY: 3.5 kW SHF: 0.90 INPUT: 820 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 4.11 2.96 0.72 3.94 2.84 0.72 3.78 2.72 0.72 3.64 2.62 0.72 4.29...
  • Page 39 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN35VG CAPACITY: 3.5 kW SHF: 0.90 INPUT: 820 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 3.43 2.47 0.72 3.15 2.27 0.72 2.91 2.09 0.72 3.61 2.16 0.60 3.36 2.02...
  • Page 40 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN35VG2 CAPACITY: 3.5 kW SHF: 0.90 INPUT: 820 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 4.11 2.96 0.72 3.94 2.84 0.72 3.78 2.72 0.72 3.64 2.62 0.72 4.29...
  • Page 41 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN35VG2 CAPACITY: 3.5 kW SHF: 0.90 INPUT: 820 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 3.43 2.47 0.72 3.15 2.27 0.72 2.91 2.09 0.72 3.61 2.16 0.60 3.36 2.02...
  • Page 42 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN50VG MUZ-LN50VG2 CAPACITY: 5.0 kW SHF: 0.77 INPUT: 1380 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 5.88 3.47 0.59 1104 5.63 3.32 0.59 1159 5.40 3.19 0.59 1214...
  • Page 43 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN50VG MUZ-LN50VG2 CAPACITY: 5.0 kW SHF: 0.77 INPUT: 1380 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 4.90 2.89 0.59 1352 4.50 2.66 0.59 1435 4.15 2.45 0.59 1490 5.15...
  • Page 44 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN60VG CAPACITY: 6.1 kW SHF: 0.75 INPUT: 1790 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 7.17 4.09 0.57 1432 6.86 3.91 0.57 1504 6.59 3.76 0.57 1575 6.34...
  • Page 45 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN60VG CAPACITY: 6.1 kW SHF: 0.75 INPUT: 1790 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 5.98 3.41 0.57 1754 5.49 3.13 0.57 1862 5.06 2.89 0.57 1933 6.28 2.83...
  • Page 46 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN60VG2 CAPACITY: 6.1 kW SHF: 0.75 INPUT: 1790 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 7.17 4.09 0.57 1432 6.86 3.91 0.57 1504 6.59 3.76 0.57 1575 6.34...
  • Page 47 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-LN60VG2 CAPACITY: 6.1 kW SHF: 0.75 INPUT: 1790 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 5.98 3.41 0.57 1754 5.49 3.13 0.57 1862 5.06 2.89 0.57 1933 6.28 2.83...
  • Page 48 PERFORMANCE DATA HEAT operation at Rated frequency MUZ-LN25VG CAPACITY: 3.2 kW INPUT: 580 W OUTDOOR WB (°C) INDOOR DB (°C) INPUT INPUT INPUT INPUT INPUT INPUT INPUT INPUT 1.60 2.02 2.43 2.85 3.26 3.68 4.06 4.48 1.50 1.92 2.30 2.72 3.10 3.52 3.90...

  • Page 49: Actuator Control

    ACTUATOR CONTROL MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG MUZ-LN60VG MUZ-LN25VG2 MUZ-LN35VG2 MUZ-LN50VG2 MUZ-LN60VG2 10-1. 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 Compressor...

  • Page 50: Service Functions

    SERVICE FUNCTIONS MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG MUZ-LN60VG MUZ-LN25VG2 MUZ-LN35VG2 MUZ-LN50VG2 MUZ-LN60VG2 11-1. CHANGE IN DEFROST SETTING Changing defrost finish temperature <JS> To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board. (Refer to 12-6.1) Defrost finish temperature (°C) Jumper wire MUZ-LN25/35/50VG MUZ-LN60VG...

  • Page 51: Troubleshooting

    TROUBLESHOOTING MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG MUZ-LN60VG MUZ-LN25VG2 MUZ-LN35VG2 MUZ-LN50VG2 MUZ-LN60VG2 12-1. 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. Take care of the following during servicing 1) 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.
  • Page 52 12-2. 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 (12-3.) disappears, the memorized failure details can be recalled. 1.
  • Page 53 2. Flow chart of the detailed outdoor unit failure mode recall function Operational procedure The outdoor unit might be abnormal. Check if outdoor unit is abnormal according to the following procedures. Make sure that the remote controller is set to the failure mode recall function. 1.
  • Page 54 NOTE: Blinking patterns of this mode differ from the ones of 3. Outdoor unit failure recall mode table TROUBLESHOOTING CHECK TABLE (12-3.). Indoor/outdoor Outdoor unit POWER lamp Abnormal point LED indication unit failure Condition Remedy failure mode (Indoor unit) (Failure mode/protection) (Outdoor P.C.
  • Page 55 NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (12-3.). Indoor/outdoor Outdoor unit POWER lamp Abnormal point LED indication unit failure Condition Remedy failure mode (Indoor unit) (Failure mode/protection) (Outdoor P.C. board) mode recall recall function function 10-time blink Discharge temperature...
  • Page 56 12-3. TROUBLESHOOTING CHECK TABLE Abnormal point/ Con- Symptom LED indication Condition Remedy dition Outdoor unit 1-time blink every Outdoor power sys- Overcurrent protection cut-out operates 3 consecutive times • Reconnect connector of compres- does not op- 2.5 seconds within 1 minute after the compressor gets started. sor.
  • Page 57 Abnormal point/ Con- Symptom LED indication Condition Remedy dition MUZ-LN25/35 Outdoor unit Outside temperature When the outside temperature thermistor shorts or opens, • Refer to 12-5. Check of outdoor operates. thermistor protec- protective operation without that thermistor is performed. thermistors. 5-time blink tion 2.5 seconds OFF...
  • Page 58 12-4. TROUBLESHOOTING CRITERION OF MAIN PARTS MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG MUZ-LN60VG MUZ-LN25VG2 MUZ-LN35VG2 MUZ-LN50VG2 MUZ-LN60VG2 Part name Check method and criterion Figure Defrost thermistor (RT61) Measure the resistance with a multimeter. Refer to 12-6. “Test point diagram and voltage”, 1. “Inverter P.C. Fin temperature board”, for the chart of thermistor.
  • Page 59 12-5. TROUBLESHOOTING FLOW A How to check inverter/compressor Disconnect the connector between the compressor and the power module (IC700). Check the voltage between terminals. See 12-5. “Check of open phase”. Replace the inverter P.C. board. Are the voltages balanced? Check the compressor. See 12-5.
  • Page 60 D Check of compressor winding ● Disconnect the connector between the compressor and the power module (IC700), and measure the resistance between the compressor terminals. <<Measurement point>> At 3 points BLK-WHT * Measure the resistance between the lead wires at 3 points. BLK-RED WHT-RED <<Judgement>>...
  • Page 61 G Check of outdoor thermistors Disconnect the connector of thermistor in the inverter P.C. board (see below table), and measure the resistance of thermistor. Replace the thermistor except RT64. Is the resistance of thermistor normal? When RT64 is abnormal, replace the inverter P.C. (Refer to 12-6.1.) board.
  • Page 62 H Check of R.V. coil MUZ-LN25/35/50VG MUZ-LN25/35/50VG2 * First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 12-4. * In case CN721 is disconnected or R.V. coil is open, voltage is generated between the terminal pins of the connector although no signal is being transmitted to R.V.
  • Page 63 I Check of outdoor fan motor Disconnect the connectors CN931 and CN932 from the inverter P.C. board. Check the connection between the connector CN931 and CN932. Is the resistance between each ter- minal of outdoor fan motor normal? (Refer to 12-4.) Disconnect CN932 from the inverter P.C.
  • Page 64 J Check of power supply Disconnect the connector between the compressor and the power module (IC700). Turn ON power supply and Rectify indoor/outdoor press the emergency operation switch. connecting wire. Is there voltage 230 V AC Replace the indoor Does POWER lamp on the indoor between the indoor terminal electronic control P.C.
  • Page 65 MSZ-LN25/35VG K Check of LEV (Expansion valve) MSZ-LN50/60VG Turn ON the power supply. <Preparation of the remote controller> While pressing both Operation select button and TEMP button on the remote controller at the same time, press RESET button. First, release RESET button. Hold down the other 2 buttons for another 3 seconds.
  • Page 66 L Check of inverter P.C. board Check the outdoor fan motor. (Refer to 12-5. .) Is the fuse (F901) blown on the in- verter P.C. board? Check the connection of the connectors (CN931, CN932) of the outdoor fan motor. If the connection is poor, make it correct. Operate the outdoor unit by starting EMERGENCY OPERATION.
  • Page 67 M How to check miswiring and serial signal error Turn the power supply OFF. Is there rated voltage in the power supply? Check the power supply. Check for incorrect indoor-outdoor connecting wiring. Was the indoor unit ever connected to the Multi (MXZ) series and operated (turned on)? The connection information to the Multi series is stored in the indoor unit.
  • Page 68 N Check of the outdoor refrigerant circuit The operation has stopped to prevent the diesel explosion caused by air trapped in the refrigerant circuit. Close the stop Has the operation stopped during pump down? valve, and disconnect the power plug or turn the breaker OFF. CAUTION: Do not start the operation again to prevent hazards.
  • Page 69 O Check of compressor protector Disconnect the connector of compressor protector in the inverter P.C. board, and check the conduction of compressor protector. Operate the unit and Is the discharge temperature Is the compressor thermistor normal? Refer to 12-5. re-confirm if the protector conductive? “Check of outdoor thermistors”.
  • Page 70 P Electromagnetic noise enters into TV sets or radios Is the unit earthed? Earth the unit. Is the distance between the antennas Extend the distance between the antennas and and the indoor unit within 3 m, or is the the indoor unit, and/or the antennas and the distance between the antennas and the outdoor unit.
  • Page 71 12-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUZ-LN25VG MUZ-LN35VG MUZ-LN50VG MUZ-LN50VG2- Smoothing Smoothing Smoothing R.V. coil capacitor capacitor capacitor (CN721) DB61 Back side of unit (C63) (C62) 230 V AC (C61) 260 - 370 V DC Fuse (F701) (LN50) T3.15AL250V 230 VAC...
  • Page 72 MUZ-LN25VG2- MUZ-LN35VG2- R.V.coil Smoothing Smoothing (CN721) DB61 capacitor capacitor Back side of unit 230 V AC 260 - 370 V DC (C63) (C62) 230 V AC Fuse (F901) Fuse (F801) Fuse (F701) T3.15AL250V T3.15AL250V T3.15AL250V Fuse (F61) Fuse (F62) 25 A 250V 15 A 250 V Output to drive...
  • Page 73 MUZ-LN25VG2- MUZ-LN35VG2- MUZ-LN50VG2- R.V.coil Smoothing Smoothing Smoothing DB61 (CN721) capacitor capacitor capacitor Back side of unit 260 - 370 V DC 230 V AC (C61) (C62) (C63) Fuse (F801) 230 V AC Fuse (F701) T3.15AL250V T3.15AL250V Fuse (F62) 15 A 250 V Output to drive compressor...
  • Page 74 MUZ-LN60VG Jumper wire for pre-heat control setting (JK) LEV (CN724) Jumper wire for changing defrost setting (JS) Ambient temperature thermistor/RT65 (CN672) Heater (CN601) Outdoor heat exchanger 230 V AC temperature thermistor R.V. coil (CN602) /RT68 (CN671) 230 V AC Discharge temperature thermistor/RT62 (CN671) Defrost thermistor...
  • Page 75 MUZ-LN60VG2 Back side of unit Smoothing Smoothing Smoothing Output to drive Capacitor Capacitor Capacitor Fuse (F880) outdoor fan motor Heater (CN601) T3.15AL250V 230 V AC (CB1) (CB2) (CB3) (CN932) Fuse (F601) T3.15AL250V 230 V AC R.V. coil/ 21S4 (CN602) 230 V AC Fuse (F62) 15 A 250 V Fuse (F901)

  • Page 76: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS <Detaching method of the terminal with locking mechanism> The terminal which has the locking mechanism can be detached as shown below. There are following 2 types 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.
  • Page 77 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly and inverter P.C. Photo 4 Screw of the P.B. support board and the separator (1) Remove the cabinet and panels (refer to section 1). Screws of Screw of the heat sink (2) Disconnect the lead wire to the reactor and the following con- the terminal block support and the separator nectors:...
  • Page 78 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing R. V. coil Photo 7 (1) Remove the cabinet and panels (refer to section 1). Outdoor heat (2) Disconnect the following connectors: exchanger tempera- <Inverter P.C. board> ture thermistor CN721 (R.V. coil) (3) Remove the R.V. coil. Ambient tem- perature thermistor (Position refer to...
  • Page 79 OPERATING PROCEDURE PHOTOS/FIGURES 6. Removing the compressor and 4-way valve Photo 9 (1) Remove the cabinet and panels (refer to section 1). Discharge pipe Suction pipe brazed part brazed part (2) Remove the inverter assembly (refer to section 2). (3) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 kg/cm...
  • Page 80 13-2.MUZ-LN25VG2 - MUZ-LN35VG2 - NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS/FIGURES 1. Removing the cabinet Photo 1 Screws of (1) Remove the screws fixing the service panel. Screws of the top panel the top panel (2) Pull down the service panel and remove it. (3) Disconnect the power supply cord and indoor/outdoor connecting wire.
  • Page 81 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly and inverter P.C. board Photo 4 (1) Remove the cabinet and panels. (Refer to section 1.) Screw of the P.B. support Screws of the terminal block (2) Disconnect the lead wire to the reactor and the following con- and the separator support and the back panel nectors:...
  • Page 82 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing R.V. coil Photo 7 (1) Remove the cabinet and panels. (Refer to section 1.) Outdoor heat (2) Disconnect the following connectors: exchanger tempera- <Inverter P.C. board> ture thermistor CN721 (R.V. coil) (3) Remove the R.V. coil. Ambient tem- perature thermistor (Position refer to...
  • Page 83 OPERATING PROCEDURE PHOTOS/FIGURES 6. Removing the compressor and 4-way valve Photo 9 (1) Remove the cabinet and panels. (Refer to section 1.) Compressor protector Discharge pipe Suction pipe (2) Remove the inverter assembly. (Refer to section 2.) brazed part brazed part (3) Recover gas from the refrigerant circuit.
  • Page 84 13-3. MUZ-LN50VG MUZ-LN50VG2 - NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS/FIGURES 1. Removing the cabinet Photo 1 Screws of the top panel (1) Remove the screws of the service panel. (2) Remove the screws of the top panel. (3) Remove the screw of the valve cover.
  • Page 85 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly and inverter P.C. Photo 3 Screw of the P.B. support board and the separator (1) Remove the cabinet and panels (refer to section 1). (2) Disconnect the lead wire to the reactor and the following con- Screw of the heat sink nectors: support and the separator...
  • Page 86 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing R. V. coil Photo 6 (1) Remove the cabinet and panels (refer to section 1). Screw of the R.V. coil (2) Disconnect the following connectors: <Inverter P.C. board> CN721 (R.V. coil) (3) Remove the R.V. coil. Discharge temperature thermistor Outdoor heat Photo 7...
  • Page 87 OPERATING PROCEDURE PHOTOS/FIGURES 6. Removing the compressor and 4-way valve Photo 9 (1) Remove the cabinet and panels (refer to section 1). Discharge pipe Suction pipe (2) Remove the inverter assembly (refer to section 2). brazed part brazed part (3) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 kg/cm...
  • Page 88 13-4. MUZ-LN50VG2 - NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS/FIGURES 1. Removing the cabinet Photo 1 Screws of the top panel (1) Remove the screws of the service panel. (2) Remove the screws of the top panel. (3) Remove the screw of the valve cover.
  • Page 89 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly and inverter P.C. board Photo 3 (1) Remove the cabinet and panels (refer to section 1). Screw of the heat sink Screw of the P.B. support (2) Disconnect the lead wire to the reactor and the following support and the separator and the separator connectors:...
  • Page 90 OPERATING PROCEDURE PHOTOS/FIGURES * Connection procedure when attaching the inverter P.C. Photo 5 board (Photo 5) Lead wires of Lead wires of the heat Lead wires of 1. Connect the lead wires of the heat exchanger temperature the ambient exchanger temperature, the expansion thermistor, the defrost thermistor and discharge tempera- temperature...
  • Page 91 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing R. V. coil Photo 6 (1) Remove the cabinet and panels (refer to section 1). Screw of the (2) Disconnect the following connectors: R.V. coil <Inverter P.C. board> Discharge CN721 (R.V. coil) temperature (3) Remove the R.V. coil. thermistor Compressor protector...
  • Page 92 OPERATING PROCEDURE PHOTOS/FIGURES 6. Removing the compressor and 4-way valve Photo 9 (1) Remove the cabinet and panels (refer to section 1). Discharge pipe Suction pipe (2) Remove the inverter assembly (refer to section 2). brazed part brazed part (3) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 kg/cm...
  • Page 93 13-5. MUZ-LN60VG NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS/FIGURES 1. Removing the cabinet Photo 1 (1) Remove the screws of the service panel. Screws of the top panel (2) Remove the screws of the top panel. (3) Remove the screw of the valve cover.
  • Page 94 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly and inverter P.C. Photo 3 Screws of the relay panel board Inverter P.C board (1) Remove the cabinet and the service panel (refer to section 1). (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C.
  • Page 95 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing R.V. coil Photo 5 Screw of the R.V. coil (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the following connector: <Inverter P.C. board> CN602 (R.V. coil) (3) Remove the R.V. coil. Brazed parts of 4-way valve 4.
  • Page 96 OPERATING PROCEDURE PHOTOS/FIGURES 5. Removing outdoor fan motor Photo 7 (1) Remove the top panel, cabinet and service panel (refer to Propeller fan section1). (2) Disconnect the following connectors: <Inverter P.C. board> Propeller fan CN931, CN932 (Fan motor) (3) Remove the propeller fan nut. (4) Remove the propeller fan.
  • Page 97 13-6. MUZ-LN60VG2 NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS/FIGURES 1. Removing the cabinet Photo 1 (1) Remove the screws of the service panel. (2) Remove the screws of the top panel. Screws of the top panel (3) Remove the screw of the valve cover.
  • Page 98 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly and inverter P.C. Photo 3 board Screw of the heat sink Lead wires of the (1) Remove the cabinet and panels. (Refer to section 1.) support and the separator reactor (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C.
  • Page 99 OPERATING PROCEDURE PHOTOS/FIGURES Photo 5 Connection procedure when attaching the inverter P.C. board (Photo 6, 7) 1. Attach the heat sink support to the P.C. board support. 2. Hook the lead wires of the compressor, the reactor and the P.C. board to each hooks on the heat sink support as shown Photo 7.
  • Page 100 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing the discharge temperature thermistor, Photo 8 Outdoor heat exchanger defrost thermistor, outdoor heat exchanger tempera- temperature thermistor ture thermistor and ambient temperature thermistor (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C.
  • Page 101 OPERATING PROCEDURE PHOTOS/FIGURES 5. Removing the compressor and 4-way valve Photo 10 (1) Remove the top panel, cabinet and service panel. (Refer to Brazed part of Brazed part of section 1.) the discharge pipe the suction pipe (2) Remove the back panel. (Refer to section 1.) (3) Remove the inverter assembly.
  • Page 102 HEAD OFFICE: TOKYO BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2016 MITSUBISHI ELECTRIC CORPORATION Issued: Nov. 2023. No. OBH767 REVISED EDITION-G Issued: Dec. 2022. No. OBH767 REVISED EDITION-F Issued: Feb. 2021. No. OBH767 REVISED EDITION-E Issued: Dec. 2020. No. OBH767 REVISED EDITION-D Issued: Jul.

This manual is also suitable for:

Muz-ln25vg-er1Muz-ln25vg-et1Muz-ln35vg-e1Muz-ln35vg-er1Muz-ln35vg-et1Muz-ln50vg-e1 ... Show all

Table of Contents