Faulty meter?

[skye16]

Hi

I have noticed that recently my electricity use has shot up. When I did some checks I was surprised to see that my meter is still recording, even when everything is switched off and the main fuse box switch is off.
I've phoned the power company and they have arranged a visit for 16 days time. I told them my meter must be faulty, but they say the electricity must be going somewhere. They said there is a £90 call out charge if the meter isn't faulty.
I live in a house at the end of a village, with one other house. Could there be a fault in the supply line to our two houses? Or can the fault be in my house, when everything is off?

Thanks for any advice.

 

[Lectrician]

Photo of metering and consumer unit(s)?

 

[bernardgreen]

Take photos of the meter each day for your records for reclaiming the money the supplier will have over charged if the meter is faulty

A video of the meter recording usage that also show in the same image main switch and all MCBs at OFF will also help make your case.

 

[PrenticeBoyofDerry]

Also note down the usage of the meter over the period you are waiting and any periods when the useage increases/reduces.
If you could post pictures of you installation it may help, some systems have more than one isolation switch, I would be tempted to remove all loads from the system, so unplug everything and remove any fuses from FCUs keep lights off and see if the usage has reduced/stopped.

 

[ericmark]

I would switch off main isolator on the consumer unit / fuse board and then look at meter does it turn.

Then switch on isolator and switch off all MCB's/remove fuses again does it turn.

Never stripped down a meter but wonder if a neutral earth connection would cause it to turn? If it does then a loss of earth could make the meter change readings.

Since the main isolator will isolate neutral and MCB's will not if with isolator off it stops and with MCB's off it does not then it will point to a neutral to earth fault.

 

[Lectrician]

Since the main isolator will isolate neutral and MCB's will not if with isolator off it stops and with MCB's off it does not then it will point to a neutral to earth fault.

Or reverse polarity, and an N to E fault somewhere in the installation.

 

[bernardgreen]

In almost all meters the neutral is only a voltage take off with no current measurement of the neutral current. Often there is just a metal block with terminals for incomer neutral and outgoing neutral and a small terminal for the metering circuit to get the neutral reference. The exception might happen in a three phase meter where the neutral current is measured to monitor load balancing on the phases.

Neutral to earth faults are unlikely to affect the meter as it has no earth connection.

One reason for higher than expected readings is when the next door neighbours taps into your wiring by accident ( or intentionally to get free electricity )

 

[ericmark]

Thanks I have never stripped a meter.

As to next door yes had that. Road was steep and houses staggered as they went up the road. New owner asked me to remove a socket half way up the wall.

Since house still not occupied turned off main isolator by luck I was using a neon screwdriver which lit up. Meter out and yes was live. Re-checked isolation and yes isolated.

Knocked on next door and asked if they would turn off power and yes connected to their supply. Seems there had been a few owners and it was normal practice to give key to next door to feed cat while on holiday.

It also taught me a lesson always test for dead and neon screwdrivers are a good safety item for identifying when something has gone wrong like borrowed neutrals or power returning while working for any other reason.

However he says everything is turned off. The big question is where is it turned off? If at consumer unit then clearly a problem. But if just a sockets may be something has been missed.

Main problem with high bills is items like faulty fridge or freezer. I use a power meter from time to time on fridge and freezer as any insulation break (heat not electric) down will cause the motor to run for longer so power used over 24 hours is what is required not just power motor is using.

Also had faulty switches but this was in the days of valves where the heaters used a lot of power.

With thoughts on heat my wife uses same setting for most washes and tends not to look at the dial but washer and dish washer my grand children have in the past twiddled the dial.

 

[skye16]

Hi
It's strange, but when I checked today, it's back to normal.
I didn't mention that I had Economy 7, with a separate circuit for 3 storage heaters. The night time meter was correct, but the day time was definitely wrong. Could the units somehow be going into the storage heater circuit? Should I be getting an electrician in, rather than getting the meter checked by the power company?
The wiring for the heaters was only done about four years ago, by a professional, and approved by the electricity provider.
One last thing, which may sound daft, but I'm not sure about these things. If the underground cable to the two houses was damaged, it couldn't put electric from the other house on my meter could it?

Thanks.

 

[securespark]

You must have two fuseboxes?

One for regular circuits and one for E7?

If this is the case, were both off when you checked the meter for rotation?

If the movement was on the normal reading were all your regular household circuits off?

Because it could be that something (like a water heater) was on "boost" during the day, running around 3 kW and that would show fair movement on the meter.

 

[plugwash]

Neutral to earth faults are unlikely to affect the meter as it has no earth connection.

That is true if the meter is wired correctly.

However if the meter is wired incorrectly so it measures the netural current instead of the live current then a neutral to earth fault could affect it.

Not that any of this is relavent to the current case. The thread starter cliams it happens when the main switch is off, so either there is a faulty main switch, a branch in the wiring before the main switch or the meter is faulty.

 

[JohnW2]

Neutral to earth faults are unlikely to affect the meter as it has no earth connection.

That is true if the meter is wired correctly. ... However if the meter is wired incorrectly so it measures the netural current instead of the live current then a neutral to earth fault could affect it.

You appear to be contemplating an incredibly improbable combination of circumstances!

However, if the meter were (incorrectly) measuring neutral current and if there also were an N-E fault, wouldn't that have the effect of reducing, rather than increasing, the metered electricity usage?

Kind Regards, John

 

[JohnD]

how about those photos?

 

[ericmark]

I read the last post with interest there are many ways to meter off peak power and we have no idea of which is being used. I will admit at first I though economy 7 was a system and expected every house with it to have a white meter but that is not the case it's a tariff.

In some early systems one would have two immersion heaters the one from the white meter being set to a higher temperature to the one off the black meter and the black meter one was placed higher in the tank.

I have seen where a white meter immersion heater fails the user being unaware as black one auto took over. In the more modern system we had the manual boost button which does seem a better idea.

I don't know if we still have white meters or have they all now gone?

The other point from original post is although he states main fuse box switch is off he does not say how many fuse boxes. Fact he says fuse box I assume an old installation and I know with many houses it's common to add extra consumer units where there are no spare ways. With my mother for example the chair lift is on it's own mini consumer unit and the battery charger must always be causing a small amount of power to be used.

I would guess something to do with the off peak system and something which should be only using off peak is instead using non off peak power. It only needs a clock to be set wrong. If something switches off too late it could have absorbed enough power when we have warm weather but not in cold weather.

But really we need that first comment to be satisfied. Pictures of meters and fuse boxes will show what is likely going on.

Personally I would have just swapped supplier with a threat of £90 I am sure one will check meter for free?

 

[plugwash]

I read the last post with interest there are many ways to meter off peak power and we have no idea of which is being used. I will admit at first I though economy 7 was a system and expected every house with it to have a white meter but that is not the case it's a tariff.

AIUI with economy 7 you have one meter with two rates on. So at night you get all your electricty at off-peak rates. There may or may not also be a switched supply that only comes on at off-peak times.

This is different from the old white meter system where only the dedicated off-peak supply was at the lower rate.

I don't know if we still have white meters or have they all now gone?

I think my granny still has such a setup.