Kill A Watt Home Wattage Meter

Acrobat PDF of the Kill A Watt instructions The Kill-A-Watt Meter is a small device that allows home owners to measure the power use of their home appliances. I have found it to be invaluable in understanding how my devices (and lifestyle!) adds to my power needs and electricity bill.

I first came across the device while reading Home Power magazine (Issue 90, Page 116). It got a great review in the "Things That Work!" column [View PDF of article in new window] for being just right for enthusiasts, if not professionals. Of course there were ads for the device (manufactured by a company called P3) in the same and following editions. I found my KillAWatt meter at Radio Shack on closeout for $20. Often, they go for $35 or more, so that was a pretty good deal.

 I've included the text copy here for search engines and people without downlaod capabilities, but I have also recreated the instruction sheet as a 125 kb PDF.


The Text

P4400 Kill A Watt™ Operation Manual

Congratulations on your purchase of the Kill A Watt™ Power Meter. Cared for properly, this unit will provide you with years of service.

  1. The LCD shows all meter readings: Volts, Current, Watts, Frequency, Power Factor, and VA. The unit will start to accumulate KWH and powered duration time (hour) after power is applied.
  2. Press Volt Key for true RMS Voltage (Volts) display.
  3. Press Amp Key for true RMS output current (Amps) display.
  4. The Watt/VA Key is a toggle function key. Press the Watt/VA key once to display Watt meter, then press key to display VA meter. The LCD will display Watts as the active power, where VA is the apparent Power. (VA=Vrms Arms)
  5. The HZ/PF is a toggle function key. Press the HZ/PF key once to display the frequency (Hertz), then press key to display the Power Factor. HZ is the Frequency of output Voltage, where PF is the Power Factor (PF=W/Vrms Arms).
  6. The KWH/Hour is a toggle function key. Press the KWH/Hour key once to show the cumulative energy consumption since power was applied to the unit. Then press key to display the cumulative time since power was applied to the unit.
  7. Consumption will be displayed in Kilowatt-Hours (from 0.01 KWH to 9999 KWH). Time will initially be displayed as Hours:Minutes (from 00:00) and switch to Hours (to 9999). Counters will recycle to zero when they reach their maximum. To reset, remove power from unit momentarily.

WARNING: Do not exceed maximum ratings as detailed on label.

If you experience difficulty in the operation of your unit, or if your unit requires repair please contact:

71 West 23rd Street
Suite 1201
New York, NY 10010-4102
Tel: 212-741-7289 Fax: 212-741-2288

Email: techsupport (at)


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