of the panel to be removed easily. This is a significant
made to choose connectors that will allow signal and
difference from box- or wall-mounted receptacles, which
power leads to be bundled separately.
have only one easily removable connection.
(3) The current to be passed through each
(4) There is also a variety of connector plug
contact must be determined. The contact size then can
assemblies used on vehicles, and the primary physical
be established with a safety factor sufficient to provide
difference between them is the backshell configuration.
safe operation under conditions of temporary overload.
This backshell is used to direct the connecting wire or
Another important safety factor is mechanical strength.
cable either axially or in angles up to 90 degrees from the
In many applications, size 12 contacts are used, even
axis of the connector, as well as to provide a water seal
though the current may be less than 100 mA because the
and strain relief for the cable or wire.
mechanical strength of the size 12 contact is needed.
(4) Great care should be exercised in the
selection of connectors to make certain that they will
(1) Electrical connectors must be capable of
meet mechanical strains placed upon them in application.
withstanding the effects of the military environment.
On vehicles, connector housings are used as personnel
Protection against damage due to temperature extremes,
steps if they happen to be in the right location, and it is
water, oil, and physical abuse is mandatory.
not an uncommon sight to see military equipment lifted or
carried by one or more of its connectors even though
(2) It is good practice to provide one or more
connectors or thin housings are not intended for these
spare contacts in the connector pair more than the actual
number required for the circuits to carry. Then, any
increase in circuits necessitated by functions added later
(5) The selected connector must have the
will not require the use of another connector. It is
means to prevent incorrect mating built into it. This may
advisable to keep the number of contacts per connector
be effected through dissimilar-size guide pins, a
down to a number that can be mated and separated
nonsymmetrical arrangement of contact barriers, or the
without excessive force. Where a large number of
design of the connector shell housing. Contact pins
circuits must be handled, it may be advisable to use
should never be used for alinement or polarization.
more than one connector pair. Every effort should be