mbrooke
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When running running dedicated EGCs to circuits in conduit, can table 250.122 be used without having to up-size them to the largest circuit?
EGC size in Conduit
- Thread starter mbrooke
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I believe so. The branch circuit EGC must be sized per the overcurrent device rating and any factor for conductor oversize due to voltage drop. A common application for this is isolated ground receptacles where each gets it own dedicated EGC. If not isolated ground EGC's, watch the rules for splices in boxes -- all must be connected together if they are spliced.
mbrooke
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jaggedben
Senior Member
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See 250.148 in the 2020 NEC.
mbrooke
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You can pass them through unspliced if you wish. But if a circuit splits and is therefore spliced, all grounds that got spliced must be connected.
For example, lets say there are 4 circuits in the conduit. Two pass through a junction box unspliced and two others split left and right to go to multiple locations. So the 6 spliced grounds (two incoming and 4 outgoing) must be all connected together. The unspliced ones can remain unspliced.
For example, lets say there are 4 circuits in the conduit. Two pass through a junction box unspliced and two others split left and right to go to multiple locations. So the 6 spliced grounds (two incoming and 4 outgoing) must be all connected together. The unspliced ones can remain unspliced.
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That is a terribly written code section.
petersonra
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A lot of the grounding and bonding sections are horribly written, and in my opinion, much of what is in them really doesn't serve much in the way of real purpose.
electrofelon
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I don't mean to turn this thread into a rant, but this probably frustrates me the most about the NEC is the frequent poor wording that they just REFUSE to fix.
petersonra
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I think they are afraid that in changing it they will make it worse as has happened many times in the past.
electrofelon
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I think they need something like a committee of English majors to write/ review the wording - or... I don't know, it just blows my mind some of the ridiculous wording they come up with and everyone involved thought it was fine.
electrofelon
Senior Member
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Anyway, back to the OP......can EGC's smaller than 1/0 be run in parallel? If you have to connect then all together at a box, doesn't that make them all in parallel?
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The purpose of an equipment grounding conductor is to clear a fault. As you know there is no current normally running ion the equipment grounding conductor so what does it matter if it were in parallel.
petersonra
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You can run them in parallel but you can't run parallel conductors to make up an egc.
mbrooke
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mbrooke
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So if I have a number 6, 10 and 12 all need to be put under a split bolt in every j-box and then the box needs to be bonded with a #6?
If you've spliced each of them, then yes. If this is just a pull box or a direction change and you can pull all or some the grounding wires in and out without splicing, then no splice required for the ones passing through (assuming the box is adequately bonded with a metallic wiring method - otherwise you need to splice or tap the largest one to bond the box).
Not sure if a split bolt is legal for 3 wires and that size mix though.
Not sure if a split bolt is legal for 3 wires and that size mix though.
mbrooke
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kwired
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If the 6 and 10 are for 20 amp circuits but are sized because of voltage drop, you should be able to make a #12 pigtail to the box. Otherwise yes in general pigtail would normally need to be no smaller than the largest conductor it connects to.
kwired
Electron manager
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I agree can have all sorts of paralleling involved, even with metal raceways, but can't run them parallel with intent of creating effectively larger conductor. NO 1/0 minimum either like for other conductors in that are in parallel for the purpose of creating a larger overall conductor.
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