How does this work

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hhsting

Senior Member
Location
Glen bunie, md, us
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Junior plan reviewer
If one has generator with main breaker how does one go about grounding it?

I mean plan shows system bonding jumper in generator factory installed. I can see where to get phase conductors , neutral conductors from generator to gen main breaker.

250.30(A)(2) if source of separately derived system and first disconnect means are located in separate enclosure a supply side shall be install. However in mine I have generator and generator main breaker all in one. Please attached sketch.

4dbb6309711e3f06bf5a0e2c653feb36.jpg



How does one get EGC from generator if system bonding jumper is factory installed at generator? Is EGC not EGC would it be supply side bonding jumper? But how can it be supply side bonding jumper if not in separate enclosure?
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
I would not look at the breaker on the generator as a disconnect. The first disconnect that your house is connected two, in most cases that would be you ATS, and you would ground there.


“ shoot low boys their riding shetland ponies”
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
I would not look at the breaker on the generator as a disconnect. The first disconnect that your house is connected two, in most cases that would be you ATS, and you would ground there.


“ shoot low boys their riding shetland ponies”

Huh? Are you serious? First disconnect is Not generator main breaker? How can ATS be a disconnect?
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
Are you trying to figure out where to pick up your EGC?

I am trying to figure out supply side bonding jumper should be if one has main breaker and generator in one enclosure and system bonding jumper is at the generator factory installed.

I see that if generator breaker is separate from generator enclosure then system bonding jumper need to be installed as mentioned in NEC 2014 Section 250.30(A)(2).

How does one go about if you have generator with generator main breaker all in one enclosure? How does one wire supply side bonding bonding jumper etc?
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
If you have a factory generator with a factory installed breaker I would say not to worry. Your wiring should start at the load side of the breaker. The listing agency and design engineers handled the line side.
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
Huh? Are you serious? First disconnect is Not generator main breaker? How can ATS be a disconnect?

I mostly install service rated ATS, right after the meter before any thing else. So my ATS has a “main” Breaker on it and it’s my first disconnect


“ shoot low boys their riding shetland ponies”
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
If you have a factory generator with a factory installed breaker I would say not to worry. Your wiring should start at the load side of the breaker. The listing agency and design engineers handled the line side.

Let’s say system bonding jumper is not factory installed. Then how would one go about it if it’s wire?
 

augie47

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Location
Tennessee
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State Electrical Inspector (Retired)
Wouldn't it be great if the Code had a Table for system bonding jumpers ? Oh, wait ...................................................................
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
Wouldn't it be great if the Code had a Table for system bonding jumpers ? Oh, wait ...................................................................

No I meant wiring configuration. Would their be bus bar in enclosure exactly how does everything gets tied?
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
Look at the manufacturers cut sheets / specs.

Roger

If someone selected generator manufacturer sheet/specs then I can look. No generator manufacturer selected yet. I don’t have spec


Anyone know generally how it is internally with generator main breaker and generator all in one enclosure and where one wire the system bonding jumper? Any bars etc etc? Please
 

roger

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Fl
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If someone selected generator manufacturer sheet/specs then I can look. No generator manufacturer selected yet. I don’t have spec


Anyone know generally how it is internally with generator main breaker and generator all in one enclosure and where one wire the system bonding jumper? Any bars etc etc? Please
Well if you don't have the information you can't make a comment. Generator manufacturers do not necessarily use the same designs. Just make a note to the designer to make sure the installation complies with applicable codes and leave it there. You are asking the forum members to do your job without giving them the specs.

Roger
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
Well if you don't have the information you can't make a comment. Generator manufacturers do not necessarily use the same designs. Just make a note to the designer to make sure the installation complies with applicable codes and leave it there. You are asking the forum members to do your job without giving them the specs.

Roger

The designer came with #2 or #1

#2 has neutral going to gen main breaker and from there neutral and equipment grounding conductor to ATS. Bonding jumper go from gen wye to bar factory bonded to enclosure

#1 shows gen neutral going to terminal bar and from bar neutral and supply side bonding jumper to gen main breaker.


However how can #1 be applied their would code says no supply side bonding jumper if gen main breaker is in same enclosure as gen?

Also how can #2 apply system bonding jumper would at gen main breaker that’s where neutral to ground meet while system bonding jumper needs to be at source?


Please please anyone help. Which is more code compliant?

65b24027b16807b0a841f862ef5fce93.jpg
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Irrelevant on a factory generator unit. Built to approved design of listing agency. NEC not involved.
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
Irrelevant on a factory generator unit. Built to approved design of listing agency. NEC not involved.

I guess what I am asking is if NEC does not apply factory installed generator listed and ATS is 4 pole then one needs to make sure their is neutral to ground bond somewhere in that generator correct? NEC rules of where it is in the generator enclosure itself ie in main breaker, source may not apply but one needs to verify there is neutral to ground bond? Or even that doesn’t apply
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
One should confirm the existence. As Roger poits in in Post 11 & 13, refer to generator cut sheets as they normally provide details.
 

hhsting

Senior Member
Location
Glen bunie, md, us
Occupation
Junior plan reviewer
One should confirm the existence. As Roger poits in in Post 11 & 13, refer to generator cut sheets as they normally provide details.

augie47, roger, electrofelon and all don’t know what one does without this forum. All you guys are so helpful and knowledgeable

Thanks for all your input
 
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