Trying to find an induction Kill-a-watt meter

[Joe Hillmann]

I am trying to track down where my high electric bill is coming from and would like to find a tool similar to a Kill-a-watt meter but that works on induction rather than being plugged in. I want to be able to put it on circuits that don't have a plug in and on 230 circuits.

I know I could just buy an induction amp meter and do the math myself with the circuit running but I would prefer something that I could clamp on the circuit for a week or so at a time that would tell me how many kwh's it used so I can get an idea of average usage.

[Jesse Bishop]

I use a Current Cost EnviR (http://www.currentcost.com/product-envir.html) at my house to measure my consumption. I got a third clamp, so I have 2 on the main feed to my panel, and one on the hot wire of my HVAC circuit to pull out that usage too. The clamps need to go around the wire, so you'll need access inside your panel. You could move the clamps from circuit to circuit over time to see where the usage comes from. The display that comes with it is very informative, but I took advantage of the serial output and have it hooked to a Raspberry Pi computer so I can store all of the data coming in and produce my own graphs of usage at different intervals.

It really helps. I thought I was being pretty efficient in my house before I had the monitor, but I was able to cut my usage by about 25%! Bringing the baseload of the house down as low as I can has really made a difference. Now I'm trying to decide if I want to separate out my shop usage...

[Joe Hillmann]

I use a Current Cost EnviR (http://www.currentcost.com/product-envir.html) at my house to measure my consumption. I got a third clamp, so I have 2 on the main feed to my panel, and one on the hot wire of my HVAC circuit to pull out that usage too. The clamps need to go around the wire, so you'll need access inside your panel. You could move the clamps from circuit to circuit over time to see where the usage comes from. The display that comes with it is very informative, but I took advantage of the serial output and have it hooked to a Raspberry Pi computer so I can store all of the data coming in and produce my own graphs of usage at different intervals.

It really helps. I thought I was being pretty efficient in my house before I had the monitor, but I was able to cut my usage by about 25%! Bringing the baseload of the house down as low as I can has really made a difference. Now I'm trying to decide if I want to separate out my shop usage...

Can that be put on individual circuits? Or does it just measure the entire house? It is more than I want to spend ($140) but in the long run it may be worth it if I can use it to reduce my electric bill.

[Jay Runde]

I've used the Brultech ECM-1240 before. It can monitor both your mains and individual circuits. They also have a new product that monitors more circuits called the GreenEye Monitor. The ECM-1240 starts at $180 and GreenEye Monitor starts at $319. If I remember correctly, you'll need to hook them up to a PC to monitor them. You can go to http://brultech.com for more info.

[Jesse Bishop]

The EnviR comes with a wireless transmitter with 2 sensors. There is room for a third sensor in the transmitter. You can buy additional transmitters and sensors to monitor up to 10 "items" at once. For a 120 circuit, you need one sensor. For a 240 circuit that draws the same on both legs, you can use one sensor and multiply your usage by 2. For a 240 circuit that is unbalanced (your mains, a clothes dryer, etc), you need two sensors and you add the two values together.

With 2 sensors on my mains and a third on my HVAC, I have a pretty good idea of what my house is doing as far as the baseload goes. After watching for a while, I can tell when the refrigerator or freezer come on just from the pattern I see in the graph I produce.

Here's a snapshot of what I see from my web dashboard that I built. The first shows a snapshot of the last couple of hours and the second shows total daily usage (bars) as compared to the average for that day of the week in the current season (points). The red indicates that I've used more energy than average.
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What's even more helpful is that I'm getting usage data about ever 10 seconds, so I built another webpage that shows the latest value recorded by the EnviR. I load this on my smartphone and can walk around the house turning things on and off and watch the values change. It's like a Kill-a-watt, but you don't have to unplug things and can also understand your switched loads and 240v loads!

[Paul Wunder]

When I had a similar need I called my Electric Provider (In my case it was United Illuminating in CT. They lent me a device that had a regular watt hour meter attached to some electrical stuff. I plugged my refrigerator into one end and plugged the meter device into the wall receptacle. In a few days I had the total killowatt-hours that I used.

[Joe Hillmann]

When I had a similar need I called my Electric Provider (In my case it was United Illuminating in CT. They lent me a device that had a regular watt hour meter attached to some electrical stuff. I plugged my refrigerator into one end and plugged the meter device into the wall receptacle. In a few days I had the total killowatt-hours that I used.


I already have one of them the problem is it doesn't work on 230 volt or on circuits that don't have a plug.

[Kevin Gagne]

http://www.powerhousedynamics.com/buy-emonitor-dealers/

(http://www.powerhousedynamics.com/buy-emonitor-dealers/)If you want to monitor individual circuits here is a option for monitoring 14, 24 or 44 circuits. Looks interesting. If it can help you save on the electricity bill would pay for itself in no time probably.

[Art Mann]

I hope you realize that any clamp on type meter will only work if you have access to the individual current carrying leads. Access to just the cable won't do you any good. Just about the only place you can get that access is in the breaker box, which is not at all like the Kill-A-Watt device. The average instantaneous current through both leads are the same magnitude but in opposite directions so the fields cancel each other.

[Lon Crosby]

Look at "The Energy Detective", 1 watt accuracy and you can calibrate to delineate the use of individual components (watts and time of use) on multiple circuits. Pretty neat.