M16878/6 - Type ET

How Is M16878/6 - Type ET Wire Made?

Military specification MIL-W-16878/6 is covered by the National Electrical Manufacturers Association specification NEMA HP-Type ET. The wire has a single conductor with extruded PTFE insulation.

Conductor

The conductor material is silver-plated copper. Silver plating lowers the resistance of copper while preventing high-temperature oxidation and degradation. A further benefit of silver plating is the slightly lower skin impedance that reduces the effective resistance of the conductor in high-frequency AC circuits. You have a choice between solid and stranded conductors. Stranded conductors have seven or 19 strands. Solid conductors hold their shape better while stranding increases flexibility and wire strength.

Insulation

These cables have extruded PTFE insulation. PTFE has thermoset characteristics and doesn't shrink or burn when heated, a factor that’s important during manual or automated soldering processes. The insulation is very thin, typically being no more than 0.006 of an inch thick.

Jacket

The wire does not usually have a jacket, although UL 1371 allows for one.

Where Is M16878/6 Used?

MIL W 16878 applications include demanding aerospace, military, and civilian electronic equipment. Its primary use is for internal wiring of low voltage electronic equipment. Low power loss characteristics together with a low dielectric constant make it ideal for high-frequency applications. It's suitable for use in very high and extremely low-temperature applications found in demanding terrestrial, aerospace, and space environments.

Difference Between NEMA HP3-Type ET and UL 1371 Standards

The military version of this wire falls under the NEMA HP3-Type ET standard, while UL 1371 covers civilian applications. The main differences relate to the maximum allowed temperature, fire resistance, and voltage.

The military specification allows its use to a maximum temperature of 200°C while UL 1371 permits only 105°C. UL 1371 doesn't specify a minimum temperature, whereas MIL-W-16878/6 allows use down to -60°C.

Wire to the UL 1371 standard must pass a horizontal flame test. The maximum allowed voltage for NEMA HP3-Type ET wire is 250 volts RMS, UL 1371 is silent on this, leaving that to the manufacturer's discretion.

M16878/6 Hook-Up Wire Specifications