Sinclair SCV-750EB Service Manual page 130

Procedure
For SCV-750EB and SCV-1400EB
Discharge temperature sensor connection
on main PCB is loose
Temperature or pressure sensor has
short-circuited or failed
Discharge pipe temperature sensor at the
top of the compressor falls or is not
insulated.
Electronic expansion valve coil connection
on main PCB is loose
Electronic expansion valve coil has
Discharge pressure is too high
Replace outdoor main PCB
Notes:
1. Electronic expansion valve coil connections are port CN70, CN71 and CN72 on the main PCB (labeled 31, 32, 30 in Part 4, 2.2.1 Main PCB component).
2. The normal resistances between EXV coil wiring terminals is 40-50Ω. If any of the resistances differ from the value, the EXV coil has malfunctioned.
128
F2
No
NO
1
No
malfunctioned 2
No
No
Yes
Ensure the sensor is connected properly
Yes
Replace the sensor
Yes
Ensure that the sensor is installed in an
accurate position and well insulated
Yes
Ensure the sensor is connected properly
Yes
Replace the EXV
The temperature difference between water
Yes
inlet and water outlet or water inlet is too
No
Water flow is insufficient
Refer to E9 error
high
Yes
Yes