Frequently asked questions
What are the different residual current device categories?
FAQ000218859
14 October 2021
IEC 60755 describes general requirements for residual current operated protective devices.❶ Vigi modules (Vigi NG125, see example in the figure)
The add-on Vigi module is the most flexible residual current device (it is installed in combination with a circuit breaker).
Vigi are covered by the IEC 61009 and IEC 62423 series of standards.
❷ Residual Current operated Circuit Breakers without integral overcurrent protection (RCCB) (Acti9 iID, see example in the figure)
The Acti 9 iID RCCB is the main residual current device in the facility and is used as the main incomer. RCCB are covered by the IEC 61008 and IEC 62423 series of standards.
❸ Residual Current operated circuit Breakers with integral Overcurrent protection (RCBO) (Acti 9 iCV40N, see example in the figure)
RCBO = combination of circuit breaker and residual current device function in the same product. This can be obtained by combining the circuit breaker with its Add-on Vigi Module.
RCBO are covered by the IEC 61009 and IEC 62423 series of standards.
❹ Socket RCD (SRCD) (see example in the figure) SRCD are covered by the IEC 62640 series of standards.
❺ Industrial type circuit breakers incorporating the RCD function must comply with Annex B of IEC 60947-2.
Residual current devices with a separate toroid are standardized in Annex M of IEC 60947-2.
Reference document - CA908066E