Small-gauge wire: UL vs. MIL-W

Status
Not open for further replies.
G

geerhed

Member
Location
Your six.
I'm not sure where else to post this, so I'll try here. Mods please move as you think necessary.

A while back I was burned by my UL auditor for lacking UL tags on a few wire spools. Fortunately, I had nothing I needed to rip it out of, I just learned a lesson.

A had a small spool come in recently, and I'm not sure what my reaction should be. The wire is 24AWG, 600V, 105?C. This is used in products rated up to 600V (diagnostic panel, sense wire, etc. inside the device enclosure).

The spool is marked, "MIL-W-16878E Type B." Does this mean I need no UR tag? Is the wire of a gauge which does not require such a thing? If so, what is the cut-off point?

Thanks for any help yall can give me.

Doug
 
If you are talking about making UL508a panels, here is the applicable requirements.

29.2 Conductor requirements
29.2.1 All internal wiring of power circuits shall have a temperature rating of 90?C (194?F) minimum and
shall be one of the following:
a) Machine tool wire that complies with the Standard for Machine-Tool Wire and Cables, UL
1063. Flexing or Class K type machine tool wires and cables shall be installed in accordance
with 29.3.11;
b) Thermoset insulated wire that complies with the Standard for Thermoset-Insulated Wires and
Cables, UL 44;
c) Thermoplastic insulated wire that complies with the Standard for Thermoplastic-Insulated
Wires and Cables, UL 83;
d) Appliance wiring material that complies with the Standard for Appliance Wiring Material, UL
758; or
e) Welding cable installed in accordance with 29.3.11.
Click to expand...

I realized after i posted that a 24 gauge wire would not be suitable for any power circuit. I think the wire in a UL panel still has to be all UL, although I think for control cirucits it does not have to be one of the specified types, just UL.
 
Last edited:
Last edited:
ooops

ooops

gndrod said:
This is a UL Style 1569 300V, 105 deg C FR1 rated conductor listed wire for 90 deg service solid tinned copper as appliance wiring material. Most electronic hookup wire falls under the Mil-W-16878 for internal wiring of meters, panels and electronic equipment up to 1000V applications. rbj

Note: The type E is TFE or Teflon insulated temp rated for -65 C to +260 C
Click to expand...

Correction due to time (mind) lapse: This type Bu (Unjacketed) wiring meets UL style 1061 or type Bn (nylon jacketed) meets 1004, 1005, & 1006. The 16878E type B is primary vinyl 600V RMS -54 C to +105 C or +115 C (Bn) most commonly used for internal electronic wiring. As you can see the confusion of where the E is placed in the Mil number can even trip up old guys who have used this stuff over a half century ago.
 
Last edited:
Status
Not open for further replies.
Top