Oil pressure controls, oil failure controls, oil safety controls… They’re a pain in the neck when they trip, and diagnosing those problems can really tax even the best of techs. As semi-hermetic compressors get larger, they can no longer rely on simple splash or “sling” type lubrication strategies where oil is just flung around inside […]

Educators love lockout relays, and we also love pretending you will still see them out in the field all the time. Sometimes, I have to look myself in the mirror in the morning and sadly repeat, “Lockout relays are dead.” I have to say it several times before the reality sinks in. Before I get […]

Most of the laws we refer to in air conditioning and refrigeration are pretty obvious and practical. Dalton's law of partial pressures is no exception. John Dalton observed that the air pressure was equal to the added pressures of each gas that make up air. That means that the pressure and density of air can […]