Self contained transformer and relay with SPST dry contacts rated at 20 Amp 120VAC, 230VAC, or 277VAC. Internal power source provides for low voltage control of line voltage contacts, thus eliminating the need for a separate step down transformer. Low voltage switching of line voltage lighting circuits up to 20 Amp ballasts, tungsten or resistive loads. Also up to 1.5 HP motors for ventilating and exhaust fans. For simple installation of low voltage wiring between 3-way switches. Low voltage switching by digital or mechanical controls for higher amperage loads including those of two different voltages. For multi-channel digital controls, TORK offers TRPs which are available in groups of 4 or 8 conveniently prewired in metal enclosure.