Passenger area heating switches the heaters many times per hour, and electromechanical contacts wear out at this rate faster than the rest of the equipment. POWERSWITCH solid-state switches switch without wear and without noise: relays for mounting on a cooling plate and contactors with a matched heat sink for DIN rail, in single-, two- and three-phase versions. Variants for resistive loads switch at zero crossing, variants with an analogue input control the heater power by pulse packets, and variants with load current monitoring detect a burnt-out heater without additional measurement.
For DC circuits from the onboard battery the PK 9265 contactor with a MOSFET interrupts the current without arcing and without contact bounce.
Selection requires checking the load current against the derating curve at the temperature of the installation location, the peak blocking voltage against overvoltages in the vehicle network, and short-circuit protection with a semiconductor fuse; the datasheets of the individual types state which versions carry UL approval.
