MIL-DTL-17361G(SH)
a. Actual trip times shall not vary more than ±15% of the specified upper limit (see 3.1) from the actual trip
times recorded before shock testing as part of test no. 3 of Table VI.
b.
Where no upper limit is specified, the actual trip times shall be greater than the specified lower limit (see
3.1).
c. Readjustment of the circuit breaker trip unit to specified calibration limits (see 3.1) is permissible between
test nos. 6 and 7 of Table VI.
4.5.10.3.2 Instantaneous. For thermal magnetic and electronic trip unit circuit breakers, instantaneous
calibration shall be in accordance with the test of 4.5.10.1.2 but tested at the intermediate instantaneous setting only.
For calibration testing after shock (test no. 6 of Table VI) and after vibration (test no. 9 of Table VI), the following
caveats apply for thermal magnetic trip unit type circuit breakers only:
a. The no-trip event shall occur at an applied current level of ±15% of the specified minimum pickup
tolerance (see 3.1).
b. The trip event shall occur at an applied current level of ±15% of the specified maximum pickup tolerance
(see 3.1).
4.5.10.3.3 Short-time delay. For electronic trip unit type circuit breakers only, STD shall be tested in
accordance with 4.5.10.2.3 and Table XV but at the intermediate STDPU setting only.
4.5.11 Inclined operation. With the circuit breaker inclined, forward, backward and to each side at an angle of
45 degrees from the vertical position, the circuit breaker, fuses and fuse units (if applicable), and attachments shall
pass the tests specified in 4.5.6 and 4.5.11.1.
4.5.11.1 Manual cycling. The circuit breaker shall be manually cycled three times in each direction of
inclination.
4.5.12 Temperature rise.
4.5.12.1 Circuit breaker.
4.5.12.1.1 Test circuit. The circuit breaker shall be operated at rated current and any convenient voltage in a
50 °C ambient. Bus bars shall be used for connecting to the top studs and cable shall be used for connecting to the
bottom studs. Size of the bus bar and cable shall be as specified in the applicable specification sheet (see 3.1). The
copper cross-section of the leads shall remain constant for at least 3 feet from each stud on the circuit breaker.
4.5.12.1.2 Sensor locations.
4.5.12.1.2.1 Ambient. The ambient temperature shall be determined by two temperature sensors
(thermometers, thermocouples, or other approved method). The sensors shall be located within two feet of each side
of the circuit breaker at half the depth and half the height of the circuit breaker.
4.5.12.1.2.2 Circuit breaker. The temperature rise shall be determined by sensors located at, but not limited to,
the following locations:
a.
At the circuit breaker line and load side slip-type connectors on each phase.
b.
At the mounting base/block line and load terminals on each phase.
c.
At the molded case material nearest the main contacts on each phase.
d. At any point where a current-carrying part is in contact with the insulating material including areas nearest
the main contacts.
4.5.12.1.3 Temperature stabilization and temperature rise determination. All temperature readings shall be
recorded during the same time frame and shall be of sufficient duration to allow stabilization of the measured
temperatures to a rate of rise within 2 °C per hour. Ambient temperature shall be maintained at 50 °C ±5 °C. An
average ambient temperature shall be determined by averaging together the ambient sensor readings. The average
ambient temperature shall be used to determine the temperature rise of monitoring points specified in 4.5.12.1.2.2.
4.5.12.1.4 Pass/fail criteria.
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