William Fisher said:
Can anyone explain to me how an electricity meter switches between to
different charge rates, as with Ecco7 in the UK, I believe its something to
do with contactors?
Any ideas
You talking 'electro-mechanical' or 'electronic'?
Seen quite a few electronic ones. They have an internal clock and simply
totalize the kWhr into two different 'registers' based on time-of-day. Both
are measured by the 'meter-reader' and then billed accordingly.
Another technique for high-usage has been to record peak-power and total
demand every 15 minute interval with a 'timestamp' supplied by an internal
clock. Then the meter 'phones-home' every week or two, downloading all its
recorded data directly to the utility's computer system. These require a
dedicated phone line for the meter, typically not your residential service.
(these are US techniques, don't know in UK)
daestrom
