extra IO pin on Omnimeter V3 meter?

[noisette123]

Our local utility in Quebec, Canada has a special tier rate based on outside temperature (which activates a dry relay contact on the Utility Meter) . When temperature gets lower than -12 degrees Celsius, the electricity is billed at 18 cents per KWH, otherwise, it is billed at 4 cents.

Is there any available IO pin on the header of the Omnimeter V3 that could be activated to track two tiers based on a digital input with a special firmware ?

If not, how would you go about capturing this info with minimal hardware?

Cheers,
Jean-Francois

[Jameson]

Hello Jean-Francois

That is interesting! I have never heard of this type of Utility Tariff Scheme before. In parts of California there are customers that get charged more if the local average temperature is projected to be over a set level (this is not measured at each individual meter).

Interfacing a switch state to the meter is not something that we currently offer, but it is something that we do want to offer in the not too distant future. We would offer the ability to connect a switch to a meter and then be able to poll the meter to see if the switch is open or closed. We will let you know when we have this ability.

We would not be providing the temperature switch however. I think you would essentially be looking for a thermostat that allows you to set it to activate at -12 Celsius. You would then connect this to the meter.

Or you could read your meter quite often with the EKM Dash software and export the reads to a .csv file. Then if you had temperature data you could add it to the same .csv and use this to determine how much power was used below -12 deg C and how much was used above -12 deg C. Should be fairly close.

As an aside:
What seems strange to me about this scheme is: wouldn't you get penalized if the meter were installed on the cold/shady side of your house? Or wouldn't you benefit if you kept your meter warm? Im not advocating manipulating this, it just seems curious. Is this a mechanical utility meter or digital?

Let me know if you have any questions.

[Nevland]

Here is something you could try, if you are not using the 3rd phase inputs. You could use a thermostat to switch an ac voltage to L3 input. If there is no current input there should be no watts, therefore no change in total KWH. New Dash software could log it for you, else write your own software to detect it. I have not tried this. EKM folks might tell us if this might work.
No warranty expressed or implied.

Bill

[Jameson]

Interesting idea Bill!

I like it. This is a unique idea for sensing on the 3rd voltage input (the 3rd input is not used on the EKM-Omnimeter in a single phase 3-wire system)

If the meter does not have a CT input on line 3 and you were to have a switched voltage input (controlled by a thermostat) on line3 this would not affect the Total kWh of the meter (in a Single Phase 3-wire system). Your software would only have to detect if there was voltage present or not present on line3.

Or you could use the EKM Dash. You would log your meter reads and then create a csv file from the database. You would then use Excel to separate your usage. Any usage that had voltage on line3 would go in one category and any usage that did not have voltage on line3 would go in a different category.

Thanks for the ideas, let us know how your project works out.

Regards,

[noisette123]

As an aside:
What seems strange to me about this scheme is: wouldn't you get penalized if the meter were installed on the cold/shady side of your house? Or wouldn't you benefit if you kept your meter warm? Im not advocating manipulating this, it just seems curious. Is this a mechanical utility meter or digital?

Hi Jameson and Bill,

Thanks for the ideas, i will order one meter and try this out...

Yes, some meters are obviously installed north are penalized compared to the ones on the south facing walls. I guess our utility does not have the willpower to make sure that all meters are registering the same temps in a given area... Thats a whole other question obviously

The meters are Itron digital Centron types.

Would i be able to use the inputs that are reserved for pulse counting on your meter?

Cheers,
JF

[Jameson]

Hello JF,

Would i be able to use the inputs that are reserved for pulse counting on your meter?

Yes, we are working on a meter that will allow this through the pulse inputs (not available yet). In the future when you read your Pulse Counting meter you will be able to tell how many Pulse Counts there are as well as if the pin is currently pulled high or low. You would attach a temperature switch (thermostat) to this input pin and you could tell in real-time if the switch is open or closed.

If you have any questions, please let us know.