v4 First look

[Nevland]

New meter arrived today.
!Wow!
I am impressed.
Read every word I could find on it. Can't wait to get it installed and run it through it's paces. My imagination is running amuck and I keep thinking of neat things that I could due with it.

1st question
Could I monitor 3 separate items like Freezer, Well pump, Etc.
How about running 2 wires through the same ct. (Same side of the line) Maybe using the unused 3rd input.

If it checks out like it reads, Sandy Claws may have to rob the piggy bank and come up with an additional one.

Bill

[Jameson]

Bill,

Glad you like the looks of the EKM-Omnimeter Pulse v.4! This meter does come with a load of new features that really open up a world of possibilities.

Yes, this meter has separate kWh registers for each line, so yes you can have a 120 volt 2-wire load on each of the 3 lines and get back both Total and Reverse kWh on each of these 3 lines. So this meter can act like 3 separate 120 volt meters or a 120/240 volt 3-wire meter and a 120 volt 2-wire meter. Or on foreign 230 volt 2-wire systems, it can also act as 3 separate meters.

Just be sure you are looking at "Total Kilowatt Hour L1" for the kWh value on line 1 only. (separate from "Total Kilowatt Hour" which is the overall meter total). We are working to implement more of the features that the EKM-Omnimeter Pulse v.4 is capable of in the EKM Dash.

Here is more information about the EKM-Omnimeter Pulse v.4: http://www.ekmmetering.com/omnimeter-pulse

Yes, you can run 2 or more wires through the same CT on any of our External CT meters. The wires must be from the same phase and pass through the CT in the same direction. This is useful for combining circuits or in the case of large systems, for metering parallel feeds.

We will be interested in seeing what you come up with. Are you planning on using the controllable outputs?

Regards,

[Nevland]

It's installed and working with Dash .383

Is protocol available like the v3 ?

Yes I have plans for the outputs.
I think I can add a dummy load to the genni and test it remotely.

How about this:
Install a couple of relays to switch ct's and volts to a difference source.
Install a third ct so you can now monitor a single ckt (Well use etc)
All kinds of stuff to think about.

More to come
Bill

[Jameson]

Hi Bill,

Yes we do have the protocol available. Here is the v.4 request/response protocol: http://documents.ekmmetering.com/Omnime ... arsing.pdf
Here is the v.4 settings document: http://documents.ekmmetering.com/Omnime ... otocol.pdf

Be careful not to set your meter password to an unknown value. We cannot recover a password.

You can also use the EKM Dash to teach yourself how to write your own software. We have included the Hex Inspector under the Help menu item. You can use this to see how the EKM Dash sends a Hex request to the meter including the meter number and if it is an A type request or a B type request. You can then see how we parse out the data from the return string.

Let us know if you have any questions.

[Nevland]

Thanks for the the info.

I did not find the "Total Forward KWH" on the parceing page.

Did I miss it, or is it calculated, if so from what ?

Not sure what KVARs are How measured?

Just thought of a neat thing, I think I can now do.
If the genni goes outside of my predetermined limits (governor lost control/voltage regulator fault etc.) the software can issue a command to shut the genni down before any real damage to the generator windings. (Big $$$ to fix.)

Bill

[Jameson]

Hello Bill,

Our meters return Total Kilowatt Hours (forward kWh + reverse kWh) and Reverse kWh (reverse kWh only). To find Forward kWh you would use this formula: Total kWh - Reverse kWh = Forward kWh.

This is the formula we use in the EKM Dash.

VARs are volts amps reactive (real time value similar to watts)
kVARh's are kilovolts amps reactive hours (a cumulative amount similar to kWh)

If you have perfect power factor you will not have any VARs or kVARh. You can use VARs and kVARh to isolate certain loads and determine device signatures. So theoretically you can use one meter and know exactly which loads are turning on and off by analyzing the load profiles of each load. For example a clothes dryer will have a different signature than a toaster, or a pool pump.

Some utility customers are also penalized for accumulated kVARh.

Good idea about automating the system to react to events. By using the EKM Metering system as a sensor or a monitor, you could save machinery (money) in the case of failures or save energy (money) by preventing waste. We would like to incorporate what we are calling "Alerts and Triggers" into the EKM Dash. Having the Dash react like you are suggesting will be a very powerful addition. Turn off loads or send emails if the voltage is too low, or the amps are too high for example.

Regards,

[Nevland]

Please explain "Devise Signature"
Just how are VARs derived.? Wikipedia was not much help.

Bill

[Jameson]

Bill,

Here is a long winded answer to your question about "Device Signatures": http://www.doc.ic.ac.uk/teaching/distin ... .kelly.pdf

Here is another: http://www.cse.psu.edu/~smclaugh/cse598 ... ughman.pdf

The idea behind this is that any given electrical device or appliance has a certain set of parameters that it affects. For example a small motor could pull 324 watts when starting and 142 watts when running. It could also affect the power factor by + Inductive 0.02 on Line 2, VARs +3, etc These would be learned and interpreted. We do not have the tools to do this ourselves, but others have been successful at doing this with 15 minute watt data only, or inaccurate Energy Monitors (in the pdf above), so using the EKM meters should be easy by comparison.

VARs is a bit of a mind bender for me. I found this article to be very useful: http://www.allaboutcircuits.com/vol_2/chpt_11/2.html

Especially knowing that the combination of Volt-Amps-Reactive and Volt-Amps = Watts

The more the volt sine wave is out of sync with the amperage sine wave the higher your VARs measurement will be.

As far as I understand, by and large for economic reasons, Power Factor and Reactive Power really only need to be understood, or corrected by very large utility customers who get penalized by their utility for creating bad power factor. We use a metering SOC that returns these parameters for us.

If you have any questions, please let us know.

[gilroy]

HEllo this nice and good You can use this to see how the EKM Dash sends a Hex request This is used if you have multiple wires which will not fit through one CT that you want to meter. You are correct that all line1 wires must be from Line1 and must pass