Troubleshooting - Mitsubishi Electric MUZ-GB50VA - E1MUZ-GB50VA - E2 Service Manual

9-3. Relation between main sensor and actuator
Sensor
Discharge temperature thermistor
Indoor pipe temperature thermistor
Defrost thermistor
Fin temperature thermistor
Outdoor heat exchanger temperature
Ambient temperature thermistor
10

TROUBLESHOOTING

MUZ-GB50VA
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 miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, then after con-
firming the horizontal vane is closed, turn off the breaker and / or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic
control P.C. board.
3) When removing the electrical parts, be careful to the residual voltage of smoothing capacitor.
4) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
5) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the abnormality indication is flashing on and off before starting service work.
2) Before servicing check that the connector and terminal are connected properly.
3) When the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.
4) When troubleshooting, refer to 10-2., 10-3. and 10-4.
Purpose
Compressor
Protection
Defrosting Protection
Defrosting
Protection
Protection
Protection
Lead wiring
15
Actuator
Outdoor
LEV
fan motor R.V. coil
Housing point