kennym
Member
- Location
- New Jersey
I have a 1800 amp 120/208 service, with 5-sets of 500kcmil conductors feeding it, what would the minimum wire size
grounding conductor size
- Thread starter kennym
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
Re: grounding conductor size
Is this a service or a feeder?
Don
Is this a service or a feeder?
Don
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Re: grounding conductor size
It sounds to me that the question relates to a Grounding Electrode Conductor that is to be installed for a service. If that is true, you are at the maximum required size of 3/0 copper, per Table 250.66. But there are similar sounding terms (e.g., ?Equipment Grounding Conductor?) and similar terms that do not sound similar (e.g., ?Main Bonding Jumper?), and different rules apply to them. So I repeat Don?s question (Is this a service or a feeder?), and add one of my own: ?If you mean a service, do you mean the wire from the ground terminal to planet Earth or the wire from the ground terminal to the neutral terminal?
It sounds to me that the question relates to a Grounding Electrode Conductor that is to be installed for a service. If that is true, you are at the maximum required size of 3/0 copper, per Table 250.66. But there are similar sounding terms (e.g., ?Equipment Grounding Conductor?) and similar terms that do not sound similar (e.g., ?Main Bonding Jumper?), and different rules apply to them. So I repeat Don?s question (Is this a service or a feeder?), and add one of my own: ?If you mean a service, do you mean the wire from the ground terminal to planet Earth or the wire from the ground terminal to the neutral terminal?
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: grounding conductor size
I agree that more information is needed. Since Charlie brought it up, I might add that if a main bonding jumper is needed it will have to be 350 KCMIL, which is 12.5% of 2500 KCMIL.
I agree that more information is needed. Since Charlie brought it up, I might add that if a main bonding jumper is needed it will have to be 350 KCMIL, which is 12.5% of 2500 KCMIL.
kennym
Member
- Location
- New Jersey
Re: grounding conductor size
This is a service
This is a service
- Location
- Illinois
- Occupation
- retired electrician
Re: grounding conductor size
Ken,
We still need to know exactly what conductor that you are asking about.
Don
Ken,
We still need to know exactly what conductor that you are asking about.
Don
G
Guest
Guest
Re: grounding conductor size
The thread topic is:
[ September 18, 2003, 07:44 PM: Message edited by: awwt ]
The thread topic is:
[ September 18, 2003, 07:44 PM: Message edited by: awwt ]
pierre
Senior Member
- Location
- Westchester County, New York
Re: grounding conductor size
By using the term grounding conductor is not enough. Not all people mean the same thing when they say grounding conductor. Using Article 100 and the .2 in 250 come up with the proper term and we can better explain, and the guys/gals reading can also better understand what is being asked/explained.
Pierre
By using the term grounding conductor is not enough. Not all people mean the same thing when they say grounding conductor. Using Article 100 and the .2 in 250 come up with the proper term and we can better explain, and the guys/gals reading can also better understand what is being asked/explained.
Pierre
- Location
- Illinois
- Occupation
- retired electrician
Re: grounding conductor size
Wayne,
I do not know what the poster is asking about. There are many types of "grounding conductors" and until he tells us the function of the conductor in question, we cannot give an answer.
Don
Wayne,
I do not know what the poster is asking about. There are many types of "grounding conductors" and until he tells us the function of the conductor in question, we cannot give an answer.
Don
- Location
- Illinois
- Occupation
- retired electrician
Re: grounding conductor size
jro,
What is your answer based on? If the question is about the GEC, then Bennie has posted the correct answer.
jro,
What is your answer based on? If the question is about the GEC, then Bennie has posted the correct answer.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: grounding conductor size
To reiterate what Don has been saying, allow me to submit some definitions:
Grounded. Connected to earth or to some conducting body that serves in place of the earth.
Grounded, Effectively. Intentionally connected to earth through a ground connection or connections of sufficiently low impedance and having sufficient current-carrying capacity to prevent the buildup of voltages that may result in undue hazards to connected equipment or to persons.
Grounded Conductor. A system or circuit conductor that is intentionally grounded.
Grounding Conductor. A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.
Grounding Conductor, Equipment. The conductor used to connect the noncurrent-carrying metal parts of equipment, raceways, and other enclosures to the system grounded conductor, the grounding electrode conductor, or both, at the service equipment or at the source of a separately derived system.
Grounding Electrode Conductor. The conductor used to connect the grounding electrode to the equipment grounding conductor, to the grounded conductor, or to both, of the circuit at the service equipment or at the source of a separately derived system.
Again, what is the question being asked?
[ September 18, 2003, 09:27 PM: Message edited by: ryan_618 ]
To reiterate what Don has been saying, allow me to submit some definitions:
Grounded. Connected to earth or to some conducting body that serves in place of the earth.
Grounded, Effectively. Intentionally connected to earth through a ground connection or connections of sufficiently low impedance and having sufficient current-carrying capacity to prevent the buildup of voltages that may result in undue hazards to connected equipment or to persons.
Grounded Conductor. A system or circuit conductor that is intentionally grounded.
Grounding Conductor. A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.
Grounding Conductor, Equipment. The conductor used to connect the noncurrent-carrying metal parts of equipment, raceways, and other enclosures to the system grounded conductor, the grounding electrode conductor, or both, at the service equipment or at the source of a separately derived system.
Grounding Electrode Conductor. The conductor used to connect the grounding electrode to the equipment grounding conductor, to the grounded conductor, or to both, of the circuit at the service equipment or at the source of a separately derived system.
Again, what is the question being asked?
[ September 18, 2003, 09:27 PM: Message edited by: ryan_618 ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: grounding conductor size
Be cause someone doen't know that it is not required.
250.53 (E)
Supplemental Electrode Bonding Connection Size. Where the supplemental electrode is a rod, pipe, or plate electrode, that portion of the bonding jumper that is the sole connection to the supplemental grounding electrode shall not be required to be larger than 6 AWG copper wire or 4 AWG aluminum wire.
[ September 19, 2003, 01:34 AM: Message edited by: hurk27 ]
Be cause someone doen't know that it is not required.
250.53 (E)
Supplemental Electrode Bonding Connection Size. Where the supplemental electrode is a rod, pipe, or plate electrode, that portion of the bonding jumper that is the sole connection to the supplemental grounding electrode shall not be required to be larger than 6 AWG copper wire or 4 AWG aluminum wire.
[ September 19, 2003, 01:34 AM: Message edited by: hurk27 ]
Re: grounding conductor size
Ok so tell us how do you ground the 1800 amp service, and what is the size of the GEC, is what the poster wants to know, all we have thrown out is opinions and thougts but no answer, much like my answer it has been shot down, Joe Tedesco where are you!
The way I understand this is, the main grounding electrode is the cold water pipe, ground rods, ground loops, building steel, etc. are all supplemental electrodes, per the 1999 Nec handbook:
If a gec is run from the service equipt. or separatly derived system to a water pipe or structural steel, the gec must be full size per T. 250-66. If the gec from the service equipt. were run , for example , to the ground rod first and then to the water pipe, the conductor to the ground rod would also have to be full size.
In the area where I work (DFW, Texas) it is common practice to run 1 gec to cold water pipe then 1 gec to the ground rod, both full size, if bldg. steel is present we bond, with a full size gec, from water pipe to bldg. steel we also bond the ground and nuetral bars at the main service. Now what the poster wants to know is what size gec is needed for his 1800 amp service he is not asking the size of the bonding jumper from the main gec to the ground rod, that is why, according to my math the main gec is 3/0.
DON I have edited my post sorry for the misprint at the start of my post.
[ September 19, 2003, 08:15 PM: Message edited by: jro ]
Ok so tell us how do you ground the 1800 amp service, and what is the size of the GEC, is what the poster wants to know, all we have thrown out is opinions and thougts but no answer, much like my answer it has been shot down, Joe Tedesco where are you!
The way I understand this is, the main grounding electrode is the cold water pipe, ground rods, ground loops, building steel, etc. are all supplemental electrodes, per the 1999 Nec handbook:
If a gec is run from the service equipt. or separatly derived system to a water pipe or structural steel, the gec must be full size per T. 250-66. If the gec from the service equipt. were run , for example , to the ground rod first and then to the water pipe, the conductor to the ground rod would also have to be full size.
In the area where I work (DFW, Texas) it is common practice to run 1 gec to cold water pipe then 1 gec to the ground rod, both full size, if bldg. steel is present we bond, with a full size gec, from water pipe to bldg. steel we also bond the ground and nuetral bars at the main service. Now what the poster wants to know is what size gec is needed for his 1800 amp service he is not asking the size of the bonding jumper from the main gec to the ground rod, that is why, according to my math the main gec is 3/0.
DON I have edited my post sorry for the misprint at the start of my post.
[ September 19, 2003, 08:15 PM: Message edited by: jro ]
kennym
Member
- Location
- New Jersey
Re: grounding conductor size
This is the grounding electrode conductor to cold water main
This is the grounding electrode conductor to cold water main
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