MIL-STD-188-125 should be applied by a shielding
specialist experienced in the standard's
requirements and applications.
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Insertion loss shall meet or exceed the levels complying with EM shielding
effectiveness attenuation requirements herein when measured in accordance
with MIL-STD-220. Insertion loss measurements shall be performed in
accordance with MIL-STD-220 and the paragraph ELECTORMAGNETIC FILTERS.
2.6.2.7
Operating Temperature Range
Individual filters mounted in the filter enclosure operating at full load
amperage and rated voltage shall not exceed plus 85 degrees C 185 degrees F
based on an ambient temperature of 65 degrees C 150 degrees F outside the
filter enclosure. Continuous operation from minus 55 to plus 85 degrees C
minus 67 to plus 185 degrees F shall be demonstrated according to paragraph
"Filter Life Test (at Elevated Ambient Temperature)". Filters shall also
withstand temperature cycling as specified in paragraph ELECTORMAGNETIC
FILTERS. The filter shall remain at rated voltage and full-load current
until temperature equilibrium is reached or 24 hours, whichever is greater.
2.6.2.8
Current Overload Capability
Filters shall be capable of operating at 140 percent of rated current for
15 minutes, 200 percent of rated current for 1 minute, and 500 percent of
rated current for 1 second when tested in accordance with paragraph
2.9.2.9
Reactive Shunt Current
The reactive shunt current drawn by the filter operating at rated voltage
shall not exceed 30 percent of the rated full-load current when measured in
accordance with paragraph Reactive Shunt Current Measurements.
2.6.2.10
Dielectric Withstand Voltage
Filters shall be provided which conform to the minimum values of dielectric
withstanding voltage. Filter dielectric withstand voltage test shall be in
accordance with paragraph "Dielectric Withstand Voltage Test". HEMP
filters shall be capable of operating continuously at full-rated voltage
and of withstanding an overvoltage test of 2.8 times the rated voltage for
1 minute. In addition, each filter shall be capable of withstanding a
20-kV or 4-kA peak transient pulse of approximately 20 ns pulse width at
full operating voltage, without damage.
2.6.2.11
Insulation Resistance
The insulation resistance between each filter terminal and ground shall be
greater than 1 megohm when tested in accordance with paragraph Insulation
2.6.2.12
Parallel Filters (Current Sharing)
Where two or more individual filters are electrically tied in parallel to
form a larger filter, they shall equally share the current. Equally
sharing is defined to be within 5 percent of the average current. The
tests shall be in accordance with paragraph ELECTORMAGNETIC FILTERS.
SECTION 13095A
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