Can I use 10-2 ufg wire to carry 20 amps for 40' ?

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  #1  
Old 02-28-15, 10:04 AM
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Can I use 10-2 ufg wire to carry 20 amps for 40' ?

I am looking to add another 20 amp breaker circuit to my panel and run it about 40' to supply an 20 amp 110 welder.

Will a 10-2 wire dedicated to one plug on its own breaker run 20 amps without dropping voltage or over heating?

The manual says if using an extension cord to use...

10 awg for -30'
8 for 30'-50'
6 for 50'+

Would what I'm doing be consider a ext cord? from what I read the 10-2 should be good for about 65' at 20 amps
 
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  #2  
Old 02-28-15, 10:36 AM
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That would work,why are you using 10/2 UF, is this underground?
Geo
 
  #3  
Old 02-28-15, 10:39 AM
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Its not going to be buried however it will be outdoors exposed and possibly buried at some point. it will run directly from home electric panel out to a garage in a box shed and end there. Should I set another grounding rod and ground the bare copper wire to it at the point of the shed?


and its on sale for $1 per foot
 
  #4  
Old 02-28-15, 10:41 AM
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12-2 will be fine for 20 amps. The welder would likely draw something less than 20 amps anyway. 40' is nothing for voltage drop.
 
  #5  
Old 02-28-15, 10:46 AM
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it states at high setting witch is 90 amps that it will draw a full 20 amps and will not work correctly if not supplied 20 amps....

I figured the 10-2 would be a safer bet.
 
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Old 02-28-15, 10:49 AM
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If it is going to draw a full 20 amps, the breaker might not hold. If you use #10 wire I would suggest installing a 30 amp breaker, which #10 is rated for.
 
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Old 02-28-15, 10:52 AM
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Thanks guys this makes me feel a little better about this, Ive replaced my 220 hot water heater, all outlets, switches and lights along with the complete electric panel out to the meter so I wont have an issue adding the 20 amp breaker I just was unsure on what wire to use to be safe.

I found one calc. that said 10-2 will run 20 amps 65' before any loss so I figured Id be safe with it.
 
  #8  
Old 02-28-15, 10:54 AM
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Have you considered using PVC and individual stranded conductors? 10/2 UF can be difficult for a novice to work with.
Just a thought
Geo
 
  #9  
Old 02-28-15, 10:58 AM
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good point Tolyn, 30 amp is what I think Ill do. I have some 20's on hand I could try but there not to much that I cant just grab a 30 amp breaker.
 
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Old 02-28-15, 11:02 AM
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Its not going to be buried however it will be outdoors exposed and possibly buried at some point. it will run directly from home electric panel out to a garage in a box shed and end there.
A couple of red flags there. what does "will be outdoors exposed" mean?

Second do you already have power to the shed perhaps for light or receptacles? If so you can not run a second power source to it. You will most likely need to install a subpanel.
Should I set another grounding rod and ground the bare copper wire to it at the point of the shed?
No. the purpose of a ground rod is to provide partial protection from atmospheric electrical charges at a breaker panel.

It almost sounds like you are making an extension cord. If so UF-b would not be used and it would not be hard wired at your panel.
 
  #11  
Old 02-28-15, 11:07 AM
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I did directional boring for years and did consider sliding the 10-2 uf through some 3/4" water line I have laying around, it just comes natural after utility work to do this almost basic instinct.

Can I ask why you consider it difficult to work with?

I've done a lot of wiring for different projects so fastening and twisting wires is not really new however I have never done any planning I have just replaced what was there with new, same spec. ( I don't go out to peoples homes or anything just stuff I've done on my own property over the years.)
 
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Old 02-28-15, 11:13 AM
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I did directional boring for years and did consider sliding the 10-2 uf through some 3/4" water line I have laying around, it just comes natural after utility work to do this almost basic instinct.
Waterline can not be used for conduit. If conduit is used best practice is to use individual conductors not cable.

UF can be hard to strip because the outer jacket is fused around the inner wires and is more difficult to pull in conduit.
 
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Old 02-28-15, 11:30 AM
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I had planned on dropping it into the area beneath a mobile home from the electric panel, where its pretty much exposed but not buried, then it has 2' before it hits the shed once outside the skirting of mobile home. So I was either going to run it over attached to a piece of lumber or bury it then have it on a 20 amp plug box setup, something like you would have ran outdoors for a pool or hot tub. just inside the shed with open (rock floor) failed to mention Id have a GFI type breaker. (setup to stay just be switched to off position when not in use.)

The existing power is just ran by a heavy extension cord however nothing more than a couple twist style lights and 4.5" angle grinder is used at most.

i figured Id be better off doing this than getting the correct sized extension cord and plugging it into the existing 20 amp circuit that has other things ran on it.
 
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Old 02-28-15, 11:33 AM
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I've seen the local power company use roll pex pipping to lay under sidewalks and other things as a conduit.
 
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Old 02-28-15, 12:10 PM
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Power companies are not bound by the NEC. However, likely what you saw was HDPE conduit.
 
  #16  
Old 02-28-15, 12:22 PM
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Could have been however seemed same as ours, Ill deal with the wire being harder to use that's ok with me, Guess bury it and not put in a conduit. If I used single stranded wire I still use 10awg wouldnt I ?
 
  #17  
Old 02-28-15, 12:33 PM
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If you already have power to the shed you can not run another cable to the shed. Do you already have power to the shed?

If you do have power already that needs to be abandoned. You will need to run at least 10-3 and install a subpanel. I would recommend 8-3 for the subpanel.

Even if you don't have power at the shed it still makes since to install a subpanel so you can have lights and receptacles.
 
  #18  
Old 02-28-15, 12:56 PM
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What do the welder specs state? Does it already have a cord and plug attached?
 
  #19  
Old 02-28-15, 02:43 PM
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It won't be single strand cable,it will be several strands to make up a 10 ga. Conductor.
Geo
 
  #20  
Old 03-03-15, 11:43 PM
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The welder is pre wired for 110 20 amp with a pretty small gauge.

New plan......

I picked up some 10/3 and plan to do a 30 amp sub panel in the temp shed setup. I have done a little more research and spoken to a few electrical guys. I will add a double pole 30 amp breaker in the main panel then run it less then 20' to a 30 amp sub panel located in the temp shed. I will then run 2 15 amp breakers for plugs and lights, along with one 20 amp breaker supplying a 20 amp plug for the welder with 10/2 within 15' of the sub panel.

I realize 30 amp panel would be pushing it if I was to run the 20 amp circuit at max and then run lights with something also running in the plugs on the other 15 amp circuits. The 20 amp circuit would not be used if anything more than a couple small shop lights was running on the other.

I understand that they should also be a main shut off in the sub panel, that matches the breaker on main panel that feeds sub panel, that all green screws should be removed from the sub panel and that the neutral and ground bars can not be connected in the sub panel, that the neutral can not be connected to the sub panel enclosure, and that the ground bar must be connected to the sub panel enclosure along with its own 8' ground rod connected to the ground bar with 6 awg wire....

Does this plan sound better? any issues with this? am I understanding this correctly? I hope I didn't open a new can of worms.
 
  #21  
Old 03-03-15, 11:46 PM
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this is a 2 or 3 year setup at most then it will be removed
 
  #22  
Old 03-04-15, 12:54 AM
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Yes, that is a better plan.
 
  #23  
Old 03-04-15, 06:45 AM
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Sounds good,don't forget you need GFCI protection for the receptacle's and 60 amp panel will be the smallest you will find, 30 amp will still be fine for the main.
Geo
 
  #24  
Old 03-04-15, 07:57 AM
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I found some 10-3 for $1.00 a foot same as the 10-2 so I figured why not and I think I have a 50 or 60 amp panel from a camper that was tore apart.

I plan on using gfi's I did forget to mention though. Thanks for all the help
 
  #25  
Old 03-04-15, 07:19 PM
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Welder cord is 6' long, reads 15 awg and 300v
 
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