Economy 7 - possibly faulty meter/wiring - help please

Tallerdave

A clip on energy monitor will help with the detective work.

TheLookingGlass

Thanks for the tips all.
We will run these tests shortly. Both tied up with work and back and forth from the flat at the moment but will do them soon and come back to you.
I'll also come back with photos of the meter board and consumer unit if you think that could be helpful.
TBH coffeehound, we'd love a smart meter switch. Then at least we could easily see what's going on.
If we're struggling with the accuracy tests on the wheel, then would something like this work?
https://www.amazon.co.uk/geo-Minim-Energy-Monitor-Self-Installed/dp/B018WB6IXG/ref=sr_1_6?dchild=1&keywords=House+Energy+Monitor&qid=1623336917&s=diy&sr=1-6

Carrot007

TheLookingGlass said:

Thanks for the tips all.
We will run these tests shortly. Both tied up with work and back and forth from the flat at the moment but will do them soon and come back to you.
I'll also come back with photos of the meter board and consumer unit if you think that could be helpful.
TBH coffeehound, we'd love a smart meter switch. Then at least we could easily see what's going on.
If we're struggling with the accuracy tests on the wheel, then would something like this work?
https://www.amazon.co.uk/geo-Minim-Energy-Monitor-Self-Installed/dp/B018WB6IXG/ref=sr_1_6?dchild=1&keywords=House+Energy+Monitor&qid=1623336917&s=diy&sr=1-6

No that one monitors the led. You need on to clamp onto the incoming cables. (they are bad at low usage but great for a test using a 2kw heater or something).

Gerry1

If anyone uses a 'flashing LED' monitor to check a meter that is telling lies, by definition they'll never get the truth !

Carrot007

Gerry1 said:

If anyone uses a 'flashing LED' monitor to check a meter that is telling lies, by definition they'll never get the truth !

Possibly. I have dissasembled a few meters in my time. The led flash is often a complete seperate circuit to the monitoring side. And so it should be. Of course that could be faulty too and I ebt more modern meters cut corners and don't have seperate circuits.

coffeehound

To be honest you could probably not bother with a separate monitor.  The 'blackout test' shows that there is no other property drawing power, and the level of usage therefore appears unrealistic.  Maybe worth repeating that test a few times at different times just to be sure.

The known-load test suggested by posters earlier should be good enough to prove if there is a gross metering inaccuracy.  
If the meter is shown to be inaccurate, the OP can safely then ask the energy company to formally check the accuracy, and then use the result to reclaim for over-charging on past usage.
If the known load test is inconclusive, maybe that would be a good time to double check with an energy meter.
If the known-load test shows that the meter is under-reading (which seems unlikely), then maybe that would be a good time to request a Smart meter to be installed

Gerry1

Carrot007 said:

Gerry1 said:

If anyone uses a 'flashing LED' monitor to check a meter that is telling lies, by definition they'll never get the truth !

The led flash is often a complete seperate circuit to the monitoring side. And so it should be.

But surely there should be just One Source of The Truth?  It wouldn't make sense to have one (calibrated and expensive) measuring device with outputs to the LCD display and comms hub plus another measuring device with an output to a red LED.  That would be a waste of money and achieve less nothing: the LED signal just makes it easier to see the instantaneous consumption at a glance as well as offering a simple interface for external devices.  It would really set the cat among the pigeons if the results differed.

Such duplication only makes sense in safety critical voting systems, e.g. sensors on aircraft.

Carrot007

Gerry1 said:

Carrot007 said:

Gerry1 said:

If anyone uses a 'flashing LED' monitor to check a meter that is telling lies, by definition they'll never get the truth !

The led flash is often a complete seperate circuit to the monitoring side. And so it should be.

But surely there should be just One Source of The Truth?  It wouldn't make sense to have one (calibrated and expensive) measuring device with outputs to the LCD display and comms hub plus another measuring device with an output to a red LED.  That would be a waste of money and achieve less nothing: the LED signal just makes it easier to see the instantaneous consumption at a glance as well as offering a simple interface for external devices.  It would really set the cat among the pigeons if the results differed.

Such duplication only makes sense in safety critical voting systems, e.g. sensors on aircraft.

Well yes, though the meters with dual circuits are more expensive ones not used in the domestic market. I would suspect the 10 year throw away domestic ones used are pretty poor quality! Also I would bet the led section would not be officialy calibrated where is is seperate. But that's just me thinking as I have really not looked into it that much!

QrizB

Carrot007 said:

TheLookingGlass said:

If we're struggling with the accuracy tests on the wheel, then would something like this work?
https://www.amazon.co.uk/geo-Minim-Energy-Monitor-Self-Installed/dp/B018WB6IXG/ref=sr_1_6?dchild=1&keywords=House+Energy+Monitor&qid=1623336917&s=diy&sr=1-6

No that one monitors the led. You need on to clamp onto the incoming cables. (they are bad at low usage but great for a test using a 2kw heater or something).

If you're into your DIY and/or are knowledgeable and confident with electricity, something like this might be more use in the longer term:

https://www.ebay.co.uk/itm/393241392590 (I have the HT206D which also measures DC current, but that's twice the price).

TheLookingGlass

My mistake, I had read "Minim+ reads the current going through the live cable of the electricity meter" on that product page.
Qriz - how does that one work?
Looks same as this - I can just put it round the meter cables and it should show the kw usage?
https://www.amazon.co.uk/Meterk-Multimeter-Capacitance-Resistance-Temperature/dp/B073Y162BZ/ref=sr_1_10?dchild=1&keywords=energy+monitor+clamp&qid=1623417404&s=diy&sr=1-10
I imagine it would be tricky getting it round those cables though.