In article ,
"George \(dicegeorge\)" writes:
I've read here that clamp meters are about 5% accurate,
so if I bought one like this for £20 (+vat+postage)
http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/

0.1amp = 24 watts
so could I have one before the Consumer Unit
and use it to check if anyone's left lights on,
or got a electric fire on etc?


http://www.tlc-direct.co.uk/Manufact...Test_Meters_7/
Digital Clamp Test Meter

This is what the Eco meter (discussed in another thread) would
be perfect for, and better than your proposal. As long as you
don't want to take accurate readings from it, it will give a
clear indication of significant loads.

Heaters cycle on and off on thermostats, and you will only see
the heater load when it's cycled on though.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]