Duel redundant control system

This project was to design a control circuit for a safety critical system. The system comprised 2 independent ventilation fans in a sump pit below a re-fuelling rig. In order to keep the area clear of hazardous and harmful fumes at all times it is crucial that the fans run without interruption. To this end the panel which I designed would be fed with 2 redundant 3 phase power supplies. The panel would switch automatically between a primary and secondary supply, with switch over to backup power supply in the event of the primary supply failure happening automatically. Further more provision was made on the front of the control panel to allow manual designation of which supply should be assigned primary duty and which should be assigned back up duty.

The system was designed based upon a control philosophy document which was agreed with the client prior to any further design work. To view this document click here.