How many wires Required in Conduit

[Tedison]

I am putting up lights in my 1 car heated garage (10' x 24') and will be running part of the circuit in 1/2 inch PVC conduit. It is all on one 15 amp circuit. There will be two fluorescent 2 bulb lites on switch 1 and four 2 bulb fluorescent lites on switch 2. There will also be an unswitched outlet for the garage door opener.

My question is whether I can run 1 neutral and 1 ground wire to share for all devices. It is my understanding that if it is one circuit in the conduit, they can safely share and meet code. This would mean I would have a maximum of 5 14 ga thn wires in the conduit at any point (N, G, H, H-sw1, H-sw2).

The attached diagram may or may not help - at the top where I labelled 14-2 - that is the romex wire feeding the box where the conduit starts.

Do I need to run multiple neutral and ground wires in the conduit?

 

[pattenp]

You do not need multiple neutrals and grounds. I assume you'll have junction boxes where the hots, neutrals and grounds will be split to the different fixtures.

 

[wyliesdiesels]

One EGC can actually be shared by multiple circuits as long as its sized correctly.

A neutral can be shared by 2 circuits as long as theyre fed by opposite phases/240v.

Of course this doesnt apply to the op with only one circuit but thought i would throw it out there.

 

[Tedison]

Thanks. Yes I am using junction boxes. Your help is appreciated.

 

[Nhrafan26]

One EGC can actually be shared by multiple circuits as long as its sized correctly.

A neutral can be dhared by 2 circuits as long as theyre fed by opposite phases/240v.

Of course this doesnt apply to the op with only one circuit but thought i would throw it out there.

So are you saying that if someone were to run 2 separate circuits for outlets contained in the same conduit and boxes that they would only have to run 2 black wires, 1 white and 1 green as long as each black is connected to a separate phase?

 

[Charles (in GA)]

So are you saying that if someone were to run 2 separate circuits for outlets contained in the same conduit and boxes that they would only have to run 2 black wires, 1 white and 1 green as long as each black is connected to a separate phase?

Lots of ifs to doing this. This is known as a Mutli-Wire Branch Circuit, or MWBC and is addressed by the code. Breakers must have the handles tied together (or better, simply use double pole breakers), There are other restrictions in the code I don't recall right now........... really best to stay away from a MWBC unless you really know what you are doing and it is a limited use, specialized circuit. Otherwise it will cause grief in the future.

Charles