On Fri, 17 Jul 2020 07:59:47 -0600, bud-- wrote:

In the NEC thing changed to high voltage at 600 V. In the 2017 NEC in
many places that was raised to 1000 V.

Sort of, they really just added the category "1000v or less" but there
are still plenty of articles that deal with "600 or less". That is
mostly driven by the materials we use.