 |
|||
|
Page Title:
Temperature, nonoperating and ready nonoperating. |
|
||
| ||||||||||
|
|  MIL-M-82433A(OS)
4.5.2.4.1 Temperature, nonoperating and ready nonoperating. The
unpackaged motor shall be placed in a temperature controlled chamber.
The chamber shall then be subjected to the following temperature
cycles:
(a) Heat chamber to +140 +5 -O degrees F in 2.5 0.5 hours.
(b) Maintain at +140 +5 -O degrees F for 4 hours minimum, then
within 2.5 O.5 hours cool chamber to -45 +0 -5 degree F.
(c) Maintain at -45 +0 -5 degrees F for 4 hours minimum,then
within 2.5 0.5 hours return chamber to room temperature.
Repeat this schedule for a minimum of three cycles.
4.5.2.4.2 High temperature operating. The motor shall be operated
for one or more duty cycles as specified in 3.3.3 (load included)
at an ambient temperature of 200 5 degrees F. The motor shall be
conditioned in the test chamber at 200 5 degrees F for 1 hour prior
to the test. After the 10-minute operating period, the motor shall
be left in the test chamber and the insulation resistance shall be
measured. The resistance reading shall be taken at 7 1/2 minutes
following termination of the operating period, using the method of
4.7.3.1, and shall be not less than 100 megohms.
4.5.2.4.3 Low-temperature operating. The motor shall be conditioned
in the test chamber at a temperature of O 5 degrees F for 1 hour
prior to testing. The tests to be made in this environment are as
follows:
(a) Using a motor operating circuit equivalent to that shown
in Figure 3, energize the motor in each direction with the supply
voltage adjusted to 28.0 O.5 volts and with zero load on the shaft.
The steady-state input current shall be determined within 3 seconds
after start in each direction and shall not exceed O.5 ampere.
(b) The motor time constant shall be determined as in Section
4.7.3.8. The same criteria shall be met.
4.5.2.5 Humidity. The motor, ready for installation, shall be ex-
posed to an atmosphere of 95 percent relative humidity at a controlled
temperature of 110 5 degrees F for a period of 8 hours. The motor,
at room temperature, shall be placed in the test chamber with the shaft
horizontal or inclined downward. After the exposure, the motor shall
be wiped dry and placed in room environment for not more than 1 hour
and shall then be tested according to 4.7.3.1; the insulation resist-
ance shall exceed 20 megohms. After standing in room environment for
not more than 24 hours the insulation resistance shall exceed 100
megohms.
16
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals