Mitsubishi Electric MUZ-DM25VA Service Manual

Outdoor unit of split-type air conditioner

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Installation manual (4 pages)

Operating instructions manual (29 pages)

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Summary of Contents for Mitsubishi Electric MUZ-DM25VA

Page 1: Table Of Contents
OUTDOOR UNIT No. OBH751 utilized SERVICE MANUAL R410A Models MUZ-DM25VA MUZ-DM35VA Indoor unit service manual MSZ-DM•VA Series (OBH750) CONTENTS 1. TECHNICAL CHANGES ······························2 2. PART NAMES AND FUNCTIONS ··················3 3. SPECIFICATION ········································4 4. NOISE CRITERIA CURVES ··························6 5. OUTLINES AND DIMENSIONS ·····················7 6.
Page 2: Technical Changes
Do not touch the hot or cold areas in the refrigeration cycle. When the repair or the inspection of the circuit needs to be done without turning off the power, exercise great caution not to touch the live parts. TECHNICAL CHANGES MUZ-DM25VA - MUZ-DM35VA - 1. New model OBH751...
Page 3: Part Names And Functions
PART NAMES AND FUNCTIONS MUZ-DM25VA MUZ-DM35VA Air inlet (Back and side) Piping Drain hose Air outlet Drain outlet ACCESSORIES Drain socket OBH751...
Page 4: Specification
SPECIFICATION MUZ-DM25VA MUZ-DM35VA Outdoor model Power supply Single phase, 230 V, 50 Hz Cooling 2.5 (1.3 - 3.0) 3.15 (1.4 - 3.5) Capacity Rated frequency (Min.-Max.) Heating 3.15 (0.9 - 3.5) 3.6 (1.1 - 4.1) Breaker Capacity Cooling 1,020 Power input 1 (Set)
Page 5 Specif cations and rated conditions of main electric parts Model MUZ-DM25VA MUZ-DM35VA Item Smoothing capacitor (C62) 800 μF 420 V (DB61) 15 A 600 V Diode module (DB65) 25 A 600 V Fuse (F701, F801, F901) T3.15AL250V Power module (IC700)
Page 6: Noise Criteria Curves
NOISE CRITERIA CURVES MUZ-DM25VA MUZ-DM35VA 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...
Page 7: Outlines And Dimensions
OUTLINES AND DIMENSIONS MUZ-DM25VA MUZ-DM35VA Unit : mm REQUIRED SPACE Air in *1 100 mm or more when front and sides of the unit are clear Drain hole ø33 Air in Air out 2 - 10.3 X 19.3 Oval hole 349.5...
Page 8: Wiring Diagram
WIRING DIAGRAM MUZ-DM25VA MUZ-DM35VA OBH751...
Page 9: Refrigerant System Diagram
REFRIGERANT SYSTEM DIAGRAM MUZ-DM25VA MUZ-DM35VA Unit : mm 4-way valve Refrigerant pipe ø9.52 (with heat insulator) Muffler Stop valve (with service port) Outdoor Muffler Discharge heat Flared connection exchanger temperature thermistor RT62 Compressor Defrost thermistor RT61 Strainer #100 Flared connection Capillary tube ø...
Page 10: Performance Curves
PERFORMANCE CURVES MUZ-DM25VA MUZ-DM35VA 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 11 8-1. CAPACITY AND INPUT CURVES Cooling capacity (at Rated frequency) Outdoor intake air Dry-bulb temperature (°C) Total input (Cooling :at Rated frequency) Outdoor intake air Dry-bulb temperature (°C) Heating capacity Total input (at Rated frequency) (Heating at Rated frequency) 22.9 20.6 21.1 19.0...
Page 12 8-2. CAPACITY AND INPUT CORRECTION BY OPERATIONAL FREQUENCY OF COMPRESSOR MUZ-DM25VA Correction of Cooling capacity Correction of Cooling total input Correction of Heating total input Correction of Heating capacity (Hz) (Hz) (Hz) (Hz) The operational frequency of compressor The operational frequency of compressor...
Page 13 COOL operation Dry-bulb temperature (°C) Relative humidity (%) Both indoor and outdoor unit are under the same tempera- ture/humidity condition. Operation: TEST RUN OPERATION (Refer to 8-3.) Outdoor low pressure MUZ-DM25VA MUZ-DM35VA (kgf/cm [Gauge])(MPa [Gauge]) (kgf/cm [Gauge])(MPa [Gauge]) (°C) (°C) Ambient temperature(°C)
Page 14 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 8-3.) Outdoor unit current MUZ-DM25VA MUZ-DM35VA Ambient temperature (°C) Ambient temperature (°C) OBH751...
Page 15 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-DM25VA CAPACITY: 2.5 kW SHF: 0.89 INPUT: 710 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 2.94 2.09 0.71...
Page 16 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-DM25VA CAPACITY: 2.5 kW SHF: 0.89 INPUT: 710 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 2.45 1.74 0.71 2.25 1.60 0.71...
Page 17 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-DM35VA CAPACITY: 3.15 kW SHF: 0.87 INPUT: 1020 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 3.70 2.55 0.69 3.54 2.45...
Page 18 PERFORMANCE DATA COOL operation a t Rated frequency MUZ-DM35VA CAPACITY: 3.15 kW SHF: 0.87 INPUT: 1020 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) SHC SHF INPUT SHC SHF INPUT SHC SHF INPUT 3.09 2.13 0.69 1000 2.84 1.96 0.69 1061...
Page 19 PERFORMANCE DATA HEAT operation at Rated frequency MUZ-DM25VA CAPACITY: 3.15 kW INPUT: 850 W OUTDOOR WB (°C) INDOOR DB (°C) INPUT INPUT INPUT INPUT INPUT INPUT INPUT 1.98 2.39 2.80 3.21 3.62 4.00 4.41 1.89 2.27 2.68 3.06 3.47 3.84 4.24...
Page 20: Actuator Control
ACTUATOR CONTROL MUZ-DM25VA MUZ-DM35VA 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 21: Service Functions
SERVICE FUNCTIONS MUZ-DM25VA MUZ-DM35VA 10-1. CHANGE IN DEFROST SETTING <JS> When the JS wire of the inverter P.C. board is cut/ soldered, the defrost finish temperature is changed. (Refer to 11-6-1.) Defrost f nish temperature (°C) Jumper wire MUZ-DM25/35VA Soldered...
Page 22: Troubleshooting
TROUBLESHOOTING MUZ-DM25VA MUZ-DM35VA 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. 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 23 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.
Page 24 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 25 3. Outdoor unit failure mode table The upper lamp of Indoor/outdoor Outdoor unit OPERATION Abnormal point LED indication unit failure Condition Remedy failure mode INDICATOR (Failure mode/protection) (Outdoor P.C. board) mode recall recall function lamp function (Indoor unit) None (Normal) —...
Page 26 The upper lamp of Indoor/outdoor Outdoor unit OPERATION Abnormal point LED indication unit failure Condition Remedy failure mode INDICATOR (Failure mode/protection) (Outdoor P.C. board) mode recall recall function lamp function (Indoor unit) 11-time f ash DC voltage 8-time f ash DC voltage of inverter cannot be •...
Page 27 11-3. TROUBLESHOOTING CHECK TABLE Abnormal point/ Symptom LED indication Condition Remedy Condition Outdoor unit 1-time f ash 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, or failure of sor.
Page 28 Abnormal point/ Symptom LED indication Condition Remedy Condition Outdoor unit 7-time f ash Low discharge tem- Temperature of discharge temperature thermistor has been • Refer to 11-5. "Check of LEV". operates. 2.5 seconds OFF perature protection 50°C or less for 20 minutes. •...
Page 29 11-4. TROUBLE CRITERION OF MAIN PARTS MUZ-DM25VA MUZ-DM35VA Part name Check method and criterion Figure Measure the resistance with a tester. Defrost thermistor (RT61) Refer to 11-6. “Test point diagram and voltage”, 1. “Inverter P.C. board”, for the chart of thermistor.
Page 30 11-5. TROUBLESHOOTING FLOW A How to check inverter/compressor Disconnect the connector (CN61) between compressor and the power module (IC700). Check the voltage between terminals. See 11-5. “Check of open phase”. Replace the inverter P.C. board. Are the voltages balanced? Check the compressor. See 11-5.
Page 31 C Check of compressor Refer to 11-5. “Check of compressor Replace the compressor. winding”. Is the compressor normal? Refer to 11-5. “Check of compressor operation time”. Refer to 11-5. “Check of compressor start failure”. Does the compressor operate continuously? D Check of compressor winding ●...
Page 32 F Check of compressor start failure Make sure that is normal. •Electrical circuit check . Contact of the compressor connector (Including CN61) . Output voltage of inverter P.C. board and balance of them (See 11-5. ) . Direct current voltage between DB61(+) and (-) on the inverter P.C. board .
Page 33 H Check of R.V. coil First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 11-4. In case CN721 is not connected or R.V. coil is open, voltage is generated between the terminal pins of the connector although any signal is not being transmitted to R.V.
Page 34 I Check of outdoor fan motor Check the resistance of fan motor. (Refer to 11-4.) Is the resistance of Replace the outdoor fan motor normal? fan motor. Disconnect the connector CN771 on the inverter P.C. board. Disconnect the connector (CN61) between compressor and power transistor module.
Page 35 250 - 370 VDC J Check of power supply DB61 Disconnect the connector (CN61) between compressor and power module. Rectify indoor/outdoor Turn ON power supply and press connecting wire. EMERGENCY OPERATION switch. Inverter P.C. board (Solder side) Is there voltage 230 VAC Replace the indoor Does the upper lamp of OPERATION electronic control P.C.
Page 36 L How to check miswiring and serial signal error Turn OFF the power supply. Is there rated voltage in the Check the power supply. power supply? 1. Turn ON the power supply. 2. Press the emergency operation switch. Has the relay 52C been turned on 3 minuets later ? [The relay will be turned on in 3 to 7 seconds by bridging the timer short mode point (Refer to the indoor unit service manual.).] Initializing the determination of the power...
Page 37 M Check of outdoor refrigerant circuit The unit occasionally stops when the Was the operation started with Has the operation stopped stop valve is opened or closed during the stop valve closed, and was during pump down? operation. Open the stop valve and it opened during operation? start the cooling operation again.
Page 38 N 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 39 11-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUZ-DM25VA MUZ-DM35VA Back side of unit R.V. coil Fuse (F901) (CN721) Smoothing Fuse (F801) DB61 T3.15AL250V 230 VAC capacitor (C62) T3.15AL250V Fuse (F701) 250 V - 370 VDC T3.15AL250V 230 VAC...
Page 40: Disassembly Instructions
Pull the terminal while pull out the terminal pushing the locking slowly. Locking lever lever. Connector 12-1. MUZ-DM25VA MUZ-DM35VA NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS Photo 1 1. Removing the cabinet and the panels Screws of Screws of the (1) Remove the screws fixing the service panel.
Page 41 OPERATING PROCEDURE PHOTOS Photo 4 2. Removing the inverter assembly, inverter P.C. board Screws of the terminal Screw of the heat (1) Remove the cabinet and the panels. (Refer to 1.) block support and the sink support and (2) Disconnect the lead wire to the reactor and the follow- back panel the separator ing connectors:...
Page 42 OPERATING PROCEDURE PHOTOS Photo 6 4. Removing the discharge temperature thermistor, Suction pipe brazed part the defrost thermistor, the ambient temperature R.V. coil thermistor and the outdoor heat exchanger tem- perature thermistor (1) Remove the cabinet and the panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the follow- ing connectors: <Inverter P.C.
Page 43 OPERATING PROCEDURE PHOTOS 6. Removing the compressor and the 4-way valve Photo 9 (1) Remove the cabinet and the panels. (Refer to 1.) 4-way valve Suction pipe (2) Remove the inverter assembly. (Refer to 2.) brazed part brazed part (3) Remove the screws of the reactor and remove the reactor.
Page 44 HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2015 MITSUBISHI ELECTRIC CORPORATION Distributed in Dec. 2015. No. OBH751 New publication, effective Dec. 2015 Made in Japan Specifications are subject to change without notice.

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Mitsubishi Electric MUZ-DM25VA Service Manual

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