Multiple switches for different circuits in the same box, question about neutrals

[signcrafter]

I'm slowly redoing the wiring for the shop when I get time. The previous owner has a mess of romex wires strung all over and stuff added and added and added. So I'm starting fresh. I'm doing all mine in conduit since I have a bunch and it kind of future proofs things if I want to add a circuit down the road it will be easy. Breaker box is in the house and a block wall separates the house from the shop. So I cored a hole through the block wall and ran a piece of 2" pvc from the panel out to the shop and put in a 12"x12" pull box there. Then running 3/4" and 1/2" conduit from pull box to the various circuits in the shop. There won't be too much out there, 220 welder(already ran), 220 compressor(still need to run), 3 lighting circuits(ran in romex now but will be changing soon), an exhaust fan, then some outlets. I'm sure there will be other things but that is it for now.

My plan is to put all the switches by the man door leading into the shop from the house. There will be the 3 lighting circuit switches, a 220 switch for the air compressor, a switch for the exhaust fan, and a switch for a wall mounted cooling fan. Want to be able to turn everything off from this location since these items are located around the shop and depending on what's being worked on can be a pain to get to sometimes.

So my question is what if any neutrals do I need at these switches? The switches will be located away from these items( I will put a disconnect located at each item as needed to meet code). So the easiest way to do this would be to pull a hot wire for each circuit from the panel to the switches and then a switch leg from the switches to each item. This could be done by running conduit from my main shop pull box to a J box centrally located between my items. I would run a neutral for each circuit to this J box also. From this J box I would run conduit down to my switches. In this conduit I could run the hot from the breaker for each circuit down to the switch and then a switch leg back to this J box. So to make it work really only need a hot and switch leg to the switch boxes. But code requires you to have a neutral at every switch location right? So do I have to run a neutral for every single switched circuit I'm running? Seems like a waste to me since there will be around 6 switches and the neutrals will all be dead ended in the boxes.

Hopefully my description and question makes sense. I would draw a picture of the layout but not sure how to do that on my computer. Just seems like such a waste to me to have to have a neutral from every circuit pulled to the switch boxes just to be dead ended and capped off. Plus would mean I will need to run more then one run of conduit because of the amount of wires in the conduit then, I think, didn't count them all up yet.

 

[Terry D]

Read 404.2(C) Exemption (1) from the 2011 NEC when this was adopted.
It basically says if the lighting loads enter box through a raceway and the raceway is sized to add a grounded conductor, it may be omitted until needed in the future.

This is assuming that a grounded conductor is not needed now. Some kinds of switches now require that grounded conductor to operate, example a occupancy sensor. You only need to be concerned about the switches for lighting.

 

[TRWham]

404 only requires neutrals for switches that control lighting, and specifically excludes switches that control receptacles, so your fans are already excluded. The 240V loads are also obviously excluded (but you need to explore that compressor a bit to be sure you understand what it needs). Now you are only looking at neutrals for the 3 light switches.

I would have been tempted to put a small sub-panel where you have the 12x12 box and only run a single feeder from the main panel. Then the CBs in the sub could have served as disconnects for the shop equipment as needed.

 

[Terry D]

A sub panel can make it easier on you

 

[signcrafter]

Read 404.2(C) Exemption (1) from the 2011 NEC when this was adopted.
It basically says if the lighting loads enter box through a raceway and the raceway is sized to add a grounded conductor, it may be omitted until needed in the future.

This is assuming that a grounded conductor is not needed now. Some kinds of switches now require that grounded conductor to operate, example a occupancy sensor. You only need to be concerned about the switches for lighting.

Ok so only lighting needs it and it can be left out as long as there is room in conduit to add later if needed. Perfect, thanks.

404 only requires neutrals for switches that control lighting, and specifically excludes switches that control receptacles, so your fans are already excluded. The 240V loads are also obviously excluded (but you need to explore that compressor a bit to be sure you understand what it needs). Now you are only looking at neutrals for the 3 light switches.

I would have been tempted to put a small sub-panel where you have the 12x12 box and only run a single feeder from the main panel. Then the CBs in the sub could have served as disconnects for the shop equipment as needed.

Compressor should be good to go, already have a switch for it now located right by it. So will just add another one at the remote location and leave the current switch ON all the time, just use it as a means of disconnect.

I thought about doing a subpanel in the shop but decided against it. The main panel is right on the other side of the wall. So it doesn't take much effort to get to. Also with the big pull box and 2" conduit it makes it easy to pull wires. As far as disconnects there is only my air compressor and welder that need it within site. So I put a switch on my compressor. And the welder uses a plug so that counts but I also put a 60 amp disconnect above the outlet so that is good to go also. I might put fans on 3 way switches so there a switch right by them and one at the main switch location. Would count as disconnect(if required) and also be able to switch in both locations.

Another thought I had while writing this is if I switch to LED lights they probably could all go on one switch. I usually have them all on when in the shop anyway and LED would be such low load they could all be on one circuit. Then could do an occupancy sensor if I wanted to turn them on and off and would only need one neutral then. Something to think about.

 

[matt_i]

I'd look into a contactor for your 240vac circuit(s)

It doesn't make sense to me to pull (assuming) heavy wire, both poles from the circuit panel to a switch box and then back to the load.

If you use 120vac controls you can run a single loop of wire down&back (maybe a pair depending on how you look at it) to the enable/disable switch which is carrying milliamps.

 

[exranger06]

Keep in mind, if you have more than 3 current carrying conductors in the same conduit, you need to derate them. And as you add more circuits/wires to the conduit in the future, you'll need to derate them even more, and you may need to upsize them to maintain the same ampacity.

Also keep in mind that occupancy sensors typically can handle about 800W max, so be sure that your total lighting load doesn't exceed that if you're connecting them all to one switch.