Substation only to cases where no development line transformer unit wiring

Substation has only one incoming line and a transformer, but no developments in the case group using line transformer wiring.
Bridge connection: There are two  electric transformer  lines, two transformers, and no development in the case of using the bridge-connected. For transformer,  electric meter  into the circuit breaker in the two within the inner bridge connection, contact breaker into the circuit breaker in the two outside of the outer bridge connection.
Single bus: substation inlet and outlet is large, the single bus, there are two incoming lines, generally powered all the way, all the way back (not the same power supply), the two can be mutually equipment power from the cast, multi-channel outlet leads by a bus .