MIL-PRF-39019 Circuit Breakers, Magnetic, Low-Power Sealed, Trip-Free General Specification ForThis specification covers the requirements and test procedures for single and multipole, trip-free, sealed, low-power, magnetic circuit breakers with current ratings of 0.050 amperes to 20.0 amperes inclusive, up to and including 240 volts, 60 hertz \(Hz\) and 400 Hz alternating current \(ac\), and 50 volts direct current \(dc\) \(see 6.1 and 6.7\). These circuit breakers may also include auxiliary contacts \(see 6.6.1\) and terminals for monitoring circuits. Designers are CAUTIONED that these circuit breakers may contain a pure tin finish on some of the component parts \(see 6.5\).

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MIL-PRF-39019F

3.24 Interrupting capacity. When tested as specified in 4.8.21, circuit breakers shall trip automatically and the

indicating fuse shall not open. There shall be no dielectric breakdown, and when applicable (see 3.1 and 3.4.8.2), the

auxiliary contacts shall operate, indicating position of the main contacts. Circuit breakers shall also meet the

following requirements.

Dielectric withstanding voltage (see 3.6)

Calibration at 200 percent of rated current (see 3.9).

Insulation resistance (see 3.7).

Seal (see 3.11).

3.25 Marking (see 3.1).

3.25.1 Identification marking. The following information shall be marked on the circuit breaker in accordance with

Part number (see 3.1).

Current rating, voltage, and operating frequency (see 3.1).

Supplier's name or code symbol and date code.

Circuit diagram using symbols in accordance with IEEE STD 315-1975.

Terminals shall be permanently identified in accordance with figure 1. Terminals not used need not be

identified.

3.25.2 Other marking. The main "LINE" terminal (see 6.6.2) and, where applicable, the auxiliary contact terminals

(see 3.4.8.2) shall be clearly and permanently marked on each unit.

3.25.3 Resistance to solvents. When circuit breakers are tested as specified in 4.8.1.1, the marking shall remain

legible and there shall be no blistering or peeling in the marking area.

3.26 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally

preferable materials should be used to the maximum extent possible, provided that the material meets or exceeds the

operational and maintenance requirements, and promotes economically advantageous life cycle costs.

3.27 Workmanship. Circuit breakers shall be processed in such a manner as to be free from cracked or displaced

parts, sharp edges, burrs, and other defects which will affect life, serviceability, or appearance.