Kill-a-watt help?

[1stmate]

Hello all-

I just got a Kill-a-watt meter to help point me toward which items will be next on my "solar inclusion" project.
My first check, just for grins, was the fridge. After 24 hours, it read 1.22 kwh, & while running was ~150 watts actual usage.
The plate on the fridge says it uses 8 amps, which would be over 900 or so watts; why the disparity?
Is the higher amperage for the "frost-free" heater? Or did they just pull a number out of their posterior?

Thanks,
Jack

[johnjmw]

900W would be the max draw. Defrost on as the motor starts up. There is a surge there till the motor reaches operating speed. I don't know if the kill o watt will show the surge because it only lasts a second or three. Is there a button that shows the max draw on it?
Good luck. They are a neat toy to find and eliminate ghost draws on a system.
John

[1stmate]

Thanks John. That's kinda what I figured, but I am surprised at the huge difference in running watts (keeping the food cold) vs. defrosting (warming up the box that should be keeping the food cold)!

I wonder if the defrost cycle can be disconnected?

And unfortunately, no, there isn't a "max watts" button; that seems like a no-brainer for this device, but there I go, re-engineering someone else's product ;)

[johnjmw]

Oh our Fridge there is another switch. One for keeping extra humidity from condensing on the out side of the fridge. Basically another heating circuit on the out side skin of the fridge. I don't know if the defrost cycle can be disabled or changed in any way.
Good luck and let us know what you find.
John

[randallhilton]

Oh our Fridge there is another switch. *One for keeping extra humidity from condensing on the out side of the fridge. *Basically another heating circuit on the out side skin of the fridge. *I don't know if the defrost cycle can be disabled or changed in any way.
Good luck and let us know what you find.
John

Echo the reply re: Defrost using the most juice. Our fridge runs at about 140 watts but with both doors open, there were 8 40w light bulbs that lit up -- more juice than the compressor! I downsized the wattage to 15 apiece and yanked a few that I deemed redundant -- keep in mind that all those light bulb watts result in heat that must be removed once the door is closed again.

The defrost circuit is resistance heat -- lots of amperage. We're about to put the fridge and the laptop on solar power but if the grid goes down for a significant period, the defroster and light bulbs will be neutered so that we can maximize our battery power.

By the way -- re: the fridge with the "power saver switch." Odds are that box is old enough that it should be seriously considered for replacement. Today's units use significantly less juice than older models. We immediately saw a difference in our electric bill after upgrading. Money well spent.

[rodamala]

Defrosting is an important part of efficient freezer operation. In a freezer, you are trying to remove heat from the cold space and dump this heat outside of that cold space (the exterior coils on the back or under the unit).

As frost accumulates inside the cold compartment, the heat transfer rate is slowed. Basically, the unit will run longer to remove the same heat, that is, consuming more energy to do the same amount of work.

Also, with a refrigerator with an automatic defrost cycle, another large draw to consider is the electrical resistance element used to evaporate the water that that has melted by the defrost cycle and gathered in the pan under the unit..

I suppose you could disable that and manually drain the pan. That would be a pain.

Easiest way to save money (asides from not having to refrigerate your food) would be to reduce the amount of time you have the fridge door open.

Sorry if all this isn't all that helpful.