The Ringway Relay Switch for Backup I.S. Power Supplies (RWREL27V4A) enables safe live-line changeover between one of two possible I.S. power supplies to field equipment in the hazardous area. The relay switch achieves this by ensuring that the necessary isolation between the two power supplies is maintained at all times even under fault conditions as required by the Intrinsic Safety concept.

The Relay Switch meets category 'ia' requirements and is certified for Groups I, IIC and IIIC applications