The RCM 202-AB measurement device from Janitza enables continuous monitoring of residual currents in earthed TN systems according to DIN EN 62020/VDE 0663/IEC 62020.

Continuous residual current monitoring enables residual currents to be detected at an early stage, thereby avoiding damage to the system as well as production downtimes. The key here is to detect the usually gradual increases in residual currents before fuses or residual current circuit breakers trip or data transmission/production is disrupted. A proper RCM measurement monitors consumers and cable installations for residual currents and offers an alternative to insulation measurement for fixed electrical installations (see IEC 60364-6:2016). This avoids having to shut down high availability systems and reduces testing costs significantly. There are also other advantages such as preventive fire protection and detecting stray return conductor currents that are causing EMC problems.

The RCM 202-AB measurement device is recommended for this task. It can detect, analyze, and monitor all residual current types A, B, and B+. The evaluation covers all residual current types with an associated frequency analysis. For example, 50 Hz, pure DC, or high-frequency residual currents in the 20 kHz range can be displayed as a spectrum with frequencies. This makes the type of error apparent relatively quickly and the user then knows where to look.

RCM 202-AB can be combined with standard Janitza residual current transformers and also enables Type B+ measurement with divisible transformers. The converters can be used flexibly thanks to their wide frequency range and patented measuring method. With these performance characteristics, RCM 202-AB is the first RCM type B+ device for retrofitting in existing systems. It is ideal for high availability systems where no shutdowns are possible and good EMC has to be guaranteed, such as data centers, hospitals, production facilities or logistics centers.