MIL-B-49030A
4.7.1.1.1 Flowing or shrinking. Potting and sealing compounds, when used, shall be placed in a container,
approximately 3 inches (76 mm) wide by 6 inches (152 mm) long by .75 inch (19 mm) high to within .25 inch (6.35
mm) of the top. The temperature of the compound within the container shall be raised to 160 °F ±5 °F (71.1 °C
± 2.8 °C) and the container shall be held in an inverted position for 24 hours. Then the temperature of the compound
shall be lowered to -40 °F ±5 °F (-40 °C ±2.8 °C). The flow, cracking, or shrinking of the compound from the sides of
the container shall be noted and the batteries shall be examined to determine that there is no impairment of electrical
contact. If flow is noted at 160 °F ±5 °F (77.1 °C ± 2.8 °C), five batteries of type involved shall be exposed to 160 °F
±5 °F (77.1 °C ± 2.8 °C) storage for 24 hours with terminals resting in lowest possible position. At the end of this
exposure period, batteries shall be examined to determine that there is no impairment of electrical contact (see
3.5.2).
4.7.2 Electrolyte penetration. Applicable specimens of materials and components shall be placed on a metal plate,
and a cylindrical plastic tube 2 inches (50.80 mm) high with an internal diameter of 1.5 inches (38.1 mm) shall be
clamped over the material. The tube shall then be filled to a depth of 1 inch (25.4 mm) with a solution of
approximately 31 percent KOH by weight or the specified electrolyte to be used in the batteries. A metal electrode
shall be inserted into this solution to a depth of approximately .5 inch (12.7 mm). A direct-current potential of 22.5
volts shall be applied between this electrode and the metal plate with a milliammeter of proper range in the circuit.
The test shall continue for a period of 72 hours, but may be terminated if failure occurs sooner.
4.7.3 Dielectric strength. Applicable specimens of material and components shall be conditioned for 48 hours at
160 °F ±2 °F (71.1 °C ±1.1 °C) and a relative humidity of 50 ± 15 percent, then for 1 hour at 70 °F ±5 °F (21.1 °C
±2.8 °C) and a relative humidity of 50 ±15 percent. Each specimen of material shall then be placed between two
electrodes in such a manner that the electrodes shall make contact with both sides of the specimen being tested.
Each electrode shall have a diameter of 2 inches (50.8 mm) with the edge rounded to a radius of .25 inch (6.35 mm),
so that the contact surface is a circle 1.5 inches (38.10 mm) in diameter. The specimen shall extend at least .5 inch
(12.7 mm) beyond the electrode surfaces around the entire circumference of the electrode to prevent flashover at the
edge of the specimen. The specimens of material shall be subjected to a potential of 1,000 volts root mean square,
alternating current, at commercial frequency, for a period of 1 minute. The transformer used shall be rated not less
than .5 kilovolt-ampere and shall be capable of delivering up to 10,000 volts root mean square, 60-cycle alternating
current, to the electrodes. The applied voltage shall be increased, starting at zero voltage, at an approximate rate of
500 volts per second.
4.7.4 Terminals.
4.7.4.1 Snap-on terminals.
4.7.4.1.1 Contact resistance. Contact resistance between the stud and socket shall be measured during
engagement numbers 1, 5, 6, and 10 when a current of 5 amperes is flowing through the point of contact (see
4.7.4.2 Socket terminals.
4.7.4.2.1 Contact resistance. Contact resistance between each socket insert and the applicable pin of the mating-
plug shall be measured after insertions number 1, 10, 11, and 20 while a current of 5 amperes is flowing through the
point of contact (see 3.5.8.5.2).
25
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business