Mitsubishi Electric MXZ-2B20NA Service Manual
Mitsubishi Electric MXZ-2B20NA Service Manual

Mitsubishi Electric MXZ-2B20NA Service Manual

Outdoor unit
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SPLIT-TYPE AIR CONDITIONERS

OUTDOOR UNIT

SERVICE MANUAL

Models
MXZ-2B20NA
MXZ-2B20NA -
Revision A:
• MXZ-2B20NA-
1
CONTENTS
1. TECHNICAL CHANGES· ·································· 2
2. PART NAMES AND FUNCTIONS ····················· 2
3. SPECIFICATION ················································ 3
4. NOISE CRITERIA CURVES ······························ 4
5. OUTLINES AND DIMENSIONS ························ 5
6. WIRING DIAGRAM ············································ 6
7. REFRIGERANT SYSTEM DIAGRAM ··············· 7
8. DATA ·································································· 9
9. ACTUATOR CONTROL ··································· 17
10. SERVICE FUNCTIONS ···································· 17
11. TROUBLESHOOTING ····································· 18
12. DISASSEMBLY INSTRUCTIONS ···················· 34
INDOOR UNITS COMBINATION SHEETS
9700058
33223
has been added.
1
No. OBH560
HFC
utilized
REVISED EDITION-A
R410A
Indoor unit service manual
MSZ-A·NA Series (OB450)
MSZ-FD·NA Series (OBH497)
MSZ-FE·NA Series (OBH542)
MSZ-GE·NA Series (OBH548)
SEZ-KD·NA.TH Series
The Slim Line.
From Mitsubishi Electric.
TM

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Summary of Contents for Mitsubishi Electric MXZ-2B20NA

  • Page 1: Table Of Contents

    Revision A: • MXZ-2B20NA- has been added. SPLIT-TYPE AIR CONDITIONERS OUTDOOR UNIT No. OBH560 SERVICE MANUAL utilized REVISED EDITION-A R410A Models MXZ-2B20NA MXZ-2B20NA - Indoor unit service manual MSZ-A·NA Series (OB450) MSZ-FD·NA Series (OBH497) MSZ-FE·NA Series (OBH542) MSZ-GE·NA Series (OBH548) SEZ-KD·NA.TH Series...
  • Page 2: Technical Changes

    MXZ-2B20NA - 1. Outdoor fan motor has been changed. 2. Outdoor electronic control P.C. board has been changed. 3. LEV coil has been changed. PART NAMES AND FUNCTIONS MXZ-2B20NA MXZ-2B20NA - Air inlet (Back and side) Air outlet Drain outlet...
  • Page 3: Specification

    SPECIFICATION Outdoor model MXZ-2B20NA MXZ-2B20NA - Item Indoor type Wall (09+09) Duct (09+12) Cooling 18,000 20,000 Btu/h Capacity Heating 47 22,000 22,000 Btu/h Heating 17 12,500 12,500 Btu/h Cooling 1,440 2,190 Power Heating 47 1,650 1,780 consumption Heating 17 1,350...
  • Page 4: Noise Criteria Curves

    NOISE CRITERIA CURVE MXZ-2B20NA FAN SPEED FUNCTION SPL(dB LINE MXZ-2B20NA - High Cooling High Heating NC-70 NC-60 NC-50 NC-40 NC-30 APPROXIMATE THRESHOLD OF HEARING FOR NC-20 CONTINUOUS NOISE 1000 2000 4000 8000 BAND CENTER FREQUENCIES, Hz...
  • Page 5: Outlines And Dimensions

    OUTLINES AND DIMENSIONS MXZ-2B20NA MXZ-2B20NA - Unit: inch 6-9/16" 19-11/16" 6-21/32" 2-1/2" 9-3/16" 11-11/32" Rear Air Intake Side Air Intake 3- (1-5/16") Drain Hole Discharge 4-(13/32"×13/16") Oval Hole (Foundation Bolt M10) 33-1/16" 1-3/16" 7-7/8" 1-3/16" 13" 1/2" 3- 7/8" Punched holes (Connecting wire hole) 1-5/32"...
  • Page 6: Wiring Diagram

    WIRING DIAGRAM MXZ-2B20NA MXZ-2B20NA -...
  • Page 7: Refrigerant System Diagram

    REFRIGERANT SYSTEM DIAGRAM Unit: mm MXZ-2B20NA MXZ-2B20NA - Service port Compressor R.V. coil Discharge Service temperature Refrigerant flow in cooling port thermistor RT62 Refrigerant flow in heating Oil separator Capillary tube O.D.0.10 x I.D.0.02 x 39.37 Stop valve with Indoor unit...
  • Page 8 Operating Range MXZ-2B20NA MXZ-2B20NA - Indoor intake air temperature Outdoor intake air temperature Maximum 95°FDB, 71°FWB 115°FDB Cooling Minimum 67°FDB, 57°FWB 14°FDB Maximum 80°FDB, 67°FWB 75°FDB, 65°FWB Heating Minimum 70°FDB, 60°FWB 6°FDB, 5°FWB MAX. REFRIGERANT PIPING LENGTH & PIPE SIZE SELECTION...
  • Page 9: Data

    DATA MXZ-2B20NA MXZ-2B20NA - Model Indoor type Wall (09+09) Duct (09+12) Item Unit Cooling Heating Cooling Heating Total Capacity But/h 18,000 22,000 20,000 22,000 – – – – – Input 1.44 1.65 2.19 1.78 Electrical Power supply (V,phase,Hz) 208/230, 1, 60...
  • Page 10 (2) OPERATION Intake air Indoor Outdoor temperature Function Condition DB (°F) WB (°F) DB (°F) WB (°F) "A" Cooling steady state (75) at rated compressor speed "B-2" Cooling steady state (65) at rated compressor speed "B-1" Cooling steady state Cooling (65) at minimum compressor speed Low ambient cooling steady state...
  • Page 11 MXZ-2B20NA MXZ-2B20NA - 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 pro- vided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.
  • Page 12 8-2. CAPACITY AND THE INPUT CURVES MXZ-2B20NA MXZ-2B20NA - Cooling capacity (at Rated frequency) 11.2 15.5 14.2 Indoor intake air Wet-bulb 10.3 14.2 13.1 temperature(°F) 13.1 12.1 11.9 11.2 10.8 10.1 Outdoor intake air Dry-bulb temperature(°F) Total input (Cooling :...
  • Page 13 8-3. CAPACITY AND INPUT CORRECTION BY MEANS OF INVERTER OUTPUT FREQUENCY (OUTDOOR UNIT: MXZ-2B20NA MXZ-2B20NA - 1. 06-class unit in single operation <COOL>Capacity <COOL>Total input <HEAT>Capacity <HEAT>Total input Frequency Frequency Frequency Frequency 2. 09-class unit in single operation <COOL>Capacity <COOL>Total input <HEAT>Capacity...
  • Page 14 8-4. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT 1. 09-class unit in single operation (OUTDOOR UNIT: MXZ-2B20NA MXZ-2B20NA - (1) COOL operation Data is based on the condition of indoor humidity <How to work fixed-frequency operation> 1. Set emergency switch to COOL or HEAT. The switch is located Air flow speed: High on indoor unit.
  • Page 15 2. 12-class unit in single operation (OUTDOOR UNIT: MXZ-2B20NA MXZ-2B20NA - (1) COOL operation Data is based on the condition of indoor humidity <How to work fixed-frequency operation> 1. Set emergency switch to COOL or HEAT. The switch is located Air flow speed: High on indoor unit.
  • Page 16 3. 15-class unit in single operation (OUTDOOR UNIT: MXZ-2B20NA MXZ-2B20NA - (1) COOL operation Data is based on the condition of indoor humidity <How to work fixed-frequency operation> 1. Set emergency switch to COOL or HEAT. The switch is located Air flow speed: High on indoor unit.
  • Page 17: Actuator Control

    ACTUATOR CONTROL MXZ-2B20NA MXZ-2B20NA - Relation between main sensor and actuator Actuator Purpose Sensor Outdoor 4-way Compressor fan motor valve Discharge temperature thermistor Protection Indoor coil thermistor Defrosting Protection Defrost thermistor Defrosting Fin temperature thermistor Protection Ambient temperature thermistor Control...
  • Page 18: Troubleshooting

    TROUBLESHOOTING MXZ-2B20NA MXZ-2B20NA - 11-1. 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 of the following during servicing. 1) Before servicing the air conditioner, be sure to turn off the unit first with the remote controller, and then after confirm- ing the horizontal vane is closed, turn off the breaker and/or disconnect the power plug.
  • Page 19 2. Outdoor unit failure mode table The left lamp of LED indication Indoor/outdoor Abnormal point OPERATION INDICATOR (Outdoor P.C. board) Condition Remedy unit failure mode (Failure mode/protection) recall function lamp (Indoor unit) LED 1 LED 2 None (Normal) Lighting Lighting 2-time flash Outdoor power system Lighting Lighting...
  • Page 20 LED indication The left lamp of Indoor/outdoor Abnormal point Remedy (Outdoor P.C. board) Condition OPERATION INDICATOR unit failure mode (Failure mode/protection) recall function lamp(Indoor unit) LED 1 LED 2 Communication error 11-time flash Communication error occurs Lighting 6 times • Check the connecting between P.C.
  • Page 21: Troubleshooting Check Table

    P.C. board, noise filter P.C. board and power board. Outdoor electronic control P.C. board (Parts side) NOTE 1. The location of LED is illustrated at the right figure. Refer to 11-7.1. MXZ-2B20NA, MXZ-2B20NA- 2. LED is lighted during normal operation. LED2 LED1 The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
  • Page 22 NOTE 1. The location of LED is illustrated at the right figure. Refer to 11-7.1. 2. LED is lighted during normal operation. MXZ-2B20NA, MXZ-2B20NA- The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF. LED2 LED1 (Example) When the flashing frequency is “2”.
  • Page 23 11-5. TROUBLE CRITERION OF MAIN PARTS MXZ-2B20NA MXZ-2B20NA - Part name Check method and criterion Defrost thermistor (RT61) Fin temperature Measure the resistance with a tester. thermistor (RT64) Refer to 11-7. “Test point diagram and voltage”,1. “Outdoor electronic control P . C.
  • Page 24 11-6. TROUBLESHOOTING FLOW MXZ-2B20NA MXZ-2B20NA - Outdoor unit does not operate. Check of power supply Check the connecting of parts of main power supply circuit. Turn ON the power supply. Is there voltage of 208/230 V AC in the Check the power supply cable.
  • Page 25: How To Check Mis-Wiring And Serial Signal Error

    Is serial signal error indicated 6 minutes later ? disconnection of the Correct them. MXZ-2B20NA indoor/outdoor MXZ-2B20NA - connecting wire ? Outdoor electronic control P.C. board (Parts side) LED3 LED2 LED1 Blinking Turn OFF the power supply.
  • Page 26 The cooling operation or heating operation does not operate. Check of R.V. coil CN912 Noise filter P.C. board CN781 Outdoor electronic control P.C. board • When heating operation does not work. 1. Disconnect the lead wire leading to the compressor. 2.
  • Page 27 • When cooling, heat exchanger of non-operating indoor unit frosts. • When heating, non-operating indoor unit get warm. Check of LEV Turn ON the power supply to the outdoor unit after checking LEV coil is mounted to the LEV body securely. Is "click - click"...
  • Page 28 • When heating, room does not get warm. • When cooling, room does not get cool. How to check inverter/compressor Disconnect the terminal of the compressor. 3 minutes after turning ON the power supply, start EMERGENCY OPERATION. 1 • After the outdoor fan starts running, wait for 1 minute or more before measuring the voltage.
  • Page 29 • When thermistor is abnormal. Check of outdoor thermistors Replace the thermistor except RT64. Disconnect the connector in the following table and Abnormal In case that RT64 is abnormal, replace the measure the resistance of the thermistor to check outdoor power board since RT64 is combined whether the thermistor is normal or not.
  • Page 30 • When the operation frequency does not go up from the lowest frequency. The other cases Indoor unit does not operate. (different operating models in multi system) • When you try to run two indoor units simultaneously, one for cooling and the other for heating, the unit which transmits signal to the outdoor units first decides the operation mode.
  • Page 31 Defrost thermistor (RT61) Ambient temperature thermistor (RT65) 1. Outdoor electronic control P.C. board Discharge temperature thermistor (RT62) Outdoor heat exchanger temperature MXZ-2B20NA MXZ-2B20NA - thermistor (RT68) 86 104 122 140 158 176 194 212 230 248 Temperature (°F) Temperature (°F)
  • Page 32 2. Noise filter P.C. board MXZ-2B20NA MXZ-2B20NA - CN901 To electronic CN903 control To power P.C. board CN902 board To power board CN61 CN912 208/230 V AC R.V. coil 208/230 V AC Output 208/230 V AC Output FUSE T6.3AL250V 208/230 V AC...
  • Page 33 3. Outdoor Power board Fin temperature thermistor (RT64) MXZ-2B20NA MXZ-2B20NA - DM00N019 or DM00N095 32 50 68 86 104 122 140 158 176 Temperature (°F) Connect to the compressor Voltage among phases: 5 V to 180 V Connect to the earth...
  • Page 34: Disassembly Instructions

    Pull the terminal while pull out the terminal pushing the locking slowly. Locking lever lever. Connector 12-1. MXZ-2B20NA MXZ-2B20NA - OUTDOOR UNIT OPERATING PROCEDURE PHOTOS 1. Removing the compressor Photo 1 Screws of the (1) Remove the screws of the top panel, and remove the top top panel panel.
  • Page 35 OPERATING PROCEDURE PHOTOS Photo 3 Screw of the rear guard Screw of the back panel R.V. coil Photo 5 4 way valve Screws of the back panel LEV coil E Expansion valve E Suction pipe Screws of welded part the back panel Screw of the back panel Photo 4...
  • Page 36 OPERATING PROCEDURE PHOTOS 4. Removing the 4-way valve Photo 7 (1) Remove the top panel (Photo 1). (2) Remove the service panel, the cabinet, and the back panel (Photo 1, 2, 3). 4 way valve (3) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 PSIG.
  • Page 38 HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN Copyright 2009 MITSUBISHI ELECTRIC ENGINEERING CO., LTD Distributed in Dec. 2009. No. OBH560 REVISED EDITION-A 5 Distributed in Sep. 2009. No. OBH560 5 New publication, effective Dec. 2009 Made in Japan...
  • Page 39: Mxz-2B20Na

    MXZ-2B20NA MXZ-2B20NA - Cooling ndoor units ndoor type Cooling capacity(BTU/h) Power consumption Current(A) P/F(%) ombination 208V 230V Unit A Unit B Total Wall 6000 6000 2.68 2.43 ( 5400 - 9000 ) ( 490 - 680 ) Wall 9000 9000 3.44...
  • Page 40 MXZ-2B20NA MXZ-2B20NA - Heating Indoor units Indoor type Heating capacity(BTU/h) Power consumption Current(A) P/F(%) combination 208V 230V Unit A Unit B Total Wall 7400 7400 3.09 2.79 ( 5200 - 14400 ) ( 480 - 1400 ) Wall 11000 11000 4.45...

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