Mitsubishi Electric SUZ-SWM30VA TH Series Service Manual page 32

H Check of R.V. coil
SUZ-S(H)WM30/40, SUZ-SWM60
* First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 12-4.
* In case CN721 is disconnected or R.V. coil is open, voltage is generated between the terminal pins of the connector
although no signal is being transmitted to R.V. coil.
Check if CN721 is connected.
Unit operates in COOL mode even if it is set to HEAT mode.
Disconnect connector between the
compressor and the IGBT module
(IC700).
Turn ON the power supply and press
the emergency operation switch
twice (HEAT mode).
Unit operates in HEAT mode even if it is set to COOL mode.
Disconnect connector between the
compressor and the IGBT module
(IC700).
Turn ON the power supply and press
the emergency operation switch
once (COOL mode).
SUZ-SHWM60, SWM80/100
* First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 12-4.
* In case CN602 is disconnected or R.V. coil is open, voltage is generated between the terminal pins of the connector
although no signal is being transmitted to R.V. coil.
Check if CN602 is connected.
Unit operates in COOL mode even if it is set to HEAT mode.
Disconnect connector between the
compressor and the power module
(IC700).
Turn ON the power supply and press
the emergency operation switch
twice (HEAT mode).
Unit operates in HEAT mode even if it is set to COOL mode.
Disconnect connector between the
compressor and the power module
(IC700).
Turn ON the power supply and press
the emergency operation switch
once (COOL mode).
OCH796A
Is there 230 V AC between CN721
and on the inverter P.C. board 3
minutes after the power supply is turned
ON?
Yes
Replace the 4-way valve.
Is there 230 V AC between CN721
and on the inverter P.C. board 3
minutes after the power supply is turned
ON?
No
Replace the 4-way valve.
Is there 230 V AC between CN602
and on the inverter P.C. board 3
minutes after the power supply is turned
ON?
Yes
Replace the 4-way valve.
Is there 230 V AC between CN602
and on the inverter P.C. board 3
minutes after the power supply is turned
ON?
No
Replace the 4-way valve.
32
Replace the inverter
No P.C. board.
Replace the inverter
Yes P.C. board.
Replace the inverter
No P.C. board.
Replace the inverter
Yes P.C. board.