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E Z Peaces

wrote:

The KillA Watt does not compensate for the terrible power factor of
an idle transformer - It will be indicating significantly higher than
the actual power disipation of the transformer.
The incandescent lamp in the lighted doorbel button is likely 80% of
the real draw.

Put a power factor correction capacitor across the transformer primary
and I'll bet the KillAWatt reads less than 1 watt.

The 4400, which I think is their base model, is supposed to show volts,
amps, volt-amps, power factor, watts, Hertz, kilowatt hours, and hours.
Accuracy is advertised at 0.2%.

Almost all customers love it. I was about to buy one until I read a
review by someone who claims to have bought several for an R&D lab.

He found them inaccurate when new, and they were likely to freeze when
current exceeded 7 amps. This made them useless for anything with a
starting surge that high.

All failed between 30 and 50 hours, giving wild readings or none at all.

I believe him because his description is good. It reminds me of
problems I've had with DMMs that can measure up to 10 amps. If you run
several amps through a resistor with little mass, I suppose sudden
temperature changes can lead to microscopic cracks, which affect
accuracy and cause increasingly fast deterioration. I imagine
Kill-a-watt's manufacturer could solve the problem with R&D.