How is the digital electric meter and the economy 7 switch syncronised, does the digital meter change over automaticaly or is a signal sent by the mechanical economy 7 changeover switch,i e the one that allows the storage heater board to become energised at midnight.
You will have a timer, or a radio teleswitch near your meter. This ells the meter to switch over to the night rate.
It can also signal other equipment to turn on, but this can also be done with a separate timer.
If you take some photos of your meter and associated equipment, I can probably tell you how your's is wired!
(Don't post the pictures here, upload them somewhere (like Photobucket) and then post the links here)
Sparks...
I have loaded it onto photobucket what is the thin grey wire for, from the timeswitch to the meter?
You need to post the link here before we can see the pictures!
sorry here it is
timeclock back to the meter will change between rates.
Owain
OK - don't take this as gospel...
White cable entering from top right is your incoming supply, changing to black in circular junction box and going to the cutout black box, bottom left.
meter, top left. From the meter (both brown again) they go the Henley block in the centre.
the box, presumably to your consumer unit.
The other phase and neutral from the Henley block, neutral goes straight out (top right), and phase goes through the mechanical timer (where it's switched) and then follows the neutral (top right) out of the box and presumably to your off peak consumer unit.
Finally there's 2 thicker grey wires that are the permanent power supply to the timer and a single thinner grey wire to your meter which signals which tariff to charge.
That white cable is an outgoing supply to the garage from my main fuseboard, the signal to change tariff is just a 240v supply then?
Nope, that's an installation cable, looks to be no more than 2.5mm TWE. Probably goes to outside lights, pond, garage.....
You can't see the very bottom of the box, which would probably show both cables exiting through the same hole.
Hey - I'm confused then. I was assuming that the black cable coming into the bottom of the cutout (bottom left) looped round just out of shot and ws the same black cable that comes up on the extreme right?
I was thinking it looked a bit odd for the supply cable! Funny how my eye filled in a loop of black cable at the bottom.
It must be doing substantially more that that...
Look again at the photo. The supply to the timeclock ( and it's downstream load ) is unmetered! ( The grey tails bypass the meter, coming directly from the incoming supply)
Unless this is some kind of un-metered off-peak tarriff (!), then there must be some metering components ( Current transformers, and perhaps more ) within the timeclock unit.
The thin grey wire must be providing metering info back to the meter for it's off-peak rate.
I can't see any other way the off-peak can be metered from that photo.
The grey tails bypassing the meter are for the timeswitch motor ONLY. The customer is not charged for the electricity consumed by the supplier's timeswitch motor. There's no way those weedy wires would be suitable for full off-peak heating.
The timeclock's switch supply is the extreme-right-rear wire on the Henley block (metered) to the left-hand timeclock terminal, and its load is the right-hand terminal.
The timeclock's switch does not have a neutral,
No.
The off-peak is metered by the single grey wire (probably) going live, as it appears to be on the switched live side of the timeclock, which switches the meter from high to low rate.
Owain
The key here is that your terminology was exactly correct. ;-)
Those grey tails to the clock are just the supply to power the clock and nothing else[1].
The actual power that is fed out to the switched CU comes from the rightmost position of the henley block via the red/brown tails. (the neutral going directly to the switched CU bypassing the clock)
Follow the red/brown tails and it all makes sense.
[1] While they look rather heavy (16mm^2 I would guess) for just a clock supply, they probably wired it like that to save needing a secondary fuse after the main one to protect the clock tails - which is what was happening with that install I posted about a few weeks ago:
Perhaps the reason the tails for the motor supply are so large ( compare to the 2.5 T+E in the picture.. ) is that anything smaller would be inadequately protected by the only protection it has - the supplier's fuse?
Or just that you can't secure anthing as tiny as 1.0 mm^2 into the incoming terminals?
Or both?
I presume you mean my terminology about looking at the photo again :-) Yes indeed.
I see that now... I also theorised later about why the motor supply was so heavy.
It's good to learn something every day :-)
Thanks
Yes, fused at probably 100A
You can if you do it carefully.
Owain
... And which is far more usual. I've never seen this type of set-up before without a separate small fuse (sealed, of course) for the clock supply.
Another interesting thing about this type of set-up is that the switching which controls the meter is in the neutral - i.e. the thin grey-sheathed wire is connected to an auxiliary contact in the timeswitch which connects to neutral to request night-rate metering, and goes o/c for day-rate.
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