This panel was built to provide auxiliary supply in a 132/33kV Distribution Centre. In view of the critical function provided, continuity of supply was an essential design aspect. The panel had 2 transformer incomer sources from two different 11kV networks. One transformer was on standby. Furthermore, a generator backup made up the 3rd source in the event that both transformers were lost. The interlocking and sequencing of the source supply was controlled by a PLC in addition to a manual override via a selector switch.
The switchboard has a Form 4 layout. Circuit breakers and contactors are Schneider Electric and Allen Bradley PLC.