Used on air curtain. nema 1 plunger style door switch description: suitable for use w/ksa/ksb w/single phase control station, ksa/ksb w/three phase control panel, ksa single phase power 2 motors at 120/1; 3 motors at 208-240/1, ksb single phase power 1 motor at 120/1; 2 motors at 208-240/1