Owl Energy Meter CM119 ???
 

http://www.allthingsgreen.net/market...m119-thumb.gif

It's from the UK, but it looks like it's USA compatible.. (It does dollars).

OWL | Wireless Electricity Monitor Designed To Save You Money & The Environment - OWL Wireless Electricity Monitor

It seems to only need one current probe. It snaps around one of the 230vac cables.

My application isn't whole house. I want to monitor only the power used by my new Sanyo heat pump..
http://ecorenovator.org/forum/projec...l-project.html

I would just snap the probe onto one of my heatpump 230 lines in the breaker box..

Would this work??

According to Mr. Electricity, you can't use a unit from Europe over here because we have 'split phase' and they have straight 240V. Not sure what that means, but he says it won't work. Perhaps it has something to do with the frequency.

I did some googling and it seems the Tesla guys are having the same problem as they want to track their car's energy usage. Their solution was basically a utility grade meter which actually doesn't look that expensive.

Best meter for garage charging outlet - Tesla Motors Club Forum

It does not have voltage sense so it cannot calculate power as a vector. That would make it inaccurate with nonlinear loads.

split phase?
 

Split-phase electric power - Wikipedia, the free encyclopedia

"A split phase electricity distribution system is a 3-wire single-phase distribution system, commonly used in North America for single-family residential"

"it is appropriate to call this power distribution system a 3-wire, single-phase, mid-point neutral system."


My dryer uses 230v across the heating elements, but uses 115v on it's motor.
So, that motor is connected across one of the 230 lines and the Neutral (red).

So, measuring one line with a single probe on my dryer would be tricky.
Have to get the probe on the 230 side that was powering both the motor and element.

Re: my heat pump, I don't think there is anything in it that uses 115v..
It's driven by 230v, so measuring one side of the 230 seems like it would work.


Found this page that explains things. (I'm starting to remember this stuff)!
BeanAnimal's Bar and Grill - Electricity and the Aquarium

http://www.beananimal.com/media/3180...se%20small.gif

If you ignore the neutral, and stick your meter on the two hot lines,
it's a plain old 230vac (RMS). The 30:1 transformer isn't doing anything magical.
It just providing you with 230 or 115 vac.. If you plug in an AC or HP
that only uses 230 and no 115, there should not be any current flow
in the neutral line.
So, a current probe placed on one of the hot lines of my Sanyo should
work just fine.

Check it out.. The 230 AC input to my Sanyo.
http://i46.photobucket.com/albums/f1...r/NCL/F104.jpg
Wires 5&6 are the 230vac, the neutral is the fat green wire over on the left.
That green wire is there to pop a breaker, should one side of the 230 short out to the chassis.

It has a voltage select function on the setup menu. (Page 5).
http://www.theowl.com/uploads/downlo..._userguide.pdf

So, if I select 220,230,240 or 250 volts, it's probably not going to be lab grade,
but going to be good enough for my needs..

My worry is the cable diameter of 12g cable is kinda small for the probe clamp.
I would have to an insert inside the jaws to hold the wire,
so it wouldn't move around and kill the accuracy.

Once installed, I could check it against the Centron meter.

http://ecorenovator.org/forum/conser...-yourself.html

And calibrate the CM119 by changing the voltage select..?.

If you connect a capacitor to AC power, it will draw current but not dissipate much power as the average power, computed using vectors, is close to zero. (The instantaneous power is changing sign as the capacitor charges and discharges.) A complex electronic load is even worse.

After emailing a friend on this, he said you should be able to use the international unit as long as nothing in that line uses 120V. He has been wanting to do the same since he just got his 240V AC electric car running.

I'm 99% sure that my Sanyo isn't using any 120V.
Just the way the neutral is grounded to the chassis is a dead giveaway.

I've found another similar UK model that looks pretty good too.
http://www.efergy.com/images/elite_1.jpg

efergy.com | elite

The spec sheet http://www.efergy.com/download.php?f...ta%20Sheet.pdf
Says "Measuring Current 50 mA to 95 A", which makes me think this model
may have better sensitivity than some of the others.

Can't find any American users of these UK made devices.. :confused:

Edit Dec 12:
I've been using this unit for a while now and it seems to be working very well.
Ordered it from a company in the UK. Took a while to get here, but was well worth the wait.

My guess is the Sanyo presents a complex load.

Indoor unit:
http://i46.photobucket.com/albums/f1...indoorunit.jpg

Outdoor unit:
http://i46.photobucket.com/albums/f1...CL/outdoor.jpg

These diagrams aren't very detailed, but I get the feeling that both PCBs
have diode & cap inputs. The PCBs take th 230VAC and make DC to use.
None of the motors in the indoor unit looks like an AC motor.

The only thing I can see that might be AC operated is the crankcase heater.