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Looking to confirm plan for running power to detached garage

Looking to confirm plan for running power to detached garage

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  #1  
Old 07-18-11, 11:08 AM
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Looking to confirm plan for running power to detached garage

Hello, I'm going to be running power to my detached garage which is about 200ft from the main panel. It's a 100 amp panel with plenty of room to install a 50 amp breaker for the garage. I have a few questions that hopefully someone can help me out with.
First the wire I think I need is 6/3 romex from the main to the sub in the garage, is this the correct gauge and number of wires needed?

I will be installing 1.5 pvc in a 20" trench from foundation to garage. The one item I'm not sure on is this. The wire from the main panel will need to travel about 15' through a block foundation that is filled in with dirt. There is zero room for me to enter this space but I was able to feed a string through so I can pull the wire. This area fully enclosed except for a vent (wire will be run through vent) do I need to run the wire through PVC in this area and connect that PVC to the pipe in the trench? If I do need to connect the pipe this could pose a roadblock. The area where the wire comes out is only big enough to feed the wire and I doubt that I could get an 1.5" pipe through.

Thanks in advance for any help!
 
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  #2  
Old 07-18-11, 11:27 AM
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First the wire I think I need is 6/3 romex from the main to the sub in the garage, is this the correct gauge and number of wires needed?
You NEVER use romex outdoors or in wet/ddamp locatons. You can use UF cable or THHN/THWN in conduit. You need 3 conductors plus ground.
I will be installing 1.5 pvc in a 20" trench from foundation to garage.
18'' for Conduit, 24" for cable.
The one item I'm not sure on is this. The wire from the main panel will need to travel about 15' through a block foundation that is filled in with dirt. There is zero room for me to enter this space but I was able to feed a string through so I can pull the wire. This area fully enclosed except for a vent (wire will be run through vent) do I need to run the wire through PVC in this area and connect that PVC to the pipe in the trench? If I do need to connect the pipe this could pose a roadblock. The area where the wire comes out is only big enough to feed the wire and I doubt that I could get an 1.5" pipe through.
You can fish the cable through there. What type of vent is there? You may or may not be able to fish the cable through the vent legally.
 
  #3  
Old 07-18-11, 11:31 AM
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Romex is never used outside. If not in conduit except for short pieces for protection you use UF cable. If you use conduit as you propose you would use individual THWN wires not cable. Because of distance and depending on actual load you probably need to use at least #4. 1-1/2" conduit is over kill. 1" or 1-1/4" should be fine.

but I was able to feed a string through so I can pull the wire. This area fully enclosed except for a vent (wire will be run through vent) do I need to run the wire....
What kind of vent? I doubt you can use it for this purpose.
 
  #4  
Old 07-18-11, 11:35 AM
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Thanks for the info, so for the wire I need 2 hots, neutral and a ground?

The vent is pretty much chicken wire over a concrete foundation block turned so the three holes in the block are facing out not up. There appears to be a foundation piling right on the other side which makes it difficult to run a piece of rigid pipe around.
 
  #5  
Old 07-18-11, 11:39 AM
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Originally Posted by haukers View Post
Hello, I'm going to be running power to my detached garage which is about 200ft from the main panel. It's a 100 amp panel with plenty of room to install a 50 amp breaker for the garage. I have a few questions that hopefully someone can help me out with.
A. 200 feet length is pretty good distance and I will like to know if you going to run welder in the garage or not if not it will be ok with voltage drop but if you need a full 50 amp service then you have to bump up the conductor size to #4(copper ) or #2 alum to advirt the voltage drop issue.

And just be aware that all 120 volt circuit have to be GFCI protection there is no extempts anymore unless stated otherwise with your local code so check this out first.

First the wire I think I need is 6/3 romex from the main to the sub in the garage, is this the correct gauge and number of wires needed?

A. First of all you can not direct bural the romex cable it is not legit so either UF { underground feeder } DB {Direct bural cable } or run this in the conduit with THHN/THWN conductors and be aware you will need four conductors , hot et hot et netural et ground. { typically Black , Red , White and Green }

The conduit can be 18 inch deep but DB cables have to be in 24 inches.


I will be installing 1.5 pvc in a 20" trench from foundation to garage. The one item I'm not sure on is this. The wire from the main panel will need to travel about 15' through a block foundation that is filled in with dirt. There is zero room for me to enter this space but I was able to feed a string through so I can pull the wire. This area fully enclosed except for a vent (wire will be run through vent) do I need to run the wire through PVC in this area and connect that PVC to the pipe in the trench? If I do need to connect the pipe this could pose a roadblock. The area where the wire comes out is only big enough to feed the wire and I doubt that I could get an 1.5" pipe through.

A. if just a 8X16 vent window { for ventation in crawl space only } it can be done anyway but some local code may not allow this fashon so if you can open up vent window and punch a hole to run the conduit all the way thru then you should not have a issue with it.

If that part of HVAC then gernally no it is not legit in most case { return air have limited rules so hard to say unless I did see it }



Thanks in advance for any help!
All my answer in Bleu

Merci.
Marc
 
  #6  
Old 07-18-11, 11:45 AM
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Thanks for the help!

The vent is pretty much chicken wire over a concrete foundation block turned so the three holes in the block are facing out not up. There appears to be a foundation piling right on the other side which makes it difficult to run a piece of rigid pipe around.
 
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Old 07-18-11, 11:54 AM
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Assuming you use conduit you could use a section of weather proof flexible metallic conduit (AKA Seal-tite) between two sections of PVC.
 
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Old 07-18-11, 12:16 PM
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If you use sealtite, you will need to ground it.
 
  #9  
Old 07-18-11, 12:30 PM
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Originally Posted by ray2047 View Post
Assuming you use conduit you could use a section of weather proof flexible metallic conduit (AKA Seal-tite) between two sections of PVC.
OK, sounds like I will need to figure a way to get conduit through this area.

Thanks to all for the advice!
 
  #10  
Old 07-18-11, 01:30 PM
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I would not recommend UF cable exposed in a tight crawlspace like that. Rodents love to chew up UF cable for some reason. You will get much more protection if you can get a piece of conduit through the space.
 
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