As noted, meters can run fast, although it is rare compared to how many run slow.
The braking magnet can be weakened by lightning hits. The worst I saw was 30% fast...but the lightning also fried everything in the house as well. The newer (>40 years old) alnico magnets are hard to mess up and the electromechanical meter is one of the most dependable, accurate mass produced products there is.
Considering bearing failure, register drag, debris on the disk, fire ants, fire ants, FIRE ANTS and (did I mention??) fire ants, there are lots more reasons for it to run slow. So look for a reason for the high bills BEFORE you call the POCO, because if the meter turns out to be slow, they WILL speed it up.
Can't comment yet on the electronic ones. They don't have that much of a track record yet in my neck of the woods.
Qoute:
"If the power factor of a load is low, then the meter will register more watts than are actually used. Correct with capacitors, and the power bill goes down!"
I'll have to contest that. The single phase house meter is a Kwh meter. It will read watts accurately regardless of powerfactor. I think you are confusing Kva with Kw. There are meters that log Kvah and, in that case, you are correct that the Kva could be lowered by powerfactor correction. But not watts.
Quote:
"Around 1998 we still took out in Devonport, Auckland NZ, Ferranti FDb meters and Chamberlain & Hookham 10 Amps LR meters which were last tested in 1926. These had an average error of around 7 % at 10 Amps Inom. "
Curious as to whether they averaged fast or slow.
[This message has been edited by WFO (edited 12-25-2005).]
