SDS bonding question

[Smart $]

Ok. I think I understand what your saying. Metal conduit can only be used as an egc not an ebj.

Not true, but yet not explicitly so. 250.102 leaves that up to the AHJ as to whether it qualifies as a similar suitable conductor. Most will, but it may depend on which side of the bed the inspector woke that morning :grin:

I also understand that egc's only exist after the sbj.

So what I am understanding is that the only difference between a egc and ebj is one is on the load side of sbj and the other on the line side. But they do the exact same thing: Form an effective ground fault current path. So I wonder why the rules are different for one and the other?

Thanks for clearing this up for me.

In my mind, an EBJ is an EGC, only it is a specific EGC.

 

[augie47]

In these situations (A and B) would a metallic conduit be suitable as the connection between the transformer and the panel ??(depicted by the green line)

 

[raider1]

View attachment 3469

In these situations (A and B) would a metallic conduit be suitable as the connection between the transformer and the panel ??(depicted by the green line)

Yes.

Chris

 

[Smart $]

View attachment 3469

In these situations (A and B) would a metallic conduit be suitable as the connection between the transformer and the panel ??(depicted by the green line)

IMO and others, yes... but it is left up to the AHJ to make that determination.

 

[don_resqcapt19]

Ok. I think I understand what your saying. Metal conduit can only be used as an egc not an ebj.

I also understand that egc's only exist after the sbj.

So what I am understanding is that the only difference between a egc and ebj is one is on the load side of sbj and the other on the line side. But they do the exact same thing: Form an effective ground fault current path. So I wonder why the rules are different for one and the other?

Thanks for clearing this up for me.

The real difference is that the EGCs are on for fault clearing on the load side of the OCPD. The equipment bonding jumper is on the line side of the OCPD.
After thinking about it, the grounding conductor between the transformer and the OCPD is an equipment bonding jumper in both cases. You will need an equipment bonding jumper in the raceway between the transformer and the OCPD, no matter where you install the system bonding jumper.

 

[Smart $]

...You will need an equipment bonding jumper in the raceway between the transformer and the OCPD, no matter where you install the system bonding jumper.

Unless the raceway is the EBJ...

 

[don_resqcapt19]

...
I always thought that this book was put out by the NEC. Surely it would have to be approved by the NEC, right?
...

From the front of the NEC handbook.

The commentary and supplementary materials in this handbook are not a part of the Code and do not constitute Formal Interpretations of the NFPA (which can be obtained only through requests processed by the responsible technical committees in accordance with the published procedures of the NFPA). The commentary and supplementary materials, therefore, solely reflect the personal opinions of the editor or other contributors and do not necessarily represent the official position of the NFPA or its technical committees. ?Registered Trademark National Fire Protection Association, Inc.