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 05-24-2009, 08:21 AM   #1
Newbie
 
Join Date: May 2007
Posts: 23
Share |
Default

Trying to Understand 240v wire selection


Hey Folks,

Concerning installing 240v power I've noticed sometimes its required to have a 3 wire/wgrnd and other times it seems only a 2 wire/wgrnd is required. Can someone explain when and why there are sometimes different requirements? Is it an Amp related reason?

It helps when I can understand the concept/reasoning.

Thanks

Bama is offline   Reply With Quote
Old 05-24-2009, 08:36 AM   #2
My License Ain't 4 Sale..
 
Join Date: Feb 2008
Location: Atlanta, Ga/Hamilton, Al
Posts: 1,813
Default

Trying to Understand 240v wire selection


Quote:
Originally Posted by Bama View Post
Hey Folks,

Concerning installing 240v power I've noticed sometimes its required to have a 3 wire/wgrnd and other times it seems only a 2 wire/wgrnd is required. Can someone explain when and why there are sometimes different requirements? Is it an Amp related reason?

It helps when I can understand the concept/reasoning.

Thanks
It is a voltage question. 240 V equipment needs two wires and a ground. But 120/240 V equipment needs three wires and ground. Your electric clothes dryer, for instance is NOT a 240 V appliance. It is 120/240 V. The dual voltage rating means that the appliance itself has some internal equipment that use 120 V, and other parts that use 240 V. A neutral is needed in this case to supply the 120 V loads.

Wire size, on the other hand, is determined by amps. An amp is an amp, no matter what voltage.

InPhase277 is offline   Reply With Quote
Old 05-24-2009, 08:38 AM   #3
Member
 
Bigplanz's Avatar
 
Join Date: Apr 2009
Location: Louisville KY
Posts: 517
Default

Trying to Understand 240v wire selection


Quote:
Originally Posted by Bama View Post
Hey Folks,

Concerning installing 240v power I've noticed sometimes its required to have a 3 wire/wgrnd and other times it seems only a 2 wire/wgrnd is required. Can someone explain when and why there are sometimes different requirements? Is it an Amp related reason?

It helps when I can understand the concept/reasoning.

Thanks
Two hots and a neutral are needed for a 120/240 circuit, like a dryer. Part of the dryer runs on 120, while the heating element requires 240. The neutral allows for a return path for the 120V portion of the circuit. A 'straight' 240V circuit requires two hots and a ground. The two hots complete the 240V circuit, no neutral is required. The ground is required for both, of course.
Bigplanz is offline   Reply With Quote
Old 05-24-2009, 09:36 AM   #4
Newbie
 
Join Date: May 2007
Posts: 23
Default

Trying to Understand 240v wire selection


Thanks. I understand now. I appreciate you taking the time.
Bama 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
New Stove, old wires - 2 wire vs 3 wire DIYGST Electrical 22 03-02-2009 04:13 PM
hooking up dryer....bronx ny code SURFBUG Appliances 6 10-14-2008 09:41 PM
Dryer Grounding??? Traci_howdyadothat Electrical 7 05-27-2008 01:14 PM
Installing Fluorescents in Garage rzrbkpk Electrical 26 04-08-2008 09:00 PM
Stranded wire on screw connections BigJimmy Electrical 7 01-19-2008 02:42 PM




Top of Page | View New Posts

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