Residual Current Circuit Breaker

Frequency converters, medical devices and UPS systems are seeing increasing use in industry. Smooth DC residual currents or currents with low residual ripple may occur in the event of faults on these devices. Type A residual current protective devices are unable to detect these smooth DC residual currents. Furthermore, such smooth DC residual currents make Type A devices increasingly insensitive to AC residual currents and pulsating DC residual currents. If a fault occurs, there is therefore no tripping and the desired protective function is no longer assured.
Universal current-sensitive residual current protective devices of Type B have an additional transformer, which is supplied with a control signal. It is therefore possible to evaluate the change of the transformer's operating range caused by smooth DC residual currents, thus ensuring the desired protective function.  
The devices in this series are designed as residual current operated circuit breakers (RCCBs) up to 80 A and as residual current circuit breakers with integral overcurrent protection (RCBOs) for 100 A or 125 A in Characteristics C or D. 

Betagard Residual Current Circuit Breakers 5SM3
• Standards: IS 12640, Part 1:2008/IEC 61008-1:1996
• Voltage: 240/415Vac, 50…60Hz
• With ISI marking: CM/L No. 7676092
• The tripping characteristic is adapted to the increase of leakage currents at higher frequencies in
   systems with capacitive impedances and results in increased operating safety.