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MIL-M-82433A(OS) Enclosure. The purpose of this test is to verify that the
case around the body of the motor is effectively splash-proof.  The
output shaft of the motor, its bearing, and the adjacent portion of
the housing shall be suitably enclosed to prevent entry of moisture.
The test shall be similar to the Rain Tests, Procedure 11, as de-
scribed in MIL-E-5272, with exceptions and/or special provisions
as follows:
(a) The water introduced as rain shall be 5 percent sodium-
chloride solution prepared as in Federal Test Method Standard No.
151, Method 811, except that tap water may be used instead of dis-
tilled water.  Alternatively, natural sea water may be used if avail-
able and clean.
(b) The rainfall rate shall be reduced to 2.0 O.5 inches per
hour and the droplet diameters shall be mainly within the range of
2 to 5 millimeters.
(c) variation of direction of rainfall from the vertical is
not required but is permitted.
(d) The motor shall be placed with its longitudinal and major
axes horizontal, i.e., X and Z axes as shown in Figure 1.
(3) The motor shall be exposed to the rainfall for 10 minutes
in each of two positions, 180 degrees apart, for a total test dura-
tion of 20 minutes.
After the exposure, the residual salt water shall be washed or
flushed off and the motor wiped dry.  After standing in room environ-
ment for not more than 1 hour, the motor shall be tested according to; the insulation resistance shall be not less than 20 megohms.
After standing in room environment for a total of 24 hours, the insula-
tion Resistance shall exceed 100 megohms. Life test.  The motor shall be subjected to an operating
life test consisting of 150 duty cycles as described in 3.3.3. Pressure. The motor shall be placed in the test chamber
and the pressure reduced to 2.7 O.5 psia,  The rate of pressure re-
duction shall not exceed 0.5 psi per second. The pressure shall then
be increased uniformly to 20 O.5 psia at the rate of 0.5 0.05 psi
per second.  This pressure cycle shall be repeated five times.  The
pressure shall be reduced gradually to ambient after the final cycle.
The motor housing shall show no deformation from this exposure nor
shall the effectiveness of splash-proofing elements be compromised.

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