Diesel writes:

(Michael Moroney)
news alt.home.repair, wrote:

Up the street from me, they upgraded a MV distribution circuit
from a lower voltage to a higher one (13,800V I believe).

Have they been adding on to the circuits in your area? New buildings,
etc? What was the previous voltage?

No new construction/new loads in that area. It may have been done to
allow that circuit to provide an additional 13.8K feed to a medical center
a ways upstream. I am uncertain of the old voltage but the nameplate for a
regulator transformer on a nearby old circuit reads 2400V which seems kind
of low. The utility seems to have been upgrading other older/lower voltage
circuits in the area as well.

I've also seen the results of that type of surge. The top of a
pole broke in a storm and the 4800V MV distribution wires made
contact with the 120V/240V feed to houses. Two of them burned to
the ground.

Ouch! I've seen this happen before too. Doesn't typically end well for
the building and/or the electrical system/attached devices inside.