Mitsubishi Electric PLA-A12EA8 Service Manual
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Mitsubishi Electric PLA-A12EA8 Service Manual

Mitsubishi Electric PLA-A12EA8 Service Manual

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SPLIT-SYSTEM HEAT PUMP
SERVICE MANUAL
Indoor unit
[Model Name]
PLA-A12EA8
PLA-A18EA8
PLA-A24EA8
PLA-A30EA8
PLA-A36EA8
PLA-A42EA8
PLA-A48EA8
Grille model
[Model Name]
PLP-41EAEU
Model name
indication for
MAIN UNIT
INDOOR UNIT
WIRELESS REMOTE
CONTROLLER
(Option)
TCH120A
[Service Ref.]
PLA-A12EA8
PLA-A18EA8
PLA-A24EA8
PLA-A30EA8
PLA-A36EA8
PLA-A42EA8
PLA-A48EA8
Model name
indication for GRILLE
ON
RETURN SELECT
MENU
HOLD
OFF
WIRED REMOTE
CONTROLLER
(Option)
CONTENTS
1. REFERENCE MANUAL ........................ 2
2. SAFETY PRECAUTION ........................ 3
4. SPECIFICATIONS ................................. 7
5. NOISE CRITERION CURVES ............. 10
7. WIRING DIAGRAM ............................. 13
9. TROUBLESHOOTING ........................ 15
10. FUNCTION SETTING ......................... 30
11. SPECIAL FUNCTION .......................... 31
13. REMOTE CONTROLLER ................... 41
PARTS CATALOG (TCB120)
1
August 2023
No. TCH120
REVISED EDITION-A
Revision:
• Some descriptions have been
revised in REVISED EDITION-A
TCH120 is void.

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Summary of Contents for Mitsubishi Electric PLA-A12EA8

  • Page 1: Table Of Contents

    SPLIT-SYSTEM HEAT PUMP August 2023 No. TCH120 REVISED EDITION-A SERVICE MANUAL Indoor unit [Model Name] [Service Ref.] PLA-A12EA8 PLA-A12EA8 Revision: • Some descriptions have been PLA-A18EA8 PLA-A18EA8 revised in REVISED EDITION-A PLA-A24EA8 PLA-A24EA8 TCH120 is void. PLA-A30EA8 PLA-A30EA8 PLA-A36EA8 PLA-A36EA8...

  • Page 2: Reference Manual

    REFERENCE MANUAL OUTDOOR UNIT SERVICE MANUAL Model Name Service Ref. Service Manual No./Parts Catalog No. PUZ-A12/18/36/42NKA7 PUZ-A12/18/36/42NKA7 PUZ-A24/30NHA7 PUZ-A24/30NHA7 OCH636 / OCB636 PUY-A12/18/36/42NKA7 PUY-A12/18/36/42NKA7 PUY-A24/30NHA7 PUY-A24/30NHA7 PUZ-A12/18/36/42NKA8 PUZ-A12/18/36/42NKA8 PUZ-A24/30NHA8 PUZ-A24/30NHA8 OCH764 / OCB764 PUY-A12/18/36/42NKA8 PUY-A12/18/36/42NKA8 PUY-A24/30NHA8 PUY-A24/30NHA8 PUZ-HA24NHA1 PUZ-HA24NHA1 PUZ-HA30/36NKA PUZ-HA30/36NKA OCH750 / OCB750 PUZ-HA42NKA1...

  • Page 3: Safety Precaution

    SAFETY PRECAUTION 2-1. ALWAYS OBSERVE FOR SAFETY Before obtaining access to terminal, all supply circuits must be disconnected. 2-2. CAUTIONS RELATED TO NEW REFRIGERANT Cautions for units utilising refrigerant R410A Precautions during the repair service. Preparation before the repair service. •...
  • Page 4 [1] Warning for service (1) Do not alter the unit. (2) For installation and relocation work, follow the instructions in the Installation Manual and use tools and pipe components specifically made for use with refrigerant specified in the outdoor unit installation manual. (3) Ask a dealer or an authorized technician to install, relocate and repair the unit.
  • Page 5 [2] Cautions for service (1) Perform service after recovering the refrigerant left in the unit completely. (2) Do not release refrigerant in the air. (3) After completing service, charge the cycle with specified amount of refrigerant. (4) When performing service, install a filter drier simultaneously. Be sure to use a filter drier for new refrigerant.

  • Page 6: Parts Names And Functions

    PARTS NAMES AND FUNCTIONS Drain pipe Air outlet Filter Liquid pipe Gas pipe Signal receiver i-see Sensor (Option) (Option) Model name Model name indication for Vane indication for GRILLE MAIN UNIT Air intake (Intake grille) TCH120A...

  • Page 7: Specifications

    SPECIFICATIONS Service Ref. PLA-A12EA8 Power supply (phase, cycle, voltage) Single phase, 60 Hz, 208/230 V Max. Fuse Size Min Circuit Ampacity External finish (Panel) PLP-41EAEU: Munsell 1.0Y 9.2/0.2 Heat exchanger Plate fin coil Fan (drive) × No. Turbo fan (direct) × 1 Fan motor output 0.05...
  • Page 8 Service Ref. PLA-A30EA8 Power supply (phase, cycle, voltage) Single phase, 60 Hz, 208/230 V Max. Fuse Size Min Circuit Ampacity External finish (Panel) PLP-41EAEU: Munsell 1.0Y 9.2/0.2 Heat exchanger Plate fin coil Fan (drive) × No. Turbo fan (direct) × 1 Fan motor output 0.12 Fan motor...
  • Page 9 Service Ref. PLA-A48EA8 Power supply (phase, cycle, voltage) Single phase, 60 Hz, 208/230 V Max. Fuse Size Min Circuit Ampacity External finish (Panel) PLP-41EAEU: Munsell 1.0Y 9.2/0.2 Heat exchanger Plate fin coil Fan (drive) × No. Turbo fan (direct) × 1 Fan motor output 0.12 Fan motor...

  • Page 10: Noise Criterion Curves

    NOISE CRITERION CURVES PLA-A12EA8 PLA-A18EA8 NOTCH SPL(dB) LINE NOTCH SPL(dB) LINE High High Medium1 Medium1 Medium2 Medium2 NC-70 NC-70 NC-60 NC-60 NC-50 NC-50 NC-40 NC-40 NC-30 NC-30 APPROXIMATE APPROXIMATE THRESHOLD OF THRESHOLD OF HEARING FOR HEARING FOR NC-20 NC-20 CONTINUOUS...
  • Page 11 PLA-A36EA8 PLA-A42EA8 NOTCH SPL(dB) LINE NOTCH SPL(dB) LINE High PLA-A48EA8 High Medium1 Medium1 Medium2 Medium2 NC-70 NC-70 NC-60 NC-60 NC-50 NC-50 NC-40 NC-40 NC-30 NC-30 APPROXIMATE APPROXIMATE THRESHOLD OF THRESHOLD OF HEARING FOR HEARING FOR NC-20 NC-20 CONTINUOUS CONTINUOUS NOISE NOISE 1000 2000...

  • Page 12: Outlines And Dimensions

    OUTLINES AND DIMENSIONS PLA-A12EA8 PLA-A18EA8 PLA-A24EA8 PLA-A30EA8 PLA-A36EA8 PLA-A42EA8 PLA-A48EA8 Unit: inch (mm) TCH120A...

  • Page 13: Wiring Diagram

    WIRING DIAGRAM PLA-A12EA8 PLA-A18EA8 PLA-A24EA8 PLA-A30EA8 PLA-A36EA8 PLA-A42EA8 PLA-A48EA8 TCH120A...

  • Page 14: Refrigerant System Diagram

    REFRIGERANT SYSTEM DIAGRAM PLA-A12EA8 PLA-A18EA8 PLA-A24EA8 PLA-A30EA8 PLA-A36EA8 PLA-A42EA8 PLA-A48EA8 Strainer (#50) Heat exchanger Refrigerant GAS pipe connection (Flare) Condenser/evaporator temperature thermistor (TH5) Refrigerant flow in cooling Refrigerant flow in heating Refrigerant LIQUID pipe connection (Flare) Pipe temperature thermistor/liquid (TH2)

  • Page 15: Troubleshooting

    TROUBLESHOOTING 9-1. TROUBLESHOOTING <Check code displayed by self-diagnosis and actions to be taken for service (summary)> Present and past check codes are logged, and they can be displayed on the wired remote controller and control board of out- door unit. Actions to be taken for service, which depends on whether or not the trouble is reoccurring in the field, are summa- rized in the table below.
  • Page 16 • Refer to “13-7. SELF-DIAGNOSIS” to search for the error history. [Output pattern A] Beeper sounds Beep Beep Beep Beep Beep Beep Beep OPERATION · · · Repeated INDICATOR lamp blink pattern Approx. 2.5 s 0.5 s 0.5 s 0.5 s Approx.
  • Page 17 • On wireless remote controller The continuous buzzer sounds from receiving section of indoor unit. Blink of operation lamp • On wired remote controller Check code displayed in the LCD. * The check code in the parenthesis indicates PAR-41MAA model. ●...
  • Page 18 9-3. SELF-DIAGNOSIS ACTION TABLE Note: Errors to be detected in outdoor unit, such as codes starting with F, U or E (excluding E0 to E7), are not covered in this document. Please refer to the outdoor unit service manual for the details. Check code Abnormal point and detection method Cause...
  • Page 19 Check code Abnormal point and detection method Cause Countermeasure Drain overflow protection operation 1 Malfunction of drain pump 1 Check if drain-up machine works. 1 Suspensive abnormality, if drain float 2 Defective drain 2 Check drain function. switch is detected to be underwater for 1 Clogged drain pump 3 Remove drain float switch connector CN4F minute and 30 seconds continuously with...
  • Page 20 Check code Abnormal point and detection method Cause Countermeasure Pipe temperature 1 Slight temperature difference 1–4 Check pipe <liquid or condenser/ <Cooling mode> between indoor room evaporator> temperature with room Detected as abnormal when the pipe tem- temperature and pipe <liquid temperature display on remote con- perature is not in the cooling range 3 min- or condenser/evaporator>...
  • Page 21 Check code Abnormal point and detection method Cause Countermeasure Forced compressor stop 1 Drain pump trouble 1 Check the drain pump. 2 Drain defective 2 Check whether water can be drained. (due to water leakage abnormality) • Drain pump clogging 1 The unit has a water leakage abnormality •...
  • Page 22 Check code Abnormal point and detection method Cause Countermeasure Indoor/outdoor unit communication 1 Contact failure, short circuit or, Check LED display on the outdoor control error (Signal receiving error) circuit board. (Connect A-control service miswiring (converse wiring) of tool, PAC-SK52ST.) 1 Abnormal if indoor controller board indoor/outdoor unit connecting cannot receive any signal normally for 6...
  • Page 23 9-4. TROUBLESHOOTING OF PROBLEMS Note: Refer to the outdoor unit's service manual for the detail of remote controller. Phenomena Cause Countermeasure (1)LED2 on indoor controller board • When LED1 on indoor controller board is also off. is off. Power supply of rated voltage is not supplied to out- Check the voltage of outdoor power door unit.
  • Page 24 Note: Refer to the manual of outdoor unit for the detail of remote controller. Phenomena Cause Countermeasure (3)Upward/downward vane The vane is not downward during defrosting and heat Normal operation (The vane is set to hori- performance failure preparation and when the thermostat is OFF in HEAT zontal regardless of remote control.) mode.
  • Page 25 9-5. EMERGENCY OPERATION 9-5-1. When wireless remote controller troubles or its battery is exhausted When the remote controller cannot be used When the batteries of the remote controller run out or the remote control- ler malfunctions, the emergency operation can be done using the emer- gency buttons on the grille.
  • Page 26 9-6. HOW TO CHECK THE PARTS PLA-A12EA8 PLA-A18EA8 PLA-A24EA8 PLA-A30EA8 PLA-A36EA8 PLA-A42EA8 PLA-A48EA8 Parts name Check points Room temperature Disconnect the connector then measure the resistance with a tester. thermistor (TH1) (At the ambient temperature of 50 to 86˚F [10 to 30˚C])
  • Page 27 9-6-1. Thermistor <Thermistor characteristic graph> <Thermistor for lower temperature> Room temperature thermistor(TH1) Thermistor for Pipe temperature thermistor/liquid(TH2) lower temperature Condenser/evaporator temperature thermistor(TH5) Thermistor R =15 k" ± 3% Fixed number of B=3480 ± 2% t(:)Rt=15exp { 3480( 273+t T(˚F)Rt=15exp { 3480( T-32 273+ 32˚F...
  • Page 28 9-7. TEST POINT DIAGRAM Indoor controller board PLA-A12EA8 PLA-A18EA8 PLA-A24EA8 PLA-A30EA8 PLA-A36EA8 PLA-A42EA8 PLA-A48EA8 LED2 CN90 CN4Z Power supply Connect to the wireless i-see Sensor (Sensor) (Wired remote controller) remote controller board (CNB) Connect to wired remote controller Vane motor (MV) 10.4-14.6 V DC...
  • Page 29 9-8. FUNCTIONS OF DIP SWITCH AND JUMPER WIRE Each function is controlled by the DIP switch and the jumper wire on indoor controller board. PLA-A12EA8 PLA-A18EA8 PLA-A24EA8 PLA-A30EA8 PLA-A36EA8 PLA-A42EA8 PLA-A48EA8 ■ The black square ( ) indicates a switch position.

  • Page 30: Function Setting

    FUNCTION SETTING 10-1. UNIT FUNCTION SETTING BY THE REMOTE CONTROLLER Each function can be set as necessary using the remote controller. The setting of function for each unit can only be done by the remote controller. (1) Functions available when setting the unit number to 00 Refer to the service manual that comes with each outdoor unit.

  • Page 31: Special Function

    SPECIAL FUNCTION 11-1. ROTATION FUNCTION (AND BACK-UP FUNCTION, 2ND STAGE CUT-IN FUNCTION) 11-1-1. Operation (1) Rotation function (and Back-up function) Outline of functions • Main and sub unit operate alternately according to the interval of rotation setting. Note: Main and sub unit should be set by refrigerant address. (Outdoor DIP switch setting) Refrigerant address "00"...
  • Page 32 • System constraint · This function is available only in cooling mode. Ex.) Set temp. by R/C = 68°F [20:] [2nd stage cut-in function]··· Request code number "322–324" Set point = 79°F [26:] When request code number is “323”. Room temp. ] Set point Room temp.
  • Page 33 11-2. BACK-UP HEATING FUNCTION 11-2-1. Operation The back-up heater turns ON when both of the following conditions have been satisfied: A) When the room temperature has not risen after the heater ON delay time has passed. Note: The heater ON delay time starts when the condition of “set temperature − room temperature > 1°F [0.5 ]”...

  • Page 34: Disassembly Procedure

    DISASSEMBLY PROCEDURE PLA-A12EA8 PLA-A18EA8 PLA-A24EA8 PLA-A30EA8 PLA-A36EA8 PLA-A42EA8 PLA-A48EA8 Be careful when removing heavy parts. OPERATING PROCEDURE PHOTOS/FIGURES Figure 1 1. Removing the filter Knob Air intake grille (1) Slide the knob of air intake grille toward the arrow to open the air intake grille.
  • Page 35 OPERATING PROCEDURE PHOTOS/FIGURES 4. Removing the room temperature thermistor (TH1) Photo 3 (1) Remove the electrical box cover. (See Photo 1 and 2.) Thermistor (TH1) (2) Disconnect the connector CN20 (Red) from the indoor Electrical box controller board. Indoor controller CN20 (3) Remove the room temperature thermistor with its holder.
  • Page 36 Be careful when removing heavy parts. OPERATING PROCEDURE PHOTOS/FIGURES Photo 6 Bell mouth fixing screws 6. Removing the electrical box (1) Remove the electrical box cover (See Photo 1 and 2.) and the connectors (Refer to procedure 5.). (2) Remove the electrical box fixing screws (M5 × 10: 2 Bell mouth screws).
  • Page 37 OPERATING PROCEDURE PHOTOS/FIGURES Nuts and washers Photo 10 8. Removing the fan motor (MF) Rubber mounts (1) Remove the turbo fan. (See Photo 7 and refer to procedure 8.) (2) Remove the lead cover (tapping screw 4×10: 2 screws). (See Photo 10.) (3) Loosen the 2 clamps.
  • Page 38 OPERATING PROCEDURE PHOTOS/FIGURES Photo 13 10. Removing the drain pan (1) Remove the electrical box. (See photo 3 and refer to 7.) Drain pan (2) Remove the bell mouth (tapping screw 4×10 : 2 screws). (See Photo 6.) (3) Remove the drain pan (screw M5×10: 4 screws). Drain pan Drain pan fixing screws...
  • Page 39 OPERATING PROCEDURE PHOTOS/FIGURES Photo 15 12. Removing the drain pump (DP) (1) Remove the drain pan. (Refer to procedure 10) (2) Cut the hose band and remove the hose. Float switch (3) Loosen the clamp of the drain pump. Drain pump (4) Remove the drain pump (tapping screw 4×10: 2 screws/2 hooks).
  • Page 40 OPERATING PROCEDURE PHOTOS/FIGURES 14. Removing the heat exchanger Photo 17 (1) Remove the drain pan. (Refer to procedure 10.) Coil support fixing screw (2) Remove the piping cover (tapping screw 4×10: 3 Heat exchanger fixing screws screws). (3) Remove the coil plate (tapping screw 4×10: 2 screws). Coil support (4) Remove the heat exchanger fixing screws (tapping screw 4×10: 2 screws).

  • Page 41: Remote Controller

    REMOTE CONTROLLER 13-1. REMOTE CONTROLLER FUNCTIONS <PAR-41MAA> Controller interface The functions of the function buttons change depending on the screen. Refer to the button function guide that appears at the bottom of the LCD for the functions they serve on a given screen. When the system is centrally controlled, the button function guide that corresponds to the locked button will not appear.
  • Page 42 Display The main display can be displayed in two different modes: “Full” and “Basic”. The initial setting is “Full”. To switch to the “Basic” mode, change the setting on the Main display setting. (Refer to operation manual included with remote controller.) <Full mode>...
  • Page 43 Menu structure Main menu Press the button. MENU Move the cursor to the desired item with the buttons, and press the button. SELECT/HOLD Operation Vane · Louver · Vent. (Lossnay) High power Comfort Manual vane angle 3D i-See sensor Timer menu Timer ON/OFF timer Auto-OFF timer...
  • Page 44 Continue from the previous page. Maintenance menu Error information Filter information Cleaning Auto descending panel Descending operation Descending adjustment Service menu Test run menu Test run Drain pump test run Maintenance information Model name input Serial No. input Dealer information input Initialize maintenance info.
  • Page 45 Main menu list Main Setting and display items Setting details menu Operation Vane · Louver · Vent. Use to set the vane angle. (Lossnay) • Select a desired vane setting. Use to turn ON/OFF the louver. • Select a desired setting from "ON" and "OFF." Use to set the amount of ventilation.
  • Page 46 Setting and display Main menu Setting details items Initial Display Main display Use to switch between "Full" and "Basic" modes for the Main display, and use setting setting to change the background colors of the display to black. Display de- Make the settings for the remote controller related items as necessary.
  • Page 47 <PAR-SL101A-E> Controller interface Transmission area Remote controller display Set Temperature buttons OFF/ON button Mode button (Changes operation mode) Fan Speed button (Changes fan speed) Airflow button (Changes up/ i-see button* down airflow direction) Timer ON button Menu button Timer OFF button SET/SEND button Weekly timer ON/OFF button* CANCEL button...
  • Page 48 13-2. ERROR INFORMATION When an error occurs, the following screen will appear. Check the error status, stop the operation, and consult your dealer. 1. Check code, error unit, refrigerant address, model name, and se- Error information rial number will appear. Error code The model name and serial number will appear only if the informa- Error unit...
  • Page 49 • Checking the error information Maintenance menu While no errors are occurring, page 2/2 of the error information can be Error information viewed by selecting "Error information" from the Maintenance menu. Filter information Errors cannot be reset from this screen. Cleaning Main menu: RETURN Cursor...
  • Page 50 13-3. SERVICE MENU Maintenance password is required 1. Select "Service" from the Main menu, and press the [SELECT/HOLD] button. Main Main menu *At the main display, the menu button and select "Service" to make the maintenance setting. Service 2. When the Service menu is selected, a window will appear asking for the pass- Service menu word.
  • Page 51 13-4. TEST RUN 13-4-1. PAR-41MAA 1. Select "Service" from the Main menu, and press the [SELECT/HOLD] button. Test run Input maintenance info. Settings Check Select "Test run" with the F1 or F2 button, and press the [SELECT/HOLD] button. Others : RETURN SELECT MENU RETURN...
  • Page 52 13-4-2. PAR-SL101A-E 1. Press the button to stop the air conditioner. • If the weekly timer is enabled ( is on), press the button to disable it ( is off). 2. Press the button for 5 seconds. • comes on and the unit enters the service mode. 3.
  • Page 53 4. Use the F1 or F2 button to move the cursor to select the mode number, and Function setting change the setting number with the F3 or F4 button. Ref. address Grp. Mode 1 Mode 2 Mode 3 Mode 4 Request: SELECT Cursor Cursor...
  • Page 54 13-5-2. PAR-SL101A-E 1. Going to the function select mode Press the button between of 5 seconds. (Start this operation from the status of remote controller display turned off.) [CHECK] is lit and "00" blinks. (Fig. 1) Press the button to set the "50". Direct the wireless remote controller toward the receiver of the indoor unit and press the button.
  • Page 55 13-6. ERROR HISTORY 1. Select "Service" from the Main menu, and press the [SELECT/HOLD] button. Test run Input maintenance info. Settings Check Others : RETURN Select "Check" with the F1 or F2 button, and press the [SELECT/HOLD] button. SELECT MENU RETURN HOLD 2.
  • Page 56 13-7. SELF-DIAGNOSIS 13-7-1. PAR-41MAA 1. Select "Service" from the Main menu, Diagnosis and press the [SELECT/HOLD] button. Self check Remote controller check Select "Check" from the Service menu, and press the [SELECT/HOLD] button. Service menu: MENU Cursor Select "Diagnosis" from the Check menu, and press the [SELECT/HOLD] button.
  • Page 57 4. Resetting the error history Self check Press the F4 button (Reset) on the screen that shows the error history. Ref. address Delete error history? A confirmation screen will appear asking if you want to delete the error history. Cancel Press the F4 button (OK) to delete the error history.
  • Page 58 13-8. REMOTE CONTROLLER CHECK If operations cannot be completed with the remote controller, diagnose the remote controller with this function. 1. Select "Service" from the Main menu, and Diagnosis press the [SELECT/HOLD] button. Self check Remote controller check Select "Check" from the Service menu, and press the [SELECT/HOLD] button.
  • Page 59 13-9. SMOOTH MAINTENANCE Check menu 1. Select "Service" from the Main menu, and press the [SELECT/HOLD] button. Error history Diagnosis Smooth maintenance Request code Select "Check" with the F1 or F2 button, and press the [SELECT/HOLD] button. Service menu: MENU Cursor Select "Smooth maintenance"...
  • Page 60 ■ Refrigerant address Single refrigerant system Multi refrigerant system (group control) In the case of single refrigerant system, the refrigerant address Up to 16 refrigerant systems (16 outdoor units) can be con- is "00" and no operation is required. nected as a group by 1 remote controller. To check or set the Simultaneous twin, triple units belong to this category refrigerant addresses.
  • Page 62 HEAD OFFICE: TOKYO BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN MITSUBISHI ELECTRIC CONSUMER PRODUCTS (THAILAND) CO., LTD. 700/406 MOO 7, TAMBON DON HUA ROH, AMPHUR MUANG, CHONBURI 20000 THAILAND Issued: Aug. 2023. No. TCH120 REVISED EDITION-A Published: Mar. 2023. No. TCH120 Specifications are subject to change without notice.

This manual is also suitable for:

Pla seriesPla-a18ea8Pla-a24ea8Pla-a30ea8Pla-a36ea8Pla-a42ea8 ... Show all

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