Revision A: • MUZ-HJ50VA- E1 has been added. Please void OBH648. SPLIT-TYPE AIR CONDITIONERS OUTDOOR UNIT SERVICE MANUAL HFC utilized No. OBH648 REVISED EDITION-A R410A Models MUZ-HJ25VA MUZ-HJ35VA MUZ-HJ50VA - E1 - E1 - E1 Indoor unit service manual MSZ-HJ•VA Series (OBH647) MUZ-HJ25VA MUZ-HJ35VA CONTENTS 1. TECHNICAL CHANGES ··································· 3 2. PART NAMES AND FUNCTIONS ····················· 3 3. SPECIFICATION ················································ 4 4.
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. Prepare the proper tools.
1 TECHNICAL CHANGES MUZ-HJ25VA - E1 MUZ-HJ35VA - E1 MUZ-HJ50VA - E1 1.
3 SPECIFICATION Outdoor model MUZ-HJ25VA Power supply Capacity Rated frequency (Min.-Max.
Outdoor model MUZ-HJ50VA Power supply Single phase, 230 V, 50 Hz 5.0 (1.3 - 5.0) 5.4 (1.4 - 6.5) 12 2,050 1,480 9.0 6.6 99 97 9.0 2.44 3.65 SNB130FGBHT 900 8.5 5.9 0.45 (NEO22) RC0J50-FA 0.27 0.34 800 × 550 × 285 36 2.2 1,872 1,872 1,086 2,088 1,776 1,386 50 51 810 810 490 900 770 610 3 1.15 Capacity Rated frequency (Min.-Max.
Specifications and rated conditions of main electric parts Item Smoothing capacitor Diode module Fuse Power module Expansion valve coil Reactor Switching power transistor Circuit protection Terminal block Relay R.V. coil Model MUZ-HJ25VA (C61) (DB61) (DB65) (F701, F801) (IC700) (LEV) (L61) (IC821) (PTC64) (TB) (X61) (X63) (X64) (21S4) MUZ-HJ35VA 800 μF 420 V 15 A 600 V 10 A 600 V T3.
4 NOISE CRITERIA CURVES MUZ-HJ35VA MUZ-HJ25VA FUNCTION SPL(dB(A)) LINE 50 HEATING LINE 90 OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.
5 OUTLINES AND DIMENSIONS Unit : mm MUZ-HJ25VA MUZ-HJ35VA REQUIRED SPACE Air in 100 mm or more 100 mm or more 100 mm Air out or m ore 19.6 Air in 285 Bolt pitch for installation 294~267 41.5 Drain hole ø33 2 - 10.3 X 19.3 Oval hole 349.5 249 17.9 200 mm or more 350 m mo rm ore 157.7 102.7 13.5 ° 40 43° 270.3 538 Liquid refrigerant pipe joint Refrigerant pipe (flared) ø6.35 Gas refrigerant pipe joint Refrigerant pipe (flared) ø9.52 259 121.4 121 500 55.
6 WIRING DIAGRAM MUZ-HJ25VA MUZ-HJ35VA OBH648A 9
MUZ-HJ50VA OBH648A 10
7 REFRIGERANT SYSTEM DIAGRAM Unit : mm MUZ-HJ25VA MUZ-HJ35VA Refrigerant pipe ø9.52 (with heat insulator) 4-way valve Muffler (HJ35 only) Stop valve (with service port) Discharge temperature thermistor RT62 Flared connection Outdoor heat exchanger Muffler Compressor Defrost thermistor RT61 Flared connection Refrigerant pipe ø6.35 (with heat insulator) Strainer #100 Capillary tube ø3.0 × ø1.4 × 260 LEV R.V.
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE Refrigerant piping: m MUZ-HJ25VA MUZ-HJ35VA Max. Length A Max. Height difference B 20 12 Piping size O.D: mm Gas Liquid 9.52 6.35 12.7 MUZ-HJ50VA Indoor unit Max. Height difference B Max.
8 PERFORMANCE CURVES MUZ-HJ25VA MUZ-HJ35VA MUZ-HJ50VA 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. (1) GUARANTEED VOLTAGE 198 ~ 264 V, 50 Hz (2) AIR FLOW Air flow should be set at MAX.
7.2 8.0 11.4 6.7 7.4 10.5 6.1 6.8 9.6 5.6 6.2 8.7 5.1 5.6 7.9 4.6 5.1 7.1 4.1 4.5 6.3 Cooling capacity (at Rated frequency) 1.5 Capacity correction factor Indoor air Wet-bulb temperature difference (°C) 8-1. CAPACITY AND INPUT CURVES 1.4 1.3 26 1.2 Indo or in 1.1 1.0 8.7 5.6 7.9 4.6 5.1 7.1 4.1 4.5 6.3 3.6 4.0 5.5 MUZ-HJ35VA 22.9 24.7 19.0 21.1 22.8 17.4 19.3 20.9 15.8 17.6 19.0 14.3 15.8 17.1 15.2 12.3 13.3 9.5 10.5 11.4 MUZ-HJ50VA 14.1 11.
8-2. CAPACITY AND INPUT CORRECTION BY OPERATIONAL FREQUENCY OF COMPRESSOR MUZ-HJ25VA 1.5 Input correction factors Capacity correction factors Correction of Cooling total input 1.0 1.0 0.5 0.5 0 50 100 150 (Hz) 0 50 100 150 (Hz) Correction of Heating total input 1.5 Correction of Heating capacity Input correction factors 1.5 1.5 Capacity correction factors Correction of Cooling capacity 1.0 0.
8-4. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT COOL operation Dry-bulb temperature (°C) 20 25 30 Both indoor and outdoor unit are under the same temperature/humidity condition. Operation: TEST RUN OPERATION (Refer to 8-3.) Relative humidity (%) 50 60 70 Outdoor low pressure MUZ-HJ25VA (kgf/cm2 [Gauge])(MPa [Gauge]) 9 0.9 MUZ-HJ35VA (kgf/cm2 [Gauge])(MPa [Gauge]) 8 0.8 MUZ-HJ50VA (kgf/cm2 [Gauge])(MPa [Gauge]) 7 0.7 8 0.8 7 0.7 6 0.6 7 0.7 6 0.6 5 0.5 6 0.6 5 0.5 4 0.4 5 0.
PERFORMANCE DATA COOL operation at Rated frequency MUZ-HJ25VA CAPACITY: 2.5 kW INDOOR INDOOR DB (°C) WB (°C) 21 21 22 22 22 23 23 23 24 24 24 24 25 25 25 25 26 26 26 26 26 27 27 27 27 27 28 28 28 28 28 29 29 29 29 29 30 30 30 30 30 31 31 31 31 31 32 32 32 32 32 NOTE 18 20 18 20 22 18 20 22 18 20 22 24 18 20 22 24 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 SHF: 0.
PERFORMANCE DATA COOL operation at Rated frequency MUZ-HJ25VA CAPACITY: 2.5 kW INDOOR INDOOR DB (°C) WB (°C) 21 21 22 22 22 23 23 23 24 24 24 24 25 25 25 25 26 26 26 26 26 27 27 27 27 27 28 28 28 28 28 29 29 29 29 29 30 30 30 30 30 31 31 31 31 31 32 32 32 32 32 NOTE 18 20 18 20 22 18 20 22 18 20 22 24 18 20 22 24 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 SHF: 0.
PERFORMANCE DATA COOL operation at Rated frequency MUZ-HJ35VA CAPACITY: 3.15 kW INDOOR INDOOR DB (°C) WB (°C) 21 21 22 22 22 23 23 23 24 24 24 24 25 25 25 25 26 26 26 26 26 27 27 27 27 27 28 28 28 28 28 29 29 29 29 29 30 30 30 30 30 31 31 31 31 31 32 32 32 32 32 NOTE 18 20 18 20 22 18 20 22 18 20 22 24 18 20 22 24 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 Q SHF: 0.
PERFORMANCE DATA COOL operation at Rated frequency MUZ-HJ35VA CAPACITY: 3.15 kW INDOOR INDOOR DB (°C) WB (°C) 21 21 22 22 22 23 23 23 24 24 24 24 25 25 25 25 26 26 26 26 26 27 27 27 27 27 28 28 28 28 28 29 29 29 29 29 30 30 30 30 30 31 31 31 31 31 32 32 32 32 32 NOTE 18 20 18 20 22 18 20 22 18 20 22 24 18 20 22 24 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 18 20 22 24 26 Q SHF: 0.
PERFORMANCE DATA COOL operation at Rated frequency MUZ-HJ50VA CAPACITY: 5.0 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.70 INPUT: 2050 W OUTDOOR DB (°C) 21 25 27 30 SHF INPUT 21 18 5.88 3.06 0.52 1640 5.63 2.93 0.52 1722 5.40 2.81 0.52 1804 5.20 2.70 0.52 1886 21 20 6.13 2.45 0.40 1722 5.88 2.35 0.40 1825 5.70 2.28 0.40 1866 5.50 2.20 0.40 1948 22 18 5.88 3.29 0.56 1640 5.63 3.15 0.56 1722 5.40 3.02 0.56 1804 5.20 2.91 0.56 1886 22 20 6.13 2.
PERFORMANCE DATA COOL operation at Rated frequency MUZ-HJ50VA CAPACITY: 5.0 kW INDOOR INDOOR DB (°C) WB (°C) SHF: 0.70 INPUT: 2050 W OUTDOOR DB (°C) 35 40 46 SHF INPUT 21 18 4.90 2.55 0.52 2009 4.50 2.34 0.52 2132 4.15 2.16 0.52 2214 21 20 5.15 2.06 0.40 2091 4.80 1.92 0.40 2194 4.45 1.78 0.40 2317 22 18 4.90 2.74 0.56 2009 4.50 2.52 0.56 2132 4.15 2.32 0.56 2214 22 20 5.15 2.27 0.44 2091 4.80 2.11 0.44 2194 4.45 1.96 0.44 2317 22 22 5.45 1.
PERFORMANCE DATA HEAT operation at Rated frequency MUZ-HJ25VA CAPACITY: 3.15 kW INDOOR DB (°C) 15 21 26 -10 Q INPUT 1.98 566 1.89 609 1.70 653 MUZ-HJ35VA CAPACITY: 3.6 kW INDOOR DB (°C) 15 21 26 INPUT: 870 W -5 Q INPUT 2.39 679 2.27 722 2.11 766 OUTDOOR WB (°C) 0 5 10 Q INPUT Q INPUT Q INPUT 2.80 766 3.21 827 3.62 879 2.68 800 3.06 861 3.47 905 2.49 844 2.90 905 3.31 948 Q 4.00 3.84 3.69 15 INPUT 905 931 974 Q 4.41 4.24 4.10 20 INPUT 922 966 1001 OUTDOOR WB (°C) 0 5 10 Q INPUT Q INPUT Q INPUT 3.
9 ACTUATOR CONTROL MUZ-HJ25VA MUZ-HJ35VA MUZ-HJ50VA 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 R.V. COIL CONTROL MUZ-HJ25VA MUZ-35VA Heating . . . . . . . . . . . . . . . . . OFF Cooling . . . . . . . . . . . . . .
10 SERVICE FUNCTIONS MUZ-HJ25VA MUZ-HJ35VA MUZ-HJ50VA 10-1. CHANGE IN DEFROST SETTING When the JS wire of the inverter P.C. board is cut/ soldered, the defrost finish temperature is changed. (Refer to 11-6-1.) Jumper wire JS Soldered (Initial setting) None (Cut) Defrost finish temperature (°C) MUZ-HJ25/35VA MUZ-HJ50VA 8 11 15 10-2. PRE-HEAT CONTROL SETTING PRE-HEAT CONTROL When moisture gets into the refrigerant cycle, it may interfere the start-up of the compressor at low discharge temperature.
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.
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. With the remote controller headed towards the indoor unit, press TOO COOL or TOO WARM button to adjust the set temperature to 25°C.
3. Outdoor unit failure mode table The upper lamp of OPERATION INDICATOR lamp (Indoor unit) Abnormal point (Failure mode/protection) LED indication (Outdoor P.C. board) OFF None (Normal) 1-time flash 2.5 seconds OFF Indoor/outdoor communication, receiving error — Indoor/outdoor communication, receiving error — 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.
11-3. TROUBLESHOOTING CHECK TABLE No. 1 Symptom Outdoor unit does not operate. Abnormal point/ Condition 1-time flash every Outdoor power sys2.5 seconds tem LED indication 2 3 6-time flash 2.5 seconds OFF 11-time flash 2.5 seconds OFF 14-time flash 2.5 seconds OFF 4 5 6 7 8 9 Condition Remedy Overcurrent protection cut-out operates 3 consecutive times • Reconnect connector of compreswithin 1 minute after the compressor gets started, or failure of sor. restart of compressor has repeated 24 times.
11-4. TROUBLE CRITERION OF MAIN PARTS MUZ-HJ25VA MUZ-HJ35VA MUZ-HJ50VA 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. Measure the resistance with a tester. Discharge temperature Before measurement, hold the thermistor with your hands to warm it up. thermistor (RT62) Fin temperature thermistor Refer to 11-6.
11-5. TROUBLESHOOTING FLOW A How to check inverter/compressor Disconnect the connector (CN61) between compressor and the power module (IC700). See 11-5. Check the voltage between terminals. Are the voltages balanced? Yes Check the compressor. No “Check of open phase”. Replace the inverter P.C. board. See 11-5. “Check of compressor”.
C Check of compressor Refer to 11-5. “Check of compressor winding”. Is the compressor normal? Yes Refer to 11-5. “Check of compressor operation time”. Does the compressor operate continuously? Yes No No Replace the compressor. Refer to 11-5. “Check of compressor start failure”. OK. D Check of compressor winding ● Disconnect the connector (CN61) between the compressor and power module, and measure the resistance between the compressor terminals.
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 . Voltage between outdoor terminal block S1-S2 Does the compressor run for 10 seconds or more after it starts? Yes Check the refrigerant circuit. Check the stop valve.
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. coil. Check if CN721 is connected. MUZ-HJ25VA MUZ-HJ35VA Unit operates COOL mode even if it is set to HEAT mode. Disconnect connector (CN61) between the compressor and the power module.
I Check of outdoor fan motor MUZ-HJ25VA MUZ-HJ35VA Check the resistance of fan motor. (Refer to 11-4.) Is the resistance of fan motor normal? Yes Replace the outdoor fan motor. No Disconnect the connector CN771 on the inverter P.C. board. Disconnect the connector (CN61) between compressor and power transistor module. Turn ON the power supply and press the EMERGENCY OPERATION switch. After 3 minutes, is there voltage 230 VAC between CN771 and on the inverter P.C.
250 - 370 VDC J Check of power supply DB61 Disconnect the connector (CN61) between compressor and power module. Turn ON power supply and press EMERGENCY OPERATION switch. Rectify indoor/outdoor connecting wire. Does the upper lamp of OPERATION INDICATOR lamp on the indoor unit light up? Yes No Is there voltage 250 - 370 VDC between DB61 (+) and DB61 (–) on the inverter P.C. board? (Refer to 11-6.1.
L Check of inverter P.C. board MUZ-HJ50VA Check the outdoor fan motor. (Refer to 11-5. .) Is the fuse (F901) blown on the inverter P.C. board? No Yes 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. Check the LED indication on the inverter P.C. board. Does the LED flash 10 times? No Check the corresponding parts following LED indication. (Refer to 11-3.
M How to check miswiring and serial signal error Turn OFF the power supply. Is there rated voltage in the power supply? Check the power supply. No Yes 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 short circuiting the timer short mode point (Refer to 10-7.).
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.
11-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUZ-HJ25VA MUZ-HJ35VA Back side of unit DB61 250 V - 370 VDC 230 VAC Smoothing capacitor (C61) Fuse (F801) T3.15AL250V Output to drive outdoor fan motor (CN771) Fuse (F701) T3.15AL250V (-) (+) R.V.
MUZ-HJ50VA Back side of unit DB61 250 - 370 VDC (-) (+) Smoothing capacitor (C62) Smoothing capacitor (C63) Smoothing capacitor (C61) R.V.coil (CN721) 230 VAC Fuse (F701) T3.15AL250V Fuse (F801) T3.15AL250V 230 VAC Fuse (F901) T3.
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.
OPERATING PROCEDURE PHOTOS Photo 4 2. Removing the inverter assembly, inverter P.C. board Screw of the heat sink and the separator (1) Remove the cabinet and the panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors: CN721 (R.V. coil) CN771 (Fan motor) CN641 (Defrost thermistor and discharge temperature thermistor) CN724 (LEV) (3) Remove the compressor connector (CN61). (4) Remove the screws fixing the heat sink support and the separator.
OPERATING PROCEDURE PHOTOS Photo 6 4. Removing the discharge temperature thermistor and the defrost thermistor Suction pipe brazed part (1) Remove the cabinet and the panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors: CN641 (Defrost thermistor and discharge temperature thermistor) (3) Pull out the discharge temperature thermistor from its holder. (4) Pull out the defrost thermistor from its holder. R.V.
12-2. MUZ-HJ50VA NOTE: Turn OFF power supply before disassembly. OPERATING PROCEDURE PHOTOS 1. Removing the cabinet and the panels Photo 1 (1) Remove the screw fixing the service panel. (2) Pull down the service panel and remove it. (3) Disconnect the power supply and indoor/outdoor connecting wire. (4) Remove the screws fixing the top panel. (5) Remove the top panel. (6) Remove the screws fixing the cabinet. (7) Remove the cabinet.
OPERATING PROCEDURE PHOTOS 2. Removing the inverter assembly, inverter P.C. board (1) Remove the cabinet and the panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors: CN721 (R.V. coil) CN931, CN932 (Fan motor) CN641 (Defrost thermistor and discharge temperature thermistor) CN644 (Outdoor heat exchanger temperature thermistor) CN724 (LEV) (3) Remove the compressor connector (CN61).
OPERATING PROCEDURE PHOTOS 5. Removing the outdoor fan motor Photo 6 (1) Remove the cabinet and the panels. (Refer to 1.) (2) Disconnect the following connectors: CN931, CN932 (Fan motor) (3) Remove the fan motor lead wire from where it is fastened on the separator. (4) Remove the propeller nut. (5) Remove the propeller. (6) Remove the screws fixing the fan motor. (7) Remove the fan motor. Outdoor heat exchanger temperature thermistor 6.
HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2012 MITSUBISHI ELECTRIC CORPORATION Distributed in Mar. 2013. No. OBH648 REVISED EDITION-A Distributed in Dec. 2012. No. OBH648 Made in Japan New publication, effective Mar. 2013 Specifications are subject to change without notice.
