"Peter Andrews" wrote in message
...

"Arfa Daily" wrote in message
...
A few months back, my old mechanical meter was replaced with one of these
small white Landis & Gyr jobs that has an LCD display, and a small blue
button to cycle through the available displays of recorded units, totals,
time etc. I check it most days, and was surprised to find that this
morning, at 9am, it was still reading Economy 7 units - or whatever they
call them these days. A few minutes later, the reading had increased by
one, confirming that it was indeed still recording night units. I scrolled
through the readings, and was intrigued to find that the clock was 4 hours
slow, so the meter did indeed 'think' that it was still in the Economy 7
period.

So, does anyone know how the clock is set on these ? I was present,
chatting to the fitter the whole time he was doing the job, and I don't
recall him doing anything to the meter, other than removing it from the
box, screwing it to the board, and wiring it in.

I'm thinking that maybe time synchronisation signals are superimposed on
the grid, and that these meters can read them, or maybe that they have a
DSF type receiver in them for getting the time - in fact now that I think
about it, I have a dim recollection of reading that somewhere. But in
either case, I would have thought that the update was every few seconds,
or minutes at worst, so how did my clock get 4 hours behind in the first
place, and why has it not 'caught up' ? It was correct yesterday, so it's
something that's happened 'suddenly'.

At 11am, it changed over, confirming that this is all down to the clock
having the wrong time. I wonder who, in the event of this carrying on for
any length of time, is responsible for the fact that I would be getting
'cheap' (er!) electricity for 4 hours longer than I should be ... ? :-)

Arfa


Our flats communal lighting hallways, stairs and car park switches to
cheap rate at night - except that the time switch was hours slow so we
paid peak rate all night the other winter as nobody (including the now
sacked managing agents) was monitoring the charges. EDF put the clock
right but wouldn't discuss any refund. Fortunately not a fortune between
24 flats but it is worth checking the clock. I also had a work colleague
whose clock was 12 hours slow/fast, now that was worth not complaining
about!

Peter



This morning, I spoke to my NDN, who is himself a fully qualified
electrician, and for many years owned quite a large electrical installation
company. I explained to him what seemed to have happened, and he said that
it could be quite intentional. He thinks that the electricity supply company
may well have 'altered' the clock by whatever method they use for
communicating with the meter, in order to implement load even-ing during the
night. As he said, if a 'proper' storage heater circuit, which is switched
by the meter, is in place, then it makes no odds when exactly that circuit
is live, as long as it's roughly during the night, and the meter is clocking
units at the 'appropriate' rate, which I suppose makes some sense. I did
query why, if the meter was able to be communicated with, the company would
choose to alter the clock, rather than reprogramming the switchover times,
and the only thing he could come up with there, is that it might be 'easier'
for them to do it that way, as the data overhead would be a lot less
altering a single parameter, than multiple ones. Valid point I suppose, but
I'm not convinced.

In the meantime, I flashed an email off to the meter manufacturer's tech
support department to see if they can throw any light on whether this is
deliberate, or a fault. I don't know if they will see fit to bother replying
to a lowly end-user, but you never know. I'll keep you posted if anything
interesting comes out of it.

Arfa