The MZC - 304, manufactured by Sonel®, is a short circuit loop measuring device. Wherein, it measures L-PE circuit, L-N, L-L circuit, and the L-PE(RCD) circuit that is without circuit breaker causing to trip in less than > 30mA. In addition, the low current contains a DC current of +200mA that includes a resistivity reset wire and an acoustic signalling. Furthermore, there are possible installation in 220/380V, 230/400V, 240/415V measurements along with 45...65Hz frequency range. Plus, it has 10 banks of each 99 cells memory and a wireless radio communication.