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AEM, Inc. 11525 SORRENTO VALLEY RD
SAN DIEGO, CA 92121-1306. TITLE
P700L SPECIFICATION
NUMBER P700L REVISION J ECN 2139 SHEET 14 of 23
5.8.10 Vibration (Gr oup C / Qualification Only). Fuses s hall be tested in accordance with Method 204 of
MIL-STD-202. The following details and exceptions shall apply :
a) Mounting - Fuses shall be securely fastened to the table of the vibration machine to prevent relative
motion between the fuses and the table.
b) Test Level - Sinusoidal vibration from 5 to 3000 hertz, 0.4 inch double amplitude or 30G's peak,
whichever is less.
c) Sweep Rate - Approximately 1/2 octave per minute.
d) Test Duration - 12 hours total (4 hours in each of three major axes).
e) Loading during Testing - Rated DC current on half of the samples tested.
f) Measurements - DC resistance measurements shall be taken before and after the vibration
exposure in accordance with 5.8.2.
5.8.11 Resistance to Soldering Heat (Group C / Qualification Only). Fuses shall be tested in a vapor
phase test device and the boiling liquid shall be FC-70 or equivalent. A thermocouple (wire size 28 to 32 AWG) shall
be attached to the body of one fuse for the purpose of monitoring case temperature during testing. The test
sam ples shall be placed in the vapor f or a period of 180 +/- 10 seconds after the case temper ature has reached a
temperature of +215°C. After the vapor exposure, the fuses shall be allowed to cool for 10 minutes at room
temperature. The DC resistance of the fuses shall be measured before and after the test in accordance with 5.8.2.
5.8.12 Low Temperature Operation (Group C / Qualification Only). Fuses shall be soldered to test boards
and placed in a low temper ature chamber . The cham ber temperatur e shall be lowered gradually to –55°C +0/-3°C
within a period of 1 hour. After stabilizing at the low temperature for a period of 1 hour, rated DC current shall be
applied to the fuses f or a period of 4 +1/-0 hours while at the low temper atur e. T he c hamber shall then be gradually
raised to room temperature within a 4 hour period and maintained at room temperature for a period of 8 hours
minimum. After this time, the DC current shall be removed from the fuses and the fuses removed from the
chamber. The DC resistance of the fuses shall be measured before and after the test in accordance with 5.8.2.
5.8.13 Life (2000 Hour s, Group C / Qualif ication Only). Fus es shall be solder ed on a s uitable test board
and placed in a chamber at +125°C +3/-0°C ambient. The fuses shall be electrically connected to a DC source
supplying 64 percent of the +25°C rated current. The current source shall supply an open circuit voltage equal to the
voltage rating of the f us es . The fus es s hall r emain in the chamber at the spec if ied c ur rent for 2000 +/- 8 hour s. T he
electrical c ircuit shall pr ovide a suitable indicator, which s hall be monitored daily during the length of the lif e test, to
identify f ailure (blowing) of any fuse. T he time of failure s hall be recorded to the neares t +/-12 hours and the blown
fuse replaced with a short circuit for the remainder of the test. The DC resistance of the fuses shall be measured
before and after the test in accordance with 5.8.2.
5.8.14 Overload Current. F uses s hall be subjec ted to the applic able perc ent of DC curr ent (250%, 400%
or 600%) as specified in Table VI. For Group B and Group C inspections, the fuses shall be tested while at case
temperatures of +25° to +35°C. For qualification inspection (Subgroup II, Table V) and Group C inspection
(Subgroup II, Table IV) the fuses shall be divided equally and tested at +25°C to 35°C, and at +125°C to +130°C.
The low impedance source shall be adjusted to supply an open circuit voltage equal to the rating of the fuse. The
time to "blow" (the interval measured from the application of the current to the time the current drops below the
rating of the fuse) shall be measured f or each fus e. Each fuse shall r emain in the test cir cuit for 1 m inute after the
fuse opens to check for restrike conditions. The maximum clearing I2T shall be determined using an oscillogram
showing the current tr ace. The determ ination shall be m ade by application of Sim pson's rule. A rec omm ended test
circuit is shown in Figure 3.
5.8.15 Resistance after Firing. The open resistance of the "blown" fuse shall be measured by applying
rated DC voltage across the terminals of the fuse. The resistance value shall be taken after a one-minute
application of the test voltage.