Originally posted by: awaygood
Does anyone have a definitive answer to why (in the UK, at least) transmission/distribution voltages are multiples of eleven.
Except 400V and 400 kV....?
declared, nominal, line-voltages are divisible by 11 and some are not. I've seen the form factor explantion (which is 1.111 for a sine wave, although transmission line voltages are never pure sine waves). Its tenuous - what would be the real-world benefit?
I'm more inclined to think it was a 10% volt-drop safety-factor back in the day, which given the distances involved, and the lack of decent on-load voltage regulation, seems reasonable.
21 February 2014 at
07:38 PM by