KETOTEK Single Phase Energy Meter, DIN Rail Power Meter KWH Meter AC 80-300V 100A, Kilowatt Hour Volt Amp Watt CT Sensor

Initial:This is a small DIN rail mountable multi power meter.Cosmetically, it looks pretty nice. The LED displays are bright and easily legible even through a smoked plastic cover, such as the one I will be installing it into for its final home.The lower wattage/kwh display is green, to make it visually distinct when glancing at the panel.The main power feed comes in to the two bottom terminals.The meter uses this both to power itself and to measure incoming voltage.Current measurement is accomplished using a current tap loading coil permanently installed in the meter. I see no provision to "upgrade" this.From there, the meter is able to calculate a diverse range of electrical device parameters.> Voltage: Line incoming voltage at the meter. Fixed point, XXX.X, ranges across the safe operating capabilities of the meter.> Current: Detected amperage through the current coil. Fixed point, XXX.XX, 0.1-100A.> Watts: Real power determined between the detected voltage and current values. XXXX.X, MAY be floating point but my test setup cannot pull that much power safely.** Press the front panel button to switch displays.> Power Factor: The meter is able to judge the phase relationship between voltage and current, and use this to determine the power factor of the load. Fixed point, X.XXX.> Run Hours: The meter uses the processor's internal clock to determine how long it has been running. Fixed point, HHH.MM. Parameter is saved on power down.> kWh: The meter uses real watts over load hours to accumulate kilowatthours. Floating point, KK.WWW to KKKKK. Parameter is saved on power down.** Press and hold the front panel button to reset kWh and load hours.Handily, the status indicator LEDs are red when in "standard" mode (V/A/W), and green when in kWh/hours/PF mode. As you become familiar with the meter, this indication will be easier to read - especially if the meter is partially obscured by a panel cover, or in a dark environment - than trying to make out the legend labels.Test Methodology:For testing, I placed the meter in series with my Hopi 9800 "kill-a-watt" digital power meter.Both meters were allowed to warm up for a little while. I took the pictures before this warmup, so it looks less accurate.The Hopi uses a digital KWH smart meter processor and a current shunt resistor that, while not calibrated, is known accurate within reason.The DIN rail meter is installed AFTER the Hopi.This is very slightly reducing the Hopi's accuracy.I did discover that the quality of the wiring to the meter matters greatly. Use at minimum 16awg for best accuracy.Test load is a desktop personal computer, booted to a steady state at BIOS.To test the clock, the meter's timer was reset on the second of a known time, and tracked using a quartz digital clock.To test the kWh, I reset both meters' kWh accumulators at the same time, and left the test load running for the duration of the clock test.The load posed by the DIN rail meter alone is below the Hopi's minimum, so to determine what its load is, I applied a light load (my PC "powered off") and then turned the DIN meter's fuse on and off to compare readings.While doing this, I went ahead and compared the readings of the light load between the two meters and found them acceptable. However, methodology was lacking to consider this test definitive.Speaking of methodology, as I was performing the final kWh and hour-meter testing, I realized that I could have improved my test accuracy further, however I didn't want to rebuild my test setup AGAIN, as it was getting late, and I was already 30 minutes into the rather long test.Just note that accuracy could be better than you see here.Accuracy Results:Voltage: 0.2v.Current: 0.02A.Wattage: 1W.Power Factor: 0.015.Time: Vs clock, 3 seconds in 1 hour; Vs Hopi, 3 seconds in 1 hourkWh: 1Wh in 1 hourMeter's power draw: At 121.7v, it draws 50mA, giving it 6.1VA, with a real power of approximately 300mW. This makes its calculated power factor 0.049 capacitive.

The media could not be loaded. Very handy using this on our van to monitor usage. Very close to our inverter numbers, so when connecting to shore power or generator we have an idea how much amps we use. No complaints here!

Tell someone before they buy it that it does not work with modified sine wave inverters. I got mine to work with modified sine wave by soldering on two small heat sinks to two internal resistors to cool them down. I only draw 100 to 200 watts past it though

This device is very good and has lived up to expectation. I am using it to measure energy consumption in a solar system. I was worried initially that it may not work as the seller had warned that the device will fail if used for solar systems with modified sine wave current or imperfect systems outside public power supply. However, because I was using a pure sine wave inverter that has an inbuilt microprocessor, I decided to give it a trier.For almost one month now, this device has performed extremely well. I am able to measure voltage, current, power, kwh etc., that I draw from my solar system and this has really helped me in maintaining the system and keeping it running. I definitely will buy more as I increase my installed capacity.

Checked it against my Fluke multimeter at 120x, 60Hz with a variable 1A to 3A resistive load. Voltage was spot-on, current was within 0.1A and the wattage reading was accurate.

Worked as advertised. No need to say more other then I can recommend it.

CUMPLIO CON MIS ESPECTATIVAS

It was easy to wire up for service, easy to use. Measuring Watts, Volts, Amps, KWHours is great. I had to update this review to correct my error -- I thought the runtime hours was wrong but it was my mistake - it works as advertised. The accumulated runtime hours counter unfortunately rolls over at just under 1000 hours - I missed that in the specs at first but its not really a big deal. I know to add an extra 1000 or multiples thereof each time I read the meter as I do monitor the KWH counter for power expense tracking. The important thing is that the KWH hours runs to 99,999 hours so there is plenty of room there to properly track a pretty big load for at least a year before it rolls over. And after a year, if you want, you can force the counters back to zero at the start of each year or whatever works for you. The Q/A area reply from seller says 60HZ is just fine and I run standard USA 120 Volt 60Hz power and indeed - its all just fine - no issues. The device mounted easily as I also got some DIN rail to go with it and a (general purpose 6x6x3) box and it all mounted flawlessly (though I had to cut the holes et al. - I mounted two of these in one box) and they are working reliably to date. I'm very happy with this product The price was very good I thought. Instructions are terse and obviously mediocre Chinese/Asian to English translations but it does make sense. The instructions even say the mode button is on the right but its really the left as seen in the pics. It works as advertised and is actually easy to wire up and mounting on the DIN rail makes it a smooth task. It seems well made. If the runtime hours counter had at least one more digit of total range before rollover, I'd give 5 stars.Update 1: After approx 5 months of usage, I still like the thing but now I find that when taking my meter readings (monthly) I find that the KWH meter seems stuck at 4096.0 and has been some an unknown number of days. This means I now have to extrapolate my actual usage for this month and that ticks me off but the hours meter (despite its shortcomings) is helping me make the calculations. It now seems to me that my most repeatable/accurate way to do my monthly(approx) meter readings is to simply take the readings and rezero the meter. While I am disappointed and I'm not furious at the meter and it does work and is low cost and easy to wire up, for a bigger more complex setup, I'll look for other meters if there is a next time. I just do not understand this thing now that the kwh side locked up at 4096 when it was supposed to run to 99,999 before a rollover. Whatever!.!.!.!... Perhaps I was being nice by only reverting back to only 4 stars... Perhaps expecting to run for a year was too much to expect. If you read monthly and rezero it, you ought to be fine - you just need to know these things ahead of time so you can cope with it properly.UPDATE 2 -- After the re-zeroing of the meter after waiting for TWO HOURS (right to the minute!!!), I find that the meter is reading 1.59 hours of runtime - HUH How could that be!!!!!. Seems to me this this thing is clocking perhaps based on 50 hz time or something. I can no longer trust these things because of the suspect 50hz clocking (though you would think it would clock off the power cycle rate). Now I am not sure I can even trust the watts displayed although it does show my volts correctly so I have to suspect that the watts is computed from volts so I am thinking watts is okay - but for any time based computation - that seems out the window -- which means that the displayed KWH may also be computed based on the computed and inaccurate time. I'm angry enough to take away all stars but must say that it does work and if I am actually correct that this is intended to be used on 50HZ power, it probably can be trusted etc. But with USA 60Hz power, I just cannot be sure and cannot trust it and I guess I made a mistake with this even though I tried to read everything I could posted here and all the Q&A et al. Perhaps a seller or mfg will find this and properly explain. I will be going through all my 5 months of readings and calculating as I can to figure out the actual numbers and what the error is and if it is a 50HZ thing that is causing this huge PITA!!!!