Mitsubishi Electric MUZ-A18YV Service Manual

Split-type, heat pump air conditioners wireless type models

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SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS

SERVICE MANUAL

Wireless type

Models

MUZ-A18YV -

MUZ-A24YV -

MUZ-A26YV -

NOTE:

This service manual describes technical data of the outdoor units.

•As for indoor units MSZ-A18YV -

service manual OB345.

•As for indoor units MCFZ-A18WV -

OB344.

Indication of

model name

MUZ-A18YV -

MUZ-A24YV -

MUZ-A26YV -

, MSZ-A24YV -

and MSZ-A26YV -

and MCFZ-A24WV -

Revision E:

• "Check of outdoor thermistors" has been corrected.

Please void OB346 REVISED EDITION-D.

HFC

utilized

R410A

CONTENTS

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

2. PART NAMES AND FUNCTIONS······················6

3. SPECIFICATION·················································7

4. NOISE CRITERIA CURVES ·····························10

5. OUTLINES AND DIMENSIONS························11

6. WIRING DIAGRAM ··········································12

7. REFRIGERANT SYSTEM DIAGRAM ··············14

8. PERFORMANCE CURVES ······························16

9. ACTUATOR CONTROL····································31

10. TROUBLESHOOTING······································32

11. DISASSEMBLY INSTRUCTIONS·····················46

12. PARTS LIST······················································50

, refer to the

, refer to the service manual

No. OB346

REVISED EDITION-E

Table of Contents

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Summary of Contents for Mitsubishi Electric MUZ-A18YV

Page 1: Table Of Contents
Please void OB346 REVISED EDITION-D. No. OB346 REVISED EDITION-E utilized SERVICE MANUAL R410A Wireless type Models MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - CONTENTS 1. TECHNICAL CHANGES ····································3 2. PART NAMES AND FUNCTIONS······················6 3. SPECIFICATION·················································7 Indication of 4. NOISE CRITERIA CURVES ·····························10 model name 5.
Page 2: Revision E
Revision A: • MUZ-A18YV - can be connected to MCFZ-A18WV - • MUZ-A24YV - can be connected to MCFZ-A24WV - Revision B: • Part number of 4-WAY VALVE has been corrected. Part Number Part Name Model Revise point Incorrect Correct MUZ-A18YV - 12-1.
Page 3: Technical Changes
TECHNICAL CHANGES INFORMATION FOR THE AIR CONDITIONER WITH R410A REFRIGERANT • This room air conditioner adopts an HFC refrigerant (R410A) which never destroys the ozone layer. • Pay particular attention to the following points, though the basic installation procedure is same as that for R22 air conditioners.
Page 4 Conversion chart of refrigerant temperature and pressure (MPa [Gauge]) R410A NOTE : The unit of pressure has been changed to MPa on the international system of units(SI unit system). f [Gauge]) The conversion factor is: 1(MPa [Gauge]) =10.2(kgf/f -0.5 -30 -20 -10 1.Tools dedicated for the air conditioner with R410A refrigerant The following tools are required for R410A refrigerant.
Page 5 2 Flaring work and flare nut Flaring work for R410A pipe differs from that for R22 pipe. For details of flaring work, refer to Installation manual “FLARING WORK”. Dimension of flare nut Pipe diameter R410A 6.35 9.52 12.7 15.88 3.Refrigerant oil Apply the special refrigeration oil (accessories: packed with indoor unit) to the flare and the union seat surfaces.
Page 6: Part Names And Functions
PART NAMES AND FUNCTIONS MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - OUTDOOR UNIT Air inlet (back and side) Piping Drain hose Air outlet Drain outlet ACCESSORIES MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - Drain socket Drain cap [33...
Page 7: Specification
SPECIFICATION MUZ-A18YV - MUZ-A18YV - Outdoor model Indoor model Indoor model MSZ-A18YV - MCFZ-A18WV - Cooling Heating Function Cooling Heating Single phase Single phase Power supply 230V,50Hz 230V,50Hz 6.0(0.9~7.5) Capacity Rated frequency(Min.~Max.) 5.0(0.9~5.9) 5.9(0.9~7.8) 4.8(10.9~5.5) Dehumidification — — Air flow(High/Low W )
Page 8 MUZ-A24YV - MUZ-A24YV - MUZ-A26YV - Outdoor model Indoor model Indoor model Indoor model MSZ-A24YV - MCFZ-A24WV - MSZ-A26YV - Cooling Heating Cooling Heating Cooling Heating Function Single phase Single phase Single phase Power supply 230V,50Hz 230V,50Hz 230V,50Hz 5.5(0.9~6.1) 6.4(0.9~7.9) 7.1(0.9~8.3) 8.1(0.9~9.6) Capacity Rated frequency(Min.~Max.)
Page 9: Outdoor Unit
Specifications and rating conditions of main electric parts OUTDOOR UNIT Model MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - Item (CB1,2,3) Smoothing capacitor 560+ 450V Current transformer (CT1,2) ETQ19Z68AY (CT61) Current transformer ETQ19Z53AY Fuse (F801, F912) 250V 3.15A (F911) Fuse 250V 1A...
Page 10: Noise Criteria Curves
NOISE CRITERIA CURVES MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - SPEED FUNCTION SPL(dB(A)) LINE COOLING High HEATING Test conditions, Cooling : Dry-bulb temperature 35: Wet-bulb temperature (24:) Heating : Dry-bulb temperature 7: Wet-bulb temperature 6: OUTDOOR UNIT NC-70 NC-60 MICROPHONE NC-50...
Page 11: Outlines And Dimensions
Open as a rule 500mm or more if the back, 350mm or more both sides and top are open Service panel Liquid refrigerant pipe joint Refrigerant pipe (flared) [6.35 (MUZ-A18/A24YV) [9.52 (MUZ-A26YV) Gas refrigerant pipe joint Refrigerant pipe (flared) [12.7 (MUZ-A18YV) [15.88 (MUZ-A24/A26YV)
Page 12: Wiring Diagram
WIRING DIAGRAM MUZ-A18YV - MUZ-A24YV - MODELS WIRING DIAGRAM OUTDOOR UNIT...
Page 13 MUZ-A26YV - MODEL WIRING DIAGRAM OUTDOOR UNIT...
Page 14: Refrigerant System Diagram
REFRIGERANT SYSTEM DIAGRAM MUZ-A18YV - Unit:mm MUZ-A24YV - OUTDOOR UNIT Refrigerant pipe [12.7 (MUZ-A18YV) Muffler #100 (with heat insulator) [15.88 (MUZ-A24YV) 4-way valve Stop valve (with service port) Outdoor Flared connection Discharge heat temperature exchanger thermistor Defrost RT61 thermistor RT62...
Page 15 MAX. REFRIGERANT PIPING LENGTH Refrigerant piping Piping size O.D : mm Length of connecting pipe : m Model Max. length : m Liquid Indoor unit Outdoor unit MUZ-A18YV - 12.7 6.35 Gas 0.43 Gas 0 MUZ-A24YV - Liquid 0.5 Liquid 0 15.88 MUZ-A26YV - 9.52...
Page 16: Performance Curves
PERFORMANCE CURVES MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - 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.
Page 17 12.1 13.8 14.4 Outdoor intake air Wet-bulb temperature (:) Outdoor intake air Wet-bulb temperature (:) NOTE:The above curves are for the heating operation without any frost. MUZ-A18YV - MUZ-A18YV - MUZ-A18YV - MUZ-A18YV - Indoor unit : Indoor unit :...
Page 18 OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT COOL operation 1 Both indoor and outdoor unit are under the Dry-bulb temperature(°C) Relative humidity(%) same temperature/humidity condition. 2 Air flow : High speed 3 Operational frequency : 25Hz(MUZ-A18YV) 25Hz(MUZ-A24YV) 24Hz(MUZ-A26YV) MUZ-A18YV - MUZ-A18YV - MUZ-A18YV - MUZ-A18YV -...
Page 19: Heat Operation
35(˚C) 35(˚C) Ambient temperature(˚C) Ambient humidity(%) Ambient temperature(˚C) Ambient humidity(%) HEAT operation Condition indoor: Dry bulb temperature 20.0°C Operational frequency : 32Hz(MUZ-A18YV) Wet bulb temperature 14.5°C 32Hz(MUZ-A24YV) Condition outdoor: Dry bulb temperature 2,7,15,20.0°C 32Hz(MUZ-A26YV) Wet bulb temperature 1,6,12,14.5°C MUZ-A18YV -...
Page 20 PERFORMANCE DATA COOL operation Rated frequency 73Hz MSZ-A18YV - : MUZ-A18YV - SHF:0.65 INPUT:1560(W) CAPACITY:5.0(kW) OUTDOOR DB( : ) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 5.88 2.76 0.47 1248 5.63 2.64 0.47 1310 5.40 2.54 0.47...
Page 21 PERFORMANCE DATA COOL operation Rated frequency 73Hz MSZ-A18YV - : MUZ-A18YV - CAPACITY : 5.0(kW) SHF : 0.65 INPUT : 1560(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 4.90 2.30 0.47 1529 4.50 2.12 0.47...
Page 22 PERFORMANCE DATA COOL operation Rated frequency 84Hz MCFZ-A18WV - : MUZ-A18YV - CAPACITY:4.8(kW) SHF:0.65 INPUT:1830(W) OUTDOOR DB( : ) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 5.64 2.65 0.47 1464 5.40 2.54 0.47 1537 5.18 2.44 0.47...
Page 23 PERFORMANCE DATA COOL operation Rated frequency 84Hz MCFZ-A18WV - : MUZ-A18YV - CAPACITY : 4.8(kW) SHF : 0.65 INPUT : 1830(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 4.70 2.21 0.47 1793 4.32 2.03 0.47...
Page 24 PERFORMANCE DATA COOL operation Rated frequency 88Hz MSZ-A24YV - : MUZ-A24YV - CAPACITY:6.0(kW) SHF:0.64 INPUT:1990(W) OUTDOOR DB( : ) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 7.05 3.24 0.46 1592 6.75 3.11 0.46 1672 6.48 2.98 0.46 1751...
Page 25 PERFORMANCE DATA COOL operation Rated frequency 88Hz MSZ-A24YV - : MUZ-A24YV - CAPACITY : 6.0(kW) SHF : 0.64 INPUT : 1990(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 5.88 2.70 0.46 1950 5.40 2.48 0.46 2070 5.19 2.39 0.46...
Page 26 PERFORMANCE DATA COOL operation Rated frequency 102Hz MCFZ-A24WV - : MUZ-A24YV - CAPACITY:5.5(kW) SHF:0.65 INPUT:2420(W) OUTDOOR DB( : ) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 6.46 3.04 0.47 1936 6.19 2.91 0.47 2033 5.94 2.79 0.47 2130...
Page 27 PERFORMANCE DATA COOL operation Rated frequency 102Hz MCFZ-A24WV - : MUZ-A24YV - CAPACITY : 5.5(kW) SHF : 0.65 INPUT : 2420(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 5.39 2.53 0.47 2372 4.95 2.33 0.47 2517 4.76 2.24 0.47...
Page 28 PERFORMANCE DATA COOL operation Rated frequency 63Hz MSZ-A26YV - : MUZ-A26YV - SHF:0.63 INPUT:2500(W) CAPACITY:7.1(kW) OUTDOOR DB( : ) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 8.34 3.75 0.45 2000 7.99 3.59 0.45 2100 7.67 3.45 0.45 2200...
Page 29 PERFORMANCE DATA COOL operation Rated frequency 63Hz MSZ-A26YV - : MUZ-A26YV - CAPACITY : 7.1(kW) SHF : 0.63 INPUT : 2500(W) OUTDOOR DB(:) INDOOR INDOOR DB(:) WB(:) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 6.96 3.13 0.45 2450 6.39 2.88 0.45 2600 6.14 2.76 0.45...
Page 30 PERFORMANCE DATA HEAT operation MSZ-A18YV - : MUZ-A18YV - Rated frequency 82Hz CAPACITY:5.9(kW) INPUT:1730(W) WB( : ) OUTDOOR INDOOR DB( : ) INPUT INPUT INPUT INPUT INPUT INPUT INPUT 3.72 1125 4.48 1349 5.25 1522 6.02 1644 6.79 1747 7.49 1799 8.26...
Page 31: Actuator Control
ACTUATOR CONTROL MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - 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.
Page 32: Troubleshooting
TROUBLESHOOTING MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - 10-1. Cautions on troubleshooting 1. Before troubleshooting, check the following: 1) Check the power supply voltage. 2) Check the indoor/outdoor connecting wire for mis-wiring. 2. Take care of the following during servicing 1) Before servicing the air conditioner, be sure to first turn off the remote controller to stop the main unit, then after confirming the horizontal vane is closed, turn off the breaker and / or disconnect the power plug.
Page 33 10-2. Instruction of troubleshooting Start Indoor unit Indoor unit Indoor unit operates. OPERATION INDICATOR operates. doesn't receive Outdoor unit doesn't lamp on the indoor unit is Outdoor unit the signal from operate normally. flashing on and off. doesn't remote controller. operate.
Page 34 1. Troubleshooting check table LED 1 (Red) LED 2 (Yellow) Error mode Lighting Lighting Normal Symptom: Outdoor unit does not operate. Indication Abnormal point Detecting method Check points LED 1 LED 2 (Red) (Yellow) When the compressor operation has been interrupted by overcurrent protection continuously three times within 1 minute after start-up, or Lighting Twice...
Page 35 Symptom: Outdoor unit operates (The compressor operates at reduced frequency) Indication Abnormal point Detecting method Check points LED 1 LED 2 (Red) (Yellow) Once Lighting Current protection When the outdoor unit input current exceeds 14.5A. Twice Lighting High-pressure protection When the indoor gas pipe temperature exceeds 55˚C during heating. Twice Lighting Defrosting in cooling When the indoor gas pipe temperature falls to 6˚C or below during cooling.
Page 36 2. Trouble criterion of main parts MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - Part name Check method and criterion Measure the resistance using a tester. Defrost thermistor/ (Part temperature : -10°C ~ 40°C) Outdoor heat exchanger Normal abnormal temperature thermistor Open or short-circuit 5kΩ...
Page 37 Outdoor unit does not operate. (LED display: display OFF) A A Check of power supply Start Check the connecting of parts of main power supply circuit. Turn on power supply. Is there voltage of 230V AC in the Check the power supply cable. power supply terminal block? Replace the noise Is the output voltage from the noise...
Page 38 When OPERATION INDICATOR lamp flashes ON and OFF every 0.5-second. Outdoor unit doesn’t operate. (LED display: Both LED1 and LED2 lighting) How to check mis-wiring and serial signal error (when outdoor unit does not work) Start • Turn ON the power supply (Indoor/ outdoor unit). •...
Page 39 The cooling operation or heating operation does not operate. (LED display: Both LED1 and LED2 lighting) C C Check of R.V. coil • When heating operation does not work. Start 1. Disconnect the lead wire leading to the compressor. 2. 3 minutes after turning on the power supply, start EMERGENCY OPERATION in HEAT mode.
Page 40 • When cooling, heat exchanger of non-operating indoor unit is frosted. • When heating, non-operating indoor unit get warm. D D Check of LEV LED display: LED1 LED2 Lighting Lighting 6 time Goes out Start Turn on power supply to the outdoor unit after checking LEV coil is mounted to the LEV body securely.
Page 41 • When OPERATION INDICATOR lamp flashes 6-time. • When thermistor is abnormal. F F Check of outdoor thermistors Start Disconnect the connector in the electronic control P.C. board (see below table), and Replace the thermistor. measure the resistance of thermistor. Is the thermistor normal? w When RT65 is abnormal, replace the outdoor power board.
Page 42 • When the operation frequency does not go up from lowest frequency. H H Check of HPS MUZ-A26YV Start 1. Disconnect the connector CN681 in the electronic control P.C. board. 2. Check the resistance of HPS after 1 minute have passed since the outdoor unit power supply was turned off. Infinity Check the resistance between Replace HPS.
Page 43 MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - Defrost temperature thermistor (RT62) Fin temperature thermistor (RT65) Outdoor heat exchanger temperature thermistor (RT68) Outdoor electronic control P.C. board Discharge temperature thermistor (RT61) 10 20 30 40 50 60 70 80 Temperature (;) 100 110 120 Temperature (;)
Page 44 MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - Noise filter P.C. board CN901 Electronic control CN902 CN903 230V AC board Power board 50Hz Input CN912 R.V. coil 230V AC 230V AC 50Hz Output F911 FUSE F912 FUSE 1A/250V 3.15A/250V NR63 VARISTOR...
Page 45 MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - Power board Connect to the compressor Voltage among phases: 5V to 180V 325-370V DC Connect to the earth Output (Red) Connect to the controller board (–) (+)1-5(–): Signal transmission (To electronic control P.C. board)
Page 46: Disassembly Instructions
2Pull the terminal while pull out the terminal pushing the locking slowly. Locking lever lever. Connector NOTE : MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - These photos are MUZ-A26YV. Other models are almost the same as MUZ-A26YV. OUTDOOR UNIT OPERATING PROCEDURE PHOTOS 1.
Page 47 OPERATING PROCEDURE PHOTOS 2. Removing the inverter assembly, inverter P.C. board Photo 4 and power board Screws of the power board assembly (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;...
Page 48 OPERATING PROCEDURE PHOTOS 4. Removing the defrost thermistor, discharge temper- Photo 5 ature thermistor and outdoor heat exchanger tem - Discharge temperature thermistor perature thermistor (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.
Page 49 OPERATING PROCEDURE PHOTOS 6. Removing the compressor and 4-way valve Photo 8 (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.
Page 50: Parts List
PARTS LIST MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - 12-1. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS These figures show about MUZ-A26YV.
Page 51 MUZ-A18YV - MUZ-A24YV - MUZ-A26YV - 12-1. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS Part numbers that are circled are not shown in the illustration. Q'ty/unit Symbol Part No. Part Name in Wiring Remarks MUZ-A18 MUZ-A24 MUZ-A26 Diagram...
Page 52 DRAIN CAP HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN C C Copyright 2004 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD Distributed in Feb. 2007. No. OB346 REVISED EDITION - E 6 Distributed in Aug. 2006. No. OB346 REVISED EDITION - D 6 Distributed in May 2006.

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Mitsubishi Electric MUZ-A18YV Service Manual

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