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.