cripple
Senior Member
- Location
- Santa Fe, New Mexico
When did system grounding requirements first appear in NEC.
Grounding Reqirements
- Thread starter cripple
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Re: Grounding Reqirements
I no longer have access to older copies of the code. But I suggest that you clarify your question. What do you mean by "system grounding requirements"? If you could cite the current article in which you have an interest, perhaps someone could look that article up in older versions.
I no longer have access to older copies of the code. But I suggest that you clarify your question. What do you mean by "system grounding requirements"? If you could cite the current article in which you have an interest, perhaps someone could look that article up in older versions.
al hildenbrand
Senior Member
- Location
- Minnesota
- Occupation
- Electrical Contractor, Electrical Consultant, Electrical Engineer
Re: Grounding Reqirements
The 1899 NEC starts off talking about insulating generators and motors from "the ground", in as much as it was practical. That NEC left it to the "Inspection Department having jurisdiction" to determine if the insulating was "impracticable", in which case, the Inspection Department would waive the insulation requirement in writing, and then the Code said, "in which case the frame must be permanently and effectively grounded."
The 1899 NEC starts off talking about insulating generators and motors from "the ground", in as much as it was practical. That NEC left it to the "Inspection Department having jurisdiction" to determine if the insulating was "impracticable", in which case, the Inspection Department would waive the insulation requirement in writing, and then the Code said, "in which case the frame must be permanently and effectively grounded."
cripple
Senior Member
- Location
- Santa Fe, New Mexico
Re: Grounding Reqirements
What I?m interested in finding is when the first grounding requirements appear in NEC for services and the second building from a common service.
Form reading the 1897 electrical code it seems that the only grounding requirements were to control static electric, and for lightning protection.
What I?m interested in finding is when the first grounding requirements appear in NEC for services and the second building from a common service.
Form reading the 1897 electrical code it seems that the only grounding requirements were to control static electric, and for lightning protection.
al hildenbrand
Senior Member
- Location
- Minnesota
- Occupation
- Electrical Contractor, Electrical Consultant, Electrical Engineer
Re: Grounding Reqirements
The are two different formats (Acrobat Reader and MS Word) of the 1899 NEC available for viewing close to the top of this page: http://www.mikeholt.com/technical.php?id=nec/technicalnecfreestuff.
The are two different formats (Acrobat Reader and MS Word) of the 1899 NEC available for viewing close to the top of this page: http://www.mikeholt.com/technical.php?id=nec/technicalnecfreestuff.
al hildenbrand
Senior Member
- Location
- Minnesota
- Occupation
- Electrical Contractor, Electrical Consultant, Electrical Engineer
Re: Grounding Reqirements
Cripple,
The size of the machines involved in the late 1800s had a lot to do with the practicality of "floating" the source. The little ones could be "floated."
I think of todays small portable gas powered generators.
I have a 5.5 KW unit on rubber wheels and rubber feet.
I can use it, floating from connection with ground, and not introduce a personal hazard as I handle, say, an old metal body Milwaukee drill plugged into a NEMA 15R on the generator, whether the cord ground is in good condition or not.
If my portable generator comes in contact with electrical ground, then I have to be sure my Milwaukee drill is also effectively grounded, otherwise, I will run the risk of putting my body in the circuit when I pick up the tool.
Although the 1899 NEC only uses the phrase "permanently and effectively grounded" as the alternative to insulated from ground, I think it is also about protecting personnel from shock.
Cripple,
The size of the machines involved in the late 1800s had a lot to do with the practicality of "floating" the source. The little ones could be "floated."
I think of todays small portable gas powered generators.
I have a 5.5 KW unit on rubber wheels and rubber feet.
I can use it, floating from connection with ground, and not introduce a personal hazard as I handle, say, an old metal body Milwaukee drill plugged into a NEMA 15R on the generator, whether the cord ground is in good condition or not.
If my portable generator comes in contact with electrical ground, then I have to be sure my Milwaukee drill is also effectively grounded, otherwise, I will run the risk of putting my body in the circuit when I pick up the tool.
Although the 1899 NEC only uses the phrase "permanently and effectively grounded" as the alternative to insulated from ground, I think it is also about protecting personnel from shock.
- Status