On Monday, April 29, 2013 3:53:31 PM UTC+1, Dave Liquorice wrote:
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.


That's what I was thinking, the appliances would either have to have some sort of TX/RX such as bluetooth or could be controlled through the mains but the fridge again would have to have the switching electronic circuits built in.

Whole supply maybe but not just

the Fridge.

That would be worrying, one could be playing an important game just about to reach a new level and the power goes off !!!!!!


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.


Would that really save that much, surely this would be more use in kettles than fridage/freezers.
Or as the govenrment uses scotland for such things just switch scotland off should we get low on power ;-)



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.


If it wasn;t for H&S I'd get my meter out and measure the labs frequency .
My cheap maplin brought power meter says 212V at 50HZ.