Go Back   DIY Chatroom Home Improvement Forum > The Break Room > Off Topic

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

Closed Thread
 
Thread Tools Search this Thread Display Modes
Old 06-23-2010, 10:41 AM   #1
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,805
Rewards Points: 2,408
Question

Discussion on using red as a ground


Isolated ground receptacles are wired with two grounding conductors. One is for the metal box and the other is for the ground pin in the receptacle. A standard receptacle only uses one conductor for both the box and ground pin.

Why are you installing isolated ground receptacles? They are not needed if fed from a subpanel.

Perhaps the fact that in a subpanel the grounds are isolated from the neutrals has led to this confusion. This does not affect how a receptacle is wired.

__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now  
Old 06-23-2010, 12:45 PM   #2
Totally screwed together
 
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250
Default

Discussion on using red as a ground


Here is that isolated ground diagram you were trying to post: http://www.hubbellonline.com/wiring/bryant/pdf/g/g9.pdf

"Grounding of this device requires that an isolated ground
path be established from the receptacle grounding terminal to a suitable
equipment grounding point “upstream” from the device."
The text of this appears to say you can connect the isolated ground to the ground at the sub panel, as it is upstream.

Also, I've seen a bunch of people make the claim that it is against code to rename an otherwise presumably hot wire as ground... but no one has yet quoted the line number and text of the code that supports it. Which is odd considering how often I do see that stuff quoted here.

Playing devils advocate here, going with worst case scenario - what's the potential harm here? Say someone else blunders into his home later on and tries to wire another outlet off this one. They cut the wire and put on two recepticals thinking they now have two separate circuits instead of just one. One will work, the other wont. I'm not seeing where a harmful situation can occur.

xxPaulCPxx is offline  
Old 06-23-2010, 01:42 PM   #3
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,805
Rewards Points: 2,408
Default

Discussion on using red as a ground


Quote:
Originally Posted by xxPaulCPxx View Post

Also, I've seen a bunch of people make the claim that it is against code to rename an otherwise presumably hot wire as ground... but no one has yet quoted the line number and text of the code that supports it. Which is odd considering how often I do see that stuff quoted here.
Try Article 250.119.

250.119 Identi
fication of Equipment Grounding Conductors.

Unless required elsewhere in this
Code, equipment
grounding conductors shall be permitted to be bare,
covered, or insulated. Individually covered or insulated
equipment grounding conductors shall have a continuous
outer
finish that is either green or green with one or more
yellow stripes except as permitted in this section. Conductors
with insulation that is green, green with one or more
yellow stripes, or identi
fied as permitted by this section

shall be used only as an equipment grounding conductor
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now  
Old 06-23-2010, 02:39 PM   #4
Totally screwed together
 
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250
Default

Discussion on using red as a ground


... or identified as permitted by this section ...

Is there more text in this section? It sounds like they are saying that besides bare, green, green yellow stripe, there may be other ones that can also be permitted if they are correctly identified.
xxPaulCPxx is offline  
Old 06-23-2010, 02:45 PM   #5
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,805
Rewards Points: 2,408
Default

Discussion on using red as a ground


The rest of that section deals with conductors larger than #6, flexible cords ie extension cords, or multiconductor cables under maintenance or supervision.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now  
Old 06-23-2010, 03:35 PM   #6
Totally screwed together
 
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250
Default

Discussion on using red as a ground


It just seems strange that Neutral conductors can be relabeled Hot, Hot conductor can be relabeled Neutral, larger conductors can be labeled Neutral or Ground... but a Hot cannot be relabeled as Ground.

Huh?
xxPaulCPxx is offline  
Old 06-23-2010, 03:43 PM   #7
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,805
Rewards Points: 2,408
Default

Discussion on using red as a ground


White conductors in a cable assembly are the only allowance for that conductor to be re-identified. Flexible cords might be another time this is permitted.

I cannot think of where a hot is allowed to be re-identified as a neutral.

Larger conductors only come in black, so you are allowed to identify them as needed. Conductors smaller than #4 are available in the proper insulation colors as to function.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now  
Old 06-23-2010, 04:13 PM   #8
Totally screwed together
 
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250
Default

Discussion on using red as a ground


Quote:
Originally Posted by Scuba_Dave View Post
I have a black wire on my ground bus from the phone transformer which the PO connected
That's where I got that from.

You mentioned:
White conductors in a cable assembly are the only allowance for that conductor to be re-identified.

In this case it's a slightly different - I would say safer - example of a relabeled wire within a cable assembly. You are right, there is no specific allowance of the relabeled Hot within the assembly, but I'm not so sure this is actually violating the spirit of that same code. I think that is why 3 different inspectors cleared this specific setup.

Could you give an example of a future homeowner hooking this system up differently - think the red was hot instead of ground - and causing an unsafe situation?
xxPaulCPxx is offline  
Old 06-23-2010, 04:35 PM   #9
Member
 
Join Date: May 2009
Location: Brooklyn, New York (NYC)
Posts: 1,124
Rewards Points: 500
Exclamation

Discussion on using red as a ground


Paul CPxx; (Post 64). I'll just address the issue in your last paragraph; "Playing devil's advocate...... The worst case scenario can be someone thinking they have two outlets....! No. The worst case scenario can be much worse than that. The central fear in house/building wiring is that someone (who might not be very knowledgeable or will not be very careful) will, mistakenly energize a grounded wire. that's why the NEC is so strict about remarking an original color of a wire. Or using it for a different purpose than the (original) color indicates.
spark plug is offline  
Old 06-23-2010, 04:39 PM   #10
Totally screwed together
 
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250
Default

Discussion on using red as a ground


OK, how can you mistakenly energize a wire colored Hot but actually connected to ground?
xxPaulCPxx is offline  
Old 06-23-2010, 06:27 PM   #11
Member
 
Join Date: May 2009
Location: Brooklyn, New York (NYC)
Posts: 1,124
Rewards Points: 500
Exclamation

Discussion on using red as a ground


Quote:
Originally Posted by xxPaulCPxx View Post
OK, how can you mistakenly energize a wire colored Hot but actually connected to ground?
As I mentioned in the post; "People who are not very knowledgeable", who shouldn't go near electrical wiring but sometimes they do. The Code has to make provisions even for such a situation.!
spark plug is offline  
Old 06-23-2010, 06:43 PM   #12
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

Discussion on using red as a ground


Quote:
Originally Posted by xxPaulCPxx View Post
OK, how can you mistakenly energize a wire colored Hot but actually connected to ground?
And you are assuming that it will always stay connected
I ran into a lot of wires at my last house that were disconnected & hot
Scuba_Dave is offline  
Old 06-23-2010, 07:04 PM   #13
Totally screwed together
 
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250
Default

Discussion on using red as a ground


As I mentioned in the post; "People who are not very knowledgeable", who shouldn't go near electrical wiring but sometimes they do. The Code has to make provisions even for such a situation.!

And you are assuming that it will always stay connected. I ran into a lot of wires at my last house that were disconnected & hot.

There is no question people can do stupid things with their wiring. I've gotten the "Not fun funky tingle" many times on things that some other owner wired.

But you are all missing the point, which is to come up with a scenario where this red wire could be energized.

An actual hot wire misslabled as neutral or ground - yes, that is bad. But an actual GROUND wire misslabled as hot - does nothing. As a matter of fact, the only thing this setup could possibly do (say it got tied in with a bunch of other hots) is keep a breaker from being turned on. Plus, since it is an insulated path directly back to the ground bus there is no chance of it energizing anything else in its path - unlike the regular ground path.


I think you are all trying to make a boogie man out of a booger
xxPaulCPxx is offline  
Old 06-23-2010, 07:16 PM   #14
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Rewards Points: 2,000
Default

Discussion on using red as a ground


So its its tied into the grounds
Then someone connects the red to a hot feed either at the panel or at the outlet

How exactly do you not see that as a possibility ?
Scuba_Dave is offline  
Old 06-23-2010, 08:10 PM   #15
Totally screwed together
 
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250
Default

Discussion on using red as a ground


Then someone connects the red to a hot feed either at the panel
Please clarify that one, do you mean in they take the red from the ground bus in the service panel or the red from somewhere further down the line?

or at the outlet
OK, this is an easy one. You rewire for a standard duplex outlet, red and black are presumed hot, but red is actually a ground. In two receptical setup, you will have one duplex that works, and another one that doesn't. On the other one, white will be continuous with ground through a device. No energy flow.

Say both red and black to a single duplex outlet with the knockout removed. Again, one outlet works and the other one doesn't. You may have current flowing back to the shared bus via the red and white together, but then they are acting in parallel from the same start point to the same end point - again, they are insulated all the way back to the shared bus so no problems.

Say red and black to the same duplex and the knockout isn't removed. The current will flow for a millisecond before the breaker trips, but again, the current flow is along an entirely insulated path so no problems.

How about trying to use the red, black, and white for a 240v outlet? Well, the device would work poorly, since only one leg is actually energized, if it worked at all without immeditaly tripping the breaker.

In all these situations, you would have to have someone working with only live circuits all the time for them to not notice that the circuit only has one single pole breaker instead of two. You also have to remember that they had to come across the green taped red in order to work with it (just as you would have to come across the black taped white in a switch circuit). When working with only live circuits, you quickly discover what is grounded and what isn't when you touch the live wire to it!


Last edited by xxPaulCPxx; 06-24-2010 at 12:22 AM.
xxPaulCPxx is offline  
Closed Thread


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 Ground Problem cabinetman Electrical 15 01-28-2010 05:55 PM
Lost my Ground jodywoj Electrical 10 12-20-2009 07:37 PM
Live ground wire in dryer Retired sailor Electrical 10 05-04-2009 04:26 PM
12v DC ground to chassis ground of a 120V appliance? pcampbell Electrical 12 02-17-2009 10:24 PM
Grounding VS Bonding BillyD Electrical 24 06-22-2008 01:14 PM




Top of Page | View New Posts

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