4 wire or 3 wire?

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Old 12-13-14, 04:00 PM
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4 wire or 3 wire?

Hello all,

I have 200amp meter main with distribution lugs (post mounted/freestanding), my house has been wired and now I am ready to pull the line in underground from the meter main to the house panel. There are ground rods at the meter main and also a ufer ground at the house panel. Do I only need to install two hot legs and a neutral or do I also need a ground wire ran from the meter main to the house panel? The meter main is approx. 50' from the house panel.

Thanks!
 
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Old 12-13-14, 05:13 PM
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Welcome to the forums!

Is sounds to me that your pole mounted panel is the main for the property. That would make the house panel a sub panel detached from the main "building". You need 4 wires.
 
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Old 12-13-14, 09:53 PM
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Thanks for the response, I know I can buy some 4/0 4/0 2/0 aluminum URD at the local home improvement store. Would it be acceptable to buy a separate #4bare solid copper wire to run with the triplex in the same 2" conduit? This is a 200amp house panel that it will be feeding.
 
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Old 12-14-14, 05:58 AM
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3-wire URD is intended for direct burial and is extremely difficult to pull into conduit because of the way the three conductors are twisted. I would suggest just buying the 4-wire mobile home feeder and direct burying it to the house.

Shop 4/0-4/0-4/0-2/0 Aluminum Mobile Home Feeder Service Entrance Cable (By-the-Foot) at Lowes.com

If the soil is rocky and it must be in conduit, I wouldn't even attempt to pull it into anything smaller than 3" PVC.
 
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Old 12-14-14, 07:43 AM
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If using a complete conduit and not just conduit sleeves when coming out of the ground it will be individual conductors.
 
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Old 12-14-14, 02:19 PM
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Great thanks, Does anyone know if the first 18" of conduit coming up out of the ground needs to be schedule 80? Right now I am planning on using schedule 40 grey electrical pvc conduit but I thought I read somewhere that the first 18" needs to be schedule 80 pvc? This will be the stand pipe coming up out of the ground and going to the bottom of the LB.

Thank you!!
 
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Old 12-14-14, 02:25 PM
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Just to add a little info to my last question, this is not on the utility company side, this is after the meter so I am looking for NEC requirements to the last question.

Thanks again
 
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Old 12-14-14, 03:18 PM
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If the area where the conduit is to be installed is subject to physical damage (vehicle traffic, weed whips, rambunctious kids, etc.) then Sch 80 is required. Otherwise Sch 40 is fine.
 
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Old 12-14-14, 04:41 PM
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If the area where the conduit is to be installed is subject to physical damage (vehicle traffic, weed whips, rambunctious kids, etc.) then Sch 80 is required.
Is that an NEC requirement or just a good recommendation?
 
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Old 12-14-14, 05:35 PM
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Alot of times it is the POCO's call,riser must be away from traffic on the pole and a min. Of 8' above grade, but in this case the 8' would not apply.
Geo
 
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Old 12-14-14, 08:06 PM
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Alot of times it is the POCO's call,riser must be away from traffic on the pole and a min. Of 8' above grade, but in this case the 8' would not apply.
Geo
The utility company isn't involved with this, this is between the disconnect at the pole and the subpanel at the house.
 
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Old 12-15-14, 08:04 PM
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Is that an NEC requirement or just a good recommendation?
It is a NEC requirement per 352.10(F)

Conduits installed on poles are required to be PVC Sch 80, RMC, IMC, or equivalent. 300.50(C)
 
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Old 12-15-14, 08:15 PM
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Thanks TI. I wasn't familiar with that provision.
 
 

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