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Question:

Electrical conduit and wiring?

I am wiring a new screened-in porch, and i need to run wires to a switch box through conduit. I plan to run conduit from the basement out to the box and then into the ceiling, where i will then change the wire into reqular Romex when it is in the enclosed ceiling. I need to know how many wires will fit in the conduit. I was planning on using 1 inch conduit from and to the switch box. I am using 14-2 wire through a 1 conduit. thanks

Answer:

Find someone with an UGLYS book. Short of that, use the KISS principal and use 1/2 EMT. it can contain 6 no.12.
14/2 romex wire can not be ran through a conduit,unless the outer casing has been striped off.Usually a THHN type wire is run through the conduit to a junction box and then connected to romex wires.The chart in my code book shows a maximum of 39 number 14 THHN wires in a 1 conduit.This is a 1987 edition code book and I think the codes for this has changed so now you wouldn't be able to put in that many wires.I would guess that you are not going to pull that many circuits for it to be a problem though.
wHalf inch conduit is fine. Rather than try bending the conduit, you could run straight to lengths to ells with covers. The wire will push for a considerable distance through straight runs. If a ground connection is available at the point from which you take power, it would be best to run a green ground wire in the conduit, and use Romex with a ground. Also you might consider using number 12 wire all the Way, if you are connecting to a 20 amp breaker or fuse. That way you could put a receptacle out there too.
your question is how many wires will fit in the conduit? your wires should occupy 75% or 3/4 max of the diameter of your conduits (to allow movement) what i do is to take couple of wires and place it inside the conduit, using a plier i push all the wires to one side if they occupy 3/4 of the conduit then thats the max. (some times G14 and 16 wires go into a single conduit). so this is the practical way of measuring how many wires go into your conduit. yeah the other guy is right (you also can use PVC flexible conduits, so you can wire your screen directly to your panel switch. if your local electrical code permits you)
you can fit 14/2 into 3/8 conduit although not recommended. What I suggest for a pro looking job (assuming you're bending) is get 1/2 conduit and run a string/cable for pulling, and either pull the wires, or pre pull or route your pull string before you bend. If you're going with the easier don't pre pull, just fit up and cut first, then run everything you can before you connect the conduit (unless you're going steam proof) In my mind, the best way to do conduit wiring (which is great) is to have the fewest joins possible (remember, i'm industrial) so you have the fewest breaks, the fewest chances of corrosion, and the least chances of pinching in threaded joints. The trick is when bending by the way, is normal conduit has a 32% spring back, so take it a little further than you want to bend it, and low and behold, it will be darn close to exactly what you want that and bending tubing, expecially conduit, is not an exact science.

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