AP/UP, AP/MIL Series Magnetic Circuit Protectors Introduction 71 Poles 72 Configurations 75 Operating Characteristics 76 Delay Curves 77 Specifications 78 Decision Tables 79AP/UP, AP/MIL Series Hydraulic Magnetic Circuit Protectors INTRODUCTION The Airpax AP series are fully sealed, magnetic circuit Typical applications include communication, navigation and protectors that combine power switching and accurate, reliable aircraft instrumentation, radar and power supplies. circuit protection with inverse time delays and trip free features. The Airpax UP circuit protector, with UL recognition and CSA Unlike a thermal circuit protector, the AP does not change its certification, is essentially the same as the AP in construction trip current over a wide temperature span. In addition, the AP and operating principle. It is approved for operation at 50 volts magnetic circuit protector is available in either DC, 50/60Hz or DC to 20 amperes, 120 volts 50/60Hz to 15 amperes and 240 volts 400Hz versions and with various delays to match the protector to 50/60Hz to 7.5 amperes. The UP circuit protector is available in specific application requirements. single pole units only, due to UL and CSA creepage specifications and the wide glass terminals utilized. The UP series offers an One of the most important features of this protector is the trip optional FM approval (Factory Mutual Research), provided for petrochemical applications. FM approval is available for single free action, which means the circuit will not remain closed in pole, series trip, UP type units only. the presence of an overload even though the handle is held in the ON position. The delay mechanism senses the fault and the The Airpax AP-MIL protectors are produced in accordance contacts open. with MIL-PRF-39019 and the pertinent specification sheets, are subjected to an exacting production and test program to Waterproof panel integrity is provided by an O ring bushing maintain their Qualified Products Listing (QPL). One, two and seal and a silicon rubber gland within the bushing/handle three pole series trip units, with or without auxiliary contacts, assembly. Salt spray testing per MIL-STD-202, Method 101, have been accepted for this listing. Refer to specification sheets Test Condition B, with no evidence of corrosion, electrical or MIL-PRF-39019/1 through 6 for the application government mechanical damage. designations. The AIRPAX cage code number is 81541. AP Series - Introduction 71