E451-5.7A

Priority switches are used in installations where existing conductor cross-sections or the size of the power supply connection do not permit simultaneous operation of two high-power loads (e.g. storage heater and instantaneous water heater). Priority switches disconnect the long-term load (storage heater) for as long as the short-term load (instantaneous water heater) is switched on. The current coil of the priority switch is connected in series with the short-term load. When the load is switched on, the NC contact of the priority switch disconnects e.g. the contactor of the heating system.