AWG 12 for shop wircuit

John Reeves · 07-06-2006, 02:03 PM

I am tossing out a need/request for wire for adding a few circuits for my shop. I want to add at least two 220 volt and one 110 volt lines. I will run the wires through PVC conduit so I do not need ROMEX. Shop has sheet rock up so this is on top of the wall.

If anyone has any wire left over from their projects, I would take it off of your hands.

I just priced LOWES. $0.14/lf for a 500 ft spool ($70) or $0.28 if they have to cut it.

I would like to get black, green and white so I can keep track as I make the connections.

John

Steve D · 07-06-2006, 02:59 PM

Originally Posted by JMR2

so I can keep track as I make the connections.

John

That would be good, and I believe code requires the wires be color coded or identified.

Terry · 07-06-2006, 06:31 PM

John,

I have the colors you need in rolls of #12 THHN. I have used about 25' of each color if your interested in THHN. It is not the solid type but stranded kind. If you are running receptacles that might not be what you want. PM me if your interested. I will be at Woodcraft in Raleigh for the Dust collection Demo and could bring it then. Just a thought! Terry

John Reeves · 07-06-2006, 08:44 PM

Terry,

Thanks but I do not know enough to know if #12 THHN will work. As a matter of fact, I do not know what THHN means.

When is the Dust collection event at Woodcraft?

John

DaveT · 07-06-2006, 08:59 PM

It is at 1PM on Saturday. Some are meeting early to go for lunch.

Dave

Gofor · 07-06-2006, 10:18 PM

THHN is stranded wire as opposed to solid wire normally used in house wiring. Both will carry the same voltage and amperage, but solid is required by code in some locations. One of the reasons is because of the termination points (ie, wire-nut connectors, connections on outlets, etc.) It is easy to cut or fray the ends of stranded, thus giving less wire at the termination (less capacity without overheating) or cause a short. So it is a safety issue especially when inspectors can't check every outlet, etc. Stranded usually also costs more. It is easier to pull thru conduit, etc, and is less prone to breaking under repeated bending, and will carry high frequency better, which is why it is used in electronic and audio equipment/wiring. Also, if its a 20 amp circuit, #12 is required. If 15, at least #14.
Disclaimer: I am not an electrician but all this info is easily verifiable.
HTHs

junquecol · 07-06-2006, 11:26 PM

THHN and THHW refer to type of insulation found on wire. Last year these same rolls sold for $29.00. You only need one color and a couple of rolls of colored elect. tape. THHN, and THHW are suitable for use in conduit. Check out article in recent Popular Woodworking mag. on efficent shop wiring. Using a two pole breaker and a neutral wire in addition to two hot leads, you can have both 220 and 110 from same breaker. Because you are using PVC, you will have to pull a ground.

NCPete · 07-06-2006, 11:28 PM

Bruce, which issue was that? I remember having seen it in the local bookstores, but it was on a night SWMBO had not given me an allowance for such purchases

Terry · 07-07-2006, 06:48 AM

John,

I will put the rolls of THHN in my truck and bring them to Raleigh Saturday. If you happen to come to Woodcraft and want to see what I have that wil be OK. If not no biggie! Terry

NZAPP1 · 07-07-2006, 08:50 AM

The 12 AWG THHN that Terry has will work fine. When terminating the wire at a device with stranded wire I tin the end with solder to insure that you have no stray strands sticking out. I would also wrap the tined end around the screw and tape the device after all connections are made. You will need to pull a ground and if your shop is in the garage all 110V outlets will need to be GFIC protected and should be 48 inches above the floor. Nick

JohnsonMBrandon · 07-07-2006, 09:11 AM

I personally would use solid wire. Its definitely a personal preference thing for me, but it is more fool proof. No strands hanging out as others have mentioned, and things of that nature. I probably spent 400-500 dollars on wire and odds and ins wiring my shop recently. I must have guestimated pretty close though...I only had about 10' of wire left over. Its your place so I guess do what you are most comfortable with.

wapitiscat · 07-07-2006, 10:15 AM

Originally Posted by junquecol

Using a two pole breaker and a neutral wire in addition to two hot leads, you can have both 220 and 110 from same breaker. Because you are using PVC, you will have to pull a ground.

Isn't this how dryer circuits are wired? Could you use this strategy to run 220 to a tool and then run 110 from there to a receptacle? If so, how?

Todd (another electrocution waiting to happen

)

junquecol · 07-07-2006, 10:03 PM

Originally Posted by wapitiscat

Isn't this how dryer circuits are wired? Could you use this strategy to run 220 to a tool and then run 110 from there to a receptacle? If so, how?

Todd (another electrocution waiting to happen )

Yes, but- older ones used ground for neutral, except in mobile homes. The reason was if ground conductor broke, entire frame and skin of home could become electrically "hot". Reach up and grab door knob and get it! Newer design uses 4 wires- two hots, a neutral, and a ground. Motor and timer motor are 110 v while heating element is 220 v. Original article appeared in Popular Woodworking, Oct 2005, pages 82-85. Ignore what author says about DC control, and instead use system from FWW, Aug 2000. You couild actually run a recpt from dryer, but wiring wouldn't be right size. Dryer circuit is 30 amps and uses 10 gauge wire, while 110 outlets are either 15, or 20 amp and use #14, or #12 respectively. All wiring sizes indicated are using copper conductors. Several have used dryer plug to add a "plug in panel box", but I am not really wild about this idea. But sometimes you have to do what you gotta do.

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