Type [AC or A or B]
Standard IEC 60755 (General requirements for residual current operated protective devices) defines three types of RCD depending on the characteristics of the fault current.
Type
AC: RCD for which tripping is ensured for residual sinusoidal alternating currents.
Type
A: RCD for which tripping is ensured:
- for residual sinusoidal alternating currents,
- for residual pulsating direct currents,
- for residual pulsating direct currents superimposed by a smooth direct current of 0.006 A, with or without phase-angle control, independent of the polarity.
Type
B: RCD for which tripping is ensured:
- as for type A,
- for residual sinusoidal currents up to 1000 Hz,
- for residual sinusoidal currents superposed by a pure direct current,
- for pulsating direct currents superposed by apure direct current,
- for residual currents which may result from rectifying circuits, i.e.:
- three pulse star connection or six pulse bridge connection,
- two pulse bridge connection line-to-line with or without phase-angle monitoring, independently of the polarity.