jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
To clarify, I only meant that it was after 2000, I did not mean to state a particular year. The last major resi job I did was in 2000 and it was all white 14,12,10# NM.
Wire Color Coding
- Thread starter ElectricianJeff
- Start date
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To clarify, I only meant that it was after 2000, I did not mean to state a particular year. The last major resi job I did was in 2000 and it was all white 14,12,10# NM.
fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
I just checked some NM wiring in my house (built 1960) The conductors are marked "12 AWG type TW 600V" and the grounding conductor is #18 by my measurement. The grounding conductor is not big enough even for #14 which is the smallest Table 250.122 entry.
renosteinke
Senior Member
- Location
- NE Arkansas
NM has had the full size ground wire since at least the early '70's. In the late 70's they reduced the required insulation thickness on THHN wires, and changed the temper of the wire. That's when NM became both slimmer and stiffer.
The stuff got 'color' only about 2003. So, there's loads of NM-B out there that has white, or even black, jackets.
There's no requirement in any code (or even any NECA/NEMA standard) that NM be color coded. Nor was it even at the instigation of inspectors. It was simply a marketing gimmick by Southwire. For about two years the color was specific to Southwire, and supplies were spotty; On Monday the supply house would give you yellow, and on Tuesday they'd be back to white. Ultimately, all the NM makers got on the 'pretty colors' bandwagon. IMO, the gimmick was inspired by an electrician named Rex Caldwell, who wrote about marking his coils with spray paint for his own convenience in Fine Homebuilding magazine.
FWIW, one EC in Las Vegas, a guy who does tract homes, special orders his NM with pink jackets, as a way of controlling losses.
The stuff got 'color' only about 2003. So, there's loads of NM-B out there that has white, or even black, jackets.
There's no requirement in any code (or even any NECA/NEMA standard) that NM be color coded. Nor was it even at the instigation of inspectors. It was simply a marketing gimmick by Southwire. For about two years the color was specific to Southwire, and supplies were spotty; On Monday the supply house would give you yellow, and on Tuesday they'd be back to white. Ultimately, all the NM makers got on the 'pretty colors' bandwagon. IMO, the gimmick was inspired by an electrician named Rex Caldwell, who wrote about marking his coils with spray paint for his own convenience in Fine Homebuilding magazine.
FWIW, one EC in Las Vegas, a guy who does tract homes, special orders his NM with pink jackets, as a way of controlling losses.
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