ARE YOUR SAFETY DEVICES WORKING?

Ammonia was released at a recreational facility. A high pressure cut out switch failed to shut down a compressor when the compressor experienced a high pressure condition. Pressure continued to build until a safety relief device operated releasing ammonia gas to atmosphere via the relief stack,
which triggered the ammonia alarm.
The water supply line to the condenser had no protection and was subject to freezing during cold weather. The high limit switch was old (1986) and is mounted on the compressor base subjecting it to vibration. The safety relief operated as designed, venting gas to atmosphere, preventing a possible
catastrophic failure.
Source: British Columbia Safety Authority