MODUK DEF STAN 61-12: PART 21 PDF

This Defense Standard specifies the requirements for three types of lightweight wires and cables primarily intended for air craft wiring. Type 1 has a single layer extruded insulation (medium wall) and if not used under enclosed conditions will need suitable protection. Type 2 has a two layer extruded insulation ( thick wall) and map be used for aircraft wiring without additional protection. Type 3 has a single layer extruded insulation (thin wall) and is primarily intended for use in enclosed conditions.

These wires and cables are suitable for use where the potential between conductors, or between a conductor and the equipment structure, or between a conductor and a metal braid surrounding the cable does not exceed 600 v (rms), for Types 1 and 2, 250 V rms for Type 3 where the frequency does not exceed 2000 Hz and where the combination of ambient temperature and temperature rise due to the current produces a stabilized conductor temperature not exceeding 135 for tin plated or 150 C for silver plated wires or cables.

These wires and cables are suitable for fixed wiring at temperatures down to -75C and remain flexible at this temperature. The life of the cable will be greater than 20 years or 50 000 flying hours, whichever is the shorter. The cables do not support combustion. The cables meet the relevant requirements of BS G233.

The wires and cables are identified by the number of this specification. Their sizes are indicated by gauge numbers according to the cross sectional area of the conductor. Details dimensions, etc are given in Tables I (A) to I (W) inclusive and in Table N.

Varieties of wire and cable Wires with tin or silver plated copper or silver plated copper alloy conductors in sizes from 32 to 00 inclusive.

Cables of two, three, and four core twisted wires as defined in clause 1.2.1, in sizes.

Cables having a wire generally as defined in clause 1.2.1, metal braided with tin or silver plated copper strands,

Cables having a wire generally as defined in clause 1.2.1, metal braided with tin or silver plated copper strands, and jacketed. Sizes range from 30 to 12 inclusive.

Cables of two, three, and four core twisted wires as defined in clause 1.2.1, in sizes from 26 t o 10 inclusive.