Yes they change the voltage starting 1980's was switching from 240 to 230 volts it was a 20 year plan with a low limit of 216 to high limit of 253 volts. This at the meter
If you have long run from the meter to tool you then have a greater drop
So if need to adjust for a motor it simple with a buck and boost

As far as 50 Hz to 60 Hz
The tools I had it past that had 50Hz motor I just ran tools for 20 year or more on 60Hz be for selling the tools working great on 60Hz. Some castes I replace the pulley with smaller one so RPM plate was right.

Dave