Measuring Power Consumption Of 230VAC circuit?

[npalen]

P3 International P446 Kill A Watt EZ Electricity Usage Monitor - - Amazon.com

I've used this device for measuring kilowatts consumed on 120 VAC circuits and wondering how it could be used to measure the consumption in one leg of a 230 VAC circuit.

I had a one ton mini-split heat pump/AC installed recently for a sunroom addition to our home and would like to get an idea how much power it is using.

Wondering, first of all, if measuring the power used in one leg would give an accurate indication of total power if taken times two.

Then wondering how the kill-a-watt device (see above) could be temporarily wired at the breaker panel assuming it would be in series with one leg of the 230 VAC but not sure how it would simulate the neutral of a 120 VAC circuit.

Hope that makes sense and would like to hear your thoughts. I'm not an electrician but have done a lot of my own wiring over the years using advice from electricians.

 

[LittleBill21]

P3 International P446 Kill A Watt EZ Electricity Usage Monitor - - Amazon.com

I've used this device for measuring kilowatts consumed on 120 VAC circuits and wondering how it could be used to measure the consumption in one leg of a 230 VAC circuit.

I had a one ton mini-split heat pump/AC installed recently for a sunroom addition to our home and would like to get an idea how much power it is using.

Wondering, first of all, if measuring the power used in one leg would give an accurate indication of total power if taken times two.

Then wondering how the kill-a-watt device (see above) could be temporarily wired at the breaker panel assuming it would be in series with one leg of the 230 VAC but not sure how it would simulate the neutral of a 120 VAC circuit.

Hope that makes sense and would like to hear your thoughts. I'm not an electrician but have done a lot of my own wiring over the years using advice from electricians.

is there a reason you don't want to use something like this?

Digital Clamp Meter Meterk 6 Counts TRUE RMS NCV AC/DC Voltage Auto Range AC Current Clamp Multimeter Capacitance Resistance Frequency Temperature Measure (Black Digital Clamp Meter) - - Amazon.com

 

[Mendonsy]

You would probably need to install something like this:
Baomain DDS238-4 （3-1）Single Phase DIN-rail Kilowatt Hour kwh Meter - - Amazon.com

 

[chim]

is there a reason you don't want to use something like this?

Digital Clamp Meter Meterk 6 Counts TRUE RMS NCV AC/DC Voltage Auto Range AC Current Clamp Multimeter Capacitance Resistance Frequency Temperature Measure (Black Digital Clamp Meter) - - Amazon.com

The clamp-on will tell you the current draw at the time, and you could roughly calculate the power usage at the that instant. To get an idea of the power consumption would require knowing how long the equipment runs each day / week / whatever.

The Kill A Watt appears to function as a usage meter, giving the power consumption over a period of time.

 

[CobyRupert]

Do you really want to know how much power it uses, or how much energy it uses?
That is how much power it uses when it is on; or how much energy it uses over the course of several days (taking into account that it cycles off and on)?
Power is an instantaneous (immediate) measurement. Energy is over time. Comparing power to energy is like comparing your speed to distance traveled.
A watt meter (or current meter and some math) will tell you the power draw.
A watt-hour meter (Joule meter really...semantics) will tell you the energy consumed.
And remember that Kilo just means 1000 of something.
You could manually figure energy if you know the power consumption and the running time duration.

As other noted, the Kill A Watt Meter really measures kilowatt hours (energy). Plus it plugs into a 115v outlet.

 

[Chewwy]

Do you really want to know how much power it uses, or how much energy it uses?
That is how much power it uses when it is on; or how much energy it uses over the course of several days (taking into account that it cycles off and on)?
Power is an instantaneous (immediate) measurement. Energy is over time. Comparing power to energy is like comparing your speed to distance traveled.
A watt meter (or current meter and some math) will tell you the power draw.
A watt-hour meter (Joule meter really...semantics) will tell you the energy consumed.
And remember that Kilo just means 1000 of something.
You could manually figure energy if you know the power consumption and the running time duration.

As other noted, the Kill A Watt Meter really measures kilowatt hours (energy). Plus it plugs into a 115v outlet.

Power is energy per unit time, not intantaneous.
One Watt = one joule PER SECOND.

 

[npalen]

I had searched for a 230 volt version of the energy meter to no avail, so thanks for the link guys. That is exactly what I need to measure energy consumption over a period of days or even weeks. Just want to know what it costs to heat this sunroom in Kansas in the middle of January at a given thermostat setting for example. Next summer, when its a hundred degrees in the shade, how much to keep at 70 degrees?

Digital Clamp Meter AP-57C-APP Bluetooth Clamp Multimeter 4 Counts Auto-Ranging Multimeter with DC/AC Voltage & Current, Resistance, Temperature, Frequency, Duty Cycle - - Amazon.com
I have been using one of these to record the amps as I was having an issue with the mini split unit short cycling. What I found is that the internal temp sensor of the air handler (inside unit) was picking up heated air causing it to shut down the compressor. The unit would cycle off for a couple minutes and then back on for maybe ten or so minutes.

Using the "follow me" setting on the remote controller overcomes this problem by using the sensor in the remote to control the unit. The remote can be placed out of the direct path of the air handlers output thus stopping the short cycling.

The phone app used with the above clamp meter allows taking and recording the current as many as 120 times/minute or down to as few as once/minute. It also records minimum and maximum current draw and at what time each occurred. Works good for recording high current draws on 12 VDC also.

 

[npalen]

You would probably need to install something like this:
Baomain DDS238-4 （3-1）Single Phase DIN-rail Kilowatt Hour kwh Meter - - Amazon.com

What would be the result of using this on 60Hz power since its rated for 50Hz? Would it simply run 20% "faster"?

 

[npalen]

https://www.amazon.com/dp/B01MRZAFA...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Found this unit which has the advantage of resetting capability for Kw. It does bring up the question, in my mind at least, can the amperage measured in one leg of 230VAC be used to directly calculate wattage (volts times amps) or does it need to be factored by two since there are two legs at the given amperage.
I understand that the amperage required to run a given device on 230VAC would be half of what is required to run it on 120VAC but the energy calculation is not clear to me given the two legs of the 230VAC.

 

[orezok]

I have been using this one.

CrocSee AC 80-260V 100A CRS-022B LCD Display Digital Current Voltage Power Energy Frequency Power Factor Multimeter Ammeter Voltmeter with 100A Split Core Current Transformer

Just put it on one leg and double .

 

[npalen]

I have been using this one.

CrocSee AC 80-260V 100A CRS-022B LCD Display Digital Current Voltage Power Energy Frequency Power Factor Multimeter Ammeter Voltmeter with 100A Split Core Current Transformer

Just put it on one leg and double .

Looks like a better unit! I have a question on the wiring diagram, however: It shows one wire coming off the N or neutral as I take it so am wondering if it can be used for a U.S. 230VAC application. I see the specs showing its good for 80-260 volts but U.S. 230VAC doesn't use a neutral.

Edit: Also, when taking an amp reading off one leg of a a 230VAC circuit and then figuring wattage, would I need to double the result since each leg is only 120VAC?

 

[RalphVa]

P3 International P446 Kill A Watt EZ Electricity Usage Monitor - - Amazon.com

I've used this device for measuring kilowatts consumed on 120 VAC circuits and wondering how it could be used to measure the consumption in one leg of a 230 VAC circuit.

I had a one ton mini-split heat pump/AC installed recently for a sunroom addition to our home and would like to get an idea how much power it is using.

Wondering, first of all, if measuring the power used in one leg would give an accurate indication of total power if taken times two.

Then wondering how the kill-a-watt device (see above) could be temporarily wired at the breaker panel assuming it would be in series with one leg of the 230 VAC but not sure how it would simulate the neutral of a 120 VAC circuit.

Hope that makes sense and would like to hear your thoughts. I'm not an electrician but have done a lot of my own wiring over the years using advice from electricians.

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

 

[chim]

Wear a flash suit and get it on video. It will beat out the kid getting stuck upside down on the playground swing and the grandpa whose pants fall down when he sneezes on Americas Funniest Home Videos.

 

[FastEddieR]

If you are going to run it anyway, just run it and monitor your usage via your power company. your power company probably offers you an app to monitor your usage, usually not a real-time monitor but hours to a day old info.

 

[Chewwy]

What would be the result of using this on 60Hz power since its rated for 50Hz? Would it simply run 20% "faster"?

Not familiar with this device. Theoretically, power or electrical energy measurement is NOT frequency dependent. But this device could be. 50 hz is the ac standard in outside The US and a few other counties. Reactive load and pf do vary with the frequency. Residential Watt- hour meters typically do not considering the pf.

 

[npalen]

If you are going to run it anyway, just run it and monitor your usage via your power company. your power company probably offers you an app to monitor your usage, usually not a real-time monitor but hours to a day old info.

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

 

[CobyRupert]

Power is energy per unit time, not intantaneous.
One Watt = one joule PER SECOND.

If your measuring the power going into a heat pump/AC unit, you are talking about the instantaneous power, the amount of energy being consumed at that moment. The Power = amps x the volts.
Instantaneous power is the power you’ll measure with a watt (or current) meter. It will vary second by second with the load.
This is different than average power. If your power bill says you use 100 kw-hrs of energy over a 100hr period, your AVERAGE power was 1kw, even though the unit actually uses 2kw of instantaneous power, but only ran 50% of the time. Capisce?

 

[CobyRupert]

If you know the power the unit consumes (look at specs, measure amps, etc..), and then wired an old fashion clock or counter to turn on and off with the unit, you would know the amount of energy (kw-hrs) it has used over that time period.

 

[npalen]

Wear a flash suit and get it on video. It will beat out the kid getting stuck upside down on the playground swing and the grandpa whose pants fall down when he sneezes on Americas Funniest Home Videos.

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

 

[Industrial Toys]

Lots of really inexpensive panel meters on E-Bay from China. A host of models that will tell you all kinds of stuff, power factor, KW, KWH, Amps, Volts, Cost.