From 1 January 2004 the mains supply should be 230V (-6%, +10%), 50 Hz (±1%). ie a range of 216.2 - 253V
This replaces the UK's former specification which was 240V ±6% (ie a range of 225.6 - 254.4V)
Variations should still be anticipated in some areas as the voltage will drop during periods of...