Thanks for your input. When the system was energized, some secondary voltage fluctuation was observed. I'm thinking that maybe the existing downstream Y:Y transformer(s) might not have been grounded the way you describe and in some fashion the primary ground was interrupted during the new work.
we thought that the existing downstream transformers were delta:wye...everything I've read discourages the use of wye:wye transformers in distribution systems because of voltage instability and harmonics. Now that we know we've inherited the wye:wye stuff downstream, how about grounding the...
I'm in the process of design of an upgrade of an existing 4160v 3 ph distribution system to a 12470 v 3ph system in order to take advantage of primary service rates. we have selected a 12470v:4160v (wye:delta) transformer to feed a part of the existing 4160v system that is in place for awhile...
