Conduit Q

Reply

  #1  
Old 02-05-06, 08:29 AM
Member
Thread Starter
Join Date: Nov 2005
Location: Midwest
Posts: 80
Conduit Q

Ive posted here and got some excellent advice, I thank you all for that! I've been busy getting our new manufactured home all hooked up to the various utilities, so please bear with my questions.

First, I had the electrical inspector out last Wednesday to look over how I wired the meter socket and connected it to the load center. The house came already wired and inspected, I just had to hook it up to power. I passed that inspection OK, and the power is on. I'll need to have him back to inspect whatever else I wire, and I want to keep him happy, so here's the question.

What do I need to know about putting NM wire in conduit? I've got a water heater and water softener to hook up. I've ran the NM cable across the ceiling in the basement, and I'd like to drop the cables down the wall in conduit to where they need to be. Is 10/2 cable OK in 1/2" metal conduit? It fits in there fine and is not tight. I'm assuming I'd need some sort of bushing on the end of the conduit to protect the cable. What (if any) issues might come up during the inspection if I do this?

thanks,
Joe Michel
 
Sponsored Links
  #2  
Old 02-05-06, 08:49 AM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
What you are doing is a sleeve for protection. This is very typical for this type of installation.
Just use a change over fitting at the top. This is a conduit fitting on one side and an NM fitting on the other. They are available everywhere.
 
  #3  
Old 02-05-06, 08:58 AM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
1/2" combo fitting
<img src="http://s7ondemand1.scene7.com/is/servlet/izoom/DoItYourself/u220353?wid=200&hei=200&fmt=jpeg&qlt=75,0&op_sharpen=0&resMode=trilin&op_usm=0.0,0.0,0,0&iccEmbed=0">
 
  #4  
Old 02-05-06, 09:02 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
Originally Posted by Mach1
I passed that inspection OK, and the power is on.
Congratulations!




> What do I need to know about putting NM wire in conduit?
Uh-oh. There are at least three different answers.

> Is 10/2 cable OK in 1/2" metal conduit?
Some people say no. I recently saw 14-2 NM inside 1/2" cpvc.


> I'm assuming I'd need some sort of bushing on the end of the conduit
> to protect the cable.
A cable clamp.

> What (if any) issues might come up during the inspection if I do this?
Grounding fault path, heat dissipation, mechanical strength, support, how mounted.

A good solution is to run the entire length inside conduit.

My solution for you if you like NM conduit:

You have how much NM cable you need to complete the run into a junction box plus 6".

Strip the sheath for the entire length that runs inside conduit, starting 1 to 10' before making vertical drop.

Put a 1/2" NM clamp box connector at the usual place (about 1/2" onto sheath).
I assert that it does not require bonding.

Screw a female adapter onto box connector.

Add horizontal section of conduit glued into adapter.

Provide necessary support for cable and conduit across ceiling.

Glue on sweep-ell-plus-couplers (or conduit body) to turn down toward floor.

Measure, cut, and glue on vertical conduit length.

Glue male adapter onto end.

Pull into junction box through knock out. Add locknut.

Put box over nipple from water heater electrical access and secure with locknut. Make necessary electrical connections.



Don't forget to mark white wire as red (or other suitable color not green, orange, gray...).
 
  #5  
Old 02-05-06, 09:08 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
Originally Posted by Speedy Petey
What you are doing is a sleeve for protection.
Do you consider it adequate that it is supported at the top by the NM cable itself and at the bottom by the box?

Or should there be any other means of support?
 
  #6  
Old 02-05-06, 09:13 AM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
When did I say that???
He merely asked if he could put 10/2 in a conduit sleeve, and what protection was needed at the top. I told him.

The poster installed his own service, I assumed he would know to strap the conduit.
 
  #7  
Old 02-05-06, 09:24 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
Originally Posted by Speedy Petey
I assumed he would know to strap the conduit.
I assumed that it is in free space where there is nothing to which to fasten it or he would just be running NM cable down the wall.
 
  #8  
Old 02-05-06, 09:26 AM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
Originally Posted by Mach1
I've ran the NM cable across the ceiling in the basement, and I'd like to drop the cables down the wall in conduit to where they need to be.
I guess he could strap it to the wall.......
 
  #9  
Old 02-05-06, 10:31 AM
Member
Thread Starter
Join Date: Nov 2005
Location: Midwest
Posts: 80
Thanks for the replies! I knew there had to be some sort of fitting to secure the NM cable to a conduit. The guy at the hardware store sold me the wrong stuff. They didn't have what I was looking for. I'll look elsewhere.

Just to clarify, the cables will be secured with nail-on plastic staples on the floor joists prior to entering the conduit to continue down the basement wall.

thanks again,

Joe Michel
 
  #10  
Old 02-05-06, 10:55 AM
Member
Join Date: Oct 2005
Location: USA
Posts: 1,151
I just passed an inspection with 10/2 NM w/G in 1/2" EMT. I used the plastic push-on fitting at the end of the conduit, where the NM enters. I wasn't aware of the metal clamp-type. I would like those better, especially for the 12/14awg that would benefit from support in a vertical drop. I was able to do a couple of 90 bends with lube, I wouldn't recommend much more. That's prolly why some folks may frown on 10/2 in 1/2". I also hadn't even considered stripping back the NM jacket for that run. I'm sure its safe, just wasn't sure that NM conductors are marked sufficiently for use in EMT (they aren't marked at all, as I recall).
Of course, just cause I passed an inspection in my area, doesn't mean you will...
 
  #11  
Old 02-05-06, 11:25 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
Originally Posted by telecom guy
wasn't sure that NM conductors are marked sufficiently for use in EMT (they aren't marked at all, as I recall).
I've never seen PVC jacketed NM-B cable in which the individually insulated conductors were not all identified throughout their length as THHN/THWN-2.
 
  #12  
Old 02-05-06, 11:32 AM
Speedy Petey's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Nov 2003
Posts: 2,455
That's funny. I have never seen where they were marked individually. Only the sheathing.
This is why we cannot strip the wires out and use them alone.
 
Reply

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


Thread Tools
Search this Thread
Display Modes
'