Measuring Power Consumption Of 230VAC circuit?

[Chewwy]

You'll have to put in a plug across the return (usually white) across either the red or black line. Plug the Kill-a-watt into the 120v plug and just multiply by 2. Each wire is 120v. They phase together to get 240v.

Ralph

Just so wrong. The current in each 230V line is the same. Even in the unlikely event of ain unbalanced load (current flow in the neutral), the current is the average of the two line currents, not the sum.

 

[Chewwy]

Are you saying that RalphVA's suggestion won't work or are you just trying to be funny?
I think it will work.

It will NOT work as described by RalphVA. If it’s a balanced load, there is no current flow in the neutral. Even if unbalanced load, it is not times two or the sum of each.

 

[mikester]

The quickest way to get energy is with a multimeter and current transformer clamp.

Try starting with something like this if you are trying to monitor energy usage over time. Comes with two CT's.
Z-Wave electricity meter • Aeotec

You can use one of these to monitor and control an individual device
Heavy duty Z-Wave switch for indoors & outdoors

 

[workinonit]

Just so wrong. The current in each 230V line is the same. Even in the unlikely event of ain unbalanced load (current flow in the neutral), the current is the average of the two line currents, not the sum.

Bravo. A voice of reason and accuracy at last. I work in the power industry and specifically in the excitation or voltage regulator piece of the pie. As you can imagine w/h meters are the corner post of measuring commercial power so I deal with them all the time, 3 phase of course. In commercial power we use current transducers to measure line current. These are usually 10,000/5A or some appropriate turns ratio for the particular machine. To do this on most of the cheap single phase meters I see they are installed in-line or in series. This way they get the current measurement as well as the voltage in a single device. They are probably a bit of a pain to find somewhere to install but will work well. It would be easier to find one with current loops so they wouldn't need to be installed in-line but probably much more expensive.

 

[MossRoad]

You could build your own for about $30 as in this video. (multi-part video, this is the build video. Testing is in another video)

You'd have to either hard wire it in, or, put a twist lock connector on the line so you could take it in and out of the circuit.

 

[FastEddieR]

Wouldn't that give you the consumption for the entire house rather than a particular circuit?

Yes it would. But watch your consumption WITHOUT the devices running to give you a baseline first.

 

[cdaigle430]

Yes it would. But watch your consumption WITHOUT the devices running to give you a baseline first.

This is so true. I have a 7KW solar station at my house and had them install a meter at the source for an extra 500 bucks. It gives you total watts consumed along with total watts Im sending to the grid. With the total watts consumed you can easily tell what a device is using power wise simply by launching the app and monitoring total consumption when the device goes on and off. Its just a matter of subtraction after that. I learned that my ho tub with all pumps and heater consumes 6,000 watts. The dryer 3,000 watts. My garage LED lights use 300 watts and so on.

I can keep them the power company in check.....you can also do this if you have a smart meter, you can loginto your account and check your consumption....not sure if its live though or if it takes samples every so often.

 

[Chewwy]

. . . I learned that my hot tub with all pumps and heater consumes 6,000 watts. The dryer 3,000 watts. My garage LED lights use 300 watts and so on.

I can keep them the power company in check.....

Pretty easy to figure energy consumed by the hot tub pumps and heater and the dryer when they are running based on their kW or hp rating. Same for the garage led lights. The difficult part is keeping track of how often and how long they are running.

Not sure why you need to keep the power company “in check.” They don’t control the energy you consume. The consumer controls that.

 

[npalen]

Baomain Single Phase DIN-rail Type Kilowatt Hour kwh Meter 22V 6Hz 2 (1) A - Voltage Testers - Amazon.com

I see that this device, as mentioned by MENDONSY in post #3 above, is also available in 60 Hz and might work well for my application.
The only thing I'm wondering about is whether it would be accurate down to nearly zero amps. My HVAC mini split runs the indoor unit fan constantly, even when the compressor is off, drawing about 0.3 amps according to my amp probe and would like to capture this in the KW tally also.

The picture shows 20(100)A and wondering if the 20 is the minimum amps at which it will record accurately?

I really appreciate the feedback from all of you guys and the vast pool of knowledge here on TBN!

 

[WranglerX]

My utility company electric meter has digital read out, take reading with unit off, turn unit on and take reading, subtract smaller from larger to find difference, that is you power consumption...

Dale