This electrical connector is military and aerospace unique. It is a miniature, high density, threaded, environment resisting, high shock, high vibration, high corrosion resistant connector that utilizes crimp removable electrical contacts. It is capable of operating at temperatures up to 200°C. It is designed to withstand up to 500 hours of salt spray. Where weight and size is a critical consideration for military and aerospace applications, this circular electrical connector may be preferred over other military circular connector specifications. Depending on the insert arrangement and shell size, the mated connector pair may be up to 20-30 % lighter than a similar triple-start MIL-DTL-38999 mated pair. When installed with appropriate connector accessories, some classes of this connector family are suitable for severe wind and moisture problem (SWAMP) areas.
Application guidance and restrictions.
When evaluating connectors for use in new design, including new systems and support equipment, users are advised to carefully evaluate the connector characteristics herein versus their requirements:
a. Intermateability/interchangeability: See 3.4.2. Performance (function) may vary when different finishes or shell material are mated together.
b. Connectors are vulnerable to pin contact bending from scooping, with contact size 23 being the most vulnerable. Scoop proof sensitive applications connectors with a size 23 pin contact should have pins loaded in the receptacle.
c. Receptacles must be located so as to minimize the amount of required cable bending. When using size 16 and 12 contacts connectors with large cables which must be bent at right angles, the cables must have the right angle bend permanently established. A permanent bend would be utilizing an angled backshell or other acceptable wire strain relief based on the end application.
d. Connector should not be used with heavy jacketed cable and excessive overhang moments, because of possible shell damage.
e. Connector rear sealing grommet has thinner walls due to its high density contact population. Bending or gathering/bundling of wires can elongate the rear sealing hole which may allow and introduce fluids into the grommet seal. It is recommended to have all wire bundle ties be no closer than (XX) inches from the rear of the connector, less any backshell. Care should be taken using a metal insertion/extraction contact tool as to not tear the internal sealing surfaces. Tears could degrade some of sealing properties against the jacketed wire.
f. Recommended panel cutout dimensions are shown in applicable connector slash sheet.
g. Compatibility of connectors should be addressed when intermating different classes and finishes. Galvanically incompatible classes and finishes should not be intermated together. When intermating classes with different performance requirements, the lower performance requirements of the two classes apply.
h. Flange mount (Box Mount) connectors are not intended to be used on environmentally sealed boxes without any additional sealing aid. If an environmentally sealed box capability is needed, a jam-nut mount connector should be used.
i. Class T is required to be nonreflective. Class W is required to be an olive drab color in accordance with SAE AMS-QQ-P-416. Class Z is required to be black in accordance with ASTM B841. These nonreflective finishes and colors may vary in color depending on the method of manufacture. This variance in color does not alter the performance capabilities of the finish.
j. Storage, cadmium plated connectors: See SAE AMS-QQ-P-416 for packaging limitations for cadmium plated products. Users are advised that cadmium plated parts should not be packed in non-ventilated containers or in direct contact with wood or cardboard, especially under conditions of high humidity or moisture, due to a corrosive reaction that often occurs between the cadmium plating and organic acids (i.e. formic acid, butyric acid, etc.) which form under these conditions.
k. Isopropyl alcohol (i.e. TT-I-735) can be used as a lubricant aiding in insertion and removal of contacts and minimizing risk of grommet tear.
l. Sealing grommet is thinner than other connectors such as MIL-DTL-38999. It also has 2 grommet ripples for sealing against the contacts (verses 3 ripples for MIL-DTL-38999). Theses characteristics make this connector more prone fluid leakage especially when wire is torqued (wire bundle bending, zip tie bundling close (approximately less than 2") to connector which pushes on contacts in the center of the insert arrangement and pulls on the outer contacts).
m. Pin-to-pin mating prevention. Pin-to-pin contact is possible if a plug with pin contacts is inadvertently mated with a receptacle with pin contacts. Although an end user should not try to mate such a configuration, best practice should use keyways, relative position of connectors to each other, harness design, and other methods to provide redundant prevention of mis-mating.
n. Connectors should be designed such that electrical or physical pin-to-pin contact is not possible if a plug with pin contacts is inadvertently mated with a receptacle with pin contacts.
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