OB345-1.qxp 04.4.22 11:43 AM Page 1 SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS No. OB345 SERVICE MANUAL Wireless type Models MSZ-A18YV MSZ-A24YV MSZ-A26YV - E1 E1 E1 CONTENTS Indication of model name MSZ-A18YV MSZ-A24YV MSZ-A26YV - E1 E1 1. PART NAMES AND FUNCTIONS······················2 2. SPECIFICATION·················································4 3. NOISE CRITERIA CURVES ·······························5 4. OUTLINES AND DIMENSIONS ·························6 5.
OB345-1.qxp 1 04.4.
OB345-1.qxp 04.4.22 11:43 AM Page 3 REMOTE CONTROLLER MSZ-A18YV - E1 MSZ-A24YV - E1 MSZ-A26YV - 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.
OB345-1.qxp 2 04.4.22 11:44 AM Page 4 SPECIFICATION •Refer to the service manual OB346 when MSZ-A18YV - E1 , MSZ-A24YV MUZ-A18YV - E1 , MUZ-A24YV - E1 or MUZ-A26YV - E1 . •Refer to the service manual OB319 when MSZ-A18YV - E1 , MSZ-A24YV MXZ-A26WV - E1 or MXZ-A32WV - E1 as multi system units. E1 or MSZ-A26YV - E1 is connected with E1 or MSZ-A26YV - E1 is connected with Capacity Air flow(High/Med.
OB345-1.qxp 04.4.22 11:44 AM Page 5 Specifications and rating conditions of main electric parts INDOOR UNIT Model Item MSZ-A18YV - MSZ-A24YV - E1 Indoor fan capacitor (C11) 2.5+ 440V Fuse (F11) 250V 3.15A (MV1/ MV2) Vane motor Varistor Solid state relay TNR10V511K410 (SR141) S201DH1N (TB) 3P 145: Indoor fan motor thermal fuse 3 NOISE CRITERIA CURVES MSZ-A18YV - E1 FAN SPEED SPL(dB(A)) High LINE MSZ-A24YV - E1 MSZ-A26YV - E1 High OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.
OB345-1.qxp 04.4.22 11:44 AM 4 Page 6 OUTLINES AND DIMENSIONS MSZ-A18YV - E1 MSZ-A24YV - E1 MSZ-A26YV - E1 INDOOR UNIT Unit: mm Installation plate Indoor unit 7.5 173 98 414.5 414.5 173 47 2.5 47 255.5 1068 315 98 Wall hole [75 258 1100 Air in 5 Installation plate { Liquid line [ 6.35- 0.5m Gas line [ 12-0.43m Insulation [ 50 O.D [ 32 I.D for MSZ-A18/A24YV Liquid line [ 9.52- 0.5m Gas line [ 12-0.43m Insulation [ 50 O.D [ 32 I.
04.4.22 11:44 AM 5 Page 7 WIRING DIAGRAM MSZ-A18YV - E1 MODEL WIRING DIAGRAM INDOOR UNIT TO OUTDOOR UNIT CONNECTING TB 3 12V CN201 RED N BLU L POWER SUPPLY CORD ~/N 230V 50Hz BRN CN 151 BRN BLU CIRCUIT BREAKER SYMBOL NR11 3 2 1 TRANS TAB12 F11 NAME 3 1 3 4 C11 SR141 CN 111 ELECTRONIC CONTROL P.C. BOARD MF RT11 3 RECEIVER P.C. BOARD DISPLAY P.C.
OB345-1.qxp 6 04.4.22 11:44 AM Page 8 REFRIGERANT SYSTEM DIAGRAM MSZ-A18YV - E1 MSZ-A24YV - 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(main) Distributor Indoor heat exchanger Indoor coil thermistor RT12(main) Distributor Flared connection Indoor coil thermistor RT13(sub) Room temperature thermistor RT11 Flared connection Flared connection Refrigerant pipe[6.
OB345-1.qxp 04.4.22 11:44 AM 7 Page 9 SERVICE FUNCTIONS MSZ-A18YV - E1 MSZ-A24YV - E1 MSZ-A26YV - E1 7-1. 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.) 7-2. P.C.
OB345-1.qxp 04.4.22 11:44 AM Page 10 How to release “AUTO RESTART FUNCTION” 1Turn off the main power for the unit. 2Pull out the electronic control P.C. board, the receiver P.C. board and the display P.C.board. (Refer to page 19.) 3Solder jumper wire to the RESISTOR JR07 on the indoor electronic control P.C. board. (Refer to page 18.) C11 CN 21 1 CN201 SW1 RA102 CN151 CN121 CN111 CN112 TAB12 IC101 IC152 JR07 Operation 1If the main power has been cut, the operation settings remain.
OB345-1.qxp 04.4.22 11:44 AM 8 Page 11 TROUBLESHOOTING MSZ-A18YV - E1 MSZ-A24YV - E1 MSZ-A26YV - E1 8-1. 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.
OB345-1.qxp 04.4.22 11:44 AM Page 12 8-2. 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". Outdoor unit doesn't operate even in Test Run operation. Refer to "Check of inverter/ compressor". Indoor unit operates. Outdoor unit doesn't operate normally. Unit doesn't operate normal operation in COOL or HEAT mode. Refer to "Check of R.
OB345-1.qxp 04.4.22 11:44 AM Page 13 1. Troubleshooting check table • The following indication applies regardless of shape of the indicator. · Flashing of the OPERATION INDICATOR lamp (the left-hand side lamp) indicates possible abnormalities. · The OPERATION INDICATOR lamp (the left-hand side lamp) is lighting during Not lighted normal operation. Operation Indicator Lighted Before taking measures, make sure that the symptom reappears, for accurate troubleshooting. Self check table No.
OB345-1.qxp 04.4.22 11:44 AM Page 14 2. Trouble criterion of main parts MSZ-A18YV - E1 MSZ-A24YV - E1 MSZ-A26YV - E1 Part name Figure Check method and criterion Measure the resistance with a tester.
OB345-1.qxp 04.4.22 11:44 AM Page 15 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.3 and No.4 and then No.1 and No.4.
OB345-1.qxp 04.4.22 11:44 AM Page 16 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.
OB345-1.qxp 04.4.22 11:44 AM Page 17 When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second. Outdoor unit doesn’t operate. D How to check mis-wiring and serial signal error (when outdoor unit does not work) 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, 0.5-second OFF) on OPERATION INDICATOR lamp on the indoor unit.w Yes Make them sure.
OB345-1.qxp 04.4.22 11:44 AM Page 18 TEST POINT DIAGRAM AND VOLTAGE MSZ-A18YV - E1 MSZ-A24YV - E1 MSZ-A26YV - E1 Indoor electronic control P.C. board Fan motor power supply } + Fuse (F11) 250V AC 3.15A Power supply input 230V AC } 5V DC Room temperature thermistor(RT11) Indoor coil thermistor(RT12(main)) R132 Indoor coil thermistor(RT13(sub)) Emergency operation switch Timer short mode point (JPS, JPG) (Refer to page 9.) + } Receiver P.C.
OB345-1.qxp 04.4.22 11:44 AM 9 Page 19 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.
OB345-1.qxp 04.4.22 11:44 AM Page 20 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.
OB345-1.qxp 04.4.23 9:27 AM 10 Page 21 PARTS LIST MSZ-A18YV - E1 (WH) MSZ-A24YV - E1 (WH) MSZ-A26YV - E1 (WH) 10-1. INDOOR UNIT STRUCTURAL PARTS 10-2. INDOOR UNIT HEAT EXCHANGER 1 2 10 3 8 4 CATCH Optional parts (See page 23.) 5 SCREW CAP 11 12 6 7 10-1. 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.
OB345-1.qxp 04.4.22 11:44 AM Page 22 MSZ-A18YV - E1 (WH) MSZ-A24YV - E1 (WH) MSZ-A26YV - E1 (WH) 10-4. ACCESSORY AND REMOTE CONTROLLER 10-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS 1 20 19 23 24 2 3 SLEEVE BEARING 4 11 18 12 5 6 14 ROOM TEMPERATURE THERMISTOR 13 10 7 FUSE 8 9 VARISTOR 17 15 16 10-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS Part numbers that are circled are not shown in the illustration. No.
OB345-1.qxp 04.4.22 11:44 AM 11 Page 23 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.
OB345-1.qxp 04.4.22 11:44 AM Page 24 HEAD OFFICE: MITSUBISHI DENKI BLDG.,2-2-3, MARUNOUCHI, CHIYODA-KU, TOKYO100-8310, JAPAN C Copyright 2004 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD Distributed in Apr. 2004. No.OB345 6 Made in Japan New publication, effective Apr. 2004 Specifications subject to change without notice.
