Puzk,

I hope you live in a (former) 220 Volts 50Hz country and not in the States ?? (115V 60Hz)

The European Countries Line voltages are smoothly being upgraded from 220 to 240 Volts since a few years and may vary with plus- or minus 10 % under (ab)normal conditions. (Most equipment can handle this)

The 270 is too high and this needs to be corrected by your local technicians.

Looooong time ago I built myself a voltage regulator with voltage-meter : A Variac.

A Variac is able to decrease AND INcrease the voltage from 0% to 110% .
In your case a 'must-have' ??
(Costs about 150 Dollars)
Just check the voltage on the meter, re-adjust it to the voltage your equipment wants, plug in the equipment..... that's all.

Roel