Sinclair SCV-750EB Service Manual page 97

L1: Low-voltage protection
The power supply is abnormal
DC bus voltage(P, N) is abnormal
Power supply for compressor module
Wire connection between reactor and
compressor module board is abnormal
Pressure switch is open
Change compressor module board
Note:
1. The normal DC voltage between terminals P and N of CN38 of compressor inverter module board should be 450-650V. When the voltage is lower than 350V.
L1
No
1
Yes
board is abnormal
No
No
No
Yes
Check the power supply equipment
No
Change compressor module board
Check the wire connection between power
supply terminals and filter board; Check the
Yes
wire connection between filter board to
compressor module board
Yes
Rewiring according to the wiring diagram
Check whether P0 error appears or high
Yes
pressure switch broken
95