Running direct burial wire through conduit

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  #1  
Old 03-20-15, 08:15 PM
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Running direct burial wire through conduit

Is there a trick to simplify running Direct Burial Wire through PVC conduit? I'm wiring a sub panel to a detached garage and I'll be installing the conduit a I wire it. Should I run the wire through the PVC as I go or should I install all the conduit then pull the wire? I'm running 4/3 w/ Ground so 4-4 Guage wires wrapped in one insulation. Thanks for any ideas...
 
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  #2  
Old 03-20-15, 08:23 PM
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It sounds like you're running cable in conduit and you can't do that - needs to be individual wires like THWN.

Can you clarify?
 
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Old 03-20-15, 08:45 PM
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I'm running 4/3 w/ Ground so 4-4 Guage wires wrapped in one insulation.
If this is direct burial rated cable it must UF-B cable. This is extremely hard to pull into conduit. If you are going to try it, make sure your conduit is at least two sizes larger than normal and use lots of lube. I'll bet this will be the last time you try it.
 
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Old 03-20-15, 08:57 PM
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Individual conductors are the way to go with a conduit system.
 
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Old 03-21-15, 04:30 AM
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I am wiring a sub panel in a detached garage. The Main Panel in the house is 150 Amp, I'm installing a 60 Amp double pole breaker in the main panel. The sub panel will have a 60 Amp Main Breaker and 2-15 Amp & 2-20 Amp breakers. As for the feeder line, I was planning on "Double Protecting" myself by running direct burial cable inside conduit. My concern is exactly what you guys are saying, it's hard as heck to do that. I just wired my own basement w/ 14/2 w/ ground (about 300 ft of wire) and some of it was crazy to pull through floor joists. So, I'm assuming running 4/3 with Ground is virtually impossible. So, should I be running 4-single wire through the conduit? Is that enough protection? My run is approx. 30 feet (underground) and my concern is not the straight conduit, it's the entrance into the garage which is a 90 degree fitting....
 
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Old 03-21-15, 09:23 AM
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So, should I be running 4-single wire through the conduit? Is that enough protection?
Yes and Yes. That is the usual way and provides the necessary protection.
 
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Old 03-21-15, 10:38 AM
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I'm running 4/3 w/ Ground so 4-4 Guage wires wrapped in one insulation.
Looking at the online Southwire catalog, 6-3 is the largest UF-B cable made for direct burial. I don't know what type 4-3 w/Ground cable you had planned to use, but I doubt it is direct burial rated.


So, should I be running 4-single wire through the conduit? Is that enough protection?

Yes and Yes. That is the usual way and provides the necessary protection.
I agree with Ray.
 
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Old 03-22-15, 07:29 PM
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So when running the individual cables (#4 red, black, white, green), how should it be run from the main panel box to where it exits the house? It will run approx. 30 feet inside the house from the main panel to the exit to the outside conduit. does it have to e in conduit inside the house?
 
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Old 03-22-15, 07:34 PM
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Individual conductors need to be in a complete conduit system.
 
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Old 03-22-15, 07:59 PM
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So when running the individual cables (#4 red, black, white, green),
Those are wires not cables. You can transition to cable once it is in the house.
 
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Old 03-22-15, 09:36 PM
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Your equipment grounding (green) needs to be no larger than #8 for up to a 100 ampere circuit breaker.
 
  #12  
Old 03-23-15, 04:48 PM
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Thanks Furd, I thought I had this all figured out, but... I calld the local electrical supply shops looking for 4-#4 copper THWN Wires (1 Green, 1 White, 1 Black, 1 Red) assuming 1 neutral, 1 ground, 2 hot and none of them had #4 THWN in any color except black. Am I looking for the wrong stuff? I'm running a 60 Amp Breaker in the Main Panel, then a 60 Amp Sub panel 100 feet away in a detached garage. Is the 4 - #4 single THWN conductors run in conduit not the correct gauge? Should I be using #6 conductors?
 
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Old 03-23-15, 04:59 PM
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Non white wires #6 and smaller can not be redesignated as neutral. #4 can be so often just black is used. You need to put bands of white tape on both ends. No need to mark one black red. You can have two blacks. You only need #8 for ground and that should be available in green.
 
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Old 03-23-15, 07:07 PM
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Thanks Ray2047, so I can use 2- Black #4 (Hots), 1- Green #8 (Ground), and you're saying to use 1- Black #4 (Neutral) and color the ends white, correct? Does that pass code?
 
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Old 03-23-15, 07:16 PM
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Yes. that passes code and is commonly done. (That is why it is hard to find anything but black #4 or larger.)
 
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Old 03-23-15, 07:37 PM
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Thanks Ray2047, that explains a lot...
 
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Old 03-24-15, 10:16 AM
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so I can use 2- Black #4 (Hots), 1- Green #8 (Ground), and you're saying to use 1- Black #4 (Neutral) and color the ends white, correct?
It's just 100 feet, I'd use #6s rather than #4s and a #10 ground.
 
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Old 03-24-15, 10:59 AM
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#6 will be available in color so a white and two blacks.
 
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