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Without mentioning smart meters, can anyone recommend a real time usage monitor for electricity? Easy to use/install (clamp on?) and preferably cheap. Thanks.
Real time electricity usage monitor
- Thread starter Ihavenojob
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A wired one, seen ones where a sensor is clamped to the supply cable at the meter.
The electricity meter is not that precise.
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I have looked at Energenie MiHome, but only because I already have their stuff. I had a free one from Scottish Power, but the first question has to be why?
The Scottish power device did basic same as smart meter, it was before smart meters, and idea was it connected to internet and sent info on how much power used to Scottish power so my bills were closer to what I had actually used, not spot on as it did not measure voltage, but over the year bill was within £10 of what I had used on the electric meter, so in real terms near enough.
I now use three plug in devices, the internet connected ones Energenie give me this
not bad, but the non internet also gives power factor etc.
The one giving all was rather useless, to check one item, you need nothing else switched on, it did as designed it told Scottish power what to charge me, but it was to me no better than a toy, in fact the plug in ones are really toys, the one shown is monitoring what power my beer brewing is using, if it is switching on/off then beer warm enough, if not then beer under temperature. I have also used them to monitor my smart chargers, and check the freezers using the power it should use.
It was an error buying the first smart plug, I thought I could use it with the remote control, however it did not work with it.
I suppose when I go on holiday I could see how much my RCBO's use, but what is the point, not going to switch them off, and could use the clamp on ammeter to do that, so the big question is why do you want to measure power used?
The Scottish power device did basic same as smart meter, it was before smart meters, and idea was it connected to internet and sent info on how much power used to Scottish power so my bills were closer to what I had actually used, not spot on as it did not measure voltage, but over the year bill was within £10 of what I had used on the electric meter, so in real terms near enough.
I now use three plug in devices, the internet connected ones Energenie give me this
not bad, but the non internet also gives power factor etc.The one giving all was rather useless, to check one item, you need nothing else switched on, it did as designed it told Scottish power what to charge me, but it was to me no better than a toy, in fact the plug in ones are really toys, the one shown is monitoring what power my beer brewing is using, if it is switching on/off then beer warm enough, if not then beer under temperature. I have also used them to monitor my smart chargers, and check the freezers using the power it should use.
It was an error buying the first smart plug, I thought I could use it with the remote control, however it did not work with it.
I suppose when I go on holiday I could see how much my RCBO's use, but what is the point, not going to switch them off, and could use the clamp on ammeter to do that, so the big question is why do you want to measure power used?
Really? I don’t believe it.
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To try and see what energy is used at specific times, whether there is a certain peak load to see if solar panels are viable.
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My clamp on meters will show current flowing 
but they do not record time, so I can put it around the tails, and see by turning off all the RCBO's then turning them on one at a time what each circuit is using, but what does that tell me?
If I take my old Sky+ box as an example, it has around three power ratings, in full stand-by only one LNB is powered, around 5 watt, and most the box is dormant, it uses more when supplying the TV with a signal, around 12 watt, and even more when the second LNB is activated around 18 watt, which I found out years ago before going to SkyQ, where the free to air satellite box in stand-by used less than the meter could measure, but if a program was running early or late, it would not adjust record times. Knowing the Sky+ box was using the power did not change what I did, so it was of no benefit knowing.
However when my mothers freezer was using 68 watt when running, and 680 watt/hours when running for 10 hours, this alerted me to fact it was not switching off, turned out the thermostat was faulty, explained why she was complaining ready meals were cold in centre, they were at -24ºC not -18ºC. But would have never found this with a meter measuring all, needed a meter measuring just what freezer is using.
I remember fitting data loggers to tower cranes, as the client had site cameras which seemed to show cranes not being used, here looking at the time between samples, one frame every 10 minutes was missing crane being used, and the same goes for any data logger, look at the graph of date used that I have posted in last post, and clearly the heating pad switched on/off, so should be straight line graph, but it shows a slope.
An old fridge motor will likely draw around 10 amp on start up, but less than 1 amp on run, sample rate is important. I remember working on analogue PLC's but not really analogue, it was 256 steps, computers are digital, gone are the days of using the AVO Mk8 so even my clamp on meters have a sample rate.
So why you want to measure is rather important, I have never repaired the old Scottish power energy meter, the battery box has corroded, but in the main my clamp on meters do what I need, how many mA flowing to earth, how many mA DC flowing, what is total amps used.
To see if solar panels are going to help, in the main can be done by seeing what equipment is installed, but when only wanted for a short time, then hiring a data logger is the way to go.
But reading the meter every ½ hour will give you a good idea, and your only looking at approx anyway, so reading at 9 am and 4 pm is likely good enough, hardly reason for using any data logger.
but they do not record time, so I can put it around the tails, and see by turning off all the RCBO's then turning them on one at a time what each circuit is using, but what does that tell me?If I take my old Sky+ box as an example, it has around three power ratings, in full stand-by only one LNB is powered, around 5 watt, and most the box is dormant, it uses more when supplying the TV with a signal, around 12 watt, and even more when the second LNB is activated around 18 watt, which I found out years ago before going to SkyQ, where the free to air satellite box in stand-by used less than the meter could measure, but if a program was running early or late, it would not adjust record times. Knowing the Sky+ box was using the power did not change what I did, so it was of no benefit knowing.
However when my mothers freezer was using 68 watt when running, and 680 watt/hours when running for 10 hours, this alerted me to fact it was not switching off, turned out the thermostat was faulty, explained why she was complaining ready meals were cold in centre, they were at -24ºC not -18ºC. But would have never found this with a meter measuring all, needed a meter measuring just what freezer is using.
I remember fitting data loggers to tower cranes, as the client had site cameras which seemed to show cranes not being used, here looking at the time between samples, one frame every 10 minutes was missing crane being used, and the same goes for any data logger, look at the graph of date used that I have posted in last post, and clearly the heating pad switched on/off, so should be straight line graph, but it shows a slope.
An old fridge motor will likely draw around 10 amp on start up, but less than 1 amp on run, sample rate is important. I remember working on analogue PLC's but not really analogue, it was 256 steps, computers are digital, gone are the days of using the AVO Mk8 so even my clamp on meters have a sample rate.
So why you want to measure is rather important, I have never repaired the old Scottish power energy meter, the battery box has corroded, but in the main my clamp on meters do what I need, how many mA flowing to earth, how many mA DC flowing, what is total amps used.
To see if solar panels are going to help, in the main can be done by seeing what equipment is installed, but when only wanted for a short time, then hiring a data logger is the way to go.
But reading the meter every ½ hour will give you a good idea, and your only looking at approx anyway, so reading at 9 am and 4 pm is likely good enough, hardly reason for using any data logger.
Really? I don’t believe it.
My electricity meter only shows complete units (kWh), obviously I dunno if Ihave has a similar one.
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I have a current transformer on my supply leads hooked up to a Raspberry Pi PicoW.
It calculates the power drawn simply by amps*230V.
It also has an LDR which counts the 'flashes' from the electric meter (One flash = 1Wh used).
Well, it's interesting, especially as the PF isn't taken into account.
The readings from the CT correspond very well to the meter readings for purely resistive loads.
E.g. we switch on the kettle and both the CT & electric meter read an extra 3kW load.
But any kind of reactive loads, especially switched mode power supplies and the readings differ widely with the CT showing much higher readings. I'm guessing that includes all the LEDs in the house.
It calculates the power drawn simply by amps*230V.
It also has an LDR which counts the 'flashes' from the electric meter (One flash = 1Wh used).
Well, it's interesting, especially as the PF isn't taken into account.
The readings from the CT correspond very well to the meter readings for purely resistive loads.
E.g. we switch on the kettle and both the CT & electric meter read an extra 3kW load.
But any kind of reactive loads, especially switched mode power supplies and the readings differ widely with the CT showing much higher readings. I'm guessing that includes all the LEDs in the house.
I use these as they are cheap ...I use them for some storage units where we keep the contract kit dry with dehumidifiers/ heaters to work out the charge back to the clients. You will need your own box for mounting.
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I don't think the OP means that the Landis Gyr supplied by eon is incapable of accurately counting the kilowatt hours consumed by the house, more that it doesn't offer a fine enough resolution of how much was used in a specific period of time/use context, such as "on the cooker circuit, from 06:00 to 06:01 on 1st Dec 2022"
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Argument from Incredulity (also known as: argument from personal astonishment, argument from personal incredulity, personal incredulity)
Description: Concluding that because you can't or refuse to believe something, it must not be true, improbable, or the argument must be flawed. This is a specific form of the argument from ignorance.
Description: Concluding that because you can't or refuse to believe something, it must not be true, improbable, or the argument must be flawed. This is a specific form of the argument from ignorance.
Your voltage is unlikely to be 230v ever. Inaccuracy 1. No PF measurement. Inaccuracy 2.
Well that is accurate then.
If it does counts meter flashes that is all it needs. Does not even need the CT.
Makes reasonable sense PF is unity for resistive loads.
Also makes sense and proves what I have said that a CT alone is not fit for purpose.
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