250.64(D)(1) Listed connector to copper busbar

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elec_eng

Senior Member
GEC connection must be continuous or connection should be made with exothermic or irreversible connectors. But if I use a copper ground bus bar, a listed connector or by the exothermic welding.

What would be the listed connector to the copper ground busbar?
 

iwire

Moderator
Staff member
Location
Massachusetts
GEC connection must be continuous or connection should be made with exothermic or irreversible connectors. But if I use a copper ground bus bar, a listed connector or by the exothermic welding.

What would be the listed connector to the copper ground busbar?

Can you run a GEC to a bus bar?

250.24 Grounding Service-Supplied Alternating-Current
Systems.
(A) System Grounding Connections. A premises wiring
system supplied by a grounded ac service shall have a
grounding electrode conductor connected to the grounded
service conductor,
at each service, in accordance with
250.24(A)(1) through (A)(5).

(1) General. The grounding electrode conductor connection
sha]] be made at any accessible point from the load end
of the overhead service conductors, service drop, • underground
service conductors, or service lateral to, including
the terminal or bus to which the grounded service conductor
is connected at the service disconnecting means.
 

iwire

Moderator
Staff member
Location
Massachusetts
Can you not run a GEC from the grounded conductor terminal bus (or equipment grounding terminal bus if bonded) to a ground bus bar, then GE per 250.64(c)?

I am not sure on this.

I don't see that 250.64(C) changes the requirements of 250.24

(1) General. The grounding electrode conductor connection
shall be made at any accessible point from the load end
of the overhead service conductors, service drop, • underground
service conductors, or service lateral to, including
the terminal or bus to which the grounded service conductor
is connected at the service disconnecting means.

Maybe I am missing something but that does not sound to me like the GEC can run to a bus bar outside the service disconnect.
 

elec_eng

Senior Member
I am not sure on this.

I don't see that 250.64(C) changes the requirements of 250.24



Maybe I am missing something but that does not sound to me like the GEC can run to a bus bar outside the service disconnect.

I don't think 250.64(c) changes the requirements of250.24. The GEC is still connected to the grounded service conductor at the service disconnect..the GEC is spliced at the bus bar instead of continuous. That's how I read this. Do you not agree?
 

iwire

Moderator
Staff member
Location
Massachusetts
I don't think 250.64(c) changes the requirements of250.24. The GEC is still connected to the grounded service conductor at the service disconnect..the GEC is spliced at the bus bar instead of continuous. That's how I read this. Do you not agree?

I am reading that 250.24 tells us one end of the GEC has to run directly into the service disconnect.



Again, maybe I am missing something. Wait for some others to jump in.
 

elec_eng

Senior Member
I am reading that 250.24 tells us one end of the GEC has to run directly into the service disconnect.



Again, maybe I am missing something. Wait for some others to jump in.

While we are waiting for others to chime in, back to my OP, let's assume this is a tap to GEC, is there a such thing as listed connector to copper bus bar that you know of?
 

Smart $

Esteemed Member
Location
Ohio
Can you not run a GEC from the grounded conductor terminal bus (or equipment grounding terminal bus if bonded) to a ground bus bar, then GE per 250.64(c)?
Ground bar internal or external to enclosure? More than one enclosure? Service or building feeder disconnecting means?

Please elaborate on your scenario. Sometimes I get the feeling posters leave out specific information so as to influence the response. Not saying that's always true, but I am getting that feeling. :(

If this ground bar is external to more than one disconnecting means enclosure and this is a common GEC and taps scenario, yes this is permitted without irreversibe connections.

Connection of wire-type GEC to a compliantly-installed busbar can be made using any terminal that is listed for grounding. IIRC compression terminals and your typical mechanical lug are so listed.
 

elec_eng

Senior Member
Ground bar internal or external to enclosure? More than one enclosure? Service or building feeder disconnecting means?

Please elaborate on your scenario. Sometimes I get the feeling posters leave out specific information so as to influence the response. Not saying that's always true, but I am getting that feeling. :(

If this ground bar is external to more than one disconnecting means enclosure and this is a common GEC and taps scenario, yes this is permitted without irreversibe connections.

Connection of wire-type GEC to a compliantly-installed busbar can be made using any terminal that is listed for grounding. IIRC compression terminals and your typical mechanical lug are so listed.

This was not what I was asking in my OP but while we are on the subject...This is the GEC at the main service disconnect and the ground bus bar will be external to the service enclosure. The discussion was can the GEC be spliced per 250.64(c) before it hits the grounded bus bar.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Note that per the title of 250.64(D), that section only applies where there are multiple service disconnects.
(D) Building or Structure with Multiple Disconnecting Means in Separate Enclosures. ...
If you only have one service disconnect enclosure, I agree with Bob that you can't use the bus bar to splice the GEC.
If you have multiple service disconnect enclosures, you can run the GEC to a busbar and run taps to the enclosures.
 

elec_eng

Senior Member
Note that per the title of 250.64(D), that section only applies where there are multiple service disconnects.

If you only have one service disconnect enclosure, I agree with Bob that you can't use the bus bar to splice the GEC.
If you have multiple service disconnect enclosures, you can run the GEC to a busbar and run taps to the enclosures.

Then when does 250.64(C) (1) thru (4) apply? It says splices are permitted if necessary. I am confused..
 

Smart $

Esteemed Member
Location
Ohio
Then when can you apply 250.64(C)(2)?
When your grounding electrode conductor is busbar. :p


The difference between the GEC being busbar and your use is that the busbar is a means of splicing, not as the GEC itself. You have wire-type GEC running to it and wire-type GEC running from it.
 

elec_eng

Senior Member
When your grounding electrode conductor is busbar. :p


The difference between the GEC being busbar and your use is that the busbar is a means of splicing, not as the GEC itself. You have wire-type GEC running to it and wire-type GEC running from it.

Hmm..All these years, I never read this section that way..Well I stand corrected.

I am curious, how can the GEC be a busbar?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Hmm..All these years, I never read this section that way..Well I stand corrected.

I am curious, how can the GEC be a busbar?
I have never seen GEC as a busbar, but I guess you could run a busbar from the building steel to the service equipment where you are using the building steel as the grounding electrode.
 
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