Transformer bonding

[Basic Electric]

I will be installing a 408/277 transformer for a new 208/120 panel ina retail space inside a shopping center. The MPD which it will be fed from is in another part of the building. My question is I obviously have to install a disconnect on the primary side of this installation using phase wires and a ground. The building has no copper or building steel within site or any that I have seen within any of the retail spaces to ground the secondary side of the transformer. How would you guys go about achieving this ?

Thanks in advance

 

[infinity]

The building must have a GES (grounding electrode system) where is that located?

Welcome to the Forum.

 

[Basic Electric]

Thanks for the reply and welcome. I have not seen MDP side system as of yet, so I'm not sure. In all of my years this will be the first time I have installed a transformer outside of the panel room and without building steel. So it did stump me. I am meeting with the building owners representative to gain access to the mechanical room next week.


Thanks again

 

[masterinbama]

In structures such as this I pull a ground sized for the secondary bond and tie it back to the buildings GEC system.

 

[Basic Electric]

Thanks again for replies. This is easier than I thought, they installed a ground plate on the same wall in the room adjacent to my equipment room it os literally 6' on other side . Everything is bonded there.

 

[btharmy]

No steel bar joist or beams above?

 

[Basic Electric]

No, the ceiling is concrete . It's all good, the MDP on the other side of the wall along with the CT cabinet. The EGE is 6' from where my transformer will set it is a busbar mounted to the block wall everything is bonded at this point . One 1/2" hole in the wall,fire caulk and a lug then it's a done deal.