TROUBLESHOOTING
Automatic Shutdown
The compressor will not start or will shut down automatically if any of the following are open:
• the compressor motor protector switch;
• the water, oil or gas high-temperature switch;
• the motor over-current relay;
• the circuit breaker.
If the compressor has been shut down by one of these interlocks, do not restart until the
problem has been found and corrected. Refer to the Troubleshooting Guide to identify the
problem.
If the unit shuts down again, refer to the Troubleshooting section to determine the cause and
corrective action.
When the shutdown is caused by one of the high-temperature switches, the compressor will
restart only after it has cooled enough for the switch to close. After waiting for the compressor to
cool, press the power switch to restart. Should the compressor fail to start, turn it off and allow
more cooling time. Repeat the start procedure. Check the cooling water temperature and flow.
Compare with specifications listed in the Specifications section.
The motor over-current relay automatically resets after the compressor shuts down and the
relay cools. To restart the compressor, press the power switch to the “ON” position. If the
compressor fails to start, turn it “OFF” and allow more cooling time. Repeat the start procedure.
If the circuit breaker opens, reset the breaker by pushing its lever to the “UP” position.
If a fuse is open, disconnect the power from the compressor, replace the fuse, and then
restart the compressor. The four (4) fuses located in the front electrical panel protect the
control circuit cold head supply circuit.
Refer to the Troubleshooting Guide and the following procedures for checking the
compressor’s electrical components. The Troubleshooting Guide lists problems that can
occur in the compressor and suggests possible causes sand corrective actions.
AVOID ELECTRIC SHOCK. Disconnect the power to the compressor before
troubleshooting the electrical components.
AVOID ELECTRIC SHOCK. Permit only qualified electrical technicians to open
electrical enclosures, to perform electrical checks or to perform tests with the
power supply connected and wiring exposed. Failure to observe this warning can
result in serious injury or death.