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Power to my barn


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01-12-18, 10:39 AM   #1 (permalink)  
Power to my barn

New to the forum so don't beat me up to badly. I fall into the category of jack of all trades master of none. GA power connected power to my power pole which sits about 20 feet to where I would like to run power into my barn. The meter can and main box is a Eaton all in one. It is and has a 200 amp breaker installed. My barn is going to be a work shop to have misc power tools, compressor, portable welder, portable heaters and the other light duty stuff. Oh can't forget the frig for liquid energy.

The question is can I have a 200 amp sub panel in the barn. Does the sub panel have to have a breaker?
Does the sub panel have any restrictions on location in the barn?
What type of wire can I use to bury from the power pole to the barn?

FYI. I have done hours of research and see a lot of confusion. Then I figured I would read the NEC, thinking that may have been a mistake. More confused then ever. Thanks for any help that you can provide!

Gene

 
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01-12-18, 11:07 AM   #2 (permalink)  
You can install a 200A panel in the barn, and feed it with either a 200A breaker and corresponding 2/0 copper wire, or you can keep your 200A panel and feed it with 100 or 150A breaker/wire if you don't need that much power. If it's only you working there, I'd imagine even a 100A service would be sufficient.

The feeder will need to be either 4-wire underground-rated cable, or conduit with 4 wires (H-H-N-G) in it. For the short run, I'd probably go PVC conduit, but either way is code-compliant.

The panel in the barn will need a main breaker, as well as one (or two) grounding rods

The location of the panel in the barn is anywhere that has unoccupied space in front. I believe it's 36" wide, 30" deep, and 6' in height.


Good luck... what's the worst that can happen?

 
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01-12-18, 11:19 AM   #3 (permalink)  
Thank you for your response. The portable welder I have says 60 to 80 amps with 125 peak. This is the one thing I was concerned about. Was going to run a single circuit for the welder. What size breaker would you use for that circuit? Again thank you. A huge help.

 
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01-12-18, 11:25 AM   #4 (permalink)  
First thing is you need to do a load calculation to determine how much power you need in the barn. Add up all the potential loads that may be in use at one time, such as tools, lights, heat/AC. I believe you'll find you only need 100A at max. I think conduit is your best option since it's only 20ft. Once you know your load then you can size the wire and conduit.

 
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01-12-18, 11:28 AM   #5 (permalink)  
You need to consider the duty cycle of the welder to determine circuit size. What is the Brand and model of the welder? *****************************

 
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01-12-18, 11:34 AM   #6 (permalink)  
The welder is a Ironton 125 Flux-core. 115 volts, 125 amp

 
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01-12-18, 12:01 PM   #7 (permalink)  
The welder you have runs on a normal 120V 20A circuit. It wouldn't hurt to run a dedicated 120V 20A circuit for the welder. The high amperages you were stating are the output welding amperages and by themselves don't apply to the power circuit size required. The duty cycle is 20% @ 80A.

 
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01-12-18, 12:20 PM   #8 (permalink)  
Thank you for that. Like I said, jack of all trades master of none. This has been the most help I have had after a week of research. Thank you!!

 
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01-13-18, 11:28 AM   #9 (permalink)  
This has been the most help I have had after a week of research.

I didn't see this mentioned so add this to your research. You will need to install a ground bar kit in the subpanel in the barn. Panels come with a means of bonding the neutral bus to the panel box, it could be a green screw or a strap. but you do not want to do that, the neutral must be kept isolated from the grounded panel box. If there is a neutral bonding screw that comes with the panel, just throw it away. Connect your ground rod/rods at the barn to the ground bar that you installed with #6 copper wire. I prefer #6 bare stranded ground wire, but solid ground wire is also acceptable.

 
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01-14-18, 02:33 AM   #10 (permalink)  
I was going to use 4/0-4/0-4/0-2/0 aluminum to run from the power pole to the 200 amp sub panel installed inside the barn. Probably starting to over think this whole thing. With this wire I have 2 hots a netraul and a ground. So I guess my question is do I need to run the ground from the power pole where the Lightning rods are connected to the ground in the sub panel then back out to a new lightning rod. Or do I get the 3 wire and run a separate lightning rod wire just from the sub panel back outside to a new lightning rod? Thanks for the responses!

Gene

 
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01-14-18, 07:41 AM   #11 (permalink)  
You'll run your 4-conductor cable (or 4 wires in conduit) from your main panel to the barn. Each of the 4 wires get connected directly into the panel (separating the neutral and ground bars as Joe mentioned). Then, at the barn, you'll use a 6ga wire from the ground bar to at least one ground rod just outside the barn.

Your plan to use 4/0 wire is fine for a 200A supply, but you're really overdoing it. You can easily get by with a 100A feed for the tools you've mentioned. (You could probably even use a 60A without an issue). 200 is way over-done for your projected use.

Of course, there's no harm in overdoing it, other than cost. But do make sure you can get a 200A double-pole breaker for your main panel. They tend to be pricey and much less available than a 100A breaker. Also wrangling 4/0 aluminum wire will certainly be a challenge. Because of the short distance, it may be worthwhile spending a bit more and upgrade to copper, since it will be one size smaller and easier to bend.


Good luck... what's the worst that can happen?

 
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01-14-18, 08:36 AM   #12 (permalink)  
Actually 4/0 Al is rated at 180A when used for a sub feeder. If it was a main service feeder then different rules apply and 200A would be okay. If you are having an inspection done you may want to check with your inspector to see how they interpret the NEC with regards to the feeder sizing.

 
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01-14-18, 12:41 PM   #13 (permalink)  
Table 310.15(B)(6) allows the 4/0 aluminum as a 200 amp feeder.

 
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01-14-18, 01:34 PM   #14 (permalink)  
Again thank you! The main reason I was wanting 200 amps is because the barn has an upstairs. May need to somewhat make that part livable while we build our house. Then future guess house. I'm not giving up my workshop no matter what my wife say!

 
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01-14-18, 05:33 PM   #15 (permalink)  
Posted By: CasualJoe Table 310.15(B)(6) allows the 4/0 aluminum as a 200 amp feeder.
That table doesn't exist anymore and when it did it only applied to 3 wire service supplying the full service to a dwelling. My understanding under the intended use by the OP Table310.15(B)(16) is to be used.


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01-14-18, 05:55 PM   #16 (permalink)  
Or do I get the 3 wire and run a separate lightning rod wire just from the sub panel back outside to a new lightning rod?
Connecting a lightning rod to a panel seems like a very bad idea to me. I admit I've never read through NFPA 780, but it just strikes me as something that could be counterproductive.

 
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01-14-18, 06:20 PM   #17 (permalink)  
Grounding electrode system is connected at the first disconnect which is at the pole. This is the point at which the neutral is bonded. You will run #6 bare or stranded copper to two ground rods that are at least 6ft. apart from each other. You should also place ground rods off of the building subpanel. You do need to have an equipment ground conductor going from pole to building subpanel as said and the neutral is not bonded at the subpanel.

 
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01-17-18, 07:38 AM   #18 (permalink)  
Per the code it says "Not more than three current carrying conductors in raceway, cable or earth." So does that mean you can put the grounding wire in the conduit with the conductor wires or does it have to remain outside of the 3? Thanks

Gene

 
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01-17-18, 07:44 AM   #19 (permalink)  
Posted By: Ghammerstein Per the code it says "Not more than three current carrying conductors in raceway, cable or earth." So does that mean you can put the grounding wire in the conduit with the conductor wires or does it have to remain outside of the 3? Thanks

Gene
The ground wire is not considered as a current carrying conductor. The ground wire goes in the conduit with other conductors.

Code is not saying you can't have more than three. The table amp values apply to three or less, more than three you have to derate the amps.

 
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01-17-18, 09:09 AM   #20 (permalink)  
I figured as much but just want to be sure. Thank you everyone for your professional input. I'm sure I'll have more questions along the way.

Gene

 
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01-19-18, 06:07 PM   #21 (permalink)  
I've been doing way to much research. Was going to purchase the following to run from the pole to the barn. The panel will be installed inside.

https://www.lowes.com/pd/Southwire-4...e-Foot/3129329

The 200 amp panel will be located directly on the other side of the wall where the wire will be entering the wall. Does this wire have to be installed in conduit and the conduit attached directly to the panel? Read somewhere that it doesn't have the fire rating so it has to be in conduit. Also saw that it can run directly to the panel. Thanks to all.

Gene

 
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