The A770WF is a power switching DC contactor designed for high-current applications requiring reliable switching at 28 Vdc. It features a SPST NO (single-pole single-throw normally open) double-break contact arrangement with gasket sealing for environmental protection, and is rated for 300 amps resistive load and motor load with a rupture rating of 3,000 amps. The contactor operates over a temperature range of -55°C to +71°C and achieves 50,000 operating cycles at rated resistive load and 100,000 mechanical cycles minimum, with dielectric strength of 1,250 Vrms between all circuits to ground and circuit to circuit. The coil operates at a nominal 28 Vdc with continuous duty cycle capability, pickup voltage maximum of 16 Vdc at 25°C, and dropout voltage of 1.5 to 5 Vdc, with holding current of 0.4 amp for Coil Type A. This contactor is commonly used in aerospace, military, and industrial power distribution systems where high reliability and switching performance are essential.