In electrical installations with several sub-distribution boards and residual current circuit breakers, an economical central ON-OFF control can be set up using the ISK 41 and ISK 42 switching devices developed for this purpose. The central control inputs are galvanically isolated by inputs and outputs on the supply side and can be controlled with voltages of 8-230V AC or DC. The ISK 42 also has a second potential-free relay contact (10A normally open) and a central pulse input., Dimensions: 18x55mm, 230V AC - 2S pf 16/10A