The Airpax AP series are fully sealed, magnetic circuit protectors designed to combine power switching with accurate and reliable circuit protection. Unlike thermal protectors, the AP maintains a consistent trip current across a wide temperature range. Available in various versions (DC, 50/60Hz, or 400Hz) with adjustable delays, these protectors are suitable for diverse applications. The 'trip-free' action prevents the circuit from remaining closed during an overload, even with the handle in the ON position. Typical applications include communication, navigation, aircraft instrumentation, radar, and power supplies. The UP series, UL and CSA certified, offers an optional FM approval for petrochemical applications. AP-MIL protectors adhere to MIL-PRF-39019 standards, ensuring a rigorous production and testing program.