When restarting the compressor, check for any abnormal sound from the compressor, e.g.
knocking sound. This is an indication of liquid compression
which will damage the compressor. If
such sounds are heard, switch off the compressor immediately.
Allow the crankcase heater to continue warming up the compressor. Repeat the restart
again.
If the problem still persists, call for service technicians to rectify.
Section 14 Page 150