Distribution Panels

[mathew stouffer]

Can I chalk this up to the electrician having a bad day? Does anyone know what the requirements are regarding securing wires entering panels. Is it 12 inches?

[Richard Moore]

Yep...NEC 334.30...within 12" of every cabinet, box, or fitting.

[Brandon Chew]

They also cannot jam so many cables into one clamp unless the clamp is listed for it. I believe two NM cables is the limit. Could someone confim and provide a source on that for me? tx.


Wahooo.... post #100 on the new board!

[Jerry Peck]

Plus ...

They are 'bundling or not maintaining spacing' for what looks like more than 24" for 'multi-conductor cables' too.

Derating in now required.

[mathew stouffer]

There were a few other problems not visible in the photo. Wrote it up as further evaluation by electrician to correct multiple installation insufficiencies.

[Richard Abrams]

Watch Bundling of romex cables as anything over 4 wires would have to be derated. Especially if insulation material is installed in these cavitys.

[Jerry Peck]

Watch Bundling of romex cables as anything over 4 wires would have to be derated. Especially if insulation material is installed in these cavitys.

If even two NM cables (any multi-wire cable for that matter) are bundled or spacing was not maintained, then derating takes affect.

The code references "more than 3" but is also references "multi-conductor cables", because if you have 2 2-conductor cables (i.e., 2 multi-conductor cables), you have 4 conductors.

Derating then becomes
4-6 conductors - derate to 80%
7-9 conductors - derate to 70%
10-20 conductors - derate to 50%
21-30 conductors - derate to 45%
31-40 conductors - derate to 40%
41+ conductors - derate to 35%

[Raymond Wand]

Mathew,

At the top of the second picture are those cables going up into the return air duct?