Need help wiring three 220V circuits to a junction box

[strutaeng]

Hello, I need some help wiring three circuits from my breaker box, about 15' away to my patio cover. I have

1. 220V 50A circuit for my welder (I have 8/2 romex)

2. 220V 30A for a clothes dryer (I have 10/3 romex)

3. 220V 20A for air compressor (all I have is 14/2 romex, but can buy 12/2)

I have run 1 1/4" PVC conduit to this juntion box: http://www.homedepot.com/p/6-in-x-6-in-x-4-in-NEMA-3R-Enclosure-RSC060604RC/100567817

From the junction box I will come out to the individual receptacles.

I don't know if I can run all romex in that conduit. Can I strip the sheathing? What about the ground? It seems unnecessary to run three grounds?

I recently rewired my home and have left over romex. I'd hate to buy a whole roll of THHN in all colors for 15'.

Any advice is greatly appreciated.

 

[bjcouche]

Well, since you're using PVC conduit I'm assuming this is outdoors. Since it's outdoors, you are NOT allowed to use Romex, either in it's sheath or stripped it doesn't matter that it's in conduit. IF you had direct burial rated Romex, then you'd be OK to run it in conduit with it's sheath because the direct burial is rated for wet locations. You cannot strip the sheath off of romex because the individual conductors are not printed with wire ratings (manufacturer, awg, etc.)

So, you must buy new wire, either direct burial romex or individual colors of thWn wire.

Brian

 

[strutaeng]

I see. Yes, this is all outdoors. I'll have to buy THWN.

What about ground and common wires?

Can I run a Green and White 8 Ga. to my junction box and then branch out?

I'd rather do it right the first time!

Thanks.

 

[cbogg]

How about some pics? I'm assuming you're not ever planning on using more than one thing at a time? Why the junction box and not a small exterior sub panel? That way if need be you could add a plasma at some point which would need the compressor and another outlet.

 

[Charles (in GA)]

Do not attempt to run any type of Romex, even the outdoor version know as UF, in conduit. The fill calculations will basically stop you dead if you do them. Most UF is flat, but Chapter 9 says that with multiwire cable in conduit, you take the WIDEST measurement of the cable (if it is flat or oval) and do your fill calculations as if it were ROUND using that measurement to calculate a CIRCULAR AREA dimension for the wire, in determining conduit fill.

Charles

 

[strutaeng]

How about some pics? I'm assuming you're not ever planning on using more than one thing at a time? Why the junction box and not a small exterior sub panel? That way if need be you could add a plasma at some point which would need the compressor and another outlet.

Sorry, I forgot to take some photos this morning.

Here's the whole story: I just bought this little house and had it rewired completely. It has a detached garage with 120 V and my original plan was to run a sub panel for additional 220V capacity (dryer, welder, air compressor, etc.) This would require running about 35' underground. For the time being I decided to run three circuits to the patio cover so that wife could do laundry and I could have power for my upcoming welding project.

Since it is only a 15' run along the wall from the main box, I figured I would just run it directly.

At this point it seems prudent to run wiring with capacity for the three circuits loaded simultaneously.

Thanks

 

[theoldwizard1]

I see. Yes, this is all outdoors. I'll have to buy THWN.

What about ground and common wires?

Can I run a Green and White 8 Ga. to my junction box and then branch out?

I ASSUME that the purpose of the junction box is merely a place to break out the 3 sets of wires that were in a common conduit from 3 different 2 pole breakers into 3 smaller conduits !

The welder and the compressor circuits do not have a neutral (white). The dryer may or may not depending on the vintage (you may have have to upgrade the dryer pigtail to 4 wire because you can no longer buy 3 prong dryer receptacles).

Run separate grounds for each.

 

[strutaeng]

I ASSUME that the purpose of the junction box is merely a place to break out the 3 sets of wires that were in a common conduit from 3 different 2 pole breakers into 3 smaller conduits !

Correct. I didn't want to have 3 conduits running side by side

The welder and the compressor circuits do not have a neutral (white). The dryer may or may not depending on the vintage (you may have have to upgrade the dryer pigtail to 4 wire because you can no longer buy 3 prong dryer receptacles).
4 wire as I recall. It's a NEMA 14-30R. The welder plug is actually a NEMA 6-50

Run separate grounds for each.

Will Do!