How much is this thing costing me to run?

Question

I'd like to know how much certain things like computers, flat screens, refrigerators, etc. are costing me to run. Is there a meter that can help me figure this out? I know how much I pay per kilowatt hour. I'd like to measure my fridge for example versus a more efficient one and figure out if it pays to replace it. Thanks!

Answer 1

You need a clamp on ammeter and a device that you plug the appliance into then plug it into the wall (can't think of what they are called... ) It isolates the hot wire to get your reading.

When using a clamp-on ammeter, you can only clip it to the hot (black, or ungrounded conductor). If you clip it to the cord itself, it will read zero amps.

Another note: it will give an approximate reading for electronic devices (anything with a circuit board) because they don't draw power in a steady flow. You can also only check the fridge when it's running, but that doesn't tell you how efficient it is, just how much draw there is when it's running. Efficiency is determined more by how good the insulation is.

One last thing. To find the wattage, take the amp reading times the voltage (use the volt meter to do this). A kW is a thousand Watts.

Lastly, note on your power bill that you pay different ammounts per kW in different blocks. Your first 500 are one price, second 500 another price, next block is even more...

Have fun!!

Edit: I just checked out that kill-a-watt thing, now I want one for my tool bag. I already have the tools I mentioned and use them all the time professionally, but the PF is a nice add-in (kinda useless in a home though). For the homeowner, I'd recommend the kill a watt.

Answer 2

Yes, you can buy a plug in meter at radio shack or probably some building centers that shows the wattage being used by an electrical item. I have one that reads the watt usage and total kilowatt hours over time. Some of the meters that are more common include "kill O Watt" and are available online.

Answer 3

Try your local electric company! They have a ton of old 60 amp house meters they've removed from service. You want to call the department relating to energy savings. They sometimes mount these old meters for demos already fitted with a three prong plug and set of outlets for any 120V appliance.

They let me use one for six months while I checked out how different items were running up the bill.

Absolutely free.