I have a customer (kind of odd) that wants me to install a step up transformer to get him from 112V to 122V (Don't ask me why) so in theory I can just set a 35kva (based on connected load) and run the SEU into it and SEU or SER out of it to main branch circuit panel. Does the main panel now be to be wired a sub panel or not? I'm thinking old main is now sub since I need to bond grounded conducter in transformer? Is this even allowed in residential? This one has me confused a bit. I've done plenty commercial with service into the 277/480 panel then trans then Single phase sub panel but not quite like this. Any thoughts on this ?