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|  MIL-R-5757H
4. VERIFICATION
4.1 Classification of inspections. The inspection requirements specified herein are classified as
follows:
a. Qualification inspection (see 4.3).
b. Verification of qualification (see 4.4).
c. Conformance and periodic inspections (see 4.5).
4.2 Inspection conditions. Unless otherwise specified, all inspections shall be performed in
accordance with the test conditions specified in the "GENERAL REQUIREMENTS" of MIL-STD-202. All
inspections may be performed at ambient environmental conditions consistent with industry practice.
4.2.1 Power supply. Unless otherwise specified herein, the power supply shall have no more than 10
percent regulation at 110 percent of the specified test load current. A dc power supply shall have no
more than 5 percent ripple voltage. An ac power supply shall be within 1 percent of the specified
frequency and shall be sinusoidal with a form factor between 0.95 and 1.25.
4.2.2 Grounding. Unless otherwise specified (see 3.1), the negative side of the dc power supply shall
be grounded. One side of single phase ac power supply shall be grounded.
4.2.3 Load conditions during tests. The coil(s) of the relay under test shall have one side connected to
the coil power supply ground. All tests during which the contacts are loaded and being cycled, except
dielectric withstanding voltage, shall be conducted with the case of the relay connected to the power
supply ground or neutral through a normal blow fuse rated at 5 percent of the contact load maximum, but
not less than 0.100 ampere. For relays with nongrounded case ratings, tests for isolated-case ratings
may be made with the case electrically isolated from the power supply ground.
4.2.4 Testing devices. Devices used in the testing of relays shall not load the contacts above 10
milliamperes (mA) resistive at 6 V dc or peak ac maximum open circuit unless otherwise specified
herein.
4.2.5 Mounting relays for ambient temperature tests. When the relays are subjected to the testing
specified in 4.6.16 (coil life) and 4.6.22 (mixed loads), they may be mounted on a heat sink in
accordance with the following:
a. Each relay may be attached by its normal mounting means to a .063 inch (1.59 mm) thick
minimum, flat aluminum plate heat sink. The heat sink shall be designed to place every relay in
the center of its own square space whose total surface area (both sides) is eight times the outside
surface area of the relay, excluding mounting. Relays without mounts shall be held to the heat
sink with a metal strap .250 inch (6.35 mm) wide by .015 inch (0.38 mm) maximum thickness.
The heat sink assembly shall be suspended by twine or other nonheat conducting material. The
leads shall not constitute a heat sink.
b. Chamber temperature shall be controlled to maintain the temperature at the specified ambient
extremes (see 3.1).
4.2.6 Methods of examination and test. Application of coil power to relays under test shall be such
that plus polarity is applied to the color coded terminal when applicable; or to the lower numbered
terminal when color coding is not used.
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