The Novaris IDD3 range is designed for delta connected 3-wire power systems, such as the IT system, and is suitable for installation in distribution switchboards. The design utilises redundant metal oxide varistors (MOVs) between phases and a gas discharge tube (GDT) to earth, making phase to earth protection a hybrid configuration. Each phase has its health indicated by a single LED. All IDD3 models are housed metallic DIN compliant enclosures.