SYSTEM AND METHOD FOR SHARED HYBRID TRANSFER SWITCH SYSTEM WITH INTEGRATED RELAY SELF TEST

The present disclosure relates to a shared transfer switching system with built in relay testing ability, for transferring power received by a load from a preferred AC power source to an alternate AC power source, or transferring power being received by the load from the alternate AC power source to the preferred AC power source. The system selectively controls various ones of the relays used to apply power from either the preferred or alternate power sources to the load, such that the relays are switched from open to closed states at controlled times, while voltage measurements are made at select locations between the relays. The system can identify which specific ones of a plurality of relays associated with each of the preferred and alternate power sources has properly opened and closed, and thus verify that all of the relays needed to switch between the preferred and alternate power sources are operating properly.