ibewelectric
Member
- Location
- 83616
- Occupation
- Electrician
For many years I've always done a 3 or 4 hole mechanical lug bolted to the bottom of the transformer. Typically here I terminate GEC (I will run it continuous through the mechanical lug and hit XO if I only have a 3 hole lug to utilize it as a SBJ), 2 equipment grounds (or more, if primary and secondary conductors are paralleled in separate conduits), and a bonding jumper going to XO.
I was doing a new delta-wye hammond transformer today and noticed they started putting a single hole mechanical lug on the outside with a bolt going through attaching to another single lug with a grounding symbol sticker (i circled in red on the picture where they added it). They also included a descent sized xo busbar. I wasn't sure how to utilize these while being code compliant?
It almost looked like they wanted you to use the outside chair lug for GEC and possibly use the inside for system bonding jumper? I would need to swap it to a 3 hole mechanical lug to give me a place to terminate equipment ground and be bonded to the transformer. My other thought was they added room on XO busbar to now make it a SBJ busbar and I terminate everything on it. To me this seems really weird and I would still need to bond it to the frame and the exterior lug would be useless because I can't terminate my GEC there because it has to be at the same point as the SBJ.
Any thoughts on these new features/accessories would be appreciated, I could just be stuck in an old mindset of my old installs.
I attached a picture of a pretty typical install for me and circled in red where they added the single lugs on the inside and outside.
I was doing a new delta-wye hammond transformer today and noticed they started putting a single hole mechanical lug on the outside with a bolt going through attaching to another single lug with a grounding symbol sticker (i circled in red on the picture where they added it). They also included a descent sized xo busbar. I wasn't sure how to utilize these while being code compliant?
It almost looked like they wanted you to use the outside chair lug for GEC and possibly use the inside for system bonding jumper? I would need to swap it to a 3 hole mechanical lug to give me a place to terminate equipment ground and be bonded to the transformer. My other thought was they added room on XO busbar to now make it a SBJ busbar and I terminate everything on it. To me this seems really weird and I would still need to bond it to the frame and the exterior lug would be useless because I can't terminate my GEC there because it has to be at the same point as the SBJ.
Any thoughts on these new features/accessories would be appreciated, I could just be stuck in an old mindset of my old installs.
I attached a picture of a pretty typical install for me and circled in red where they added the single lugs on the inside and outside.
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