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 04-30-2011, 08:03 AM   #1
Member
 
Join Date: Aug 2009
Location: Maryland
Posts: 45
Rewards Points: 25
Default

EGC question?


Does the EGC (equipment grounding conductor) have to be run with the ungrounded conductors of a line-to-line circuit (208 V)back to the originating breaker panel? or can it be just run to another piece of equipment that is fed from another panel?

edit: Also, could you provide a NEC code reference?

Thank you,
Mike


Last edited by Mike2401; 04-30-2011 at 08:19 AM.
Mike2401 is offline   Reply With Quote
Old 04-30-2011, 08:21 AM   #2
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Rewards Points: 500
Default

EGC question?


Not to side-step your question, but why would a 208V circuit, normally found in a commercial setting, be run without a EGC in the first place? What kind of wiring method was used?

__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
Old 04-30-2011, 08:49 AM   #3
Member
 
Join Date: Aug 2009
Location: Maryland
Posts: 45
Rewards Points: 25
Default

EGC question?


Quote:
Originally Posted by SD515 View Post
Not to side-step your question, but why would a 208V circuit, normally found in a commercial setting, be run without a EGC in the first place? What kind of wiring method was used?

In an apartment building, the a/c condenser units are grouped together in the rear of the buildings. A unit was being serviced and the a/c tech said that the egc was open somewhere in the interior walls of the building between the panel and the unit's disconnect so he was going to run a #10 conductor to the adjacent a/c's units disconnect and connect to its egc which is fed from another apartments panel. He said that this would solve the problem temporarily until the wiring could be repaired properly.

Mike
Mike2401 is offline   Reply With Quote
Old 04-30-2011, 10:19 AM   #4
" Euro " electrician
 
frenchelectrican's Avatar
 
Join Date: Apr 2006
Location: WI & France { in France for now }
Posts: 5,369
Rewards Points: 2,000
Default

EGC question?


Before myself or SD515 can comment little more on this one what type of wiring methold it did use like NM cable or EMT conduit or others ??

Once we know what type of wiring methold it did bring to the disconnect swtich we will go from there.

Merci,
Marc
__________________
The answer will be based on NEC ( National Electrical code ) or CEC ( Cananda Electrical code ) or ECF ( Electrique Code France )
frenchelectrican is offline   Reply With Quote
Old 04-30-2011, 10:34 AM   #5
Member
 
Join Date: Aug 2009
Location: Maryland
Posts: 45
Rewards Points: 25
Default

EGC question?


Quote:
Originally Posted by frenchelectrican View Post
Before myself or SD515 can comment little more on this one what type of wiring methold it did use like NM cable or EMT conduit or others ??

Once we know what type of wiring methold it did bring to the disconnect swtich we will go from there.

Merci,
Marc
NM cable from panel to a/c disconnect which is mounted on the brick exterior wall and then UF from a/c disconnect to a/c compressor.

What if it would have been EMT? Would that make it legal?

Mike
Mike2401 is offline   Reply With Quote
Old 04-30-2011, 11:35 AM   #6
I=E/R
 
a7ecorsair's Avatar
 
Join Date: May 2010
Location: Minnesota
Posts: 2,052
Rewards Points: 1,000
Default

EGC question?


Quote:
Originally Posted by Mike2401 View Post
A unit was being serviced and the a/c tech said that the egc was open somewhere in the interior walls of the building between the panel and the unit's disconnect
Not to doubt the condition of the EGC, but why was the A/C tech checking the condition of the ground path since the ground path will not affect the operation of the condenser?
The first question would be, is there an EGC coming into the disconnect.
Second question would be, if this is in romex as stated, how would the ground wire get broken without any damage to the other conductors in the romex cable.
a7ecorsair is offline   Reply With Quote
Old 04-30-2011, 12:14 PM   #7
Member
 
Join Date: Aug 2009
Location: Maryland
Posts: 45
Rewards Points: 25
Default

EGC question?


Quote:
Originally Posted by a7ecorsair View Post
Not to doubt the condition of the EGC, but why was the A/C tech checking the condition of the ground path since the ground path will not affect the operation of the condenser?
I have no idea.

Quote:
Originally Posted by a7ecorsair View Post
The first question would be, is there an EGC coming into the disconnect.
Yes..and there is no continuity between the end of the egc in the disconnect and the end of the egc in the panel.

Quote:
Originally Posted by a7ecorsair View Post
Second question would be, if this is in romex as stated, how would the ground wire get broken without any damage to the other conductors in the romex cable.
Again, I have no idea.

My original question was:
Does the EGC (equipment grounding conductor) have to be run with the ungrounded conductors of a line-to-line circuit (208 V)back to the originating breaker panel? or can it be just run to another piece of equipment that is fed from another panel?


Mike

Last edited by Mike2401; 04-30-2011 at 12:29 PM.
Mike2401 is offline   Reply With Quote
Old 05-02-2011, 09:55 AM   #8
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Rewards Points: 500
Default

EGC question?


Quote:
Originally Posted by Mike2401 View Post
My original question was:
Does the EGC (equipment grounding conductor) have to be run with the ungrounded conductors of a line-to-line circuit (208 V)back to the originating breaker panel? or can it be just run to another piece of equipment that is fed from another panel?
Mike


Sorry for the delay Mike. I checked various sections of the code, long story short, my interpretation tells me…Yes, the EGC has to be run with the circuit conductors. To be honest with you, I haven’t yet found any actual wording that says it has to terminate at the point of origin. I may have missed something. For the most part, I believe their intention is that it would, in order to provide a low-impedance, effective ground fault path, that cannot be disturbed by disconnecting another piece of equipment not associated with that circuit.

Personally, I would not advocate the use of another piece of equipment fed from another panel as the EG path. True both panels should bonded back at the same service disconnect, but I don’t believe that is the intention of the code.

Referencing NEC 2008, 250.2, 250.4, 250.118, 250.134, 300.3(B) as applied to your situation.

I am more than willing to listen to anyone else that wants to chime in on this…

The following was taken from ECMWEB.COM, posted 4/23/2004

In general, under what condition in an alternating current feeder or branch circuit is an equipment grounding conductor permitted outside of a cable or raceway?
A) under no condition
B) as part of a high-impedance grounded neutral system
C) on ground-fault circuit interrupter protected circuits
D) any time
Answer: A
Explanation: There are five sections of the 2002 NEC that don't permit an equipment grounding conductor to be installed on the outside of a cable or raceway:
250.118
250.134(B)
300.3(B)(2)
300.5(I)
300.20(A).
It has been proven that separating the equipment grounding conductor from the circuit conductors greatly increases the impedance of the circuit. Separation of these conductors will increase the inductive reactance of an AC circuit, which increases grounding circuit conductor impedance values. The impedance of the equipment grounding conductor of a circuit should be kept as low as practicable. Excessive separation can render an adequately sized equipment grounding conductor ineffective in carrying enough current to operate the circuit overcurrent protective device in a reasonable amount of time to clear the fault.
__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
The Following User Says Thank You to SD515 For This Useful Post:
Mike2401 (05-02-2011)
Old 05-02-2011, 11:28 AM   #9
Member
 
Join Date: Aug 2009
Location: Maryland
Posts: 45
Rewards Points: 25
Default

EGC question?


Kyle,

Thank you very much for the detailed explanation. I genuinely appreciate it.

Is the 2002 NEC, that you referenced, available online for viewing?

Regards,
Mike
Mike2401 is offline   Reply With Quote
Old 05-02-2011, 12:37 PM   #10
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Rewards Points: 500
Default

EGC question?


You're welcome

Try
http://en.wikipedia.org/wiki/National_Electrical_Code

I Googled ‘national electrical code online’ Not 100% sure you can access the code online without paying for it. I’ve not tried before to read the code book online, I use my printed edition. You might check your local library…see if they have a current edition you can look at.

The first part of my post is actually my digging through the 2008 NEC. The second was a clip from ECMWEB.COM and their referencing of the 2002 code. ECM’s website is a great place to look also. They use references of code, and explain a lot of things in ‘lay-mans’ terms, and intention of the code.

While changes occur in between code cycles, much of the basic, fundamental things stay the same. But it’s always best to check the current code edition your area is on.

And P.S. You had a great question here...made me dig alot...trying to not leave any stone unturned.

__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
The Following User Says Thank You to SD515 For This Useful Post:
Mike2401 (05-02-2011)
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
DRIcore question trailblazer1229 Flooring 0 02-24-2010 09:25 AM
3 Phase meter socket question a320200 Electrical 4 12-11-2009 12:45 AM
An unasked question is the only dumb question jackie treehorn Kitchen & Bath Remodeling 1 09-20-2009 08:24 PM
A question about water preassure. reasonforseason Plumbing 5 04-14-2009 04:36 PM
Basement Renovation Question KUIPORNG Remodeling 234 08-26-2008 08:19 AM




Top of Page | View New Posts

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