Leakage central-blocking relay PCB/M

Leakage central-blocking relay type PCB/M, is designed for controlling the earth resistance of a 3-phase grids with operating voltage 230V/50Hz, with insulated neutral point of the transformer. The relay in cooperation with the main contactor, prevents the application of voltage to the controlled section of the grid by lowering value of insulation resistance under the setting level. PCB/M is designed for use in mine face pits in non-explosive conditions, in conditions without methane explosion hazard and classified as A coal-dust explosion hazard.