111205-0919 EST
Besoeker:
The Kill-A-Watt is a meter with a three prong plug and a three prong socket. This meter is for individual plug-in loads. In between is the meter and I suspect a resistor shunt for current measurement.
Maximum current is 15 A and it complains above this. For the EZ model the voltage range is spec'd at 85 to 125 V with 0.1 V resolution. It doesn't complain on any overvoltage to 135 V (I have not taken it higher). It is RMS reading and measures or calculates --- voltage, current, power, VA, frequency, and power factor.
Below about 1 A it resolves 0.1 W in the newer EZ units, doesn't work too well below about 2 W on some units. Above something around 1 A it switches to 1 W resolution.
For about $30 at Home Depot it is a rather good value and useful with knowledge of its limitations.
Handles reactive loads very well as indicated by data from measurements that I have made. A limited useful device for the average consumer. No data collection except by the eyeball.
The TED Systems consist of two different designs, but similar. TED stands for "The Energy Detective". These systems are basically power and energy monitors with data collection possible. Voltage and power are directly measured, albeit, with substantial error on power of non-resistive loads. Time is measured with a Dallas real time clock chip, a rather good clock. Current is measured but only available as VA. On the 5000 series power factor is obtained somehow. For low power factor they apparently fudge VA to equal about 15 possibly to avoid a divide by zero problem.
Spec'd for 100 to 130 V with 0.1 V resolution. Maximum current per current transformer is 200 A. Two current transformers are supplied, one for each phase of the center tapped single phase system. Thus, maximum power is about 200 * 240 = 48,000 watts.
Power Line Communication is used and is a major problem. Software and circuit design are also major problems. There is much to be disliked about the TED systems, but for the money it can provide useful information.
This is also a useful system for the average consumer at $165 to $240 for a minimum system. It is intended for whole house monitoring. But it is worthless for evaluating a PFC capacitor.
Will $250 plus spent of the TED system save the average consumer that amount. Maybe, if it helps them keep things turned off that do not need to be on. In other words change their life style.
webmaster:
What was wrong with the software for this site some 6 months ago? This present software is junk.
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