VAC began to develop improved crystalline 80% Nickel-Iron (NiFe) material solutions for RCCBs as early as the mid-1960's.
The breakthrough came as a result of VAC's development of the ULTRAPERM 10® material, which could achieve permeabilities up to 250,000. This development greatly increased the market for RCCBs. Now, the hazard of human contact with electric devices significantly diminished for millions of households. As a result of the ULTRAPERM 10® material, VAC became the leader in this market.
Over the following two decades, the RCCB market demanded the development of materials with even higher permeabilities. Hence currently, permeabilities up to 500,000 are possible with ULTRAPERM 250®.
Permeability versus magnetic field strength characteristics of a typical ULTRAPERM 250® core are shown in the graph above. A RCCB using a core of about 6 cm magnetic path length and rated at differential current threshold of 30 mA requires permeability over 300,000.
Second Stage of Development
Residual Current Circuit-Breaker
Letztes Update : 02.07.2012