I know that in an ungrounded system, the neutral conductor is not connected to the equpment grounding conductor. But, does the neutral conductor of an ungrounded system need to be connected to earth (to an electrode)? I am looking for the answer in the code book, but any answer'd be appreciated.
ungrounded system neutral need connect to earth?
- Thread starter unsaint34
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charlie
Senior Member
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- Indianapolis
Re: ungrounded system neutral need connect to earth?
An ungrounded system is just that. Do not connect any point of the system to any ground point, including a ground rod.
An ungrounded system is just that. Do not connect any point of the system to any ground point, including a ground rod.
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- Windsor, CO NEC: 2017
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- Service Manager
Re: ungrounded system neutral need connect to earth?
I thought an ungrounded system had no neutral, hence the term?
What is 250.24(E) talking about, then?
[ March 19, 2005, 09:42 AM: Message edited by: georgestolz ]
I thought an ungrounded system had no neutral, hence the term?
What is 250.24(E) talking about, then?
[ March 19, 2005, 09:42 AM: Message edited by: georgestolz ]
Re: ungrounded system neutral need connect to earth?
I don't have my NEC here, but I thought 250.4(B) and 250.24(B) both discuss connecting an ungrounded system to the earth.
Also, Like George is saying, how do you have a nuetral on an ungrounded system? Are you talking about a high impedance grounded system, perhaps?
I don't have my NEC here, but I thought 250.4(B) and 250.24(B) both discuss connecting an ungrounded system to the earth.
Also, Like George is saying, how do you have a nuetral on an ungrounded system? Are you talking about a high impedance grounded system, perhaps?
charlie
Senior Member
- Location
- Indianapolis
Re: ungrounded system neutral need connect to earth?
George, 250.24(E) is talking about establishing a grounding system for the frames of all electrical equipment, not grounding the center point or a leg of a transformer.
250.20 must be followed and you will find that you can not have a neutral conductor with an ungrounded system. You can, however, ground the neutral point. If this is done, then the neutral conductor must be taken to the service equipment.
George, 250.24(E) is talking about establishing a grounding system for the frames of all electrical equipment, not grounding the center point or a leg of a transformer.
250.20 must be followed and you will find that you can not have a neutral conductor with an ungrounded system. You can, however, ground the neutral point. If this is done, then the neutral conductor must be taken to the service equipment.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Re: ungrounded system neutral need connect to earth?
Okay, I guess I wasn't clear on what point in the system we were discussing. Didn't see "transformer" in the subject, or original post.
Okay, I guess I wasn't clear on what point in the system we were discussing. Didn't see "transformer" in the subject, or original post.
charlie
Senior Member
- Location
- Indianapolis
Re: ungrounded system neutral need connect to earth?
George, I didn't make a clear answer to the original question. I am answering what I am thinking, not necessarily what the person asking the question wants to know.
George, I didn't make a clear answer to the original question. I am answering what I am thinking, not necessarily what the person asking the question wants to know.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Re: ungrounded system neutral need connect to earth?
It was just one of those precarious situations where we could be giving wrong advice, based on lack of info.
Kinda scary.
It was just one of those precarious situations where we could be giving wrong advice, based on lack of info.
Kinda scary.
Re: ungrounded system neutral need connect to earth?
well, I thought by my saying "the neutral", I specified the grounding as "system grounding," not "equipment grounding."
Also, about whether can an ungrounded system have a neutral... Can an ungrounded system in a health care facility serve 120v load therefore requiring to have a neutral conductor?
well, I thought by my saying "the neutral", I specified the grounding as "system grounding," not "equipment grounding."
Also, about whether can an ungrounded system have a neutral... Can an ungrounded system in a health care facility serve 120v load therefore requiring to have a neutral conductor?
charlie
Senior Member
- Location
- Indianapolis
Re: ungrounded system neutral need connect to earth?
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