System bonding jumper vs equipment bonding jumper on a s
- Thread starter finhead
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ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: System bonding jumper vs equipment bonding jumper on a s
Yes, I agree.
Yes, I agree.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Re: System bonding jumper vs equipment bonding jumper on a s
Is the drawing on the right ok?
Is the drawing on the right ok?
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Re: System bonding jumper vs equipment bonding jumper on a s
At 1st glance, I would say both illustrations are the same. They both take the system bonding jumper to the bar that has the grounding electrode conductor.
After I studied it a bit more, I think I see what you are saying. I think the illustration would make more sense if there was a 2nd bar in the transformer that was a ground bar and was labeled like the illustration on the right. I still think the illustration is correct because the "system" ground bar is in the 1st means of disconnect. I don't know if this makes sense (it does to me, but I understand my way of thinking).
At 1st glance, I would say both illustrations are the same. They both take the system bonding jumper to the bar that has the grounding electrode conductor.
After I studied it a bit more, I think I see what you are saying. I think the illustration would make more sense if there was a 2nd bar in the transformer that was a ground bar and was labeled like the illustration on the right. I still think the illustration is correct because the "system" ground bar is in the 1st means of disconnect. I don't know if this makes sense (it does to me, but I understand my way of thinking).
Re: System bonding jumper vs equipment bonding jumper on a s
hardworkingstiff
According to 250.30 (A)(2), the function of the equipment bonding jumper is to bond the source enclosure to the first system disconnecting means enclosure. This is clearly accomplished in the right-hand illustration, but not in the left-hand illustration.
The system bonding jumper, according to 250.30 (A)(1), connects the grounded conductor to the equipment grounding conductor(s).This connecton must be made at the point where the grounding electrode conductor is terminated. Once again, the right-hand illustration depicts this requirement but the left-hand illustration does not.
Regards
hardworkingstiff
According to 250.30 (A)(2), the function of the equipment bonding jumper is to bond the source enclosure to the first system disconnecting means enclosure. This is clearly accomplished in the right-hand illustration, but not in the left-hand illustration.
The system bonding jumper, according to 250.30 (A)(1), connects the grounded conductor to the equipment grounding conductor(s).This connecton must be made at the point where the grounding electrode conductor is terminated. Once again, the right-hand illustration depicts this requirement but the left-hand illustration does not.
Regards
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Re: System bonding jumper vs equipment bonding jumper on a s
finhead,
I've been out of town working and getting ready to go again (hence the slow response).
I don't see 250.30(A)(2) saying what you claim. I read it as when you run a wire bonding jumper you need to size it according to 250.102(C).
I'll have to study a little more about the illustration comments. I'll be very busy and away for most of the next 2-3 weeks, so thanks for the homework.
finhead,
I've been out of town working and getting ready to go again (hence the slow response).
I don't see 250.30(A)(2) saying what you claim. I read it as when you run a wire bonding jumper you need to size it according to 250.102(C).
I'll have to study a little more about the illustration comments. I'll be very busy and away for most of the next 2-3 weeks, so thanks for the homework.
pierre
Senior Member
- Location
- Westchester County, New York
Re: System bonding jumper vs equipment bonding jumper on a s
The System Bonding Jumper and the Main Bonding Jumper serve the exact same purpose, but their locations are different, in regards to one being at the service, and the other being located at a separately derived system - look at the definitions in Art 100 of the '05 NEC.
I see the illustration on page 199 that is exhibit .13 as being incorrect.
A system bonding jumper will not leave one enclosure and go to another.
The System Bonding Jumper and the Main Bonding Jumper serve the exact same purpose, but their locations are different, in regards to one being at the service, and the other being located at a separately derived system - look at the definitions in Art 100 of the '05 NEC.
I see the illustration on page 199 that is exhibit .13 as being incorrect.
A system bonding jumper will not leave one enclosure and go to another.
Re: System bonding jumper vs equipment bonding jumper on a s
hardworkingstiff
I agree that while 250.32 does not appear to require the equipment bonding jumper to be run from the source to the first disconnecting means, I think that is the intent.
In the July-August IAEI News, page 52, Michael Johnston says - under the heading DERIVED SYSTEM EQUIPMENT BONDING JUMPER - "since effective bonding between the source enclosure and the first system overcurrent device enclosure is essential, a bonding jumper of some from is generally required."
finhead
hardworkingstiff
I agree that while 250.32 does not appear to require the equipment bonding jumper to be run from the source to the first disconnecting means, I think that is the intent.
In the July-August IAEI News, page 52, Michael Johnston says - under the heading DERIVED SYSTEM EQUIPMENT BONDING JUMPER - "since effective bonding between the source enclosure and the first system overcurrent device enclosure is essential, a bonding jumper of some from is generally required."
finhead
Re: System bonding jumper vs equipment bonding jumper on a s
The definition for system bonding jumper seems to me to require a connection to the same terminal strip as the grounded conductor from the transformer, and to the EGC at the derived system regardless of where those two points are. Why do you feel it will not leave the enclosure?
__________________
Wes Gerrans
Instructor
Northwest Kansas Technical College
Goodland, KS
Pierre, what am I missing here?
The definition for system bonding jumper seems to me to require a connection to the same terminal strip as the grounded conductor from the transformer, and to the EGC at the derived system regardless of where those two points are. Why do you feel it will not leave the enclosure?__________________
Wes Gerrans
Instructor
Northwest Kansas Technical College
Goodland, KS
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