Sumitomo HC-4A, Technical Manual, Page: 52 / 72

Troubleshooting
46
Troubleshooting Guide
Problem Possible Cause Corrective Action
Compressor and items
powered from it do not start
when the start switch on the
compressor is closed.
Run light is not on. No electrical power. Check that the power source is
on and the power cord is
connected.
Tripped circuit breaker in the
compressor. Check the voltage. Reset the
circuit breaker. Consult a
SCAI Service Center if the
problem persists.
Open fuse in the control
circuit. Check for a short circuit.
Replace the fuse. Consult a
SCAI Service Center if the
problem persists.
Run light comes on for about
one minute, then goes off, but
the compressor does not start.
Defective motor control
circuit. Consult a SCAI Service Center.
Wrong voltage. Compare the electric service with
system specifications.
Compressor starts but runs
roughly and does not build
significant pressure. Defective motor power circuit. Consult a SCAI Service Center.
Shipping bolt is engaged
Remove shipping bolt
Compressor starts, but shuts
down after a few minutes of
operation. Wrong equalization or
operating pressure.
Refer to Specifications and the
section on Charging and
Venting. Leak check the system
if the pressure is low.
Gas equalization solenoid
valve has failed. Replace the solenoid valve.
Low oil flow. Look for oil leaks in the
compressor capsule. Consult a
SCAI Service Center.
Orifice or the oil cooling line
filter is blocked.
Replace the orifice and the filter.
Fan or circulator runs slow or
is stopped.
See below at “Fan runs slow or
has stopped” or “Coolant flow
has stopped”.
Coolant loss is greater than
(1) liter. Consult a SCAI Service Center.