Was looking at a neighbours wiring ealier today, and noticed that it was a economy 7 setup. I had never studied exactly how they work before, but noticed a couple of interesting things...
Have a look at
J1 appears to be a split in the incoming neutral service before the meter (and in spite of appearances is not actually part of J2, just very close to it). B goes to the meter, and a secondary main cutout seems to serve the same purpose for the phase at E, which between them seem to be a dedicated feed to the timeswitch.
I am surprised that they bother to split this feed off before the meter rather than using the customers electrcity to power the timeswitch. Is this the usual way it is done?
Do these timeswitches have an internal battery or do they lose time during power cuts?
I presume the thin tail that connects to the meter from the timeswitch is just used to indicate when the timeswitch thinks it is in discount time, and cause the meter to record on the top set of figures rather than the bottom set?
Why bother putting seals on the screws of the service connection block after the meter?
The E7 has not been used since the 70s, so in a forthcoming replacement of the CU, and a rewire, the MK CU to the left will go and be replaced by a new split load unit[1] that will replace the MEM unit and the VO ELCB on the right. What is the best thing to do with the tails marked E7? I would be inclined to take them off to a service connection block where they can be made safe. That way they are still available for use at some point in the future if ever required.
[1] cascaded RCDs, one with time delay.