The Airpax™ AP series magnetic circuit protector is available in either DC, 50/60Hz or 400Hz versions and with various delays to match the protector to specific application requirements. Unlike a thermal circuit protector, the AP does not change its trip current over a wide temperature span. One of the most important features of this protector is the “trip free” action, meaning the circuit will not remain closed in the presence of an overload, even though the handle is held in the ON position. The delay mechanism senses the fault and the contacts open. Waterproof panel integrity is provided by an “O” ring bushing seal and a silicon rubber gland within the bushing/handle assembly. Salt spray testing per MIL-STD-202, Method 101, Test Condition B, with no evidence of corrosion, electrical or mechanical damage. Typical applications include communication, navigation and aircraft instrumentation, radar and power supplies.
The Airpax™ UP circuit protector, with UL recognition and CSA certification, is essentially the same as the AP in construction and operating principle. It is approved for operation at 50 volts DC to 20 amperes, 120 volts 50/60Hz to 15 amperes and 240 volts 50/60Hz to 7.5 amperes. The UP circuit protector is available in single-pole units only, due to UL and CSA creepage specifications and the wide glass terminals utilized. The UP series offers an optional FM approval (Factory Mutual Research), provided for petrochemical applications. FM approval is available for single-pole, series trip, UP type units only.
The Airpax™ AP-MIL protectors are produced in accordance with MIL-PRF-39019 and the pertinent specification sheets, are subjected to an exacting production and test program to maintain their Qualified Products Listing (QPL). One, two and three pole series trip units, with or without auxiliary contacts, have been accepted for this listing. Refer to specification sheets MIL-PRF-39019/1 through 6 for the application government designations. The AIRPAX cage code number is 81541.
AP circuit protectors will trip open on overload, even when forcibly held ON. This prevents the operator from damaging the circuit by holding the handle in the ON position.
The operating handle of the breaker moves forcibly and positively to the OFF position on overload. It is not necessary to manually “reset” to full “OFF” in order to turn it on again.
The protector will operate at any ambient between –40° C and +100° C, when tested in accordance with the requirements of MIL-PRF-39019.
Exceeds 100 megohms at a potential of 100Vdc.
The protector will withstand 1250 volts RMS, 60Hz from terminals to case and between the terminals when open.
With the circuit protector operated as an ON-OFF switch, operating life exceeds 10,000 operations at a rate of 6 per minute when tested as follows: 6000 OPS @ rated current plus 4000 OPS @ no load.
AP protectors are available in current ratings from 50 milliamperes to 20 amperes, 50 volts DC or 240 volts AC, maximum, 60 Hz or 400 Hz. UP protectors are UL 1077 and CSA approved as per the following table. Please consult factory for ratings other than those noted.
The operating lever or its seal will not be damaged by a 10 lb. force applied in any direction.
All protectors withstand 100G without tripping, even while carrying full rated current with shock applied in any plane of 6 ms duration. Test is made according to Method 213, Test Condition I or MIL-Std-202 as outlined in Paragraph 4.6.14 of MIL-PRF-39019. Delay 40, 50 and 60 breakers are tested at 80% of rated current.
All protectors withstand vibration from 10 to 55 cycles at .06 double amplitude and 55 to 2000 cycles at 10G, applied in any plane, without damage and without tripping even while operating at full rated current. Test is made in accordance with Method 204A, Test Condition C, of MIL-Std-202 as outlined in Paragraph 4.6.12 of MIL-PRF-39019. Delay 40, 50 and 60 protectors are tested at 80% of rated current.
Short Circuit Capacity
When tested in accordance with the procedures of UL1077, AP supplementary protectors have a short circuit capacity of 1000 amperes at 32Vdc, 120Vac, 240Vac, 60 or 400Hz. Parts are recognized to UL1077 for type UP1 only. The rated Rupture Capacity per MIL-PRF-39019 is 500 amperes, 50 volts DC, 500 amperes, 120 volts AC and 300 amperes, 240 volts AC, 60 or 400Hz.
The breaker is fully sealed and will not show evidence of leakage under total immersion. Meets requirements of MIL-PRF-39019.
The “O” ring provides, with the other illustrated hardware, a seal against a pressure differential of 15 psi applied for an hour.