Revision: SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS ●Information for connecting MSH-18NV- E4 with MXZ-32RV- E1 was described. ●TROUBLESHOOTING has been modified. No. OB229 REVISED EDITION-A SERVICE MANUAL Wireless type Model MSH-18NV - E4 (WH) · MUH-18NV - E4 CONTENTS MSH-18NV - E4 1. TECHNICAL CHANGES ····································2 2. PART NAMES AND FUNCTIONS······················2 3. SPECIFICATION·················································4 4.
1 TECHNICAL CHANGES MSH-18NV- 2 E4 became possible the connection to MXZ-32RV- E1 as multi system units.
OUTDOOR UNIT MUH-18NV - E4 Air inlet (back and side) Piping Drainage hose Air outlet Drain outlet REMOTE CONTROLLER MSH-18NV - E4 Signal transmitting section Operation display section OPERATE/STOP (ON/OFF)button OPERATION SELECT button TEMPERATURE buttons FAN SPEED CONTROL button VANE CONTROL button SWING button SLEEP button ON-TIMER button CLOCK SET button OFF-TIMER button RESET button HR. button MIN.
3 SPECIFICATION wRefer to the Service Manual OB185 REVISED EDITION C when MSH-18NV- E4 is connected with MXZ-32NV- E1 or MXZ-32NV- E2 as multi system units. wRefer to the Service Manual OB227 REVISED EDITION-B when MSH-18NV- E4 is connected with MXZ-32RV- E1 as multi system units. Model MSH-18NV - Power supply Dehumidification K /h INDOOR 756 OUTDOOR 2142-2244 Air flow(Hi) Outdoor fan motor 10 9.4-9.2 9.2-9.0 0.
4 OUTLINES AND DIMENSIONS Unit: mm MSH-18NV INDOOR UNIT E4 Indoor unit 4holes 11✕20 648 217 450 3 450 297 254 60 40 20 150 995 438 352 Wall hole [75 Installation plate 1015 190 5 320 Installation plate { Air in 50 775 190 Drain hose [16 Insulation [28 Air out Power supply cord Lead to right 2m Lead to left 1m 17.5 56 Liquid line [8-0.5m Gas line [12-0.43m Insulation [50 O.D [28 I.D 160 des ft si ly e l / t s on righ t or top ha ed.
WIRING DIAGRAM MSH-18NV - E4 TO OUTDOOR TB UNIT L ❈ BRN CONNECTING BRN 12VDC 3 ❈ HIC1 RED BLU WHT N❈ BLU 2 1 BLU BLU BLU BRN DSAR POWER SUPPLY CORD ~/N 220-240V 50Hz LD1 CN 151 ELECTRONIC CONTROL P.C BOARD CN CN 101 102 RT12 3 CN211 4 2 1 BRN YLW GRY WHT RED BLK CN 111 MF RT11 5 3 3 MV DISPLAY P.C.BOARD RECEIVER P.C.
6 REFRIGERANT SYSTEM DIAGRAM MSH-18NV - E4 MUH-18NV - E4 INDOOR UNIT Muffler (with heat insulator) Indoor heat exchanger OUTDOOR UNIT Reversing valve (4- way valve) Refrigerant pipe [15.88 (Option) Indoor coil thermistor RT12 Distributor Strainer Stop valve (with service port) Defrost thermistor RT61 Flared connection Room temperature thermistor RT11 Outdoor heat exchanger Accumulator Compressor Capillary tube [3.0o[1.6o750 (2 pcs) Flared connection Strainer Refrigerant pipe[ 6.
7 PERFORMANCE CURVES MSH-18NV - E4 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.
28.0 25.9 23.7 21.6 19.4 17.2 15.1 MSH-18NV - E4 12.9 NOTE:The above curves are for the heating operation without any frost. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT COOL operation 1 Both indoor and outdoor unit are under the same temperature/humidity condition. Dry-bulb temperature Relative humidity(%) 20 50 25 60 30 70 2 Air flow should be set at MAX. 3 The unit of pressure has been changed to MPa on the international system of units(SI unit system).
8 MICROPROCESSOR CONTROL WIRELESS REMOTE CONTROLLER MSH-18NV - E4 Once the operation mode are set, the same operation mode can be repeated by simply turning the OPERATE/STOP (ON/OFF) button ON. Indoor unit receives the signal with a beep tone. When the system turns off, 3-minute time delay will operate to protect system from overload and compressor will not restart for 3 minutes. 8-1. “I FEEL CONTROL” ( ) OPERATION (1) Press OPERATE/STOP (ON/OFF) button on the remote controller.
(4) The initial set temperature is decided by the initial room temperature.
② Time control When the three conditions as follows have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes. a. Compressor has been continuously operating. b. Indoor fan speed is Lo or Me. c. Room temperature is below 26°C. When compressor stops, the accumulated time is cancelled and when compressor restarts, time counting starts from the beginning. Time counting also stops temporarily when the indoor fan speed becomes Hi or the room temperature exceeds 26°C.
— HEAT mode of “I FEEL CONTROL” — 1. Indoor fan speed control (1) In AUTO the fan speed is as follows. Difference between room temperature and set temperature during operation. Initial temperature difference Fan speed Set temperature minus room temperature: 2 degrees or more················································· Hi Set temperature minus room temperature: Between 1 and 2 degrees ····································· Me 2deg. 4deg.
3. Defrosting Defrosting of outdoor heat exchanger is controlled by DEICER P.C. board, with detection by the defrost thermistor RT61. (1) Starting conditions of defrost When all conditions of a) ~ c) are satisfied, the defrosting operation starts. a) Under the heat operation, the compressor cumulative operation time exceeds 40 minutes without the defrosting operation working. b) The defrost thermistor RT61 reads - 3°C or less.
4. Reversing valve control Heating · · · · · ON Cooling · · · · · OFF Dry · · · · · · · · OFF NOTE1 The Reversing valve reverses for 5 seconds right before start-up of the compressor. NOTE2 • Refer to the Service Manual OB185 REVISED EDITION C when MSH-18NV- E4 is connected with MXZ-32NVor MXZ-32NV- E2 as multi system units. • Refer to the Service Manual OB227 REVISED EDITION-B when MSH-18NVas multi system units. Reversing valve ON OFF ON OFF Outdoor fan ON OFF Compressor 8-2.
8-5. FAN MOTOR CONTROL (1) Rotational frequency feedback control The indoor fan motor is equipped with a rotational frequency sensor, and outputs signal to the microprocessor to feed back the rotational frequency. Comparing the current rotational frequency with the target rotational frequency (Hi,Me,Lo,SLEEP), the microprocessor controls IC141 and adjusts fan motor electric current to make the current rotational frequency close to the target rotational frequency.
(5) Dew prevention During COOL or DRY operation at vane Angle 4 or 5 when the compressor cumulative operation time exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew prevention. (6) SWING MODE ( ) By pressing the SWING button ( ) the horizontal vane swings vertically. The remote controller displays “ ”. SWING mode is cancelled when the SWING button or VANE CONTROL button ( ) is pressed or the mode is changed to other mode.
PROGRAM TIMER • The OFF timer and ON timer can be used in combination. •“ ” and “ ” display shows the order of the OFF timer and ON timer operation. (Example 2) The current time is 11:00 AM. (Example 1) The current time is 8:00 PM. The unit turns on at 5:00 PM, and off at 9:00 PM. The unit turns off at 11:00 PM, and on at 6:00 AM. NOTE : TIMER setting will be cancelled by power failure or breaker functioning. 8-9.
9 SERVICE FUNCTIONS MSH-18NV - E4 9-1. COMPULSORY DEFROSTING MODE FOR SERVICE By short circuit of the connector JP607 and R853 on the outdoor deicer P.C. board, defrosting mode can be accomplished regardless of the defrost interval restriction. See page 29. Defrost thermistor RT61 must read below -3°C. 9-2. CHANGE IN DEFROST SETTING when the JPC wire of the deicer P.C. board is cut, the defrost interval time will be changed. (See page 29.) when the JPE wire of the deicer P.C.
9-5. AUTO RESTART FUNCTION When the indoor unit is controlled with the remote controller, the operation mode, set temperature, and the fan speed are memorized by the indoor electronic control P.C.board. The “AUTO RESTART FUNCTION” sets to work the moment power has restored after power failure.Then, the unit will restart automatically. However if the unit is operated in “I FEEL CONTROL” mode before power failure, the operation is not memorized.
10 TROUBLESHOOTING MSH-18NV - E4 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 the following during servicing. (1) Before servicing the air conditioner, be sure to first turn off the remote controller to stop the main unit, and then after confirming the horizontal vane is closed, turn off the breaker and / or disconnect the power plug.
10-2. Instruction of troubleshooting Start Indoor unit doesn’t receive the signal from remote controller. Indoor unit operates. Outdoor unit doesn’t Operation Indicator lamp on the indoor unit is flashing on and off. 2-time flash Outdoor unit operates in only Test Run operation. Outdoor unit doesn’t operate even in Test Run operation. Refer to B “Check of remote controller and receiver P.C. board” on page 25. 2.5-second OFF 3-time flash 2.5-second OFF 1-time flash Check room temperature thermistor.
1. troubleshooting check table Operation Indicator ❈ Before taking measures, make sure that the symptom reappears, for accurate troubleshooting. Self check table NO. Abnormal point Symptom Indication Detect method Check point 0.5-second ON Outdoor unit does not run. When serial signal stops for 4 to 5 seconds after 1st on of 52C relay by POWER turning on. ● Check wiring (visual check and conductivity check). ● Check indoor electronic control P.C.board. ● Check outdoor DEICER P.C. board.
2. Trouble criterion of main parts MSH-18NV - E4 Check method and criterion Part name Room temperature thermistor Indoor coil thermistor Figure Measure the resistance with a tester. (Part temperature 10°C ~ 30°C) Normal Abnormal 8k½ ~ 20k½ Opened or short-circuited Measure the resistance with a tester. (Part temperature –10°C ~ 40°C) Defrost thermistor Normal Abnormal 5k½ ~ 60k½ Opened or short-circuited Measure the resistance between the terminals with a tester.
A Check of indoor fan motor Indoor fan does not operate. Turn OFF the power supply. Check connector CN211 visually. No Yes Are lead wires connected? Is soldered point normal? No Resolder it. Yes Reconnect the lead wires. Disconnect lead wires from connector CN211 on the indoor electronic control P.C. board. Measure resistance between lead wires No.1 and No.4 and then No.1 and No.2. Is resistance 0 (short circuit) or ° (open circuit)? Yes ( 0 or ° ) Repair the indoor fan motor.
C Check of indoor electronic control P.C. board The unit doesn’t operate with the remote controller. Also, the OPERATION INDICATOR lamp doesn’t light up by pressing the EMERGENCY OPERATION switch. Check the both “parts side” and “pattern side” of indoor electronic control P.C. board visually. 1 Turn OFF the power supply. Remove indoor fan motor connector CN211 and vane motor connector CN151 from the indoor electronic control P.C. board and turn ON the power supply.
E How to check mis-wiring and serial signal error (when outdoor unit does not work) Start 1. Turn OFF the power supply. 2. Turn ON the power supply. 3. Press the EMERGENCY OPERATION switch. 3 min. later, when 52C contactor turns ON, what self-check result is displayed on Operation Indicator lamp on the indoor unit? ❈1 ❈1 Short circuit of JPG and JPS on the indoor electronic control P.C. board enables self-check to be displayed in 3 seconds. Serial signal error is indicated. (0.5-sec.ON, 2.5-sec.
TEST POINT DIAGRAM AND VOLTAGE MSH-18NV - E4 Fan motor power supply Fuse 250V AC 3.15A } + Power supply input 220-240V AC C144 } 5V DC C144 Room temperature thermistor(RT11) Indoor coil thermistor(RT12) JPS Time short mode point JPG Emergency operation switch JPG + } 12V DC JP41 R132 0~20V DC P.C.
MUH-18NV - E4 Outdoor deicer P.C. board } } INPUT 220-240V AC } Defrost thermistor(RT61) } } Outdoor fan motor 220-240V AC R601 Reversing valve 5~10V DC coil + 220-240V AC Fuse 2A/250V Defrost interval time short pin + J9 J8 + } + } 12V DC } 5V DC 52C 12V DC 29 Jumper wire for change in defrost setting (JPC, JPE) (See page 19.
11 DISASSEMBLY INSTRUCTIONS NOTE: <"Terminal with lock mechanism" Detaching points> In the case of terminal with lock mechanism, detach the terminal as shown below. (1) (2) 1Slide the sleeve. 2Pull the terminal while pushing the locking lever. 1Hold the sleeve, and pull out the terminal slowly. 11-1. MSH-18NV - E4 INDOOR UNIT OPERATING PROCEDURE PHOTOS 1. Removing the front panel (1) Remove the screw caps at the down of the front panel. Remove the screws.
PHOTOS OPERATING PROCEDURE 3. Removing the electrical box (1) (2) (3) (4) Remove the front panel. (Refer to 1) Remove the electrical cover. Disconnect the connector of the indoor coil thermistor. Disconnect the motor connector (CN211 and CN121) and the vane motor connector (CN151) on the electronic control P.C. board. (5) Remove the screw of the electrical box, remove the electrical box. screw Photo 3 screw 4. Removing the indoor fan motor and the line flow fan (1) Remove the front panel.
11-2. MUH-18NV - E4 OUTDOOR UNIT OPERATING PROCEDURE PHOTOS 1. Removing the cabinet (1) Remove the screws of the cabinet. (2) Hold the down of the cabinet on the both side to remove the cabinet. Photo 1 Photo 2 Screws Service panel Screws 2. Removing the deicer P.C. board Photo 3 (1) Remove the service panel and the cabinet. (2) Disconnect all the connectors and the terminals on the deicer P.C. board. (3) Remove the deicer P.C. board. Screws Deicer P.C.
OPERATING PROCEDURE PHOTOS 3. Removing the outdoor fan motor (1) Remove the cabinet. (Refer to 1) (2) Disconnect the connector remove the clamp of fan motor lead wire. (3) Remove the propeller nut and remove the propeller fan. (4) Remove screws securing the fan motor. Photo 4 propeller fan Set screws for outdoor fan motor Lead clamps Outdoor fan motor Propeller fan nut Set screws for outdoor fan motor 4. Removing the compressor Photo 5 (1) (2) (3) (4) Remove the cabinet.
12 PARTS LIST MSH-18NV - E4 (WH) 12-1. INDOOR UNIT STRUCTURAL PARTS 12-2. INDOOR UNIT HEAT EXCHANGER 8 5 1 2 3 Optional parts (See page 37.) 9 10 6 4 12-1. INDOOR UNIT STRUCTURAL PARTS Part number that is circled is not shown in the illustration. NO. Part No.
MSH-18NV - E4 (WH) 12-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS 12-4. ACCESSORY PARTS AND REMOTE CONTROLLER 21 SLEEVE BEARING 8 10 22 7 15 5 11 3 4 1 16 14 17 2 INDOOR COIL THERMISTOR 9 6 12 ROOM TEMPERATURE THERMISTOR 12-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS Part number that are circled are not shown in the illustration. NO. 1 2 3 4 5 6 7 8 Part No.
MUH-18NV - E4 12-5. OUTDOOR UNIT STRUCTURAL PARTS DEFROST THERMISTOR 17 19 12 20 8 1 10 22 3 15 16 2 4 9 14 5 6 7 Part number that are circled are not shown in the illustration. NO. Part No.
MUH-18NV - E4 12-6. ACCESSORY PARTS NO. 1 Symbol in Wiring Diagram Part Name Part No. 2 Q'ty/unit MUH-18NV- Remarks E4 1 2 E02 444 704 DRAIN SOCKET E02 444 705 DRAIN CAP 2 [33 3 E02 444 706 DRAIN CAP 1 [16.2 1 13 OPTIONAL PARTS 13-1. AIR CLEANING FILTER Model MSH-18NV- E4 , , ● AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity. ● Normal life of AIR CLEANING FILTER is 3 months.
HEAD OFFICE MITSUBISHI DENKI BLDG.MARUNOUCHI TOKYO100-8310 TELEX J24532 CABLE MELCO TOKYO C Copyright 1999 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD Issued in Apr. 1999. No.OB229 REVISED EDITION-A 294 Issued in Jan. 1999. No.OB229 305 Printed in Japan New publication, effective Apr. 1999 Specifications subject to change without notice.
