Determining wattage and estimating appliance use

[Todd Burch]

Some applicances are easy - like my radio. If it's on, it uses 12 watts. No big deal.

But I'm not sure how to calcualte wattage for my A/C unit outside. It's 220 volts. It has marking for the compressor and the fan.

The fan is rated at 1/3HP. It has an FLA=1.9. What's FLA?

The compressor says it needs a minimum of 38 amps, but a fuse/circuit breaker no bigger than 60 amps. It has an RLA=28.9, and a LRA=169. What is RLA and LRA?

Obviously, is these things aren't spinning, they're not using anything.

The fridge/freezer is rate around 200 +- 20 watts. I'm guessing this applies to when it is running only. What percent of the time should I figure this thing is cycling? (nothwithstanding how much I open the doors, age of appliance, ambient temperature, internal cooling settings, etc...)

Thanks, Todd

[Ken Garlock]

Tod,

FLA: Full Load Amperage. What the motor will pull when running at its full rating.
LRA: Locked Rotor Amperage. What the motor will pull if, for some reason, the rotor/shaft could not turn when power is applied. Kinda like a mechanical short circuit.

[Art Mulder]

Todd, got any electrician friends? They have a meter gizmo that has a clip on it that looks like a carabiner (climbers) clip. They clip it around the wire when something is on, and it measures the amps in use. That'll tell you exactly what your pulling down the wire.

Do you have an electric stove? Electric clothes dryer? dishwasher? These all suck the juice.

[Todd Burch]

Electric stove and range. High power "Advantium" microwave. Gas dryer. Electric dishwasher. The Fridge was purchased new in '88. I'm thinking "it's time" for the fridge to go. I've been fighting a leak with the ice maker for about 3 years.

I unplugged the small fridge I had out in the shop today. It's been running for 4 years. If I figure a 10% duty cycle (on 10% of the time over the 4 years), that has cost me $75. I'm not sure I've gotten $75 worth of pleasure out of it... It's probably run more than that. I think I'll turn off the compressor tomorrow too.

Art, I've been meaning to get an inductive amp meter, just never had a good reason. Now I have one!

Todd


Anyone need a small non-frostfree fridge? ;)

[Dennis Peacock]

Todd, got any electrician friends? They have a meter gizmo that has a clip on it that looks like a carabiner (climbers) clip. They clip it around the wire when something is on, and it measures the amps in use. That'll tell you exactly what your pulling down the wire.

Do you have an electric stove? Electric clothes dryer? dishwasher? These all suck the juice.

Called an Amprobe. Used to use them all the time while working as an electrician. You may can even rent one....but I bet you have a buddy somewhere that can get you one to take a few readings. ;) If I had one, I'd send it to ya....but I don't have one any longer. Sorry Todd.

[Monte Milanuk]

Not to pick nits, but Amprobe is just a brand name... clamp-on amp meter is what you want... mine says Fluke on it :D (just funnin' ya) Most electrical types will know what it is either way.

I'm looking at maybe getting one of those Kill-A-Watt meters... the ones that you plug into the outlet, and then plug the appliance into it... mainly cuz I've gotten kind of lazy about peeling back the insulation and fishing out the little wires on some of the smaller stuff to get to the ammeter hooked up :D Now that I think on it, it'd be kinda cool to see what kind of power my corded tools are pullin'...

[Jim Becker]

Todd, the old fridge really can be sucking a lot of power. Our usage dropped noticably when we got rid of the old one that came with the house and put in the new GE Arctica. Much more efficient. Same goes for our dishwasher(s). The Fisher-Paykel dishdrawers use so much less than the old dishwasher due to some really neat New Zealand motor technology. (Although, of course, the purchase price was considerably higher) That's good now as we run at least two loads a day now, rather than one every couple days. The only remaining frontier is our dryer...still electric and still working. It needs to go and will be replaced with a gas unit when it finally dies. Desipte the higher cost of gas right now, the new dryer should be more efficient. I hope.

I've made a number of changes lately to help reduce power consumption to help compensate for having kids. (Which automatically raises the energy bill...) All of our outside floods are now flourescent-based as are many of the lamps in our home that can accomodate that technology. I turned off my "lab" gear when I am not using it and am now using low-power-draw LAN gear to support the computers and IP phones in my office as well as in Dr. SWMBO's office. Unfortunately, we can only go so far and like was mentioned in the other thread, rates have really escallated in the past few years. If I take away our recent family additions from the mix, our actual usage is down from a year ago, but our costs are up. Such is life.

Oh, and the espresso machine is even on a timer...comes on about a hour before it could possibly be needed (requires 30-40 minutes for full heating) and turns off late morning...late enough for me to even have a second latte if I really want one. Like about the time I'm typing this edit... ;)