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In this box, I have a green ground wire nut with a through-wire connected to the metal box ground nut that connects it to four other ground wires on conductors entering the box. I connected three more ground wires to the through-wire with a 4-way push connector that will connect to the ground nuts on three different switches.

Is this type of connector linking generally allowed rather than putting all 7 or 8 ground wires under one large wire nut, and are there any restrictions other than exceeding box-fill limitations?

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Ryan Mortensen
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I'm pretty sure that's OK, subject only to box fill issues.

However, you have a beautiful METAL box! You don't need to do this! See my long list of metal box advantages, #8 and #9.

  • At least one incoming ground wire should go directly to the back of the box - that makes the entire box part of the ground.
  • All switches should ground automatically through the yoke to the metal box.
  • All except rock-bottom quality receptacles should be self-grounding through the yoke to the metal box.

If a switch comes with a ground pigtail attached (some smart switches and timers are designed that way) then you need to attach it to the box/other grounds. But most switches, receptacles, etc. simply have a ground screw and you get to ignore it when installing in a metal box.

manassehkatz-Moving 2 Codidact
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  • I had thought that receptacles were self-grounding through the box, but my county's inspector seems to prefer that I connect the switch grounds anyway. 2 inspections ago, he even opened a cover plate to verify that I had put a ground wire to the nut on the switch in a metal JB. – Ryan Mortensen Mar 13 '24 at 04:20
  • What jurisdiction (state, county, city/town)? – manassehkatz-Moving 2 Codidact Mar 13 '24 at 04:35
  • It's Michigan. I'm pretty sure all of Michigan just follows the NEC with no modifications. He doesn't hard require things that aren't code. For example, he asks me to pigtail all receptacles and never daisy-chain via the devices. He made it clear this isn't a code requirement, but he strongly recommends it. – Ryan Mortensen Mar 13 '24 at 04:45
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    The pigtail receptacles instead of daisy-chain has some merit - it is critical for MWBCs (though that's relatively rare) and in general can be a bit more reliable. But ground via yoke on metal box is pretty standard and is one of the key benefits of metal boxes - and solves the problem you have found of "too many grounds" – manassehkatz-Moving 2 Codidact Mar 13 '24 at 05:00
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    OP also might need to be concered about box fill and count of wire splices—not clear if/what devices will be in/on the box. (Although based on the fact that the box appears to have double knockouts on the bottom, it's likely deep enough for just about anything.) – Huesmann Mar 13 '24 at 13:07
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    @Huesmann three, two-way switches. So, there was plenty of room for four two-wire conductors, two clamps, and 3 switches. I measured the resultant box I built and I think it was about 50 inches. At the end, everything fit, and I definitely don't need to worry about losing the path to ground, which is a good thing as someone else pointed out with the switches being very close to the sink. – Ryan Mortensen Mar 13 '24 at 20:07