nkalghatgi
Member
- Location
- Mechanicsburg, PA, USA
What is the difference between ground wire; for example in a conduit if there are 4 #2 and 1 #2 ground wire; and equipment grounding conductor.
Ground wire and Equipment Grounding Conductor
- Thread starter nkalghatgi
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jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Perhaps it is me, but I do not understand your question.
Can you clarify what you are asking please?
Can you clarify what you are asking please?
nkalghatgi
Member
- Location
- Mechanicsburg, PA, USA
That's fine. Perhaps I should re frame my question. What is a ground wire and what is an equipment grounding conductor.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Ground wire is not a term found in the NEC. The NEC refers to equipment grounding conductors, grounding electrode conductors, and various kinds of bonding conductors.
- Location
- Connecticut
- Occupation
- Engineer
The term "ground wire" really doesn't mean anything. It is commonly used to describe an equipment grounding conductor, eg, 2#12 + #12 ground.
If you have more than one equipment grounding conductor in a raceway, you might have an isolated equipment grounding conductor as well as the normal equipment grounding conductor.
nkalghatgi
Member
- Location
- Mechanicsburg, PA, USA
Bob, David,
I really appreciate your replies. That means the ground wire which we use in every conduit is actually Equipment Grounding conductor. As David stated 2#12 + #12 GND. In this case the #12 GND is actually equipment grounding conductor. Am I correct ? Please correct me if I am wrong.
I really appreciate your replies. That means the ground wire which we use in every conduit is actually Equipment Grounding conductor. As David stated 2#12 + #12 GND. In this case the #12 GND is actually equipment grounding conductor. Am I correct ? Please correct me if I am wrong.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
When laypeople say ground wire they mean the EGC.
May I suggest that you first try, and many still do not understand the proper terms, to understand the definitions.
Grounded Conductor. A system or circuit conductor that
is intentionally grounded.
Grounding Conductor, Equipment (EGC). The conductive
path(s) installed to connect normally non?current-carrying
metal parts of equipment together and to the system grounded
conductor or to the grounding electrode conductor, or both.
Grounding Electrode Conductor. A conductor used to
connect the system grounded conductor or the equipment to
a grounding electrode or to a point on the grounding electrode
system.
IMHO start with these 3 first and understand what they do. And do this before you add 'bonding' to your vocabulary.
Our host has many videos that can help you understand.
Watch this video for a start. I think that understanding the electrode's purpose will help with confusion as you try to understand grounding/bonding.
http://www.bing.com/videos/search?q...&mid=7CB3E5B43C5B20B2B49B7CB3E5B43C5B20B2B49B
PS you will see us (all of us) sometimes misuse one of these terms.
nkalghatgi
Member
- Location
- Mechanicsburg, PA, USA
Thank you. I really appreciate your reply.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The equipment grounding conductor is sized by T.250.122 while the grounding electrode conductor is sized per T.250.66
- Location
- Connecticut
- Occupation
- Engineer
Yes, in most cases "ground" refers to an equipment grounding conductor.
There are some instances where "ground" may refer to something other than an equipment grounding conductor. For instance, transformer secondary conductors from a transformer to the first disconnect may be something like 4#250+#2G. In this case, the "ground" refers to the equipment bonding jumper or supply side bonding jumper (depending on your Code cycle.) So you must know the context.
San -Brooke
Member
- Location
- USA
I believe this conversation coincides with many conversations I have had with apprentices over the years. Many times the confusion stems from using different terminologies which have the same meaning such as magnetic flux vs magnetic field, amperage vs current, emf vs voltage etc.... Leaving someone entering the trade totally confused unnecessarily.
- Location
- Illinois
- Occupation
- retired electrician
A lot of people including electricians who should know better use "ground" to refer to the grounded conductor, not the equipment grounding conductor.
One other thing to note, which works better if you know what is there but not the function, is:
The grounded conductor is usually white or grey
The equipment grounding conductor is typically bare or green or green with a yellow stripe, but could also be just a metal raceway.
The ground electrode conductor has no color requirement and could be bare. Some color it green. It usually isn't white.
Bonding jumpers are similar (no color requirement and could be bare. Some color it green. It usually isn't white.).
The grounded conductor is usually white or grey
The equipment grounding conductor is typically bare or green or green with a yellow stripe, but could also be just a metal raceway.
The ground electrode conductor has no color requirement and could be bare. Some color it green. It usually isn't white.
Bonding jumpers are similar (no color requirement and could be bare. Some color it green. It usually isn't white.).
glennspark
Member
- Location
- Leeds
is it earthing & bonding you are refering to here?...if so then both perform different functions
or is it main earthing conductors,CPCs or the earthing conductor in a flex that supplies a piece of portable equipment?
glennspark
Member
- Location
- Leeds
is this what we call in the UK `supplementary bonding conductors`...or more commonly refered to as `crossbonding`?
that is to say bonding 2 (or more) pieces of extranious conductive parts together so as to maintain the equepotential zone?
gas, water, oil etc being an example....
caus for a start if you have items of metallic equipment that doesn`t represent a path to earth that has been `bonded`such as stainless movable worktops in commercial kitchens etc (trust me..i`v seen it)...then its actualy introducing a potential...and as such i`v got really anoyed at this..(under my breath) when i`v encountered it.... and have disconnected it accordingly....
so dangerous...
kwired
Electron manager
- Location
- NE Nebraska
Part of the problem is all the terms in question have the same root word "ground" in them. People either don't learn or disregard other technical descriptors added to that root word and that is what causes confusion.
They see the root word ground in any of the terms being described here and that tends to give them all the same meaning in their mind. In most cases the particular conductor in question has same/close to same potential as true earth or "ground" but there is more to the particular function then just that aspect that often is disregarded.
A neutral conductor is almost always "grounded" but sometimes it isn't, that leads to confusion. A "grounded" conductor is not always a neutral conductor, that also leads to confusion in many cases.
They see the root word ground in any of the terms being described here and that tends to give them all the same meaning in their mind. In most cases the particular conductor in question has same/close to same potential as true earth or "ground" but there is more to the particular function then just that aspect that often is disregarded.
A neutral conductor is almost always "grounded" but sometimes it isn't, that leads to confusion. A "grounded" conductor is not always a neutral conductor, that also leads to confusion in many cases.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Very true. I read Requests to Remedy that say that the "outlets" are not "grounded". or "Ground all ungrounded receptacles".
There are a lot of places in the NEC where you could have bonding jumpers. They are between ground electrodes thereby creating the "ground electrode system". There is the main bonding jumper in a service disconnect between the grounded bar and the panel chassis. They could be between sections of pipe that have been isolated by a meter or dielectric fittings. They could go between a bonding bushing on a raceway fitting and the grounding bar or chassis/box.
I'm not sure we have a requirement to create a equipotential zone very often. Bonding a steel kitchen table would not be required unless it was "likely to become energized". If so, it needs to go to a panel ground system and not to earth. If it get energized to 120V or 240V, a connection to earth will most likely NOT trip an overcurrent device, so that is of no help. Yes, the grounding/bonding system can become energized under some fault conditions or during lightning storms, but that is what you need to bond things to. If things are correct, they overcurrent device should trip. Lightning is a different problem, but not sure what you can do about it, as it will do its own thing bonded or not.
glennspark
Member
- Location
- Leeds
no.
bonding is about keeping all extranious-conductive-parts at the same potential.
so for instance you have 2 (or more) extranious conductive parts in a location....by putting supplementary bonding between them you keep them at the same potential....so...say you get 230V on one...and 110 on the other....and you physically went across them...you`d get the difference..which would be 120V....so by applying crossbonding....you reduce the potential difference to a minimum..(in the UK we work to 0.05 ohms max)..
and in regards to what you refer to as the `ground electrode system`...and it being interlinked....what your doing is creating an `earth nest`...multiple parrallel paths bringing the Ra down...and thus the Ze....
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