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Power being drawn when everything is off

Postby garysz » Wed Nov 26, 2008 2:10 pm

I recently acquired a meter, from Eon, which shows the power being used.

With this I have identified that when everything is off 70 watts are still being drawn. I have isolated this to the groundfloor lighting circuit.

When I turn the kitchen light on the watts used goes down from 70 watts to 30 watts (= the florescent tube value).

I have changed the whole lighting unit and the light switch but no effect.

Ignorance was bliss, but now I know I have 70watts going somewhere I'm a bit worried - calling an electrician in would seem to be like writing a blank cheque.

Any advice or recommandation of a good problem solving Electrician in South Hampshire would be welcome?
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Postby sparx » Wed Nov 26, 2008 10:19 pm

Hi since this is not possible there must be problem with the meter or its connection.

where does the meter connect? I am very suspicious of the accuracy of these devices.
To be certain they must have a connection to voltage and current in order to calculate power properly, most simply clip around cable for induced current and use a preset value for voltage in order not to need a voltage connection, if yours is like this then it's only approx. reading & at low values of power will be fairly random.

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Postby garysz » Thu Nov 27, 2008 8:36 am

You are correct.

There is no direct connection just a clamp over the main feed out of the bottom of the proper meter.

However I do believe that there is power being drawn as the 'proper' meter does move when everything is off.

When I turn off the the circuit at the fusebox the meters read zero - there is a definate change when the circuit is reactivated.

A colleague at work mentioned 'earth leakage' but failed to define it or give a way of testing for it.
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Postby ericmark » Thu Nov 27, 2008 11:50 am

There are many items that draw a small current.
All transformers, Some dimming switches, Smoke alarms, Security lights, Time clocks, although 70W if accurate is quite a lot. For example my 38 inch TV uses 1W on standby which is a lot less than the 10W used by the stand alone freeview box and it all adds up I suppose my printer uses 8W or 5W on standby and satellite box 20W. Makes me laugh when people switch off TV at the wall but leave the freeview box and satellite box on to get nightly updates with draws 30 times the power of TV.
But I still leave on anything with time and date held by keeping power on. My alarm clock uses 7.2W once it wakes me up should I unplug it until next evening it has battery back-up well no as the battery cost both money and to environment is more than what it uses in mains power. I would need to bin it and use clockwork one. I have 5 cordless phones at 2.7W each yes the cordless phone uses over twice what my TV uses on standby yet we are all told to turn TV’s off no one suggests we switch off all cordless phones. Using a PC now and when I finish I will click on start to stop it but I can’t reach socket so it will remain with power as will the router the printer will remain on just in case I get a fax which I get on average 1 per month.
Is it really worth it? Yes I will look a standby rating now and if one TV was 10W and another 1W all else being similar I would go for 1W model but no way would I switch it off and lose all my time setting.
And some how I think my boss would not understand why I should arrive at work when ever rather than use 7.2W on my alarm clock.

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