I am building my own workshop and am in the wiring phase. I have four lighting circuits running through a common conduit to two side-by-side metal 2-gang boxes on the wall where the switches will be. Three of the switches are 3-ways and one is a single pole. The layout of the wiring is such that these boxes are at the end of the run – no wiring will be continuing out the other side.
My question is this: can I share a single green ground conductor for these switches to reduce conduit fill (and posibly save a little wire) or does each circuit need it own? I expect the answer will fall into one of these categories: heck no, yes but…, yep do it all the time.
Thanks, Daen.
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Around here I believe that each branch circuit requires it's own independent bonding path back to the panel.
Well, used to be you'd only need one ground, sufficient for the largest circuit. But they've played with the code so much in the past ten years that most of the old rules are subject to question.
Note that one of those recent changes is that you now need a neutral (or maybe one per circuit), even if it's unconnected in the switch box.
You only need one grounding conductor in each raceway and that can actually be the raceway itself if it is all metal along the way.
It is right that the 2011 code will require a neutral at every switch location if you are runninbg a cable like Romex but that is really more a design issue. Just be sure you go to the switch first and then on to the load. If you are using a raceway you do not need the extra wire anyway (an exception to the rule) since it could be added later.
Thanks for the info.
Can't use the raceway in this particular instance because it is PVC conduit. The conduit was put in place under the concrete pad prior to pouring so used PVC. The these switches all occur first in the circuit. They will have the hot (black) feeding them and the White (with black for switched hot) returning through the conduit and then continuing on the the load.
Thanks again.