OB325-1.qxp 03.12.3 1:03 PM Page 1 SPLIT-TYPE, AIR CONDITIONERS No. OB325 SERVICE MANUAL Wireless type Models MS-A18WV MS-A24WV MS-A30WV - E1 (WH) E1 (WH) E1 (WH) CONTENTS Indication of model name MS-A18WV MS-A24WV MS-A30WV - E1 E1 E1 1. TECHNICAL CHANGES ····································2 2. PART NAMES AND FUNCTIONS······················2 3. SPECIFICATION·················································4 4. NOISE CRITERIA CURVES ·······························5 5.
OB325-1.qxp 1 03.12.3 1:03 PM Page 2 TECHNICAL CHANGES MS-18RV - E1 ➔MS-A18WV - E1 1. Indoor unit model has changed. 2. Rated voltage has changed. (220V-240V ➜ 230V) 3. Remote controller has changed. • LONG MODE and WIDE MODE have been added. 4. Indoor fan motor has changed.(RA4V27-EF ➜ RC4V32-AA) 5. Indoor heat exchanger has changed. 6. Diameter of connect pipe has changed.(Liquid:[8 ➜ [6.35) 7. Air filter has changed to catechin air filter. MS-24RV - E1 ➔MS-A24WV - E1 1.
OB325-1.qxp 03.12.3 1:03 PM Page 3 REMOTE CONTROLLER MS-A18WV - E1 MS-A24WV - E1 MS-A30WV - E1 Signal transmitting section Operation display section PM OPERATE/ STOP (ON/ OFF)button AM TOO ON/OFF WARM TOO COOL TEMPERATURE buttons Indication of remote controller model is on back. Open the front lid.
OB325-1.qxp 3 03.12.3 1:03 PM Page 4 SPECIFICATION Indoor model Function Power supply Special remarks Fan motor Electrical data Capacity Air flow(High/Med.w/Low w) K /h Power outlet A Running current A Power input W Auxiliary heater A(kW) Power factor % Fan motor current A Model Winding " resistance(at20:) Dimensions WOHOD mm Weight kg Air direction Sound level(High/Med.w /Loww ) dB Fan speed(High/Med.
OB325-1.qxp 03.12.3 1:03 PM Page 5 NOISE CRITERIA CURVES 4 MS-A18WV- E1 MS-A24WV- E1 FAN SPEED SPL(dB(A)) OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR Test conditions, Cooling : Dry-bulb temperature 27: 90 High 42 Test conditions, Cooling : Dry-bulb temperature 27: 90 Wet-bulb temperature 19: OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.
OB325-1.qxp 03.12.3 1:03 PM 5 Page 6 OUTLINES AND DIMENSIONS MS-A18WV - E1 MS-A24WV - E1 MS-A30WV - E1 Unit: mm INDOOR UNIT Installation plate Indoor unit 7.5 173 98 414.5 414.5 173 47 2.5 47 255.5 1068 315 98 Wall hole [ 75 225 1100 325 { Air in 791 56 { 253 Air out 19 Power supply cord Lead to right 2.0m Lead to left 1.0m 162 58 5 Wireless remote controller 6 Installation plate Liquid line [ 6.35- 0.5m Gas line [ 12-0.43m Insulation [ 50 O.D [ 32 I.
03.12.3 1:03 PM 6 Page 7 WIRING DIAGRAM MS-A18WV - E1 MS-A24WV - E1 INDOOR UNIT MODELS WIRING DIAGRAM TO OUTDOOR UNIT CONNECTING TB 12V CN202 BLK WHT 1 2 1 BLU L BRN NR11 3 2 1 TRANS TAB12 F11 CN 102 CN 151 RT12 CN112 CN201 N POWER SUPPLY CORD ~/N 230V 50Hz HIC1 1 2 2 BLK GRY YLW BRN WHT RED 3 CN 121 1 3 4 C11 SR141 ELECTRONIC CONTROL CN211 CN P. C. BOARD 111 CN 101 1 2 3 4 5 6 MF RT11 BRN 15 BLU 3 3 DISPLAY P. C. BOARD RECEIVER P. C.
OB325-1.qxp 7 03.12.3 1:03 PM Page 8 REFRIGERANT SYSTEM DIAGRAM MS-A18WV - E1 MS-A24WV - E1 INDOOR UNIT INDOOR UNIT Refrigerant pipe [15.88 (with heat insulator) Refrigerant pipe [12.7 (with heat insulator) Indoor heat exchanger Indoor coil thermistor RT12 Distributor Indoor heat exchanger Flared connection Room temperature thermistor RT11 Indoor coil thermistor RT12 Distributor Flared connection Refrigerant pipe[6.35 (with heat insulator) Refrigerant pipe [6.
OB325-1.qxp 03.12.3 1:03 PM 8 Page 9 MICROPROCESSOR CONTROL MS-A18WV - E1 MS-A24WV - E1 MS-A30WV - E1 WIRELESS REMOTE CONTROLLER Signal transmitting section Operation display section PM AM OPERATE/ STOP (ON/ OFF)button TOO ON/OFF WARM TOO COOL TEMPERATURE buttons CLOCK PM AM TOO ON/OFF WARM VANE button (Horizontal vane button) TOO COOL FAN STOP VANE START I FEEL COOL FAN OFF-TIMER button DRY ON-TIMER button MODE WIDE VANE HR.
OB325-1.qxp 03.12.3 1:03 PM Page 10 • Once the mode is fixed, the mode does not change by room temperature afterwards. • Under the ON-TIMER ( ) operation, mode is determined according to the room temperature at the set time the operation starts. When the system is stopped on the remote controller, and restarted within 2 hours in “I FEEL CONTROL” ( ) mode, the system operates in previous mode automatically regardless of the room temperature.
OB325-1.qxp 03.12.3 1:03 PM Page 11 8-1-1. COOL mode of “I FEEL CONTROL” 1. Indoor fan speed control Indoor fan operates at the set speed by FAN SPEED CONTROL button. In AUTO the fan speed is as follows. Initial temperature difference Fan Speed Room temperature minus set temperature : 1.7 degrees or more··························High Room temperature minus set temperature : Between 1 and 1.7 degrees················Med.
OB325-1.qxp 03.12.3 1:03 PM Page 12 Operation time chart Example ON ON Thermostat OFF OFF OFF Indoor fan OFF ON Outdoor fan Compressor OFF OFF ON OFF 8 min. ON ON ON ON OFF 3 min. 4 min. 1 min. 3. Coil frost prevention • The operation is as same as coil frost prevention during COOL mode of “I FEEL CONTROL”. • Indoor fan operates at the set speed and the compressor stops for 5 minutes, because protection(Coil frost prevention) has the priority.
OB325-1.qxp 03.12.3 1:03 PM Page 13 8-5. INDOOR 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 feedback the rotational frequency. Comparing the current rotational frequency with the target rotational frequency (High, Med.
OB325-1.qxp 03.12.3 1:03 PM Page 14 (8) ECONO COOL ( ) operation (ECONOmical operation) When the ECONO COOL button is pressed in COOL mode, set temperature is automatically set 2°C higher than that in COOL mode. Also the horizontal vane swings in various cycle according to the temperature of indoor heat exchanger(Tp(w 1)). SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher than that in COOL mode, the air conditioner can keep comfort.
OB325-1.qxp 03.12.3 1:03 PM Page 15 2. Vertical vane (1) Vane motor drive These models are equipped with a stepping motor for the vertical vane. The rotating direction, speed, and angle of the motor are controlled by pulse signals (approx. 12V) transmitted from microprocessor. (2) The vertical vane angle and mode change as follows by pressing the WIDE VANE button.
OB325-1.qxp 03.12.3 1:03 PM Page 16 2. Cancel TIMER setting can be cancelled with the ON/OFF TIMER buttons. To cancel the ON timer, press the “ON-TIMER” button. To cancel the OFF timer, press the “OFF-TIMER” button. TIMER is cancelled and the display of set time disappears. 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 1) The current time is 8:00 PM. (Example 2) The current time is 11:00 AM.
OB325-1.qxp 03.12.3 1:03 PM 9 Page 17 SERVICE FUNCTIONS MS-A18WV - E1 MS-A24WV - E1 MS-A30WV - E1 9-1. TIMER SHORT MODE For service, set time can be shortened by short circuit of JPG and JPS on the electronic control P.C. board. The time will be shortened as follows. Set time : 1 minute ➔ 1-second Set time : 3 minute ➔ 3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is shortened by short circuit of JPG and JPS.) 9-2. P.C.
OB325-1.qxp 03.12.3 1:03 PM Page 18 Table 1 1 unit operation 2 units operation 3 units operation 4 units operation No. 1 unit No modification Same as at left Same as at left Same as at left No. 2 unit – Solder J1 Same as at left Same as at left No. 3 unit – – Solder J2 Same as at left No.
OB325-1.qxp 03.12.3 1:03 PM 10 Page 19 TROUBLESHOOTING MS-A18WV - E1 MS-A24WV - E1 MS-A30WV - E1 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.
OB325-1.qxp 03.12.3 1:03 PM Page 20 10-2. Instruction of troubleshooting Start Indoor unit operates. Outdoor unit doesn't operate. Outdoor unit operates in only Test Run operation. Check room temperature thermistor. Refer to "Test point diagram and voltage" on page 26. Outdoor unit doesn't operate even in Test Run operation. Refer to "Check of outdoor unit". MS-A30WV Flash on and off at 0.
OB325-1.qxp 03.12.3 1:03 PM Page 21 1. Troubleshooting check table • The following indication applies regardless of shape of the indicator. flashing · Flashing of the OPERATION INDICATOR lamp (on the left-hand side) indicates possible abnormalities. · The OPERATION INDICATOR lamp (on the left-hand side) is lighted during normal operation. Operation Indicator Before taking measures, make sure that the symptom reappears, for accurate troubleshooting. Self check table No.
OB325-1.qxp 03.12.3 1:03 PM Page 22 2. Trouble criterion of main parts MS-A18WV - E1 MS-A24WV - E1 MS-A30WV - E1 Figure Part name Room temperature thermistor(RT11) Check method and criterion Measure the resistance with a tester.
OB325-1.qxp 03.12.3 1:03 PM Page 23 When OPERATION INDICATOR lamp flashes 3-time. Indoor fan motor doesn’t operate. A Check of indoor fan motor Turn OFF the power supply. Check connector CN211 visually. No Are lead wires connected? Yes Is soldered point of the connector correctly soldered? 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.3 and No.
OB325-1.qxp 03.12.3 1:03 PM Page 24 The unit doesn’t operate with the remote controller. Also, the OPERATION INDICATOR lamp doesn’t light up by pressing the EMERGENCY OPERATION switch. C Check of indoor electronic control P.C. board Check the both “parts side” and “pattern side” of indoor electronic control P.C. board visually. Varistor (NR11) Turn OFF the power supply. Remove indoor fan motor connector CN211 and vane motor connector CN151 from the indoor electronic control P.C.
OB325-1.qxp 03.12.3 1:03 PM Page 25 When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second. Outdoor unit doesn’t operate. D How to check mis-wiring MS-A30WV w Short circuit of JPG and JPS on the indoor electronic control P.C. board enables self -check to be displayed in 3 seconds. Start • Turn ON the power supply. (indoor/ outdoor unit) • Press once EMERGENCY OPERATION switch. After 3 minutes, mis-wiring is indicated (0.5-second ON, 0.
OB325-1.qxp 03.12.3 1:03 PM Page 26 TEST POINT DIAGRAM AND VOLTAGE MS-A18WV - E1 MS-A24WV - E1 MS-A30WV - E1 Indoor electronic control P.C. board Fan motor power supply } Power supply input 230V AC + Fuse (F11) 250V AC 3.15A } 5V DC Room temperature thermistor(RT11) Indoor coil thermistor(RT12(main)) R132 MS-A30WV Indoor coil thermistor(RT13(sub)) Emergency operation switch Timer short mode point (JPS, JPG) (Refer to page 17.) + } Receiver P.C.
OB325-1.qxp 03.12.3 1:03 PM 11 Page 27 DISASSEMBLY INSTRUCTIONS <"Terminal with lock mechanism" Detaching points> In case of terminal with lock mechanism, detach the terminal as shown below. There are two types ( Refer to (1) and (2)) of the terminal with lock mechanism. The terminal with no lock mechanism can be removed by pulling it out. Check the shape of the terminal and work. (1) Slide the sleeve and check if there is a locking lever or not.
OB325-1.qxp 03.12.3 1:04 PM Page 28 OPERATING PROCEDURE PHOTOS 3. Removing the electrical box (1) Remove the front panel. (Refer to 1.) (2) Remove the electrical cover. (Refer to 2.) (3) Disconnect the connector of the indoor coil thermistor. (4) Disconnect the motor connector (CN211 and CN121) and the vane motor connector (CN151) on the electronic control P.C. board. (5) Remove the screws of ground wire. (6) Remove the fan motor lead wire and indoor coil thermistor from the electrical box.
OB325-1.qxp 03.12.3 1:04 PM 12 Page 29 PARTS LIST MS-A18WV - E1 (WH) MS-A24WV - E1 (WH) MS-A30WV - E1 (WH) 12-1. INDOOR UNIT STRUCTURAL PARTS 12-2. INDOOR UNIT HEAT EXCHANGER 1 2 10 3 8 4 CATCH Optional parts (See page 31.) 5 SCREW CAP 11 12 6 7 12-1. INDOOR UNIT STRUCTURAL PARTS Part number that is circled is not shown in the illustration. No. 1 2 3 4 5 6 7 8 9 Part No.
OB325-1.qxp 03.12.3 1:04 PM Page 30 MS-A18WV - E1 (WH) MS-A24WV - E1 (WH) MS-A30WV - E1 (WH) 12-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS 1 20 12-4. ACCESSORY AND REMOTE CONTROLLER 19 23 24 2 3 SLEEVE BEARING 4 11 18 12 ROOM TEMPERATURE THERMISTOR 5 6 14 13 10 7 FUSE 8 9 VARISTOR 17 15 16 12-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS Part numbers that are circled are not shown in the illustration. No.
03.12.3 1:04 PM 13 Page 31 OPTIONAL PARTS AIR CLEANING FILTER ● AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity. ● Normal life of AIR CLEANING FILTER is 4 months. However, when it becomes dirty, replace it as soon as possible. ● Clogged AIR CLEANING FILTER may reduce the air conditioner capacity or cause frost on the air outlet. ● DO NOT reuse AIR CLEANING FILTER even if it is washed. ● DO NOT remove or attach AIR CLEANING FILTER during unit operation.
OB325-1.qxp 03.12.3 1:04 PM Page 32 HEAD OFFICE: MITSUBISHI DENKI BLDG.,2-2-3, MARUNOUCHI, CHIYODA-KU, TOKYO100-8310, JAPAN C Copyright 2003 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD Distributed in Dec. 2003. No.OB325 6 Made in Japan New publication, effective Dec. 2003 Specifications subject to change without notice.
