I recently bought Aldi's power meter, which I have found quite instructive - I was surprised that my Sky box and TV took 20 watts each in standby.
This led me to wonder how I could measure the power consumption of our 2 immersion heaters. I assume it is dangerous, probably illegal, to fit a power socket in the bathroom.
Is there any simple way of getting round this?
A few:
1) Look at the ratings plate 2) Clamp meter 3) Using the lekky meter
Set top boxes are imfamous for not reducing power consumption in standby mode, and are probably largely resposible for the current standby hysteria. Most modern TV's reduce their standby power to negligable levels in standby mode or they can't be sold in a number of countries. How old is your TV?
Also, as commented at the time, the Aldi power meter does not look like it understand power factors. So lightly loaded switched mode supplies (which often exhibit very poor power factors) could over-read significantly.
Are you suggesting that the Aldi power meter is not a power meter?
T.
A chum used to design cable set top boxes. He said that when the box was put into standby mode two things happened :
video and sound outputs were stopped an led came on to indicate the box was in standby mode
No power saving at all.
Guy
-- -------------------------------------------------------------------- Guy Dawson I.T. Manager Crossflight Ltd snipped-for-privacy@crossflight.co.uk
No, what I was highlighting is that the write up for it offers no clues as whether it is able to distinguish between real and apparent power consumption[1] - so take readings taken on this sort of kit with a good degree of scepticism.
[1] Unlike the Maplin equivalent device for example which measures the power factor of the load and makes allowances for it. Note however that even this one does not work well on small capacitive loads.
I'm afraid I don't fully understand. A device consuming 20W will do so irrespective of the power factor. A power meter should measure this power, just as my electricity meter does. What does making allowances for pf mean?
T
Have you seen the Aldi power meter? It actually seems quite sophisticated, certainly more so than the Maplin meter (which I have also used). Eg the manual is difficult to follow ...
It's a Sony 26in TV (not flat screen), about 8 years old I think. On re-checking I see that it only takes 12 watts in standby, while the Grundig Sky box takes 30 watts.
Actually, I don't see any way of putting the Sky box on standy - this is the consumption with the TV off.
Actually, I see that the Aldi meter does show the power factor -
0.99 in this case.
I want to calculate power consumption during over a period, so I'm not sure if these will work. Incidentally, how does a Lecky (I assume that is what is meant) meter work? Is it reasonably accurate?
OK, the one that someone linked to a week or so ago did not have any mention of it in the write up - and there was nothing obvious on the display of the unit pictured. If it does adjust for the PF then it should give you more accurate readings.
The simplest ones measure the line voltage and the current flow and from that deduce the power consumption. On kit with non unity power factors this will end up reporting the VA rating rather than the real power consumption.
I saw the one that someone linked to a little while back (can't follow the link now since they seem to have removed the special offer) - that one looked fairly basic and did not mention an ability to measure the power factor. Yours may be better - or the advert may have left out a bunch of features.
If that's the case it isn't a power meter, shouldn't be called one, and you were saying it wasn't.
T
When you measure the power factor, are you measuring it for the device in question, or are you measuring the average for the neighbourhood?
TIn message , Timothy Murphy writes
what happens when you press the button at the top right of the remote control?
There's an even simpler one available which measures only current (using a clamp-on current transformer), and assumes the mains voltage.
A plug-in device can only measure it for the load running through it.
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