250.30(C) Grounding Electrode Connection

[augie47]

As I read 250.30(A)(5) Exception it is permissible to install an appropriately sized system bonding jumper from XO to a ground bar in my transformer and the connect my grounding electrode conductor to that bar.
Another inspector feels that section requires the GEC to connect directly to XO.
Does the connection to the bar meet Code ??

 

[RUWired]

Augie, I think if an equipment ground bar is used or a 4 hole mechanical lug is used inside the transformer, ( 1 each for incoming and out going EGC, SBJ, and GEC), then yes. If single hole lugs are used for each, then no. Both 250.24(A)4 and 250.30(A)5 exception, say if connected to equipment terminal , bar, or bus.

 

[Smart $]

As I read 250.30(A)(5) Exception it is permissible to install an appropriately sized system bonding jumper from XO to a ground bar in my transformer and the connect my grounding electrode conductor to that bar.
Another inspector feels that section requires the GEC to connect directly to XO.
Does the connection to the bar meet Code ??

Yes.

The requirement is EGB<--SBJ-->GC(X0) and GEC-->GC(X0).

The exception permits GEC-->EGB<--SBJ-->GC(X0).

 

[infinity]

The 2014 will require a ground bus in transformers for these connections.

450.10 Grounding.
(A) Dry-Type Transformer Enclosures. Where separate
equipment grounding conductors and supply-side bonding
jumpers are installed, a terminal bar for all grounding and
bonding conductor connections shall be secured inside the
transformer enclosure. The terminal bar shall be bonded to
the enclosure in accordance with 250.12 and shall not be
installed on or over any vented portion of the enclosure.

 

[infinity]

A graphic from Mike:

 

[augie47]

Thanks Rob

 

[Canton]

Yes.

The requirement is EGB<--SBJ-->GC(X0) and GEC-->GC(X0).

The exception permits GEC-->EGB<--SBJ-->GC(X0).

.....not on vented openings:blink: Most transformer enclosures are all vented on the bottom, I guess I will be installing the ground buss on the side walls....

 

[GoldDigger]

I hope that what they were trying to say is that it should not block or otherwise reduce the airflow through the vents.

Tapatalk!