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 01-13-2009, 06:59 AM   #1
Newbie
 
Join Date: Jan 2009
Posts: 22
Share |
Default

neutral size question


I'm replacing my oven, which had 30 amp service, with a slightly larger one that requires 40 amp service (all 240 vac).

My original service was 240 vac single phase, using 2 10 awg stranded with a 12 awg neutral, in 1/2 inch emt conduit.

According to a NEC table I looked at, I can pull up to 3 8 awg thhn wires in 1/2, which looks like a full plate to me. Can I use the same rule of thumb as the original installer, and use two 8 awg conducters with a 10 awg neutral, as I already have an all metal conduit ground path?

tommy potatoes is offline   Reply With Quote
Old 01-13-2009, 08:00 AM   #2
My License Ain't 4 Sale..
 
Join Date: Feb 2008
Location: Atlanta, Ga/Hamilton, Al
Posts: 1,813
Default

neutral size question


Quote:
Originally Posted by tommy potatoes View Post
I'm replacing my oven, which had 30 amp service, with a slightly larger one that requires 40 amp service (all 240 vac).

My original service was 240 vac single phase, using 2 10 awg stranded with a 12 awg neutral, in 1/2 inch emt conduit.

According to a NEC table I looked at, I can pull up to 3 8 awg thhn wires in 1/2, which looks like a full plate to me. Can I use the same rule of thumb as the original installer, and use two 8 awg conducters with a 10 awg neutral, as I already have an all metal conduit ground path?
If its 240, why do you need a neutral?

InPhase277 is offline   Reply With Quote
Old 01-13-2009, 08:51 AM   #3
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,932
Default

neutral size question


Quote:
Originally Posted by InPhase277 View Post
If its 240, why do you need a neutral?
A 240 volt only branch circuit does not need a neutral. If 120 volt usage is also intended then you need a neutral; the ground does not suffice. A 240 volt (stove) receptacle that has a neutral contact must be fed with a 120/240 volt circuit (with neutral). Most electric stoves also require 120 volts including for clocks, timers, etc.

Last edited by AllanJ; 01-13-2009 at 08:57 AM.
AllanJ is offline   Reply With Quote
Old 01-13-2009, 09:15 AM   #4
Member
 
Join Date: Dec 2007
Location: Baltimore, MD
Posts: 1,802
Default

neutral size question


Quote:
Originally Posted by AllanJ View Post
A 240 volt only branch circuit does not need a neutral. If 120 volt usage is also intended then you need a neutral; the ground does not suffice. A 240 volt (stove) receptacle that has a neutral contact must be fed with a 120/240 volt circuit (with neutral). Most electric stoves also require 120 volts including for clocks, timers, etc.
I think he knows that. He's asking the OP why he needs a neutral if he states the oven is 240V load.
jerryh3 is offline   Reply With Quote
Old 01-13-2009, 09:25 AM   #5
Newbie
 
Join Date: Jan 2009
Posts: 22
Default

neutral size question


My old oven had the neutral hooked up, and the installation instructions for the new one call for it, too.. And yes, everything with electronic displays most likely utilizes the neutral to provide 120vac service to the LVPS.. I understand that much.. So, since the neutral is not called in to play for more than 120V mains for a LVPS, I guess 10 awg is plenty, eh?
tommy potatoes 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
Electrical connections TazinCR Electrical 11 01-07-2009 07:10 PM
Will reverse polarity trip breaker?? Duane 70 Electrical 60 12-05-2008 10:18 PM
Which neutral is which? Jeremy Hillary Boob, PhD Electrical 5 11-28-2008 11:11 AM
Basement Renovation Question KUIPORNG Remodeling 234 08-26-2008 08:19 AM
Ground rod or not? brotherman Electrical 30 07-15-2008 04:58 PM




Top of Page | View New Posts

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