• 6mA DC sensitive residual current monitor
  • Enables compliance with standards
  • Reduces costs of developing electric vehicle charge stations
  • Enhanced safety through reduced risk of electric shock
  • Automatic shut-down in the event of a DC fault occurring
  • For safer, more cost-effective electric vehicle charging

To satisfy new standards including IEC 62752 and IEC 60364-7-722, the charging of electrical vehicles requires residual current sensors to avoid hazardous situations in cases where the vehicle battery (DC) is connected to the home power supply (AC). Generally, AC/DC sensitive residual current sensors can be used where direct current and alternating current circuits are directly connected and therefore AC/DC leakage currents can occur.

Typically type A residual current circuit breakers (RCCBs) are installed in private households. However, these RCCBs are to identify and deactivate DC fault currents. In order to charge an electric vehicle (EV) from a home power supply, a costly type B RCCB would be required to guarantee safety in the event of a DC fault current.

By using a VAC/Bender DI sensor integrated into an IC-CPD or wall box, customers can save the high costs of installing a type B RCCB to provide all-current sensitivity and electrical safety at low cost.

A single DI sensor simultaneously monitors all currents in phases and neutral conductors sensing AC/DC fault currents. The sensors can activate automatic shut-off in the event of hazardous electrical faults. As the residual currents to be monitored only occur in the event of electrical faults and are extremely low (mA), maximum measurement precision is critical. In addition, a fast response time is required to maintain safety features.

  • Features
  • Applications
  • Ordering information
  • Downloads
  • IEC 627582 and UL 2231 version available
  • Frequency range DC to 2 kHz
  • Full load current up to 80 A r.m.s. (1-phase) or 3 x 32 A r.m.s. (3-phase)
  • Switching output for DC 6 mA/30 mA r.m.s., 5 mA r.m.s./20 mA r.m.s. or DC 6 mA/20 mA r.m.s.
  • Error output (Integrated self-monitoring and test functions)
  • Measurement resolution 0.2 mA
  • Variants with feed through opening or with integrated primary conductors
  • Residual current range 0…300 mA
  • Robust mechanical design suitable for IC-CPD environmental requirements (e. g. drop test)
  • Widely usable in harsh electronic environments (e.g. resistant to external fields)
  • Total system cost significantly reduced compared to RCD type B
    AC/DC sensitive residual current monitoring module RCMB121 for safe charging of electrical vehicles according to BS7671:2018,722.531.2.101 and IEC 62752 Suitable for use in wall boxes, charge stations and other electric vehicle charge points.


Variants of RCMB121

Version Type VAC Type Bender Art. No.
AC 30 mA/DC 6 mA T60404-N4641-X900 RCMB121-1 B94042490
5 mA r.m.s./20 mA r.m.s. T60404-N4641-X901 RCMB121-2 B94042491

Downloads for RCMB121



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