Residual current monitoring up to the final circuit

Smart sensors – integrable, multi-channel, flexible and retrofittable

In modern electrical systems, extensive monitoring by a wide range of sensors is often required in order to detect incipient insulation deterioration at an early stage and thus ensure both safety and high availability.

In addition to the high-performance products with a high current-carrying capacity for use in main distribution boards, the Bender portfolio of residual current monitoring devices now also includes compact and cost-effective sensors for monitoring the final circuits.

Integration into power distribution systems

The RCMB13x series offers AC/DC-sensitive residual current monitoring at nominal load currents of up to 32 A and, with a transformer internal diameter of 15 mm, is perfectly suited for the use of cables with a cross-section of 4 x 6 mm². This makes these devices ideal for final circuits. Evaluation electronics and measuring current transformers are combined into one enclosure and, due to their compact design, can also be used when space is limited. For example, integration into power distribution system such as PDUs (Power Distribution Units) is possible without any problems and is ideal for standard installation by the respective manufacturers (OEMs).

Multi-channel for many outgoing circuits

If a larger number of final circuit outputs is to be equipped with residual current systems, Bender offers the RCMS150, a six-channel solution that also combines measuring current transformers and evaluation electronics in one enclosure. Since the six-channel solution uses sensors for the individual channels that are located together with the electronics in one enclosure, the device only needs to be connected to the interface once. The present values of all six channels can then be called up using this connection.

Flexible and direct use in individual loads

The powerful devices from the RCMB300 series are ideal for the industrial use of residual current technology in final circuits. Due to their modular design with different transformer sizes, these sensors can be used in a wide variety of final circuit applications with low to high load currents. Even applications with special requirements for measuring accuracy or insensitivity to external interference can be monitored with this series, as the measuring current transformers are optionally available with a full magnetic shield.

Split-core for retrofit applications

Retrofitting a residual current monitoring system in existing installations presents special challenges. On the one hand, there is often very little space for sensors and evaluators, and on the other hand, the installation must be switched off in order to disconnect the cables. With the split-core devices of the RCMB330 series, Bender now offers smart, single-channel solutions that come with the huge advantage of simple installation in existing systems: open the current transformer, place it around the conductors, close it again and wire the interface – done! The installation does not need to be switched off for this.


In comparison to classic insulation measurement, Bender has a wide range of solutions for final circuits and is offering both continuous monitoring and the possibility of monitoring not only the cables but also the loads of an electrical system individually, because they in particular are often sources of leakage and fault currents.

Differenzstrom-Überwachung bis in den Endstromkreis