AC current measurement device

I was thinking about current being drawn by individual AC devices in the home and workshop recently. In my mind it wants to be something that can be held against the flex cable to what is being used, say a fan, to give a reading of what current is flowing.

I did a search to see what was available and only came up with a clamp meter which doesn't seem ideal as it needs an AC live separator that isn't readily available for our three pin plugs. With the trend to reduce electrical useage I'm surprised there isn't an inexpensive devide available, maybe there is and I didn't use the right search words...

Anyone have any suggestions for something suitable please?

Search for power meter plug, less than£10 on ebay. I think if you have a smart meter it might be possible to use the display, but then you'd have to make sure everything else was turned off

I have a “Plug-in Power & Energy Monitor”

Pro Elec PL0964 … Made in Taiwan

Sorry : No idea whether they are still available.

MichaelG.

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Edit: U.K. supplier was [is?]

Component House, Faraday Drive

Fulwood, Preston PR2 9PP

Edited By Michael Gilligan on 17/01/2023 11:01:23

Thanks chaps, terminology, don't you just love it! I'll have a look and report back...

I don't have a smart meter fortunately Duncan!

A wide variety of power monitor plugs are available on Amazon.

Mike

Michael,

That's still CPC Farnell

This sort of thing could worry you silly;

Domestic energy monitor

It might be easier to shout upstairs and tell the kids to turn all the lights off - Some hope!!!

Bob

Henry, to measure current in a cable you have to separate the phase from the neutral which is why you will not find a device to measure the current in a 3-core cable.

When in the trade I used to have a plug and socket with the three short cables separated in order to accurately measure the current draw - I could also measure any current leaking back to earth through the cable.

The plug-in adapter units work OK but are not particularly acurate but do have data collection options.

+1 for me - but don't ask me to find it and the clip on meter I use with it.

In the workshop somewhere under the bench!!

.

… < still > ?

I didn’t know it ever was

… I just quoted the address from the text on the box.

MichaelG.

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Edited By Michael Gilligan on 17/01/2023 14:19:08

And me, moving coil clamp meter and watch that motor start-up surge.

As we've recently seen Michael believes everything that boxes and adverts tell him.

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Au contraire … Michael questions the adverts, and what’s written on things.

This particular device, with its pass-thru 13A plug/socket appears to do exactly what it claims.

Good Grief … Shock, Horror … perhaps they actually break-out the wire inside the device !

Wouldn’t that be clever !?!

MichaelG.

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Correction … The Buzzer buzzes … it doesn’t whistle !

Edited By Michael Gilligan on 17/01/2023 16:49:40

Clip on Ammeter clip over the live cable only will give you the readings ,They work on a range of amperages if you double the or wind the live lead round twice this will give you a reading when divided in half will give you the correct reading if your appliance is only using a small current load that is below 1 amp They can also give you a combined voltage meter., Very usefull piece of equipment for findeing faults on appliances. Havent used mine for years since retireing .Have Fun Bee.M

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Henry

For the avoidance of doubt:

If your individual AC devices use 13A plugs, then [used as intended] the unit that I have would do the measurement nicely.

What it will not do is give give you a reading when ‘held against the flex cable’

… but nor would their toys !

So we can probably consider it a 0-0 draw, between me and the nay-sayers.

MichaelG.

Edited By Michael Gilligan on 18/01/2023 06:20:03

I have a clamp meter which I had to have for work a while ago. To use it for single phase I made a short extension cable with three single flex cables and that way it could check the current in the live conductor and check the earth is not.

David

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I rest my case, David

“What it will not do is give give you a reading when ‘held against the flex cable’

MichaelG.

I have an identical plug-in device to that pictured above. Came from Maplin years ago. Has the advantage over the clamp-type meters that it will measure consumption over a period.. So, use with your washing machine, etc, to measure total consumption over a wash cycle.

My original post was to try to illustrate what I needed, and my vague idea of how to achieve it, not being aware of the plug-in type.

The two suggestions by Michael and Duncan have come up trumps, as I said in my second post terminology can be a pain sometimes. I put Duncans words in and found several devices that would fit the bill.

In the house I can leave the meter in line as I'm trying to "educate" my wife about what device uses the most electric and, as a bonus, it will be interesting to see what the lathe and mill draws in real terms.

As promised I'll let you know how I get on.

Thanks all, Henry.

Am I missing something here?

One buys a washing machine/dryer etc because it fits in ones kitchen and is a reasonable price (and it is the one SHE wants).

Then one buys one of these energy monitoring devices that tells you it is using X number of Kw's, shock! horror! stop using the device, it costs too much to run.

So! your expensive device noiw lies idle, what was the point in buying it in the first place?

YOUR electric bill is what it is, based on what devices you have/use. If you are not going to use a device, then, what was the point of purchasing it in the first place?

If you don't now use the device, it is an expensive lump sat there doing nothing.

Yes! I did think about buying one of these energy monitors, but decided the money would be better spent on the gas/electric bill rather than on a device that actually tells me nothing I don't already know.

I don't know about the rest of you, but I counted all the devices I have that are on all the time (internet router etc) or on standby when not in actual use and was initially shocked at how many devices I have.

However, looking at my smart meter in home display, the actual energy used by all these devices actually costs very little. i can check usage when I get up to make a cuppa first thing in the morning.

See what the display reads, then take off the daily standing charge and it amounts to about 40p for the 7.5 hours from midnight when the device starts to chart your daily consumption.

I don'y know about the rest of you, but that amount to me is very reasonable and does not persuade me to turn everything on standby off. the convenience outweighs the cost to me, you may differ of course.

Over the years I have done everthing I can to cut down electrical consumption, LED bulbs, buying energy efficient washing machines dryers etc that there id little more that I can do.

So! one buys an energy monitor and checks all the devices in the home - then what are you going to do about it?

This depends what the OP wants to achieve; a general idea of power consumption per device or an accurate readout of current draw.

A general idea can be seen on the electricity meter, with a bit of logging and a bit of maths to solve for (approximate) current drawn. I am recording our gas and electricity meter readings every day, as well as outside air temperature and humidity, onto a spreadsheet which I wrote to calculate the amounts used since the previous day's reading.

On some days, the electrical consumption, (which averages around 5.78 kWh since the previous day), shows, say, 10.93 kWh, and after recovering from the heart attack, I remember that I put some washing on* and used the oven for last night's meal, or whatever.

An accurate readout of current draw will need a break-out lead to separate the wires and a current clamp. A current clamp could tell you other things, such as inrush current, or what your car starter motor draws etc, which might make a useful addition to one's toolkit.

* incidentally, having been monitoring our electricity used, I have tried setting our washing machine down to 20°C washes and longer wash cycles. I was very surprised that the washing performance is very good at this low temperature - it washes for longer but uses less electricity overall, and the cleaning seems just as good - even whites. ( I sound like a washing powder advert !! ).

Edited By John Doe 2 on 18/01/2023 11:22:46