When electrically inspecting or troubleshooting a compressor, you should always protect yourself against the possibility of terminal venting. This occurs when an electrical terminal of a compressor blows out and vents the refrigerant within the compressor and the system. Usually you discover this after the fact. Typically, you are called out for a system that is not cooling, only to discover the system has lost its entire refrigerant charge and one of the compressor terminals has blown out.

There is always the possibility of this occurring while electrically testing a compressor charged with refrigerant, so always stand to the side when placing your meter leads onto the compressor’s terminals. Never look straight at terminals; you would not want a terminal blowing out during this time. There could be sufficient force behind the terminal to cause serious injury. I have actually seen a manufacturer state in their literature not to electrically test a compressor unless you remove the refrigerant first. Not a very practical option, but it would always prevent this type of injury.