W-C-375E
4.7.16 Maximum energy (applicable only if tests in 4.7.15(b) were not required) (see 3.19). Current limiters shall be installed in a circuit breaker and prepared for test as specified in 4.7.11. One half of the current limiters shall be in the "as received" condition and the other half shall be conditioned at 90°C for 24 hours then subjected to 95 ±5 percent relative humidity at 20°C-25°C for 5 days. Conditioned samples shall be tested no later than 1 hour after removal from the conditioned environment. The limiter shall be subjected to a value of symmetrical, rms current such that the current limiter permits a peak current of 70-100 percent of the peak symmetrical component of the alternating current of the test circuit. The closing angle is to be at voltage zero of the phase where the current is to be considered. These tests may be conducted on a three phase circuit with one phase meeting these conditions. The power factor shall be 0.20 maximum. Following the test, limiters and circuit breakers shall be examined.
4.7.17 250 percent calibration at 25°C ±3°C (see 3.20). Circuit breakers shall be subjected to the calibration test specified in 4.7.2 at a temperature of 25°C ±3°C and 250 percent of the rated current. Following the test, circuit breakers shall be subjected to the dielectric withstanding voltage test specified in 4.7.9.2.
5. PACKAGING
5.1 Packaging. For acquisition purposes, the packaging requirements shall be as specified in the contract or order (see 6.2). When packaging of materiel is to be performed by DoD or in-house contractor personnel, these personnel need to contact the responsible packaging activity to ascertain packaging requirements. Packaging requirements are maintained by the Inventory Control Point's packaging activities within the Military Service or Defense Agency, or within the Military service's system commands. Packaging data retrieval is available from the managing Military Department's or Defense Agency's automated packaging files, CD-ROM products, or by contacting the responsible packaging activity.
6. NOTES
INFORMATION FOR GUIDANCE ONLY. (This section contains information of a general or explanatory nature that is helpful, but is not mandatory.)
6.1 Intended use.
6.1.1 Thermal magnetic circuit breakers.
6.1.1.1 Thermal magnetic uncompensated circuit breakers. Thermal magnetic circuit breakers are especially well suited for overload protection of conductors when circuit breakers are exposed to similar ambient temperatures because the circuit breaker continuous current rating changes in about the same ratio as the average conductor rating changes with the ambient temperatures. The magnetic trip portion of the circuit breaker offers short circuit protection.
6.1.1.2 Thermal magnetic compensating breakers. Ambient compensating circuit breakers provide overload and short circuit protection but has temperature compensating elements which counteract the effect of ambient temperature changes thereby maintaining the calibrated current setting throughout a temperature range. Typical applications are a circuit breaker located outside and protecting wire in a temperature controlled building; circuit breaker is exposed to changing temperature conditions and is protecting underground cable; overload protection of conductors are not of prime importance or protection of a portable generator designed to operate throughout varied temperature extremes.
6.1.2 Magnetic circuit breakers. Magnetic circuit breakers are available in the same operating characteristics as ambient compensating. The intended use is the same as in 6.1.1.1 and 6.1.1.2.
6.1.3 Fused circuit breakers. Fused circuit breakers incorporate fuses or current limiters in series with the circuit breaker elements to increase the interrupting capacity of a circuit breaker.
21
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business