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have two very basic electrical questions I'm hoping someone can answer for me. Did a search and didn't find an answer as to why. My questions are,

  1. Why is the ground wire usually bare and not insulated?
  2. Why is the ground wire normally connected to the junction box as opposed to connected directly to the fixture's ground wire?

Appreciate any/all replies.

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    just guesses ... 1) probably cost ... 2) the box ground should not rely on a good connection with the fixture
    – jsotola
    Commented Oct 13, 2021 at 4:39

1 Answer 1

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NEC doctrine says that grounds (and in the case of MWBCs, neutrals) should remain fully connected even if a device is removed.

Also, connecting directly to the fixture's ground wire is often redundant with metal boxes, since most things will pick up ground via the mounting screws or face-on metal contact with the box.

Bare ground is just about cost. Mineral value of the wire is the square of diameter... but cost of insulation is linear with diameter. For big wires it's all about mineral value, but for the smaller wires as are used on branch circuits, mineral value is negligible, and the cost of insulation is the dominant factor.

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  • Yellow-green insulation is allowed.
    – user263983
    Commented Oct 13, 2021 at 10:14
  • @user263983 It is more that if insulation is used, it must have green colour, more than just allowed. This is picky I know, but wording is important.
    – crip659
    Commented Oct 13, 2021 at 10:39

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