IEC 60479 deals with the effects of electricity on human beings and livestock. It defines the size and duration of the current flow which pose a risk to life and health.

Another important factor is the ventricular fibrillation threshold – in other words, the electricity level at which ventricular fibrillation can be triggered in human beings, possibly resulting in their death. It is shown in a curve.

To date, the limit curve for ventricular fibrillation ended at 100 kHz – the risk range was not defined for higher frequencies. The updated version of IEC 60479-2, which was published in October 2017, now defines this limit for frequencies of up to 150 kHz.

We have tested our type B RCDs with the NK and SK characteristic curves for the extended frequency range. They still perform their full protection function if residual currents occur with frequencies of 0 Hz to 150 kHz. They are way ahead of their device standard in terms of the definition of their tripping current frequency responses. The standard only defines trigger points for set frequency values up to a frequency of 1 kHz. The defined trip band for our switches, with an upper and lower trip limit, ensures high system availability, as faulty tripping is prevented.