I have a question, existing building has a 3-wire 1Ø feeder, which was allowed when installed, a new structure was built 29 years ago that was attached to the existing structure & a Ufer was installed in the new building but never used since the existing disconnects were left alone, fast forward almost 20 years & the original part of the building was razed in order to get proper footings & a concrete floor, a Ufer was also installed, when he existing equipment was reinstalled on the new structure, would both Ufers be required to be used? There was only a few feet between both rebar stubs so they were tied together, and it's still a 3-wire feeder, although that will change that is a advantage having a oversized UG conduit.
