Backer control units for terminal box K17 and K18 with thermostat and/or safety temperature limiter

Backer standard range of control units in stock are intended for assembly on Backer terminal boxes K17 and K18. Control unit type S18A is fitted with time relay and contactor enable 2 hours switch on delay, with half power output at power supply loss/failure. If preferred, half of power could be disconnect at overcharge via current relay. Power steps 0 - ¼ - ½ - ¾ - 1. Type S17A, B and D are intended for terminal box type K17 Type S17C intended for terminal box type K17 and heater type IU611/IU611R Type S18A with contactor and time relay intended for terminal box type K18 and heater type IU611/IU611R