Planning to use Legrand Wiremold 700 Series Metal Surface Raceway.

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Couple questions:

  1. It is a metal box (raceway) but I don't see a green screw to ground it. Does it require grounding?
  2. Is it allowed to use a cable or do I need to use individual THHN wires? If the former - is it realistic to pull it through?
  • 2
    Notice the round bubble in the top left of your photo. That’s for a 10-32 ground screw, some come with screws some don’t same with metal electrical boxes some have them and some do not but that is the point to add the screw. Usually individual wires are required as the wire way is not large enough to allow NM cable even if it fits. Verify the fill calculation won’t be exceeded.
    – Ed Beal
    Commented Feb 15, 2021 at 17:03

1 Answer 1


It can take its ground either from the underlying box or from a pigtail

From the installation instructions Legrand provides on their website for the 500/700 series products, I don't see any reference to an explicit grounding screw being driven, so it appears that it picks up its grounding from the underlying box being grounded. If that's not possible, the bump at the top-left that doesn't have a mounting hole in the cover corresponding to it should be tapped to accept a 10-32 grounding screw and corresponding pigtail.

...but always uses individual wires

Surface raceways are designed to be used with individual THHN wires, just like their conduit brethren. Furthermore, you have to obey the fill chart provided by the raceway manufacturer; if what you plan to run isn't a combination that's on the fill chart, you can't run it, as the irregular shapes of surface raceways mean that normal conduit fill calcs can't be used and the provisions of NEC 386.21 and the first paragraph of 386.22 apply instead:

386.21 Size of Conductors. No conductor larger than that for which the raceway is designed shall be installed in surface metal raceway.

386.22 Number of Conductors or Cables. The number of conductors or cables installed in surface metal raceway shall not be greater than the number for which the raceway is designed. Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles.

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