How deep to bury line?

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Old 09-19-09, 09:58 AM
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How deep to bury line?

Just bought a portable Generator. Going to run it from behind the shed to power the house during outages. It's about 100 feet away. How deep does my trench have to be? Can I just lay the line in the trench or do I use some sort of piping too? Would this be a local code question I need to ask at Town Hall?
 
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Old 09-19-09, 10:32 AM
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It isn't as simple as all that. You can either use UF cable buried at least 24" or conduit with THWN. Size of the wire depends on the output of the generator.

Unless the generator has provision for direct wiring and smaller ones usually don't, . you will need to terminate the conduit or cable in a junction box near the generator and transition to SORW cable with an appropriate male plug.

At the other end the cable or conduit will terminate at your transfer switch. If you are using an interlock and inlet it will have to terminate in a Jbox where it transitions to an SORW cable with a female plug suitable for your inlet.
 
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Old 09-19-09, 10:42 AM
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To clarify a bit. Not using the line that came with the Generator.

The plan is to run a line from the transfer switch to a remote inlet box. The box will be installed on the shed 100 feet away. I know I need line from Home Depot or Lowes (not sure on size of that line I need though) Someone told me 6 gauge I think? Generator is 7250 Watt Running 8600W Surge.

Wasn't sure how deep the line had to be buried. I don't know what THWN or SORW mean.
 
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Old 09-19-09, 10:44 AM
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Direct burial cable/wire = 24"
PVC conduit = 18"
Rigid metal conduit or IMC = 6"

It will also depend on if you are going under concrete, driveway, etc. The above measurements are for in a yard and to the top of the pipe or cable.
 
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Old 09-19-09, 10:56 AM
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Thanks. No local codes I need to worry about? Already had digsafe out to check the yard for anything else....
 
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Old 09-19-09, 11:13 AM
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I don't know what THWN or SORW mean.
THWN is what you use in the conduit. SORW is heavy duty flex cable such as used in extension cords.
Generator is 7250 Watt Running 8600W Surge.
Assuming you mean at 240v you will need 3 #8 and a #10 (copper) THWN.
 
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Old 09-19-09, 12:50 PM
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Originally Posted by canyon View Post
No local codes I need to worry about?
You would have to contact them to find out if there are any local requirements.
 
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