Brultech Electrical Power Monitoring for your Home

[Btech]

Originally posted by dBeau in the TED thread and moved to this one:

How does the software work as far as passing the data to the PC? the unit seems to store the data in real time so can you hook it up to a pc and dump out a months worth of data or does the PC need to be up 24-7 to get a full set of data?

I installed an ECM1220 a couple of months ago. It's a great device. They have some software for windows that allows both realtime readings as well as downloading of history. The device protocol is very simple to work with. It took me less than an hour to put together a python script that would run from my SuSE box and grab the realtime samples so I havnt used their software much and cant comment on it. Their protocol docs arent complete but they claim they are working on it. One of these days I'll write and bug them for an update on how to set the history sample period. But since I am constantly sampling I really dont need the feature. The sample rate is about once per second with a 1 joule (watt/sec) resolution from each of the two channels.

My biggest complaint is that they only have a usb interface. When plugged in, it appears as a serial port so programming is not a problem, it's just a bit limiting in that the device you connect it to needs to support usb and have a driver for the serial chipset. Anything I have with a 2.6 kernel or better has worked, and this includes my nslu2. I'd would have preferred ethernet or straight rs232 for more flexibility.

I'm glad you are enjoying your ECM-1220.H. FYI, we have a new firmware version

available on our site. This new version has a new packet format in addition to the

current ones. The new format offers greater flexibility and now accomodates net

metering for solar and wind systems. We hope to have more information on this available

shortly.

There are some possible alternatives to the USB only situation. One possibility would

be to use Digi's (digi.com) XBEE to RS-232 adaptor along with a zigbee equipped monitor

(we use digi ZNET2.5 zigbee modules)
http://www.digi.com/products/wireless/zigb...es2-adapter.jsp

For you hackers, you can easily interface ZNET2.5 module ($23) to a MAX3232 chip for

RS-232 communication. You can also apply a similar solution using an RS232 to ethernet

module saelig.com in conjunction with a the zigbee module for TCP/IP solution.

Our new boards can provide a TTL rs-232 signal directly from an internal header. We

currently do not populate this area of the board however anyone wishing this option

could let us know in advance. We will populate a limited number of boards during our

next production run for anyone interested.

 

[Btech]

Good call, BSR.

On a somewhat related note, I can say that I am considering this monitoring system for my home, and should that happen, then of course that means a CQC driver for it would be imminent.

It appears that a CQC driver for our ECM-1220.H will soon be in the works thanks to one

of your cocoontech members.

 

[Btech]

Just wanted to follow up on my other post. I checked the voltages on both of my phases several more times yesterday and today and I discovered that while my line voltage does seem to fluctuate some (probably a difference of 4 or 5 volts from the lowest reading to the highest reading) the voltage on the two phases seems to stay very close together.

There was a little fluctuation between the phases, but it wasn't off by more than .2 volts. Sometimes one phase was .2V higher than the other, and other times the first phase was .2V lower than the other. Sometimes they were exactly the same or just off by .1V one way or the other way.

In any event, it seems that my two phases are definitely pretty close and I don't think there would be too much inaccuracy to only measure the voltage of a single phase.

I'd still be interested to see what other people find if they try this experiment too.

Brett

The difference of phase to phase voltage is generally minimal at the panel due to the

heavy gauge feed and minimal line loss. The voltage imbalance will create a small error

which is usually acceptable. From experiments done some years ago, we discovered that

sometimes one phase voltage will be slightly lower than the other, and other times the

opposite would be true. When averaged out over the period of one month they seemed

average out and minimizing the error.

 

[Btech]

Good call, BSR.

On a somewhat related note, I can say that I am seriously considering this monitoring system, and should that happen, then of course that means a CQC driver for it would be imminent.

THat would be awesome...does CQC have an ability to store historic values in a database of somekind? I'm not very familiar with SQL, but if i need to run SQL server to store this data i suppose i would find other uses for it as well....(e.g. historic data on how often the water pump runs, how often AC turns on, etc).

I will be on a well....i know it's a bit off topic, but do these well pumps put out a flow consitent enough to approximate water usage by recording how long the pump is on?

With the ECM-1220 and a bit of creative software programming the pump's time of use (TOU) can be figured

out by looking at the load signature and power increase on the same phase as the pump

connection.

 

[Btech]

I will be on a well....i know it's a bit off topic, but do these well pumps put out a flow consitent enough to approximate water usage by recording how long the pump is on?

Depends on your system. Our well uses a constant pressure pump, so it varies the flowrate of the pump to maintain pressure, no matter how much or little water you're using. Your typical on/off pump MIGHT give you a ballpark.

Being a constant pressure pump it may be more difficult to analyse its run-time due to

the varied power caused by maintaning various pressure. With the ECM-1220 energy

monitor, You can connect the two current sensors from the main panel on to one channel which

would leave the second channel dedicated to monitor the pump seperately from the panel

circuit which feeds the pump.

 

[Btech]

I don't know if it explains the entire difference, but some of the difference between the .5% of the wattnode and the 2% of the TED could be because the TED only reads the voltage of one phase.
Brett

I suspect the major difference would be in the quality (accuracy) of the current sensor. The other issue would be that they would have to measure the phase angle between voltage and current for the power factor and depending on the A-D accuracy and the number of samples per second would affect how fine a difference they can measure. Although, a zero crossing detector on the voltage and current waveforms would be the easier way to detect PF...hmmm..sounds like a project...

I agree with your statement about the accuracy of the current sensors. It is very important to use current transformers with minimal phase shift for measuring true power. Your power factor idea using zero crossing makes a lot of sense and would work for many loads however there are so many switching power supplies out there now that you cannot assume a sinusoidal wave shape for current, which would prevent this method from working properly.

 

[brotsten]

BtechRep,

I have a 600 amp service. 3 x 200. Do you offer any configurations that would work with this?

Brian

 

[jharrell]

Originally posted by dBeau in the TED thread and moved to this one:

How does the software work as far as passing the data to the PC? the unit seems to store the data in real time so can you hook it up to a pc and dump out a months worth of data or does the PC need to be up 24-7 to get a full set of data?

I installed an ECM1220 a couple of months ago. It's a great device. They have some software for windows that allows both realtime readings as well as downloading of history. The device protocol is very simple to work with. It took me less than an hour to put together a python script that would run from my SuSE box and grab the realtime samples so I havnt used their software much and cant comment on it. Their protocol docs arent complete but they claim they are working on it. One of these days I'll write and bug them for an update on how to set the history sample period. But since I am constantly sampling I really dont need the feature. The sample rate is about once per second with a 1 joule (watt/sec) resolution from each of the two channels.

My biggest complaint is that they only have a usb interface. When plugged in, it appears as a serial port so programming is not a problem, it's just a bit limiting in that the device you connect it to needs to support usb and have a driver for the serial chipset. Anything I have with a 2.6 kernel or better has worked, and this includes my nslu2. I'd would have preferred ethernet or straight rs232 for more flexibility.

I'm glad you are enjoying your ECM-1220.H. FYI, we have a new firmware version

available on our site. This new version has a new packet format in addition to the

current ones. The new format offers greater flexibility and now accomodates net

metering for solar and wind systems. We hope to have more information on this available

shortly.

There are some possible alternatives to the USB only situation. One possibility would

be to use Digi's (digi.com) XBEE to RS-232 adaptor along with a zigbee equipped monitor

(we use digi ZNET2.5 zigbee modules)
http://www.digi.com/products/wireless/zigb...es2-adapter.jsp

For you hackers, you can easily interface ZNET2.5 module ($23) to a MAX3232 chip for

RS-232 communication. You can also apply a similar solution using an RS232 to ethernet

module saelig.com in conjunction with a the zigbee module for TCP/IP solution.

Our new boards can provide a TTL rs-232 signal directly from an internal header. We

currently do not populate this area of the board however anyone wishing this option

could let us know in advance. We will populate a limited number of boards during our

next production run for anyone interested.

BtechRep,

Any ETA on the wired ethernet version? This would be the power monitoring solution I have been waiting for, but if it's too long I may settle on the ZigBee version since it is a decent solution as well.

 

[Macca]

Hi BTechRep,

I note on your site that it says the system can measure 220V 50Hz with special firmware. Will you release a version soon to those of us living in countries that have this type of electricity supply? I for one (amongst many others in NZ) would purchase immediately as there are no resellers of realtime power monitors and dataloggers that I can find in the Southern Hemisphere....

- if anyone knows of one please PM me!!!!

 

[murphy]

Hi BTechRep,

I note on your site that it says the system can measure 220V 50Hz with special firmware. Will you release a version soon to those of us living in countries that have this type of electricity supply? .....

In Germany the price of a kWh is around 19 Euro-cent, at the current exchangerate around 25 to 30 US-cent. And we also have 230VAC with 50 Hz. So this firmware is interesting for me and some others too. There will be no problem with the 220 (some years before, or now 230 VAC. It is an easy thing connecting the powersupply and voltageindicator via a (more or less linear) transformer to 115 VAC, but the firmware must handle the timing of the 50 Hz. 230V/50Hz is standard in most (all?) European countries.

BTW , one reason I'm living partly in Texas are the energycosts: in TX 1 kWh = 6,35 cent. Together with unavoidable fuelcost the difference pay a round ticket, if I stay 2 month on my farm!

 

[Btech]

Hi BTechRep,

I note on your site that it says the system can measure 220V 50Hz with special firmware. Will you release a version soon to those of us living in countries that have this type of electricity supply? .....

In Germany the price of a kWh is around 19 Euro-cent, at the current exchangerate around 25 to 30 US-cent. And we also have 230VAC with 50 Hz. So this firmware is interesting for me and some others too. There will be no problem with the 220 (some years before, or now 230 VAC. It is an easy thing connecting the powersupply and voltageindicator via a (more or less linear) transformer to 115 VAC, but the firmware must handle the timing of the 50 Hz. 230V/50Hz is standard in most (all?) European countries.

BTW , one reason I'm living partly in Texas are the energycosts: in TX 1 kWh = 6,35 cent. Together with unavoidable fuelcost the difference pay a round ticket, if I stay 2 month on my farm!

We have been in contact with a CT member from New Zealand who will be testing our 50Hz 220V version.

The wall transformers we have is the two round pin type, 220V/50Hz. I believe this type is standard in Germany also. If you're interested in the ECM-1220.h, feel free to email me.

 

[murphy]

View attachment 1866

......
The wall transformers we have is the two round pin type, 220V/50Hz. I believe this type is standard in Germany also. If you're interested in the ECM-1220.h, feel free to email me.

Your "round pin type" is probably the "Euro-Norm" or the "Schucko-Norm" (an abbrivation of the german word for safety contact). Both will work. I'm courious what standard power plugs there are in "Down Under". Yes it looks like there are some users from this area.

And of course there are energie monitors also available in Germany. For example at ELV ( http://www.elv.de ). Also with wireless transmission to a portable box. Of course for 220V/50Hz, but -AFAIK- not with the option of transferring the datas to a PC. Most of the energy monitors here are adaptertypes, you simply plug them between the poweroutlet and the device, as an X10-module. here are some examples with "round pins":

and .

 

[dem5867]

 Btech Rep,
Who should I email for info. on the protocol ??

Can you get me the info. on the step down transformer ??

"Yes you can use a 240V/12VAC transformer as long as the transformer you use introduces minimal phase shift. This would have to be tested under a certain secondary load. Adjustment of the PT settings would also be required. There is a 240V/120V step-down transformer we have used in the past which would allow you to plug the ECM-1220's wall transformer into and can be powered from 240V. I have seen the same model that we use for sale on an ebay store for approx $10.. I can get the info for you if you wish. We have tested this particular model for phase shift and is compatible with our monitor. There would be a slight adjustment of the CT setting since the voltage ratio is not a perfect 2:1"

TIA

DEM 

 

[Btech]

 Btech Rep,
Who should I email for info. on the protocol ??

Can you get me the info. on the step down transformer ??

"Yes you can use a 240V/12VAC transformer as long as the transformer you use introduces minimal phase shift. This would have to be tested under a certain secondary load. Adjustment of the PT settings would also be required. There is a 240V/120V step-down transformer we have used in the past which would allow you to plug the ECM-1220's wall transformer into and can be powered from 240V. I have seen the same model that we use for sale on an ebay store for approx $10.. I can get the info for you if you wish. We have tested this particular model for phase shift and is compatible with our monitor. There would be a slight adjustment of the CT setting since the voltage ratio is not a perfect 2:1"

TIA

DEM 

http://cgi.ebay.com/100-Watt-Step-Up-Down-...1742.m153.l1262


email:: [email protected] or [email protected]

 

[dem5867]

Do you know if there is a US supplier for this transformer (Shipping is twice what the unit costs.) I have some Step up / down transformers here ,, How do I check them to insure that the phase shift is OK (Is smaller better [Less mass to charge ??) ??? 

It's a bummer you guys don't have a 240 to 12 wall wart.. Are you looking into supplying these units to the UK.. If so would the UK transformer work for me ???

 Btech Rep,
Who should I email for info. on the protocol ??







Can you get me the info. on the step down transformer ??

"Yes you can use a 240V/12VAC transformer as long as the transformer you use introduces minimal phase shift. This would have to be tested under a certain secondary load. Adjustment of the PT settings would also be required. There is a 240V/120V step-down transformer we have used in the past which would allow you to plug the ECM-1220's wall transformer into and can be powered from 240V. I have seen the same model that we use for sale on an ebay store for approx $10.. I can get the info for you if you wish. We have tested this particular model for phase shift and is compatible with our monitor. There would be a slight adjustment of the CT setting since the voltage ratio is not a perfect 2:1"

TIA

DEM 

http://cgi.ebay.com/100-Watt-Step-Up-Down-...1742.m153.l1262


email:: [email protected] or [email protected]