Mitsubishi Electric MUZ-AY15VG Service Manual
  1. Manuals
  2. Brands
  3. Mitsubishi Electric Manuals
  4. Air Conditioner
  5. MUZ-AY15VG
  6. Service manual

Mitsubishi Electric MUZ-AY15VG Service Manual

Outdoor unit
Hide thumbs
Table of Contents

Advertisement

Quick Links

OUTDOOR UNIT
SERVICE MANUAL
Models
MUZ-AY15VG
MUZ-AY20VG
-
,
E1
ET1
-
,
E1
ET1
CONTENTS
1. TECHNICAL CHANGES ······························2
USING REFRIGERANT R32 ·························3
3. PART NAMES AND FUNCTIONS ··················5
4. SPECIFICATION ········································6
5. NOISE CRITERIA CURVES ··························8
6. OUTLINES AND DIMENSIONS ·····················9
7. WIRING DIAGRAM ··································· 10
8. REFRIGERANT SYSTEM DIAGRAM ··········· 12
9. PERFORMANCE CURVES ························· 14
10. ACTUATOR CONTROL ····························· 23
11. SERVICE FUNCTIONS ······························ 24
12. TROUBLESHOOTING ······························· 25
13. DISASSEMBLY INSTRUCTIONS ················· 45
PARTS CATALOG (OBB938)
Revision A:
• TROUBLESHOOTING CRITERION OF
MAIN PARTS has been corrected.
[Expansion valve coil (LEV) in 12-4.]
OBH938 is void.
No. OBH938
HFC
REVISED EDITION-A
utilized
R32
Indoor unit service manual
MSZ-AY•VG Series (OBH937)

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the MUZ-AY15VG and is the answer not in the manual?

Questions and answers

Related Manuals for Mitsubishi Electric MUZ-AY15VG

Summary of Contents for Mitsubishi Electric MUZ-AY15VG

  • Page 1: Table Of Contents

    [Expansion valve coil (LEV) in 12-4.] OBH938 is void. OUTDOOR UNIT No. OBH938 REVISED EDITION-A utilized SERVICE MANUAL Models MUZ-AY15VG MUZ-AY20VG Indoor unit service manual MSZ-AY•VG Series (OBH937) CONTENTS 1. TECHNICAL CHANGES ······························2 2. SERVICING PRECAUTIONS FOR UNITS USING REFRIGERANT R32 ·························3 3.

  • Page 2: Technical Changes

    • When opening or closing the valve below freezing temperatures, refrigerant may spurt out from the gap between the valve stem and the valve body, resulting in injuries. Revision A: • TROUBLESHOOTING CRITERION OF MAIN PARTS has been corrected. [Expansion valve coil (LEV) in 12-4.] TECHNICAL CHANGES MUZ-AY15VG - MUZ-AY20VG - 1. New model OBH938A...

  • Page 3: 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 4 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 5: Part Names And Functions

    PART NAMES AND FUNCTIONS MUZ-AY15VG Air inlet (Back) Piping Drain hose Air outlet Drain outlet MUZ-AY20VG Air inlet (Back and side) Piping Air outlet Drain hose Drain outlet ACCESSORIES MUZ-AY15VG MODELS MUZ-AY20VG Drain socket OBH938A...

  • Page 6: Specification

    SPECIFICATION Outdoor model MUZ-AY15VG MUZ-AY20VG Power supply Single phase, 230 V, 50 Hz Cooling 1.5 (0.5 - 2.2) 2.0 (0.6 - 2.7) Capacity Rated (Min.-Max.) Heating 2.0 (0.5 - 3.1) 2.5 (0.5 - 3.5) Breaker Capacity Cooling Power input *1 (Set)
  • Page 7 Specifications and rated conditions of main electric parts Model MUZ-AY15VG MUZ-AY20VG Item (C61) 800 µF 420 V 600 µF/ 620 µF 420 V Smoothing capacitor (C62) — 600 µF/ 620 µF 420 V (DB61) 25 A 600 V Diode module...

  • Page 8: Noise Criteria Curves

    NOISE CRITERIA CURVES MUZ-AY15VG MUZ-AY20VG FAN SPEED FUNCTION SPL(dB(A)) LINE FAN SPEED FUNCTION SPL(dB(A)) LINE COOLING COOLING Super High Super High 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 1000 2000 4000 8000 1000...

  • Page 9: Outlines And Dimensions

    OUTLINES AND DIMENSIONS MUZ-AY15VG Unit: mm MUZ-AY20VG OBH938A...

  • Page 10: Wiring Diagram

    WIRING DIAGRAM MUZ-AY15VG - MUZ-AY15VG - İNVERTER BASKILI SİGORTA DEVRE KARTI 230V 50Hz GÜÇ KAYNAĞI NOTLAR : 1. İç ünite elektronik kablolaması için iç ünite elektronik kablo devre şemasını referans alınız. 2. Sadece bakır besleme kablosu kullanın. 3. Sembolleri gösterir.
  • Page 11 MUZ-AY20VG - MUZ-AY20VG - İNVERTER BASKILI SİGORTA DEVRE KARTI 230V 50Hz GÜÇ KAYNAĞI NOTLAR : 1. İç ünite elektronik kablolaması için iç ünite elektronik kablo devre şemasını referans alınız. 2. Sadece bakır besleme kablosu kullanın. 3. Sembolleri gösterir. :Terminal bloğu :Konnektör SEMBOL PARÇA ADI...

  • Page 12: Refrigerant System Diagram

    REFRIGERANT SYSTEM DIAGRAM MUZ-AY15VG Unit: mm Refrigerant pipe ø9.52 4-way valve (with heat insulator) Muffler Outdoor heat exchanger Stop valve temperature (with service port) Outdoor Muffler thermistor Discharge heat Flared connection RT68 temperature exchanger thermistor RT62 Ambient Compressor temperature thermistor...
  • Page 13 MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE Refrigerant piping: m Piping size O.D: mm Model Max. Length A Max. Height difference B Liquid MUZ-AY15VG 9.52 6.35 MUZ-AY20VG Indoor unit Max. Height difference Max. Length Outdoor unit ADDITIONAL REFRIGERANT CHARGE (R32: g)

  • Page 14: Performance Curves

    PERFORMANCE CURVES MUZ-AY15VG MUZ-AY20VG 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 oper- ating characteristics of the air conditioner under the conditions indicated by the performance curve.
  • Page 15 Outdoor intake air Wet-bulb temperature (°C) Outdoor intake air Wet-bulb temperature (°C) Lower limit of guaranteed operating range in heating MUZ-AY15VG: -15°C, MUZ-AY20VG: -20°C NOTE: The above broken lines are for the heating operation without any frost and defrost operation. OBH938A...
  • Page 16 9-2. CAPACITY AND INPUT CORRECTION BY OPERATIONAL FREQUENCY OF COMPRESSOR MUZ-AY15VG 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)
  • Page 17 Outdoor unit current MUZ-AY15VG MUZ-AY20VG Ambient temperature (°C) Ambient temperature (°C) Ambient humidity(%) Ambient humidity(%) HEAT operation Condition: Indoor Outdoor Dry bulb temperature (°C) 20.0 20.0 Wet bulb temperature (°C) 14.5 14.5 Operation: Test run operation (Refer to 9-3.) Outdoor unit current...
  • Page 18 PERFORMANCE DATA COOL operation at Rated frequency MUZ-AY15VG CAPACITY: 1.5 kW SHF: 0.86 INPUT: 370 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 1.76 1.20 0.68 1.69 1.15 0.68 1.62 1.10 0.68 1.56 1.06 0.68...
  • Page 19 PERFORMANCE DATA COOL operation at Rated frequency MUZ-AY15VG CAPACITY: 1.5 kW SHF: 0.86 INPUT: 370 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 1.47 1.00 0.68 1.35 0.92 0.68 1.25 0.85 0.68 1.55 0.87 0.56 1.44...
  • Page 20 PERFORMANCE DATA COOL operation at Rated frequency MUZ-AY20VG CAPACITY: 2.0 kW SHF: 0.8 INPUT: 460 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 2.35 1.46 0.62 2.25 1.40 0.62 2.16 1.34 0.62 2.08 1.29 0.62 2.45 1.23...
  • Page 21 PERFORMANCE DATA COOL operation at Rated frequency MUZ-AY20VG CAPACITY: 2.0 kW SHF: 0.8 INPUT: 460 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 1.96 1.22 0.62 1.80 1.12 0.62 1.66 1.03 0.62 2.06 1.03 0.50 1.92 0.96 0.50...
  • Page 22 PERFORMANCE DATA HEAT operation at Rated frequency MUZ-AY15VG CAPACITY: 2.0kW INPUT: 500 W OUTDOOR WB (°C) INDOOR DB (°C) INPUT INPUT INPUT INPUT INPUT INPUT INPUT INPUT 1.00 1.26 1.52 1.78 2.04 2.30 2.54 2.80 0.94 1.20 1.44 1.70 1.94 2.20...

  • Page 23: Actuator Control

    ACTUATOR CONTROL MUZ-AY15VG MUZ-AY20VG 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.

  • Page 24: Service Functions

    SERVICE FUNCTIONS MUZ-AY15VG MUZ-AY20VG 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.) Jumper wire Defrost finish temperature (°C) Soldered (Initial setting) None (Cut) 11-2.

  • Page 25: Troubleshooting

    TROUBLESHOOTING MUZ-AY15VG MUZ-AY20VG 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 26 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 27 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 28 3. Table of outdoor unit failure mode recall function NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (12-3.). Indoor/outdoor Outdoor unit Left lamp Abnormal point LED indication unit failure Condition Remedy failure mode (Indoor unit) (Failure mode/protection) (Outdoor P.C.
  • Page 29 NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (12-3.). Indoor/outdoor Outdoor unit Left 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 30 12-3. TROUBLESHOOTING CHECK TABLE Abnormal point/ Symptom LED indication Condition Remedy Condition Outdoor unit 1-time blink every Outdoor power Overcurrent protection cut-out operates 3 consecutive times • Reconnect connector of does not 2.5 seconds system within 1 minute after the compressor gets started. compressor.
  • Page 31 Abnormal point/ Symptom LED indication Condition Remedy Condition Outdoor unit 4-time blink Deceleration of the Temperature of discharge temperature thermistor exceeds • Check refrigerant circuit and refrig- operates. 2.5 seconds OFF operational frequency 111°C, compressor frequency lowers. erant amount. of the compressor by •...
  • Page 32 12-4. TROUBLESHOOTING CRITERION OF MAIN PARTS Part name Check method and criterion Figure Defrost thermistor (RT61) Measure the resistance with a multimeter. Fin temperature Refer to 12-6. “Test point diagram and voltage”, 1. “Inverter P.C. board”, thermistor (RT64) for the chart of thermistor. Ambient temperature thermistor (RT65) Outdoor heat exchanger...
  • Page 33 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 34 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 *Measure the resistance between the lead wires at 3 points. BLK-WHT BLK-RED WHT-RED...
  • Page 35 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 36 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 terminal of outdoor fan motor normal? (Refer to 12-4.) Disconnect CN932 from the inverter P.C.
  • Page 37 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. Does the left lamp of Operation Is there voltage 230 V AC Replace the indoor indicator lamp on the indoor unit between the indoor terminal...
  • Page 38 K Check of LEV (Expansion valve) 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 39 L Check of inverter P.C. board Check the outdoor fan motor. (Refer to 12-5. .) Is the fuse (F901) blown on the inverter 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 40 M How to check miswiring and serial signal error Turn the main 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...
  • Page 41 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 42 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 out- distance between the antennas and door unit.

  • Page 43: Muz-Ay15Vg

    12-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUZ-AY15VG Back side of unit DB61 Smoothing 260 V - 370 V DC 230 V AC capacitor Fuse (F801) Fuse (F701) R.V. coil/21S4 (C61) T3.15AL250V T3.15AL250V (CN721) Fuse (F61) 15A 250V...
  • Page 44 MUZ-AY20VG R.V.coil Back side of unit DB61 (CN721) 260 - 370 V DC 230 V AC Smoothing Smoothing Fuse (F801) Fuse (F701) capacitor capacitor 230 V AC T3.15AL250V T3.15AL250V (C61) (C62) Fuse (F62) 15 A 250 V Fuse (F61) Output to 25 A 250V drive compressor...

  • Page 45: Disassembly Instructions

    Locking lever Connector 13-1. MUZ-AY15VG : Indicates the visible parts in the photos. : Indicates the invisible parts in the photos. NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS/FIGURES 1.
  • Page 46 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly, inverter P.C. Photo 4 board Screw of the P.C. Screw of the heat Screws of the terminal (1) Remove the cabinet and the panels. (Refer to board support and sink support and block support and the section 1.) the motor support...
  • Page 47 OPERATING PROCEDURE PHOTOS/FIGURES 4. Removing the discharge temperature thermistor, Photo 8 the defrost thermistor, the ambient temperature thermistor and the outdoor heat exchanger tem- perature thermistor Screws of (1) Remove the cabinet and the panels. (Refer to section the reactor (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C.
  • Page 48 OPERATING PROCEDURE PHOTOS/FIGURES 6. Removing the compressor and the 4-way valve Photo 11 R.V. coil Suction pipe (1) Remove the cabinet and the panels. (Refer to brazed part section 1.) (2) Remove the inverter assembly. (Refer to section 2.) (3) Remove the screws of the reactor and remove the reactor.
  • Page 49 13-2. MUZ-AY20VG NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS/FIGURES 1. Removing the cabinet Photo 1 (1) Remove the screw fixing the service panel. Screws of the top panel Screws of (2) Pull down the service panel and remove it. the top panel (3) Disconnect the power supply cord and indoor/outdoor connecting wire.
  • Page 50 OPERATING PROCEDURE PHOTOS/FIGURES 2. Removing the inverter assembly and inverter P.C. Photo 4 board Screw of the P.B. support Screws of the terminal block (1) Remove the cabinet and panels. (Refer to section 1.) and the separator support and the back panel (2) Disconnect the lead wire to the reactor and the follow- ing connectors: <Inverter P.C.
  • Page 51 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing R.V. coil Photo 7 (1) Remove the cabinet and panels. (Refer to section 1.) Ambient temperature (2) Disconnect the following connectors: thermistor <Inverter P.C. board> CN721 (R.V. coil) (3) Remove the R.V. coil. 4. Removing the discharge temperature thermistor, defrost thermistor, outdoor heat exchanger tem- perature thermistor and ambient temperature thermistor...
  • Page 52 (1) Detaching the brazed part of pipes connected with LEV valve. Brazed parts of LEV valve HEAD OFFICE: TOKYO BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2023 MITSUBISHI ELECTRIC CORPORATION Issued: Nov. 2023. No. OBH938 REVISED EDITION-A Published: Aug. 2023. No. OBH938 Made in Japan...

This manual is also suitable for:

Muz-ay20vgMuz-ay15vg-e1Muz-ay20vg-e1Muz-ay15vg-et1Muz-ay20vg-et1

Table of Contents