Whilst replacing yet another set of lightbulbs that had
blown after only a week I thought I'd look at the supply
voltage into the house. My UPS logs the voltage so this was
easy. 253 volts.
The UK used to be 240 volts (+/-10%) but quite a few years
ago the nominal voltage was changed to be 230 volts (half
way between the UK 240 and the European 220). In practise I
read that this meant very little, they just continued to
supply 240v which was within the tolerance. 253 volts is
also just within the tolerance, but annoyingly causes my UPS
to alert me every few hours. I also read that in 2002 the
tolerances are going to be adjusted to +/-6%.
Armed with all this information I called the electricity
company who actually said 253 volts was an emergency
situation and someone will be with me shortly.
Played around with the Linux IBM ViaVoice SDK so my UPS can
speak. "Help, the voltage is too high, I'm frying,l arrrrgh"