450.10(A) and System bonding jumper

[Isaiah]

I noticed that NEC 450.10(A) requires a bond to the dry type transformer case - does this suffice for the system bonding jumper?


Sent from my iPhone using Tapatalk

 

[infinity]

It requires a terminal bar bonded to the enclosure. By connecting the SBJ to the terminal bar you have bonded the enclosure to the X0.

450.10(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.
Exception: Where a dry-type transformer is equipped with wire-type connections (leads), the grounding and bonding connections shall be permitted to be connected together using any of the methods in 250.8 and shall be bonded to the enclosure if of metal.

 

[Isaiah]

It requires a terminal bar bonded to the enclosure. By connecting the SBJ to the terminal bar you have bonded the enclosure to the X0.

So basically you still have to ensure a SBJ is attached to the enclosure— sized per T250.102(C)(1)


Sent from my iPhone using Tapatalk

 

[infinity]

So basically you still have to ensure a SBJ is attached to the enclosure— sized per T250.102(C)(1)


Sent from my iPhone using Tapatalk

Correct. For smaller transformers you can usually loop the GEC through the terminal bar on its way to the X0.

Funny thing about this code section is that it has been in the NEC for several years yet we still see brand new transformers without the required terminal bar.