Sinclair SCV-750EB Service Manual page 101

L8: Compressor frequency variation greater than 15Hz within one second protection
L9: Actual compressor frequency differs from target frequency by more than 15Hz protection
Disconnect the
power supply
L8 protection
ODU stop valves are closed
No
Compressor wiring is not properly
No
The resistance between 3 phases of
compressor is over 5Ω
No
The insulation resistance of
compressor is less than 100Ω
The compressor has less than 12 hours
preheating before initial operating
No
Replace the compressor inverter
board, restart the unit and the error is
solved
No
Refer to P1 or P3 troubleshooting
Refer to P4/P5 troubleshooting
L9 protection
Yes
Yes
Yes
Yes
Yes
Yes
Open the ODU stop valves
Reconnect the cables based on
wiring diagram
Replace the compressor
Ensure enough preheating time
Normal
99