Individual Power Metering

[dapper]

I have a customer that wants to trend power consumption of individual water source heat pumps that are scattered around his building. Unfortunately they are not all wired to a common service panel allowing for one meter. Individual meters will be needed for each unit.
The building has a BACnet control system that he wants to bring these trends into. Has anyone done this type of monitoring and what meters or devices did you have good luck with.
Thanks for your advice

[fms2k]

E-MON Class 3000 meter has BACnet/IP & BACnet MS/TP option.
Might be too pricey, though, for what your customer is looking to
do but probably worth checking out anyway.

[fms2k]

Also the Veris H8100 series with a BACnet comm card option.

[klrogers]

Did a LON/Tridium job recently with over 40 RTU's, Air compressors, Air Driers, Lighting, Chiller etc. that wanted individual power monitoring. What we did to keep cost down, on RTU's with used two current sensors feed into the RTU controllers, averaged the current draw (and multiplied by1.73). Using the two Jaces and AX supervisor we had pently of data storage available. For the Compressor, Driers, Chiller and lighting we used CCS Wattnode devices.
Customer is happy with end results.

Kevin

[381engineer]

Dap

I'm actually in the process of installing a bunch of wattnode modbus devices and bringing them into a Linx. once you set up the template it's copy and paste. Just finished the first one. Email me and I can get you a log in if you want to take a look.

[dracula]

Red Flag Warning:

If the client is just looking for the energy usage information for energy management tracking purposes, you are OK with some of the options discussed. However, if the client is thinking about using this information for billing the tenants for energy consumption cost recovery, make sure to include a "data accuracy hold harmless" clause in your contract with the client.

One of the ways I make a living is utility bill auditing, and I have found that many of these "home grown" energy metering systems can be very inaccurate and this does lead to getting my clients back large refunds on illegal, and incorrect, overbilling by building owners.

In the event the energy consumption data collection is going to be used relating to tenant billing, make sure you select metering components that are approved for this purpose by the "authority having juristriction" in the state you are doing the work with.

That usually involves NIST certified, and calibrated, metering components, and they will be higher in cost than some of the "CT to BAS" installations that are available.

For just energy usage monitoring, CT's into a BAS with some conversion software, will work cost effectively. Water based BTU metering, due to the piping, flow meter, two temp sensors, labor, etc, those can be the most expensive metering applications I have seen.

As someone did already mention, this "point of useage" energy monitoring can get expensive when compared to say a VAV zone controller. It is not unusual to see a very high "infrastructure cost" (comm backbone to the devices, and energy data interfacing components) and relatively high costs for the point of useage metering components.

It is not out of line to experience $3,000.00 to $5,000.00 per point of presense to get these systems in place, not including the front end HMI software.

Just providing words of caution to those that may be thinking of going in this direction.

Respectfully

Drac

[control_8]

EXTREMELY good information to know.



Red Flag Warning:

If the client is just looking for the energy usage information for energy management tracking purposes, you are OK with some of the options discussed. However, if the client is thinking about using this information for billing the tenants for energy consumption cost recovery, make sure to include a "data accuracy hold harmless" clause in your contract with the client.

One of the ways I make a living is utility bill auditing, and I have found that many of these "home grown" energy metering systems can be very inaccurate and this does lead to getting my clients back large refunds on illegal, and incorrect, overbilling by building owners.

In the event the energy consumption data collection is going to be used relating to tenant billing, make sure you select metering components that are approved for this purpose by the "authority having juristriction" in the state you are doing the work with.

That usually involves NIST certified, and calibrated, metering components, and they will be higher in cost than some of the "CT to BAS" installations that are available.

For just energy usage monitoring, CT's into a BAS with some conversion software, will work cost effectively. Water based BTU metering, due to the piping, flow meter, two temp sensors, labor, etc, those can be the most expensive metering applications I have seen.

As someone did already mention, this "point of useage" energy monitoring can get expensive when compared to say a VAV zone controller. It is not unusual to see a very high "infrastructure cost" (comm backbone to the devices, and energy data interfacing components) and relatively high costs for the point of useage metering components.

It is not out of line to experience $3,000.00 to $5,000.00 per point of presense to get these systems in place, not including the front end HMI software.

Just providing words of caution to those that may be thinking of going in this direction.

Respectfully

Drac

[klrogers]

Dracula, I 100% agree with you, in the application I talked about accuracy was not important. If I was doing something that involved tenant billing, then I would certainly be looking at E-Mon and similar devices.

Kevin

[s2sam]

Red Flag Warning:

If the client is just looking for the energy usage information for energy management tracking purposes, you are OK with some of the options discussed. However, if the client is thinking about using this information for billing the tenants for energy consumption cost recovery, make sure to include a "data accuracy hold harmless" clause in your contract with the client.

One of the ways I make a living is utility bill auditing, and I have found that many of these "home grown" energy metering systems can be very inaccurate and this does lead to getting my clients back large refunds on illegal, and incorrect, overbilling by building owners.

In the event the energy consumption data collection is going to be used relating to tenant billing, make sure you select metering components that are approved for this purpose by the "authority having juristriction" in the state you are doing the work with.

That usually involves NIST certified, and calibrated, metering components, and they will be higher in cost than some of the "CT to BAS" installations that are available.

For just energy usage monitoring, CT's into a BAS with some conversion software, will work cost effectively. Water based BTU metering, due to the piping, flow meter, two temp sensors, labor, etc, those can be the most expensive metering applications I have seen.

As someone did already mention, this "point of useage" energy monitoring can get expensive when compared to say a VAV zone controller. It is not unusual to see a very high "infrastructure cost" (comm backbone to the devices, and energy data interfacing components) and relatively high costs for the point of useage metering components.

It is not out of line to experience $3,000.00 to $5,000.00 per point of presense to get these systems in place, not including the front end HMI software.

Just providing words of caution to those that may be thinking of going in this direction.

Respectfully

Drac


Good day Drac,

On a secondary note, here in Canada it is similar and actually a little more involved. All equipment that is used for billing/metering purposes must be registered with Weights and Measures Canada (a government department) and is subject to periodic inspection and calibration. I am not sure, but I think it is actually illegal here in Canada to use such equipment without the appropriate governmental paper.

Cheers,

Sam

[CTC]

I have a customer that wants to trend power consumption of individual water source heat pumps that are scattered around his building. Unfortunately they are not all wired to a common service panel allowing for one meter. Individual meters will be needed for each unit.
The building has a BACnet control system that he wants to bring these trends into. Has anyone done this type of monitoring and what meters or devices did you have good luck with.
Thanks for your advice

I don't see how you can cost effectively do with a real meter for each unit. We use Veris meters and they are not too bad when metering major power, but one per unit would be too expensive unless you have some units with some serious tonage. I would use current sensors and do the math in the controller. Most of the buildings I have seen are supplied with consistant voltage. I do have a large school that does not. You Check the voltage there in the winter or in the morning and you'll get around 210 volts. Check it again in the afternoon when its loaded and you'll get 198. Utility company says the whole town is undersized. If I thought I had that problem I would check the voltage at each unit and meter the main. Your voltage drop to each unit would be a percentage and you would know what your Voltage at the service is....That would be the only way I can see you getting a system that was pretty close to correct and be somewhat affordable.

[integrator]

We had the same situation -> so we went with two methods.

1) Installed a true hydro metering system from http://www.powerlogic.com/productcategory.cfm/c_id/2.

2) Each hydro meter connects to a server that servers up web pages that can show all the real time readings, trends etc.

3) Then we used SCADA (OPC to BACnet/IP) software package which converts the Hydro information (which is OPC) to BACnet.

4) Used Johnson NAE to read in all the points and used this to provide energy managerment system to our system for demand limiting, shedding etc.

People might say this is over kill, but we are keeping billing requirements which are approved, and provide key informaiton per building to our JCI system.

[CTC]

We had the same situation -> so we went with two methods.

1) Installed a true hydro metering system from http://www.powerlogic.com/productcategory.cfm/c_id/2.

2) Each hydro meter connects to a server that servers up web pages that can show all the real time readings, trends etc.

3) Then we used SCADA (OPC to BACnet/IP) software package which converts the Hydro information (which is OPC) to BACnet.

4) Used Johnson NAE to read in all the points and used this to provide energy managerment system to our system for demand limiting, shedding etc.

People might say this is over kill, but we are keeping billing requirements which are approved, and provide key informaiton per building to our JCI system.

Whats the hydro meter for? Are you using a water density measurement to see how many btus your extracting or inserting into the water?

[xarralu]

Whats the hydro meter for? Are you using a water density measurement to see how many btus your extracting or inserting into the water?

I am assuming that is what he is doing. That is what we do.


http://www.veris.com/Item/U001-0103.aspx

[CTC]

I am assuming that is what he is doing. That is what we do.
http://www.veris.com/Item/U001-0103.aspx

How do you use the information? I can see that it would be a great tool in identifying units that have a problem. 5 idnentical units running and one if moving 3500 BTU's less than the other 4 would be a pretty good indication of a problem. I don't see that it would work well for energy consumption or load shedding. Being that unit efficiency would effect KW/BTUH conversion.