each individual filter case with rated current, rated voltage,
manufacturer's name, type of impregnating or potting compound, operating
frequency, and model number. In addition, mark individual filter cases and
the filter enclosures with the following nameplate: "WARNING: Before
working on filters, terminals must be temporarily grounded to ensure
discharge of capacitors." Attach nameplates with epoxy, rivets, or sheet
metal screws.
2.7
MARKING OF PANELBOARDS
Provide nameplate on exterior surface of supply and load panelboards of
filter circuits. Nameplate shall read: "WARNING: Before working on
circuits connected to power line filters, the circuits must be temporarily
grounded to ensure discharge of capacitors." Attach nameplates with epoxy,
rivets, or sheet metal screws.
2.8
SOURCE QUALITY CONTROL
Perform factory tests for each filter unit and filter assembly. The
Contracting Officer [will] [reserves the right to] witness the specified
factory tests. Notify Contracting Officer at least 30 days before factory
tests are scheduled to be performed. Test data shall include a detailed
description of the test instrumentation and equipment, including
calibration dates, a detailed description of test procedure, and recorded
test data. Apply electrical ratings, tests, and requirements specified
herein to unity power factor loads on the filter. Perform dielectric
withstand voltage production line test in accordance with UL 1283.
2.8.1
Insertion Loss Test
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NOTE: Use 100 dB insertion loss at 14 kHz to 10 GHz
for applications such as Red/Black communications
installations. Refer to MIL-HDBK-232A for filter
installation requirements in communications
facilities. For other applications, insert
appropriate insertion loss and frequency range for
the specific product. Most often, 400-Hz power line
filters require power factor correction of the
capacitors in the power line filters to reduce
excessive reactive current. Consult filter
manufacturer for detailed requirements. Consult
manufacturer also when leakage current is important,
such as in life safety areas. There is a tradeoff
between leakage current and insertion loss when
insertion loss is measured according to MIL-STD-220
because of the test connection and the
line-to-ground capacitance.
**************************************************************************
Perform insertion loss measurements using procedures defined in MIL-STD-220
with the buffer networks modified to permit valid measurements down to 14
kHz. The impedance of the modified buffer network shall be at least 10
times that of the filter under test when making the insertion loss test at
14 kHz. Perform insertion loss measurements at 25 percent rated load, 50
percent rated load, and 100 percent rated load over the frequency range of
[14 kHz to 1 GHz] [[_____] to [_____]]. Results of insertion loss test
shall be not less than [100] [_____] dB.
SECTION 16280N
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