The AP17-1-51-302 is a two-pole, series trip hydraulic magnetic circuit protector that combines power switching with reliable overcurrent protection. This 3A device is configured for DC operation with a short time delay, tripping between 0.4 and 4 seconds at 125% of its rated current. As a hydraulic-magnetic protector, its trip current remains stable across a wide operating temperature range of -40°C to +100°C. The unit features a trip-free mechanism that ensures the circuit opens during an overload, even if the handle is forcibly held in the 'ON' position. Its rugged, fully sealed construction and screw terminals make it ideal for use in communication equipment, aircraft instrumentation, radar, and power supplies.