It’s been interesting to figure out why a residence had dimming lights.. Once the utility companies-side of the meter was load tested fine, connections got cleaned up on the house side. The home is like 50 years old and was fed into the house, uniquely, under the garage straight into the basement. At the time of installation, 4/0 was used with a smaller bare stranded neutral. It was suspected that that bare sat in moisture inside a rusted pipe. Temporarily, new SE cable was laid on the ground around the house into basement, and dimming went away. It turned out, with the old feed hooked up again, and my right-angled drill pressed on, voltage dipped 12 ticks and rose similarly on the opposite leg! This lovely house must have felt haunted all the time!
I’ll quote it not reusing underground pipe with URD, though it’s tempting if the old wire pulls out. I’d route new 4 conductor above garage and down into basement, which would require a meter/disconnect combo and much more money. Drama begins whether home owner tackles this issue thats been going on for a year (without damaging loads), or leave it for the next homebuyers to figure out anew? I bet you these present homeowners are the tenth to own this house in this transient neighborhood, and fell unlucky to the neutral wire becoming deteriorated enough. What will they decide? I’m still newly fat.