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The AC/DC sensitive residual current monitoring module RCMB104, with patented measurement method, is used in combination with a measuring current transformer CTBC17 and a type A RCD which has to be provided in the installation for fault current monitoring of AC charging systems for electric vehicles in which AC or DC fault currents can occur. The rated voltage Un is 250 V and the rated current (charging current) In = 1 x 48 A / 3 x 32 A. The RCMB104 is suitable for integration into a charging unit (IC-CPD, wall box) according toIEC 61851-22, IEC 62752 and UL 2231-2.

The RCMB104 is only intended for purchase by the manufacturer of charging systems.

More information:


  • Three outputs (DC, RMS, Error)
  • Measuring range ±300 mA
  • Residual current resolution 0.2 mA
  • Patented measurement technology (Patents: EP 2 571 128 / US 9,397,494 / ZL 201210157968.6 / CN 103001175, EP 2 813 856)
  • Load current up to 48 A r.m.s. (single-phase) or 3 x 32 A r.m.s. (three-phase)
  • Fault output (integrated self monitoring and test functions)
  • High insensitivity to external interferences
  • Available variants for application according to DIN EN 61851-22/IEC 62752 and UL 2231-2
  • Wide range of use even in severe environments (e.g. in the event of external interference fields)
  • In applications according to DIN EN 61851-22 or IEC 62752, the RCMB104 can replace a type B RCD when combined with a type A RCD and a suitable switching device (e.g. a power relay).


  • AC charging systems for electric vehicles

Downloads for RCMB104

Manuals RCMB104 2.2 MB EN2021/11/17 06:42:0117.11.2021 06:42:01D00294
Datasheets RCMB104 601.3 KB EN2022/08/29 05:58:5829.08.2022 05:58:58D00294

RCMB104 Variants

TypeDescriptionArt. No.
RCMB104-10…2 kHz IEC 6/30 mAB94042480
RCMB104-20…2 kHz UL 2231 5/20 mAB94042481
CTBC17Measuring current transformer Ø = 17 mmB98080070
CTBC17-Cable180MMConnection cable 180 ± 30 mmB98080540
CTBC17-Cable325MMConnection cable 325 ± 25 mmB98080541
CTBC17-Cable1470MMConnection cable 1470 ± 30 mmB98080542