Mitsubishi Electronics service manual Troubleshooting check table MUZ-GB50VA

Page 21

10-4. Troubleshooting check table MUZ-GB50VA

No.

Symptom

Indication

Abnormal point / Condition

Condition

Correspondence

LED1(Red)

LED2(Yellow)

 

 

 

 

 

 

Outdoor unit

 

 

 

When over current protection stop is continuously

• Check the connection of the compressor connecting

 

does not

 

 

 

 

 

 

 

performed three times within 1 minute after the compressor gets

wire.

 

operate.

 

 

 

1

 

Lightning

Twice

Outdoor power system

started, or when converter protection stop or bus-bar voltage

• Refer to 10-6.A"How to check inverter/compressor".

 

 

 

 

 

protection stop is continuously performed three times within 3

• Check the stop valve.

 

 

 

 

 

minutes after start-up.

 

 

 

 

 

 

 

 

 

 

 

 

Discharge temperature

When a short circuit is detected in the thermistor during operation, or

• Refer to 10-6.B"Check of outdoor thirmistors".

2

 

Lightning

3 times

when an open circuit is detected in the thermistor after 10 minutes

 

thermistor

 

 

 

 

 

of compressor start-up.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fin temperature

 

• Refer to 10-6.B"Check of outdoor thirmistors".

 

 

 

 

thermistor

When a short or open circuit is detected in the thermistor during

3

 

Lightning

4 times

 

 

P.C board temperature

operation.

 

 

 

 

• Replace the outdoor electronic control P.C. board.

 

 

 

 

thermistor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ambient temperature

When a short or open circuit is detected in the thermistor during

 

 

 

 

 

thermistor

operation.

 

 

 

 

 

 

 

 

 

 

 

 

Outdoor heat exchanger

When a short circuit is detected in the thermistor during operation, or

 

 

 

 

 

when an open circuit is detected in the thermistor after 5 minutes (in

 

4

 

 

 

temperature thermistor

 

 

Lightning

5 times

cooling) and 10 minutes (in heating) of compressor start-up.

• Refer to 10-6.B"Check of outdoor thirmistors".

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When a short circuit is detected in the thermistor during operation, or

 

 

 

 

 

Defrost thermistor

when an open circuit is detected in the thermistor after 5 minutes of

 

 

 

 

 

 

compressor start-up.

 

 

 

 

 

 

 

 

5

 

Lightning

6 times

Serial signal

When the communication fails between the indoor and outdoor

• Refer to 10-6.H"How to check mis-wiring and serial signal

 

unit for 3 minutes.

error.

 

 

 

 

 

 

 

 

 

 

 

 

6

 

Lightning

7 times

Nonvolatile memory data

When the nonvolatile memory data cannot be read properly.

• Replace the outdoor electronic control P.C. board.

 

 

 

 

 

 

 

7

 

Lightning

8 times

Current sensor

Current sensor protection stop is continuously performed twice.

• Replace the power board.

 

 

 

 

 

 

 

8

 

Lightning

11 times

Communication error

When the communication protection stop between boards is

• Check the connecting wire between outdoor electronic control

 

between P.C. boards

continuously performed twice.

P.C. board and power board.

 

 

 

 

9

 

Lightning

12 times

Zero cross detecting

The protection stop of the zero cross detecting circuit is continuously

• Check the connecting wire among outdoor electronic control

 

circuit

performed 10 times.

P.C. board, noise filter P.C. board and power board.

 

 

 

 

 

 

 

 

 

 

 

 

'Outdoor unit

 

 

 

 

• Reconnect compressor connector.

 

stops and

 

 

IPM protection

When over-current is detected after 30 minutes of compressor start-up.

 

restarts 3

 

 

 

• Refer to 10-6.A"How to check inverter/compressor".

 

 

 

 

 

10

minutes

Twice

Goes out

 

 

• Check the stop valve.

 

When over-current is detected within 30 minutes of compressor

 

later' is

 

 

 

• Check the power module (PAM module).

 

repeated.

 

 

Lock protection

start-up

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3 times

Goes out

Discharge temperature

When discharge temperature exceeds 116:during operation.

• Check the amount of gas and refrigerant circuit.

11

 

protection

compressor stops. Compressor can restart if discharge temperature

• Refer to 10-6.G"Check of LEV".

 

 

 

 

 

 

 

 

thermistor reads 100: or less 3 minutes later.

 

 

 

 

 

Fin temperature

When the fin temperature exceeds 87: during operation.

•Check refrigerant circuit and refrigerant amount.

 

 

 

 

protection

12

 

4 times

Goes out

 

•Refer to 10-6.D"Check of outdoor fan motor".

 

P.C. board temperature

When the P.C. board temperature exceeds 70: during operation.

 

 

 

 

 

 

 

 

 

protection

 

 

 

 

 

 

 

 

 

 

 

High-pressure

When the outdoor heat exchanger temperature exceeds 70:

• Check around of gas and the refrigerant circuit.

 

 

 

 

protection

during cooling or when indoor gas pipe temperature exceeds 70:

• Check of stop valve.

13

 

5 times

Goes out

 

during heating.

 

 

 

 

 

 

 

 

14

 

8 times

Goes out

Converter protection

When a failure is detected in the operation of the converter during

• Replace the power board.

 

 

operation.

 

 

 

 

 

 

 

 

 

 

Bus-bar voltage

When the bus-bar voltage exceeds 400V or falls to 200V or below

 

15

 

9 times

Goes out

protection (1)

during compressor operating.

• Replace the power board.

 

Bus-bar voltage

When the bus-bar voltage exceeds 400V or falls to 50V or below

 

 

 

 

 

 

 

 

 

protection (2)

during compressor operating.

 

16

 

13 times

Goes out

Outdoor fan motor

When failure occurs continuously three times within 30 seconds after

• Refer to 10-6.D"Check of outdoor fan motor".

 

the fan gets started.

 

 

 

 

 

 

17

 

Lighting

8 times

Current sensor

When a short or open circuit is detected in the current sensor during

• Replace the power board.

 

protection

compressor operating.

 

 

 

 

 

 

 

 

 

 

 

 

18

 

Lighting

11 times

Communication between P.C.

Communication error occurs between the outdoor electronic control P.C.

• Check the connecting wire between outdoor electronic control

 

boards protection

board and power board for more than 10 seconds.

P.C. board and power board.

 

 

 

 

19

 

Lighting

12 times

Zero cross detecting circuit

When zero cross signal cannot be detected while the compressor is

• Check the connecting wire among outdoor electronic control

 

protection

operating.

P.C. board, noise filter P.C. board and power board.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NOTE 1. The location of LED is illustrated at the right figure. Refer to 10-7.1. 2. LED is lighted during normal operation.

The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF. (Example) When the flashing frequency is “2”.

0.5-second ON

ON

2.5-second OFF

2.5-second OFF

OFF

Outdoor electronic control P.C. board(Parts side)

LED2 LED1

Lighting

0.5-second ON

21

Image 21
Contents Revised EDITION-A R410A Refrigerant OBR01 ContentsMUZ-GA50VA E1 Technical ChangesSNB130FLDH SNB130FLDH1Accessories SpecificationPart Names and Functions MUZ-GB50VASpecifications and rating conditions of main electric parts Band Octave Noise Criteria CurvesMUZ-GB50VA Outdoor Unit Outlines and DimensionsOutdoor Unit MUZ-GB50VA Wiring DiagramUnitmm Refrigerant System DiagramPerformance Curves Indoor Unit Outdoor UnitCapacity and input curves MUZ-GB50VA Test RUN Operation How to operate fixed-frequency operationCool operation Performance Data Cool operation Rated frequency 79Hz MSZ-GB50VA MUZ-GB50VAOutdoor SHC SHF InputOutdoor DB Performance Data Heat operation Actuator ControlOutdoor fan motor control R.V. coil controlRelation between main sensor and actuator MUZ-GB50 TroubleshootingOFF Failure mode recall functionOperational procedure Outdoor unit failure mode table Time flash Communication error Lighting Indicator Instruction of troubleshootingOperation EmergencyOperate Lightning Twice Outdoor power system Troubleshooting check table MUZ-GB50VAOnce Lighting RED BLK BLK WHT Trouble criterion of main parts MUZ-GB50VAWHT RED RED ORNTroubleshooting flow How to check inverter/ compressorCheck of outdoor thermistors Check of R.V. coil When heating operation does not workCheck of outdoor fan motor Check of power supplyCheck of LEV Check of current-limiting resistorParts side Electromagnetic noise enters into TV sets or radios Discharge temperature thermistor RT62 Noise filter P.C. board CN2 Outdoor power boardCN3 CN5Disassembly Instructions MUZ-GB50VA Outdoor Unit Operating Procedure PhotosRemoving the cabinet Photo Removing R.V. coil Operating Procedure PhotosRemoving outdoor fan motor Photo Ture thermistor and ambient temperature thermistorRemoving the reactor Removing the compressor and 4-way valve PhotoRoHS Parts List RoHS compliant MUZ-GB MUZ-GB50 MUZ-GB50VA Accessory