Thanks.

The result was that throughout the 20th century, the US had to cope with problems such as light bulbs that burnt out rather quickly when they were close to the transformer (too high a voltage), or just the other way round: not enough voltage at the end of the line (105 to 127 volt spread !). Eventually the problems were solved by supplying all buildings and houses with 240 volts split into two 120 volt circuits which, between them, feed all the house’s receptacles. The common neutral wire is connected at the centre point of the split 240 volts on the main panel. The full 240 volts is used for powerful appliances such as ovens and clothes dryers. Mind, Americans who have European equipment should not connect it to these outlets, since the phasing is wrong.

https://www.worldstandards.eu/electricity/why-no-standard-voltage/

Devices which use Induction motors will be the most affected, from wall clocks  machine shop equipment. Valve TVs used the mains frequency as a clock pulse and some mains powered clocks rely on the "synchronous" motors to stay on time. If you connect a 60Hz clock to 50Hz mains, it will run slower and get further and further behind. Reversing the situation, means the clock will run faster.

https://www.quora.com/What-happens-if-I-use-a-60-Hz-appliance-in-50-Hz?