Sinclair SCV-750EB Service Manual page 150

Wrong module board which does not correspond to the model;

Module board fault.

Procedure
Spot check whether the dial code of the main control
board is corresponding to the unit model
Whether the module board model match the
6.13 L50: Startup failure
Description
Compressor failed to start.

After the fault, the compressor stops running, and if the fault disappears after one minute, the compressor starts again.

Trigger/resume condition
Trigger condition: Compressor failed to start.

Resume condition: After the compressor fails to start, the compressor restarts again. The fault is recovered after successful

restart.
 Reset method: Automatic recovery after successful restart.
Possible causes
There is a pressure difference when the system starts;

Compressor stuck.

Procedure
Spot check whether the dial code of the main control
board is corresponding to the unit model
Whether the module board model match the
6.14 L52: Zero speed protection
Description
Compressor locks rotor.

After the fault, the compressor stops running, and if the fault disappears after one minute, the compressor starts again.

Trigger/resume condition
Trigger condition: Compressor locks rotor.

Resume condition: Troubleshoot locked rotor.

Reset method: Automatic recovery after reaching the fault exit condition.

Possible causes
Impurities in the system or lack of lubricating oil.

148
L47
NO
compressor mode
NO
End
L50
NO
compressor mode
NO
End
Reset the dial code of the unit
Yes
model
Yes
Change the drive board
Reset the dial code of the
Yes
unit model
Yes
Change the drive board