The Velem is a combination of RCD, core balance and Earth continuity monitor all housed in a fully encapsulated construction providing excellent temperature stability together with high immunity against shock and vibration. Housed in flame retardant ABS material as standard, the Velem can also be supplied in halogen-free polycarbonate housings to special order.

The RCD section can be specified for a wide range of trip levels and response times for precise system protection and can be field calibratable if so desired. The Earth fault section will react to alternating current only and will reject stray DC signals. It will maintain accuracy over an extremely wide frequency band from 5 Hz to 800Hz thus making the unit suitable for application on variable frequency drives. The Velem can be used on solid, medium or high resistance grounded installations and, by using our recommended artificial ground package, even on ungrounded installations.