bonding

[quique001]

is there any new NEC code or AHj on transformer core bonding jumper? a inspector said that flat metal jumper that comes factory installed need to be under a mechanical lug than jump to XO plus the other GC. please advise.

 

[infinity]

The flat metal jumper is just to connect the core to the case because the core is typically mounted on rubber isolators. You do not need to do anything with it as it's factory installed. I assume that you mean one of these:

 

[augie47]

Note that it does nothing to bond your grounded (XO) terminal and you still need to adress that.

 

[texie]

I agree. This question comes up a lot in my travels.

 

[ronaldrc]

I've not got the 2011 code but use to be an option, Either bond the neutral at the transformer or at the main
but not both.

If you bond at the transformer you will need to float the neutral and separate the Eq. grds from the neutrals in the panel you feed with this secondary.

I think :roll:

 

[texie]

I've not got the 2011 code but use to be an option, Either bond the neutral at the transformer or at the main
but not both.

If you bond at the transformer you will need to float the neutral and separate the Eq. grds from the neutrals in the panel you feed with this secondary.

I think :roll:

Yes, you are correct. But the point that infinity and augie were making is that the factory strap shown in infinity's photo has nothing to do with this.
I get this question all the time. That strap is simply a bonding connection from the xforformer frame to the xformer encolsure due to the isolators in the mount that has no bearing on where you ground the SDS. Even if it was an ungrounded secondary the strap stays.