2 Meters?

nmilner · Posted: Wed Mar 16, 2005 10:00 am Post Subject: 2 Meters?

Hi,

I seem to have 2 meters on my domestic supply. One is an old disc type which is not in use and the other a smaller digital style meter. The digital meter outputs go to a terminal block which then splits to feed two fuse boxes (1 via thick twin and earth and the other by more traditional tails). For some reason the old meter still is feed from the incoming supply and there is a wire that connects from the old meter to the output of the new digital meter. What is this for? I realise that this is rather hard to understand from my description so I have a picture available here:

Any help will be very appreciated.

Thanks

Nick

ban-all-sheds · Posted: Wed Mar 16, 2005 10:29 am Post Subject:

I didn't read your question fully at first, and after I looked at the picture, I thought "what's that single tail between the two meters for?"

But mainly I thought "what's that appallingly installed bit of T/E doing there?" Is it 10mm² or 16mm²?

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I mustn't warn people that the "experts" on the plumbing forum can't be trusted to tell the truth.

nmilner · Posted: Wed Mar 16, 2005 10:32 am Post Subject:

The T/E is appalling and I want it removed! I think its 16mm2. We have Economy 7 so is the second meter and connection between the 2 meters part of this?

mapj1 · Posted: Wed Mar 16, 2005 1:11 pm Post Subject:

The thin wire looks to be connected to the economy 7 radio switch output from the new meter, and so it may be they are using the contactors in the old time switch, if the timed heating loads are connectrd through there - you should have 2 fuseboards, one of which is only live at cheap rate times. Does anything still connect to the load side of the old time switch?
The other possibility is that it is the clock feed to the old time switch, but that should really have its own small fuse, and in any case with economy 7 being radio switched (Phase shifts on the radio 4 longwave carrier) it should not be needed for that.
Otherwise its just another example of REC laziness in not removing what was already there.
As an aside you appear to have PME, looking at the company fuse, (but no statutory warning label), in which case the main earthing cables are also not man enough for prospective fault currents.
Considering the meter claims to have been put in in 2000, its not a very nice installation.

regards M.

nmilner · Posted: Wed Mar 16, 2005 1:19 pm Post Subject:

Hi mapj1

There are 2 fuse boards but both are fed from the small digital meter. There is nothing on the load side of the old time switch. How do I know if my digital meter is capable of recieving the radio time switch signal? If it can recieve this then its likely that the reason the old time switch is there is due to laziness. I agree the installation is not nice - only recently moved into the house and spotted it needs attention.

Thanks

Nick

mapj1 · Posted: Wed Mar 16, 2005 1:53 pm Post Subject:

If both fuse boards really are on all the time, you dont have economy 7 at all, whatever they are billing you for !
An E7 meter has 2 live outputs, one on all the time, and one switched by radio whne the suppiers are in over production, i.e. off peak only (the display will show a little antenna symbol whe it has synchronised)
If there is nothing on the time clock output side, but it is turning, either all the time, or just at cheap rate times, that little thin wire is probably causing it to clock round...
Probably time to either ask for proper E7 to be installed, or for the old switch to be removed.
good luck.
M.
PS hope its not southern electric !

Lectrician · Posted: Wed Mar 16, 2005 5:00 pm Post Subject:

The small cable is a signal cable from the relay in the time clock, (the time clock may or may not also switch another CU on and off).

The signal cable tells the meter which rate to record on, either rate 1 or 2, peak and off-peak respectivly.

Econ7 puts ALL electric cheap at night, not just the switched supply to the rads. (the old white meter tarrif didn't)

If you have no storage rads, I hope you are making use of the cheap rate at night for your immersion, washer, dryer etc. If not, then the higher standing charge you get with Econ7 will not be worth it.

That T+E feeding the board needs sorting.

Any chance of a wider shot? The CU's could do with examining!

nmilner · Posted: Wed Mar 16, 2005 5:05 pm Post Subject:

I'm going to get both CU's replaced as they are the fuse wire type. I am going for 1 split load CU (probably Wylex). The T+E does need sorting. I think the earth cable needs increasing to 16mm2. Also, it is missing the statutory warning label. What should this label state?

Thanks

Nick

Lectrician · Posted: Wed Mar 16, 2005 5:09 pm Post Subject:

Depends what it is warning against

ban-all-sheds · Posted: Wed Mar 16, 2005 5:45 pm Post Subject:

mapj1 wrote:

As an aside you appear to have PME, looking at the company fuse, (but no statutory warning label)

Is there no chance that inside the service head the earth is connected to the sheath of the cable?

__________________
I mustn't warn people that the "experts" on the plumbing forum can't be trusted to tell the truth.

Lectrician · Posted: Wed Mar 16, 2005 5:56 pm Post Subject:

That type of head, with an external earth block is usually only found on a TN-S supply. PME heads have the earth block enclosed adjacent or combined with the neutrals.

When I say adjacent, I do mean with a jointing link before I get shot down!

mapj1 · Posted: Wed Mar 16, 2005 7:01 pm Post Subject:

OK, looking harder, do rememeber ahem, I said 'appear' as the edge of the photo does not allow a good look.
What I should perhaps have said was "You may or may not have PME ! -if you do there should be a label, but often it is missing, if you do then the earthing looks too weedy. " I did not say that , and must now live with it!

There is another black thing in that quarter too, is that part of the earthing arrangements, or the edge of an out of use JB?
The use of the old style clock, and its massive tails, to just switch the new meter between tarrifs is a new trick on me - are we sure that it really is doing that? - and if so its not E7, at least not the radio controlled version as southern electric understand it, it must be some other fixed times cheap rate, or your REC has fixed times for economy 7?
regards M.

Lectrician · Posted: Wed Mar 16, 2005 8:25 pm Post Subject:

It is not too clear in the photo, but it does look as if one CU is switched via the time clock.

The only control cabel swiching the meter tarrif would be the smaller DI cable with the sheath stripped back too far at the meter!

securespark · Posted: Thu Mar 17, 2005 12:07 am Post Subject:

Yeah

Agree with Lec, you need proper 25mm tails from meter & get rid of those SP henley's.

And a 16mm earth from the main terminal, too.