Substation - An assembly of switchgear or control center equipment supplied directly by feeders or by adjacent transformers.
Main Substation - A substation or switch-yard which supplies all or a major part of the power to the individual substations supplying the onsite and offsite facilities of a complete facility.
Indoor Substation - A substation within a field-constructed or prefabricated building.
Outdoor Substation - Defined by construction type as one of the following:
- Standard outdoor construction is metal-clad equipment protected by a weatherproof enclosure.
- Protected-aisle outdoor construction is metal-clad equipment within a factory-assembled building-like enclosure.