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RCD (Residual Current Device)

50 Hz-Application

A residual current circuit breaker (or RCD, Residual Current Device) does not protect the main lines from overloading or short circuiting like a circuit breaker, but serves as personal and / or fire protection. There are 2- and 4-pole RCD versions.

For personal protection RCDs with a tripping current of 30mA are used, it means in the event of triggering max. 30mA current is flowing through the human body within a few ms.

The central element of the RCD is a differential current transformer, which controls a downstream mechanical relay. The residual current transformer carries all active conductors and the neutral conductor. The sum of the currents flowing through the outer conductors and the current flowing back via the neutral conductor must be compensated normally > sum of current = 0.

If this is not the case, a leakage current must obviously flow back to ground within the installation. It does not matter whether this leakage current flows directly through the protective conductor or, for example via the human body to earth; In any case, the RCD triggers when the tripping current is reached.

For more than 30 years, MAGNETEC has been producing and supplying differential current transformers for RCDs from all well-known manufacturers, thereby helping to reliably protect life and limb as well as equipment from damage.