On Mon, 29 Apr 2013 14:24:18 +0000 (UTC), Andrew Gabriel wrote:

"Can shut down supply without warning - or your consent"

That's the main function of smart meters, which I already mentioned
in another thread.

I don't think any Smart Meter installations have the ability to
selectively cut the power to appliances. Whole supply maybe but not just
the Fridge.

There's actually a large timing range for things like fridges (and
even more, freezers) that can cycle on/off without going outside
temperature spec. They do represent an excellent opportunity to store
energy. For example, if you know you're going to have a mass toilet
flushing and kettle boiling at the end of a royal wedding/funeral,
you could switch on freezers beforehand so they drop an extra 1C,
and then switch them off when the extra load is needed, and they then
won't use any more power for an extended period whilst you get the
toilet flushing and kettle boiling over and done with.

Yes, that makes sense but that *isn't* what this device claims to be able
to do, Smart Meters *might*. This device is autonomous it just looks at
the frequency and switches off below 47 Hz on above 52 Hz(*). It's not
centrally controlled from anywhere. I guess one could artificially
increase the grid frequency to that extreme to trigger the devices but
I'd put that into the "bit risky" category. Power stations will trip off
on over frequency just as well as they do for under frequency.

(*) One would hope there would be some spread in the actual frequencies
that trigger the devices. Suddenly shedding or loading the grid with the
nations fridges might not be a good idea. I think it would require a bit
more control than just component tolerances as well.

--
Cheers
Dave.