Isn’t it funny when odd things happen.  Well it’s not really funny, it’s quite unfortunately really.  Not all power meters are created even.  The more research we (Paul and I) do, the more strangeness there is.

Anyway, rather than say what has already been said, check out Paul’s notes on “Lies, Damn Lies and Cheap Power Meters” and a snippet is below:

Our Power meters lined up for comparisonI have had and used an Electus power meter for about 12mths since they became available in Australia. I figured it was just like the american Kill-a-watt. Diligently collecting and comparing devices to see what they used and how much I was wasting with standby power. Dan did an early review on DansData.

ATA reported some accuracy concerns early on, and stopped selling them. The indication was this was only minor, and at low power settings.

I recently purchased the newer Solarinverters (SI) replacement from ATA and found some VERY large discrepancies between what I had seen before. Unsure as to which one to trust, I fired up the clamp meter to validate the results. The results [were not pretty].