The meter is useful as I like to know the exact usage as I always assume 600W is 600W.
Now, it is just 120W, a relief
Topic: Playing with my new Kill-a-Watt meter! (Read 3109 times)
A fixed watt meter wired into your mains panel board for your premises is also a good investment. You can get them for about $80-150 and they are supposed to be installed by an electrician in many locales. They compliment a wall-socket type watt meter nicely. But I like to stress to people that watt meters don't save you money, learning about your appliances electrical consumption and your habits does 
And I learned that 730 watts + 560 watts + 1130 watts (which totals 21 amps) running all on one 20 amp breaker didn't trip it off. Might be a cause for concern there. I forget if anything else was running on that circuit breaker at the time.
That is normal. Circuit breakers are analog mechanical devices they aren't digital switches (20.00000A = on 20.000001A = off). At just above the threshold it will take a while for the breaker to trip sometimes minutes or even hours. At 30A it would trip within seconds but not "instantly". At 40A it would be very fast probably less than a second. At 10,000A it would be in less than an AC cycle.
The entire electrical code is designed to be conservative though. The wiring for 20amp circuit can handle more than 20A. If you use continual loads (like running miner 24/7) you should derate the circuit by 20% (12A on a 15A circuit, 16A on 20A circuit, 24A on a 30A circuit). The reason is that circuits assume a duty cycle. When current is lower the conductor will cool down. An always on circuit is more stressful. You will notice that a 30A Datacenter PDU has a circuit breaker at 24A. The 20% derate is why.
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My apartment voltage stays at 115-117 for the most part, and I found the Volt-Amp setting interesting, but measuring in WATTS is the gold standard for current measurement as far as I'm concerned. Until someone gives me a reason to think a VA measurement is more relevant.
You pay for watts. So if you are interested in economicals watts is what matters. For ATX power supplies the power factor is pretty close to 1 so there isn't much difference anyways.
I knew these existed, but I never actually thought about getting one. After reading through your post and the reviews on amazon, I'm really wishing I already had one lol. Adding this to my wish list now, should pay for itself in no time 
After reading about it a few times and realizing its usefulness for setting up grow rooms (it's a long story) and coin mining PCs, I finally bought a Kill-A-Watt meter from Amazon.
It's a pretty slick little gadget. I went around my apartment measuring everything with it!
My window AC units use 440 watts each on Low AC, and about 455 on High AC.
My mini-refrigerator uses 250 watts when running.
The 20 inch box fan venting my mining room uses 60, 75, and 90 watts on low medium and high speeds.
My 15+ year old microwave uses 1130 watts when running.
My 3x6950 mining PC uses 220 watts with the GPUs idle and 730 watts mining at normal operating temperature.
My 2x7950 mining pc uses 110 watts at idle and 560 at full GPU load and temperature.
And I learned that 730 watts + 560 watts + 1130 watts (which totals 21 amps) running all on one 20 amp breaker didn't trip it off. Might be a cause for concern there. I forget if anything else was running on that circuit breaker at the time.
My apartment voltage stays at 115-117 for the most part, and I found the Volt-Amp setting interesting, but measuring in WATTS is the gold standard for current measurement as far as I'm concerned. Until someone gives me a reason to think a VA measurement is more relevant.
It's a pretty slick little gadget. I went around my apartment measuring everything with it!
My window AC units use 440 watts each on Low AC, and about 455 on High AC.
My mini-refrigerator uses 250 watts when running.
The 20 inch box fan venting my mining room uses 60, 75, and 90 watts on low medium and high speeds.
My 15+ year old microwave uses 1130 watts when running.
My 3x6950 mining PC uses 220 watts with the GPUs idle and 730 watts mining at normal operating temperature.
My 2x7950 mining pc uses 110 watts at idle and 560 at full GPU load and temperature.
And I learned that 730 watts + 560 watts + 1130 watts (which totals 21 amps) running all on one 20 amp breaker didn't trip it off. Might be a cause for concern there. I forget if anything else was running on that circuit breaker at the time.
My apartment voltage stays at 115-117 for the most part, and I found the Volt-Amp setting interesting, but measuring in WATTS is the gold standard for current measurement as far as I'm concerned. Until someone gives me a reason to think a VA measurement is more relevant.
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