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I have EMT leading to a metal junction box, and from that box goes plastic liquid tight to some equipment. Currently I have a ground conductor running all the way back to the panel, but I'm wondering if it's enough to terminate that ground at the metal junction box (so that the EMT back to the panel forms the remainder of the equipment ground).

Related question: how do I properly bond the 10 ga grounding conductor in the liquid tight to the metal box? Crimp a ring terminal on it?

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  • Is that 10AWG solid or stranded? – ThreePhaseEel Aug 16 '19 at 11:42
  • The 10 ga is stranded, yeah. – Rick Aug 16 '19 at 11:43
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Yes, it's allowable to tie a ground wire to a junction box and let the metal conduit carry it the rest of the way back.

However, if the ground wire is already in the pipe, I'd leave it in there - belt and suspenders - unless you need the conduit fill.

You terminate a ground wire at a junction box by attaching it to a ground screw. Virtually all junction boxes have a hole tapped #10-32 specifically for ground screws, which are sold either with or without pigtails. You can put 1 wire on that screw, or any sensible number of ring terminals. Make sure the ring terminals are UL listed for use in mains power.

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  • Yeah, the hole is there, but the ground is stranded #10, kinda hard to wrap around the screw. I'll use a ring terminal. Thanks! – Rick Aug 17 '19 at 1:07
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If the panel is grounded, then the EMT connected to it will be grounded. The ground cable in the EMT is basically for the equipment at the end of the plastic liquid. It does not have to be connected to the metal junction box. If your ground cable from the equipment ends at the grounded metal junction box, you can connect a stranded ground using a ring connector or wire nut a piece of #10 solid to it and connect that to the box. A solid ground would just be connected straight to the box.

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  • I’m asking if I can avoid running the ground conductor through the emt portion. – Rick Aug 16 '19 at 11:51
  • But you say you have a ground cable running all the way back to the panel. Is that correct? – JACK Aug 16 '19 at 11:55
  • Sorry. Yes, that’s what I have currently. I’m asking if it can be run only to the junction box. – Rick Aug 16 '19 at 11:56
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    @Rick - There is a term called intrinsically safe. Meaning that if you have an existing ground wire in the box you should attach to it since it is a better ground path than an EMT ground. And you should use a ring connector as suggested or use what we call a stinger to bond to the box and the ground conductor. Now you have a ground system that is intrinsically safe. – Retired Master Electrician Aug 16 '19 at 14:20

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