Had the same problem at a house I was called to. Homeowner did a new 200A service upgrade(himself) . There was a dimming problem when condensor kicked on. Added a hard-start kit, didnt help. I went on with the job at hand, and was not asked to resolve this issue.
I have noticed a trend lately with the poco's. On the last three service upgrades I did, they just kernied up to same wire from xmfr , without upgrading "THEIR" end.
Old, ate up wires and all. I brought to the attention to the last two guys that did a reconnect for me that the two houses were fed parallel from one transformer. neighbor just had a new 200A service done too! he said "hmm......we may need to upgrade our wire one of these days" Im like, no S^%$@#!
They are feeding both houses with #2 or #3 that is at least 20 years old.
Anywho, Im sure that could be a start to resolving the issue.
