Electrode
- Thread starter bennie
- Start date
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charlie
Senior Member
- Location
- Indianapolis
Re: Electrode
Bennie, you are stirring again.
The bond wire is sized in accordance with table 250.66 (see 250.104). Since you have no water pipe grounding electrode, you must provide one (a driven ground rod at or below 25 ohms will do). In other words, the installation is the same as if it were 10 feet or longer.
Bennie, you are stirring again.
The bond wire is sized in accordance with table 250.66 (see 250.104). Since you have no water pipe grounding electrode, you must provide one (a driven ground rod at or below 25 ohms will do). In other words, the installation is the same as if it were 10 feet or longer.
karl riley
Senior Member
Re: Electrode
Bennie, your questions are very tricky. This one is very interesting, because of the past reliance on water pipe connections to allow ground faults to clear. Since the NEC says 10' of soil connection qualifies it as a grounding electrode, they are obviously thinking of it as a connection to earth, like a rod.
But the only reason water pipes can clear a fault is that they are a path back to the transformer neutral by way of a neighbor's service neutral.
My question would be: is this why many electricians thought that a connection to earth could clear a fault? (because they didn't realize the water pipe was carrying the current to the neighbor's neutral?)
Karl
Bennie, your questions are very tricky. This one is very interesting, because of the past reliance on water pipe connections to allow ground faults to clear. Since the NEC says 10' of soil connection qualifies it as a grounding electrode, they are obviously thinking of it as a connection to earth, like a rod.
But the only reason water pipes can clear a fault is that they are a path back to the transformer neutral by way of a neighbor's service neutral.
My question would be: is this why many electricians thought that a connection to earth could clear a fault? (because they didn't realize the water pipe was carrying the current to the neighbor's neutral?)
Karl
pierre
Senior Member
- Location
- Westchester County, New York
Re: Electrode
Hello Karl
I am against using the cold water for an electrode and one of the reasons is just what you mentioned in your post.
Technically - 9feet, 11 inches is a violation. Common sense may be another thing. There is an 'old' saying - "give them an inch and they will take a foot".
How about a Ufer ground being mandatory on all new services, bonding the cold water to the system?
Hello Karl
I am against using the cold water for an electrode and one of the reasons is just what you mentioned in your post.
Technically - 9feet, 11 inches is a violation. Common sense may be another thing. There is an 'old' saying - "give them an inch and they will take a foot".
How about a Ufer ground being mandatory on all new services, bonding the cold water to the system?
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: Electrode
We ask for a Ufer ground at all buildings and we have no objections at all.
Hi Pierre! Actually 9'11" wouldn't be a violation, it just wouldn't be an "available electrode"
We ask for a Ufer ground at all buildings and we have no objections at all.
- Location
- Illinois
- Occupation
- retired electrician
Re: Electrode
Bennie,
You don't need either a GEC or a bonding wire to the underground water pipe in this case. You do need a bonding conductor to the interior water piping system if it is metallic per 250.104(A).
Don
Bennie,
You don't need either a GEC or a bonding wire to the underground water pipe in this case. You do need a bonding conductor to the interior water piping system if it is metallic per 250.104(A).
Don
karl riley
Senior Member
Re: Electrode
I'm curious about wanting a uffer. No objection, but if it is basically for lightning protection, why wouldn't a ground rod do the job? Is there a lingering feeling that the earth ground is going to help with tripping a breaker?
If there is an electronic need for a low impedance ground, that's something else. I have to admit it has not been explained to me so that I can see it's benefit, but I am willing to try to understand. I do understand that quite a few companies make good money for installing a low-impedance grounding grid. But maybe I'm being cynical, since everyone gets paid for doing their thing.
Karl
I'm curious about wanting a uffer. No objection, but if it is basically for lightning protection, why wouldn't a ground rod do the job? Is there a lingering feeling that the earth ground is going to help with tripping a breaker?
If there is an electronic need for a low impedance ground, that's something else. I have to admit it has not been explained to me so that I can see it's benefit, but I am willing to try to understand. I do understand that quite a few companies make good money for installing a low-impedance grounding grid. But maybe I'm being cynical, since everyone gets paid for doing their thing.
Karl
Re: Electrode
I'm with you Karl. I am still tracing the history of using the earth for a ground plane. Switching or load shedding overvoltages don't depend on a ground reference. Low side lightning surges are rare. Lightning surges are mitigated by suppressors or arrestors.
I have a problem with all the racket about lack of proper grounding is approaching dooms day. I can see the need for a complete circuit for fault purposes but not for earth connection.
I'm with you Karl. I am still tracing the history of using the earth for a ground plane. Switching or load shedding overvoltages don't depend on a ground reference. Low side lightning surges are rare. Lightning surges are mitigated by suppressors or arrestors.
I have a problem with all the racket about lack of proper grounding is approaching dooms day. I can see the need for a complete circuit for fault purposes but not for earth connection.
alex winkler
Member
Re: Electrode
I keep waiting for Bennie to say he would not run a GEC or a bonding conductor ....
because the water line is plastic.
I keep waiting for Bennie to say he would not run a GEC or a bonding conductor ....
because the water line is plastic.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Electrode
Now I know why old electrican's carry fishing line in there tool box's LOL
Now I know why old electrican's carry fishing line in there tool box's
LOL 
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Re: Electrode
Bennie
Yes. GEC. Just because the house sits within 10' of the city's water supply does not exempt one from using it as an electrode. IMHO.
Mike P.
[ July 08, 2003, 08:08 AM: Message edited by: jxofaltrds ]
Bennie
Yes. GEC. Just because the house sits within 10' of the city's water supply does not exempt one from using it as an electrode. IMHO.
Mike P.
[ July 08, 2003, 08:08 AM: Message edited by: jxofaltrds ]
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: Electrode
I'll be the first to admit that I'm not nearly as versed in electrical theory as you are. I ask for the concrete encased electrode for 2 reasons. (1) It is available. (2) We don't inspect the water lateral and have have no assurance that there is 10' of copper. With the increase in usage of plastic water piping, 10' of electrode happens less and less now.
pierre
Senior Member
- Location
- Westchester County, New York
Re: Electrode
Bennie
I must have been doing a lot of grounding the other day at the lake, I know the fish were pissed about it.
I also think that grounding at services is a very misunderstood subject. What about the growing usuage of surge protective devices these days. Would it not be benificial to have a good ground for these?
Pierre
Bennie
I must have been doing a lot of grounding the other day at the lake, I know the fish were pissed about it.
I also think that grounding at services is a very misunderstood subject. What about the growing usuage of surge protective devices these days. Would it not be benificial to have a good ground for these?
Pierre
- Location
- Massachusetts
Re: Electrode
Pierre
Lets see if I have learned anything, from the knowledgeable members here.
It would not effect the operation of a TVSS unit if the service it was connected to had a grounding electrode or not.
For the proper operation of a TVSS unit the important part would be a good grounding conductor back to the bonding point.
Bob
[ July 08, 2003, 06:08 PM: Message edited by: iwire ]
Pierre
Lets see if I have learned anything, from the knowledgeable members here.
It would not effect the operation of a TVSS unit if the service it was connected to had a grounding electrode or not.
For the proper operation of a TVSS unit the important part would be a good grounding conductor back to the bonding point.
Bob
[ July 08, 2003, 06:08 PM: Message edited by: iwire ]
websparky
Senior Member
- Location
- Cleveland, Ohio
Re: Electrode
Hi Pierre,
(A) Electrodes Permitted for Grounding.
I can not find a code reference to back up your statement. Could you please provide one.
Thanks,
Dave
Hi Pierre,
250.52 Grounding Electrodes.
(A) Electrodes Permitted for Grounding.
I can not find a code reference to back up your statement. Could you please provide one.
Thanks,
Dave
pierre
Senior Member
- Location
- Westchester County, New York
Re: Electrode
Bob
This is a good way for all of us to learn, somebody in this forum has experience that we don't have. What understanding of surge protective devices (SPD) I have is limited, I hope here it will be broadened.
By SPD, I was refering to Surge Arrestors (Art 280), But I think the principle for TVSS (Art 285) is basically the same. I was under the belief that they discharge to ground. Does anyone know if this is true/false? whereas a groundfault goes back to the source (hence why a ground electrode) the surge needs to dissipate to ground.
Pierre
Bob
This is a good way for all of us to learn, somebody in this forum has experience that we don't have. What understanding of surge protective devices (SPD) I have is limited, I hope here it will be broadened.
By SPD, I was refering to Surge Arrestors (Art 280), But I think the principle for TVSS (Art 285) is basically the same. I was under the belief that they discharge to ground. Does anyone know if this is true/false? whereas a groundfault goes back to the source (hence why a ground electrode) the surge needs to dissipate to ground.
Pierre
pierre
Senior Member
- Location
- Westchester County, New York
Re: Electrode
Hello Dave
Ryan correctly pointed out it is not a code violation, it is not an availible electrode. 250.52(A)(1) - '10 feet or more'
If used as an electrode, it would be a violation.
Bennie's original post mentioned 9 feet 11 inches.
Pierre
Hello Dave
Ryan correctly pointed out it is not a code violation, it is not an availible electrode. 250.52(A)(1) - '10 feet or more'
If used as an electrode, it would be a violation.
Bennie's original post mentioned 9 feet 11 inches.
Pierre
- Location
- Massachusetts
Re: Electrode
The surge would need to get back to it's source too, that may end up using the earth as a conductor.
Looking at 280.22 they allow the connection from ungrounded to grounded conductor.
I do not think anything dissipates to the ground.
The surge would need to get back to it's source too, that may end up using the earth as a conductor.
Looking at 280.22 they allow the connection from ungrounded to grounded conductor.
pierre
Senior Member
- Location
- Westchester County, New York
Re: Electrode
Bob
MCG has a document for free that is called 'The Truth of The Matter"
31 pages, and in part of the document it says, "In terms of protecting your equipment from transient electrical anomalies, a good ground is important'. It shows many ways of installation, but always a wire to ground. Maybe I will contact their tech department, if we do not get more responses.
Pierre
Bob
MCG has a document for free that is called 'The Truth of The Matter"
31 pages, and in part of the document it says, "In terms of protecting your equipment from transient electrical anomalies, a good ground is important'. It shows many ways of installation, but always a wire to ground. Maybe I will contact their tech department, if we do not get more responses.
Pierre
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