The other week I took a spur off from the ground floor ring main supply (direct from the consumer unit in the garage) to feed an integrated RCD/double socket for the pond pump and filter. When all the power was switched off at the consumer unit and all the fuses were removed (old fuse wire type) the meter continued to turn, albeit very slowly.

Do they take a long time to stop? It was disconnected for about 15 mins or so and was still turning very slowly. Is the meter dodgy?

The meter/company fuse is right next to the consumer unit and I proved all circuits from the consumer unit to be successfuly broken so current leakage can't be the cause.

any ideas? If the meter is dodgy what recourse do I have if it has been overcharging me?

cheers! :D

Not sure about the meter, but I would try and record how many units are being clocked up in a set period with all the outgoing circuits disconnected.

very odd :confused: , I think there's a chap on here that works for the leccy board, Tim Grove IIRC, he may know.

Not sure about the meter, but I would try and record how many units are being clocked up in a set period with all the outgoing circuits disconnected.

very odd :confused: , I think there's a chap on here that works for the leccy board, Tim Grove IIRC, he may know.
I'll give it a go tonight and see how much its turning. I was in a rush to get the power back on last time so I can't really remember how much it was clocking up. I try not to turn off the power for longer than 30 mins or so because the occupants of my aquarium tend to go a bit mental when the filter stops or the temp drops by a couple of degrees! :eek:

You need to get a digital clamp meter on the cables and check if it is using any current.

It could be many things.. What sort of earthing is used? is it a PME installation (Neutral & Earth bonded together)??

How old is the installation? Might be worth doing an insulation test, earth loop impediance test etc.

David

PS. I was allways told to fill a lemonade bottle with hot water and drop it in the tank when we had power cuts for my tropical fish..

David

You need to get a digital clamp meter on the cables and check if it is using any current.

It could be many things.. What sort of earthing is used? is it a PME installation (Neutral & Earth bonded together)??

How old is the installation? Might be worth doing an insulation test, earth loop impediance test etc.

David
I'm not sure how its wired to be honest. I only moved in last year and this is the first time I have really touched the electrics in this house. I am pretty sure its not PME though, the house is c.1980 so the earth is probably still attached to a gas or water pipe!

The problem is that with all the fuses removed current cannot be going anywhere after the consumer unit. I have tested between each fuseholder on the consumer unit with a multimeter that goes down into milliamps and there was nothing. The wire between the meter and the consumer unit is only about 2 foot long so not really any opportunity for leakage there. The only explanation I can think of is that the meter is using current itself, which surely can't be right?

I suppose there is an outside chance some muppet has wired something into the wrong side of the consumer unit (i.e. so it doesn't go through a fuse), but I certainly couldn't see anything before. Will take a closer look tonight!

PS. I was allways told to fill a lemonade bottle with hot water and drop it in the tank when we had power cuts for my tropical fish..

David
Good tip, but I think that would make them go even more mental! They are bit "highly strung"! :D

I have tested between each fuseholder on the consumer unit with a multimeter that goes down into milliamps

So you stuck a test lead in between, instead of the fuse :o

Did you switch everything in the house off first? I wouldnt recommend this way..

I would ONLY use a clamp meter.

David
David

So you stuck a test lead in between, instead of the fuse :o

Yup! :D


Did you switch everything in the house off first? I wouldnt recommend this way..

Of course I turned everything off first.... I've lost more multimeters that way! ;)

You got economy 7? Because it might be the tele/time switch.

Nope, don't have economy 7.

Think I'll have to leave this till the weekend when I'll have the time to do some proper analysis (blow something up ;) )

..just had another thought on this,:eek: ( thanks weed&stella ;) ), you need to check that there is an earth at the meter itself.


In layman's terms (i.e mine :) ), there is a current transformer inside your meter, and a connection to both live & neutral. Your meter uses the voltage obtained from live & neutral, and the current obtained from the CT to give you KWH. When everything is running normally there is always a flow of current through the the CT, the wheel on the meter spins round and everything is swell, so to speak.

When you pull the fuses you remove the current flow ( this is assuming there are no leaks at your consumer unit ( your's sounds pre-war, so it might be worth uprading / IR testing it). Although the current flow has gone, the voltage is still present, it is this voltage that creates a magnetic field in the CT, this in turn creates a magnetic field and heat within the CT windings.

I don't know why, but when CT's are normally installed, the S2 side of the secondary winding is bonded to earth, this is to stop the CT's burning out when there is no load.

My point is, is that if there is no earth at your meter, your meter CT could be acting as the "load" you are seeing, as there is no bond to earth.

If you have a 240V to 110V transformer, plug it in for 3 hrs and then feel it for heat, they also buzz. The heat and noise does just not happen, it "uses" elastictrickery.

In fact, I'll bet you 50p :eek: you have no earth at your meter :D

I havent seen any meters that have an earth connection ? AFAIK... (im no electrician)

David

surely the transformer thing is because they arent 100% efficient?

Meters don’t have earthing point’s mate, well all the one’s I’ve come across any how:). The coil that meters the supply will be bonded down to the neutral as neutral and earth are the same thing;).

But there is another thing it could be…..

How long are the meter tails?? If they are quite long and twisted as well that could be drawing a tiny little bit of load.

When on a training day at work we were shown how a disconnected, capped and unloaded service cable which was about 5 meters long can draw a small amount of current which wasn’t a problem but it’s the voltage it induces in the neutral that hurts.

the transformer thing is because they arent 100% efficient

exactly, nothing is.
in layman's, of course :D

Meters don’t have earthing point’s mate, well all the one’s I’ve come across any how:). The coil that meters the supply will be bonded down to the neutral as neutral and earth are the same thing
If you work with HV & the 415 side of the LEB, your meters won't have an earth, at least the one's I've come across anyway.

Not all domestic supplies are N+E.

:p

All new LV services and mains we lay now are combined neutral/earth, there wasn't really any point in having separate neutral and earth in the old lead sheath cable in the first place as the neutral(neutral core) and earth(lead sheath) were bonded together in service and mains cable joints anyhow. No point in having two conductors doing the same job, might as well just split the neutral and earth at the cut-out rather that laying miles of cable with an extra unneeded conductor. Customer’s only get separate neutral/earth if they pay extra for it now-a-days, which really I cant see the point in, because as I say neutral and earth are one and the same thing because the they’re just going to be bonded together in the cable joint.:p:D

Hi

Many years ago, I used to work for a electricity meter manufacturer -

If the meter is a "spinning disk" type, then they should stop within a few seconds of the current being inturrupted - a solid state meter should stop instantly.

The meter should have a plate within the window showing the manufacturing date. most are certified for 10 years and then need recalibration - modern meters are getting so cheep that most companies simply scrap them and fit another - the normal failure mode for the rotating disk type is they read low as the friction increases in the bearings - I dont think I've heard of them registering current when there is none flowing

Anyway, back to your question - if the fuse is out and the meter keeps turning either
1) The meter is knackered - in which case you can ask your supply company to send it away for testing and then you should get some sort of refund - my Gandmothers E7 meter jammed so both registers incremented together so she was paying for her electricity twice - I think her refund was thousands of quids as it had been happening for years

2) or you have not isolated your supply - maybe something else is tapped into the supply between your meter and the fuse - again you should be able to get some sort of compensation for that if you are powering someone elses house or the streetlight

I hope this helps

Jim

Thanks Jim!

I'll investigate further this weekend. It would be great if I am due a refund :D but knowing my luck it will be that some muppet has wired something in between meter and fuses! :rolleyes:

I can't think what, because I systematically went round the house checking things were switched off. It could be something like the doorbell transformer.... we'll see!

No other add-on fuseboxes for showers or cookers anywhere?


J.

Hi

I would doubt that a doorbell transformer would take enough current to register on the meter - the current range that a domestic meter is designed to measure is upto about 100A, so a few mA wont even register - I think you can take about 50mA for "free" before it starts to register

If the supply company does not seem interested, you need to take it up with the regulator (who I think are called Offer - but they might have had a trendy name change...)

Regards

Jim