Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-06-2009, 03:07 PM   #16
Member
 
Join Date: Apr 2007
Posts: 2,231
Share |
Default

driving wire through buried conduit


so will someone actually say if buried conduit is actually a wet or dry location ?

amakarevic is offline   Reply With Quote
Old 07-06-2009, 03:09 PM   #17
General Contractor
 
MacRoadie's Avatar
 
Join Date: Apr 2008
Location: Orange County, CA
Posts: 76
Default

driving wire through buried conduit


Quote:
Originally Posted by amakarevic View Post
so will someone actually say if buried conduit is actually a wet or dry location ?
Buried conduit, even conduit "buried" in a concrete slab, is a wet location.
MacRoadie is offline   Reply With Quote
Old 07-06-2009, 04:37 PM   #18
Member
 
Join Date: Oct 2007
Posts: 2,294
Default

driving wire through buried conduit


Electrical 101. Buried conduit = wet.

The Journeyman from Missouri needs to go back to school



I" is plenty big.

Four 90's max but shoot for 2 or 3.

Avoid close back to back 90's.

Use 45's or sweeping bends in the conduit whenever possible.

Pull the wire before you bury the conduit......just in case.

A bit of wire lube is really helpful.
220/221 is offline   Reply With Quote
Old 07-06-2009, 04:38 PM   #19
Member
 
Join Date: Apr 2007
Posts: 2,231
Exclamation

driving wire through buried conduit


thanks everyone.

amakarevic is offline   Reply With Quote
Old 07-06-2009, 06:55 PM   #20
Journeyman Wireman
 
Join Date: Jun 2009
Location: Missouri
Posts: 90
Default

driving wire through buried conduit


Quote:
Originally Posted by InPhase277 View Post
Article 100: Definitions. Location, Wet: Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.

There are some of the sharpest electricians here, and some real good DIY'rs as well. This isn't like Mike Holt's forum where you would be ridiculed and beat down over it, but you got to stay on your toes, because you WILL be called out on it. I think it is fair to say that even the most experienced of us have learned something new at one time or another from this lowly DIY forum.
The wire inside the pipe is NOT in direct contact with the earth. UF would be overkill, more expensive and harder to work with.

Last edited by jbberns; 07-06-2009 at 06:57 PM.
jbberns is offline   Reply With Quote
Old 07-06-2009, 07:04 PM   #21
General Contractor
 
MacRoadie's Avatar
 
Join Date: Apr 2008
Location: Orange County, CA
Posts: 76
Default

driving wire through buried conduit


Quote:
Originally Posted by jbberns View Post
The wire inside the pipe is NOT in direct contact with the earth.
No, it's not, but the NEC doesn't care about the conduit. The code is referring to the conditions INSIDE the conduit, hence the reference to saturation (a point you actually made in your first post) and if you go to 310-8, it tells you what type of conductors can be used.

If the inside of a conduit is a dry location, then why would 310-8 even bother to list the type of conductors approved for wet locations? By your logic, any conductor can be used in a conduit buried below grade as the conduit should be considered a dry location.

Exactly when would you even use THHW if not in a conduit?
MacRoadie is offline   Reply With Quote
Old 07-06-2009, 07:13 PM   #22
Journeyman Wireman
 
Join Date: Jun 2009
Location: Missouri
Posts: 90
Default

driving wire through buried conduit


Quote:
Originally Posted by MacRoadie View Post
No, it's not, but the NEC doesn't care about the conduit. The code is referring to the conditions INSIDE the conduit, hence the reference to saturation (a point you actually made in your first post) and if you go to 310-8, it tells you what type of conductors can be used.

If the inside of a conduit is a dry location, then why would 310-8 even bother to list the type of conductors approved for wet locations? By your logic, any conductor can be used in a conduit buried below grade as the conduit should be considered a dry location.

Exactly when would you even use THHW if not in a conduit?
My basement is underground. Do I need to rip out the romex and run uf inside of pvc?
jbberns is offline   Reply With Quote
Old 07-06-2009, 07:23 PM   #23
Electrical Contractor
 
kbsparky's Avatar
 
Join Date: Sep 2008
Location: Delmarva
Posts: 3,360
Default

driving wire through buried conduit


Most of the time, --- over time --- condensation can accumulate inside of buried conduits, even if they are watertight. They can fill up with water.

We run into this all the time, especially when removing conductors that have been in underground conduits for years. They come out soaking wet.

You are not permitted to install "dry locations only" wire into a wet location, which includes the insides of buried conduits.
__________________
-KB

Life is uncertain -- eat dessert first!!
kbsparky is offline   Reply With Quote
Old 07-06-2009, 07:29 PM   #24
My License Ain't 4 Sale..
 
Join Date: Feb 2008
Location: Atlanta, Ga/Hamilton, Al
Posts: 1,813
Default

driving wire through buried conduit


Quote:
Originally Posted by jbberns View Post
My basement is underground. Do I need to rip out the romex and run uf inside of pvc?
Your basement is not a enclosed area 1" in diameter. You can write the code making panels and submit a change recommendation, but until then, the NEC is clear that a conduit in the ground, or in concrete in contact with the ground, is considered a wet location. So inside your basement, the concrete is in direct contact with the earth, so any wiring inside the concrete itself, would need to be appropriate wiring for a wet location. Wiring in wooden stud walls is NOT in contact with the earth or with the concrete, so , unless you are using a spray washer in your basement, you can use everyday normal romex, NM-B.

I don't know about you, but I have pulled countless runs of wiring in pipe, in which each end of the pipe is inside a building, yet when the fish tape and head come out of the pipe, it is wet. You pull romex in underground pipes if ou want to, but I guarantee you that stuff is like a wick and will suck up water like a sponge. Conduits being wet locations is also one reason why the code requires them to be sealed if unused or after wire installation. Water will condense inside a panel through an underground feeder conduit. Usually have to pack them with duct seal. Or foam.
InPhase277 is offline   Reply With Quote
Old 07-06-2009, 07:32 PM   #25
My License Ain't 4 Sale..
 
Join Date: Feb 2008
Location: Atlanta, Ga/Hamilton, Al
Posts: 1,813
Default

driving wire through buried conduit


Quote:
Originally Posted by jbberns View Post
The wire inside the pipe is NOT in direct contact with the earth. UF would be overkill, more expensive and harder to work with.
Right, I wouldn't pull UF into the conduit. I would pull THHN/THWN.
InPhase277 is offline   Reply With Quote
Old 07-08-2009, 06:36 PM   #26
WFO
Member
 
Join Date: Nov 2008
Posts: 89
Default

driving wire through buried conduit


Quote:
Originally Posted by kbsparky View Post
Most of the time, --- over time --- condensation can accumulate inside of buried conduits, even if they are watertight. They can fill up with water.

We run into this all the time, especially when removing conductors that have been in underground conduits for years. They come out soaking wet.

.
Bingo!
WFO is offline   Reply With Quote
Old 07-08-2009, 06:48 PM   #27
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Default

driving wire through buried conduit


Quote:
Originally Posted by jbberns View Post
The wire inside the pipe is NOT in direct contact with the earth. UF would be overkill, more expensive and harder to work with.
Quote:
Originally Posted by InPhase277 View Post
Right, I wouldn't pull UF into the conduit. I would pull THHN/THWN.
I use TWHN too
But from a DIY point of view - if the person is only making one run:
In order to do that they need black #12, white #12 & green #12
Many people won't go & find/buy individual wires
And then they need to know the exact length of wires or buy extra
OR buy a roll of each - which gets expensive
They believe the pre-made UF is "better"
Or they already have UF & don't want to buy more wire

I have way too much wire "in stock" at home

Scuba_Dave is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wire, Conduit and Voltage Drop Questions kikdrum Electrical 9 03-01-2009 06:50 AM
Burial wire and a seeming difference of opinion... SxS Electrical 19 02-24-2009 09:16 AM
Conduit for #6 wire joey b Electrical 13 11-22-2008 12:13 PM
Installing Fluorescents in Garage rzrbkpk Electrical 26 04-08-2008 09:00 PM
pulling wire through old flexible conduit cbray Electrical 1 05-20-2005 03:55 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.