"Senin" wrote in message
oups.com...
Is there any way to calculate approximately how much electricity that
my low voltage outdoor lights are using? I am trying to figure out how
they are effecting my electricty bill. Right now I have four cables
(with about 4 lights on each) running about 3 hours a day.


Look at the label on the transformer box. Look for the INPUT Amps.
I have a 500W output Malibu timer/transformer and the label says: Input =
120V @ 3.5A max.
Wattage is calculated by Volts * Amps so in my case 120 * 3.5 = 420 Watts.
420/1000 = 0.42 gives Kilo watt/ hours. From my electric bill the cost per
Kw/h is $0.063029 so it would cost me about 2.6 cents an hour to run mine at
full load. (0.42 * 0.063)
If you were only half loaded on the output then you would be using about
half of the input rating. in my case 210 Watts on the input. This would not
be totally accurate but would be close enough to give you and idea. Remember
that the transformer and timer do consume power even when the timer has
switched the lights off. So you would be consuming a few watts of power
24/7.

Kevin