The allowed tolerance band changed and older, nominal 220V designed equipment has more often problems with it since then.
Until 1987, the mains voltage in large parts of Europe, including Germany, Austria and Switzerland, was 220 (± 22) V, while it was 240 (± 24) V in the United Kingdom . The voltage of 230 (± 23) V, which has been valid in Europe since then, was specified as the standard voltage in the international standard IEC 60038 : 1983.
From 1987 onwards there was a changeover in several stages
. Since 2009, the mains voltage has been allowed to be 230 (± 23) V, which means that 207 volts to 253 volts are permitted.
Electrical consumers specified for 220 volts could also be included when taking into account the tolerances valid from 1987 to 2009
be operated without seriously violating the tolerance conditions: At
the maximum voltage was 242 V.
the maximum voltage was 243.8 volts. This no longer applies since 2009, as the maximum voltage is now 253 V.
With the minimum voltage, the tolerance band was not and is not violated: While 198 volts were previously permissible, it is now at least 207 volts.
Increasing the voltage by around 5% leads to an increase in performance in many devices. For devices whose function is based on the ohmic resistance , e.g. B. fan heater or kettle , the consumption increases quadratically in relation to the voltage increase, i.e. by about 10% of the power. In many cases, the amount of energy to be paid for remains roughly the same, since a kettle, for example, heats up the given amount of water faster and switches off earlier due to its higher output.
In the case of incandescent lamps , this increase is slightly lower due to the usual PTC thermistor characteristics of the filaments. Increased voltages cause higher currents in the lines. In the case of incandescent lamps, however, a higher filament temperature leads to a shortening of the (statistically probable) service life.
Source:
https://de.wikipedia.org/wiki/Netzspannung