In order to service and troubleshoot an air-source heat pump system, a service technician must understand the unit's sequence of operation. This is the order of events the system undergoes to cycle ...

In performing service and troubleshooting on heat pump systems, there are various electrical components to be checked. The following provides information to aid in inspecting and servicing these ...

Relays and contactors use a variety of technologies to switch signals and power connections. Many devices called relays use similar techniques and topologies, but the terminology can be confusing.