"Tom Horne" wrote in message
...
On Jul 5, 1:04 pm, RoyJ wrote:
Assuming a nominal 240VAC supply, 245V is in no way "not correct" --
it's only
about a 2% overvoltage.

And since there is likely no load in shop when the install was taking
place, the 245 would be a higher than normal reading.

But I question the use of "3phase" and "245 volts" in the OP question.
Around here, 245 volts would be perfectly normal for a single phase
circuit, very high for a "standard" 208/3 phase delta.

Roy
Three phase delta would not produce 208 volts unless it was a customer
provided special purpose transformer. Three Phase Delta can be wired
as corner grounded, grounded center tap in one phase with the opposite
phase being the odd higher voltage to ground known as the wild leg or
stinger, or completely ungrounded with or without ground fault
detection. The way you end up with three phase 208 is to wire the
transformer in a wye or star configuration with the transformer
primary taps set to produce 120 volts to ground on each of the three
secondary legs.
--
Tom Horne

The sole exception to that is if the wild leg is wired to ground. It then
yields 208 volts, at least on my panel.

No, I don't use it that way. Just tested voltage out of curiosity.

Harold