Questions for a new installation

General questions and discussions focused around the EKM Metering System. Discuss your meters, installations, and meter communications here.
Zaaphod
Posts: 20
Joined: Fri Oct 23, 2015 2:04 pm

Questions for a new installation

Post by Zaaphod » Fri Oct 23, 2015 2:29 pm

Hello, I am trying to plan out a new installation using 3 of your Omnimeter Pulse UL v.4 meters and a water meter.

I have some technical questions about your products.

The first question I have is about wire lengths, how far can the CTs be from the Omnimeter? Can I extend the leads beyond 6 feet? If so, can I use something like pairs from CAT5e or CAT6 cable to extend them, and could I send signals from 4 CT's through one CAT5e or CAT6 cable (one on each twister pair)

The next question is also about cable length.. How far could I put the water meter from the Omnimeter? Unfortunately the water enters my house almost exactly on the opposite side as all the power, so I'll have to go either around the house or through it.

Is there a way I could somehow set the output on an Omnimeter to turn ON if the incoming voltage either rises above 135Volts to neutral, or Drops below 105 volts to neutral on either of the two hot legs of a 240vac single phase 3 wire setup (two hots and a neutral)

Can someone tell me the difference between EKM push and EKM Push PRO ?

If I use either the EKM push or EKM push pro to read the Omnimeters.. could I also read the RS485 ports with a separate PLC at the same time the EKM push is monitoring?

Jameson
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Re: Questions for a new installation

Post by Jameson » Sat Oct 24, 2015 7:54 pm

Hello Zaaphod, welcome to the forum and thanks for your questions. These are common questions, so will help others who read this post.'

Extending the CT wires beyond 6ft:

It is best to locate your meter so that you do not have to extend the length of the CT wires so that you do not sacrifice any accuracy. But, if you do have to extend the wires, we recommend that you solder the wires to the wire extensions to give yourself the best possible contact. You can expect to lose roughly 1% accuracy for every 50 feet you extend your CT wires. If accuracy is not a paramount concern, then this should work. 24 AWG Cat5 wires should work as the amperages are so small, the CTs are made with 18 AWG wire. You should not have to worry about bundling the wires together like in a CAT5 cable, they will not interfere with each other.

Maximum Length of the Pulse Output wire from the water meter to the Omnimeter Pulse v.4:

We recommend up 200 feet for the Pulse Output wire. We have had customers who have successfully gone much longer. If you do go further than 200 feet, I would probably use shielded twisted pair wire.

Is there a way I could somehow set the output on an Omnimeter to turn ON if the incoming voltage either rises above 135Volts to neutral?:

At this point no, the best we can do for now is to setup a "trigger" using the EKM Dash. You can setup the EKM Dash to send you an email or text if the voltage were to increase above 135 volts on any line, for x reads in a row. The next step will be for us to develop the option to control a relay output based on triggers as well. Here are some other discussions about this topic:

http://forum.ekmmetering.com/viewtopic. ... gger#p6246
http://forum.ekmmetering.com/viewtopic. ... gger#p6330


Tell me the difference between EKM push and EKM Push PRO


There is no difference as far as how the meter gets read or the data you would get in your EKM Push account. The difference is that the EKM Push Pro has a hardened power supply for maximum reliability (think hospitals and military applications), it also has opto-isolated RS-485 which means that there is not a physical contact between the RS-485 transceiver and the main chip. There is a gap that uses light for communications. This helps if you were to have a very long outdoor run of RS-485 wire or minor lightning strikes, etc. I rarely recommend the Pro unless some of the above apply to you or if you plan on connecting 50 meters to your Push. The regular EKM Push is still extremely reliable.

Can I read my meters with an EKM Push and with my own PLC at the same time?:

Yes you can, as long as you are not trying to read your meters at the exact same moment, it will work. If you do read with both at the same moment, then you will just get bad data for that one read. You can have your EKM Push reading once per minute and your PLC reading once every 11 seconds, and you will very rarely have collisions. We do this all the time with our USB converters. As long as your PLC RS485 transceiver does not have some weird biasing resistor values you should be fine.

Hope this helps,
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371

Zaaphod
Posts: 20
Joined: Fri Oct 23, 2015 2:04 pm

Re: Questions for a new installation

Post by Zaaphod » Sun Oct 25, 2015 8:17 am

Maximum Length of the Pulse Output wire from the water meter to the Omnimeter Pulse v.4:

We recommend up 200 feet for the Pulse Output wire. We have had customers who have successfully gone much longer. If you do go further than 200 feet, I would probably use shielded twisted pair wire.


I have about 75 feet to go, could I just use one pair from a cat-5e cable for this?



Tell me the difference between EKM push and EKM Push PRO

There is no difference as far as how the meter gets read or the data you would get in your EKM Push account. The difference is that the EKM Push Pro has a hardened power supply for maximum reliability (think hospitals and military applications), it also has opto-isolated RS-485 which means that there is not a physical contact between the RS-485 transceiver and the main chip. There is a gap that uses light for communications. This helps if you were to have a very long outdoor run of RS-485 wire or minor lightning strikes, etc. I rarely recommend the Pro unless some of the above apply to you or if you plan on connecting 50 meters to your Push. The regular EKM Push is still extremely reliable.


You mention an EKM push account.. does the EKM push send the data to a server on the internet somewhere? If so, is there any way to make it work in locations that have absolutely no internet service? I have a customer out in the middle of nowhere with 7 CNC routers, he wants to get energy usage on each machine independently and monitor them all in his office, but he has no internet service, however he does have a local area network, with a dedicated server. is there a way to have the ekm push store the data logs on the LAN server instead of an internet server?

Jameson
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Joined: Fri Nov 04, 2011 7:42 pm
Location: Santa Cruz, CA
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Re: Questions for a new installation

Post by Jameson » Mon Oct 26, 2015 6:03 pm

I have about 75 feet to go, could I just use one pair from a cat-5e cable for this?

Yes a single pair from a CAT5 cable would be perfect.

You mention an EKM push account.. does the EKM push send the data to a server on the internet somewhere?

Yes, the EKM Push gateway connects to our distributed server cluster. It is not setup to connect to your local server (this would be very complicated and $$$ to setup). Please see our answer to your other post for more information about this: http://forum.ekmmetering.com/viewtopic.php?f=4&t=3468

If you want to store meter data on a local server, I would run the EKM Dash on your server and connect to the meter via a USB converter or potentially an iSerial. You can then use the EKM Dash software to read your meters and log the data.
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371

Zaaphod
Posts: 20
Joined: Fri Oct 23, 2015 2:04 pm

Re: Questions for a new installation

Post by Zaaphod » Tue Oct 27, 2015 8:26 am

Yes, the EKM Push gateway connects to our distributed server cluster.

Are there any fees associated with having an account on this server system?

If you want to store meter data on a local server, I would run the EKM Dash on your server and connect to the meter via a USB converter or potentially an iSerial. You can then use the EKM Dash software to read your meters and log the data.


I would prefer to use the iSerial approach, as it would offer me a bit more flexibility and ease of installation.. if I wanted to use USB, I would have to run the RS485 line all the way to the server, because USB signals can't be a very long distance, however with the iserial, I could put that near all the meters, and just run a cat5 cable to my network switch, which, for me anyway, would be much much easier as the switch is physically a lot closer to the meters. Would I need anything else, other than an iSerial and Dash software, to get this to work?

I see you have linux versions of EKM dash, what is the minimum hardware requirement for this? Could I for example run it on a Raspberry Pi?

Jameson
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Joined: Fri Nov 04, 2011 7:42 pm
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Re: Questions for a new installation

Post by Jameson » Tue Oct 27, 2015 8:47 am

Are there any fees associated with having an account on this server system?
No there are no ongoing fees for data access. We provide once per minute data for FREE! http://www.ekmmetering.com/meter-data
Would I need anything else, other than an iSerial and Dash software, to get this to work?
No this is all you need. http://www.ekmmetering.com/meter-software
I see you have linux versions of EKM dash, what is the minimum hardware requirement for this? Could I for example run it on a Raspberry Pi?
You need to run Linux on a machine that uses an Intel x86 based processor. ARM processors like what is on the Raspberry Pi will not work.
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371

Zaaphod
Posts: 20
Joined: Fri Oct 23, 2015 2:04 pm

Re: Questions for a new installation

Post by Zaaphod » Tue Oct 27, 2015 2:40 pm

I'm really impressed with the quick and detailed responses here on this forum, thank you for the information! I'm feeling quite confident that one way or another I will be able to get your system to work.

I'm very happy to hear that there are no ongoing fees for data access... I have walked away from many products due to monthly fees, I don't mind making the investment and even paying more for a quality product up front, but then I want to be done with it, I don't want to pay by the month to adjust my air conditioner with my phone. Part of the reason for this is that as I get older, I start planning more for retirement, and when that happens, I'll have a fixed income, and I will want all my gadgets to still work!

I have just a few more questions... is the once per minute... per meter or per account? what if I have 5 meters, would that be once per minute on all 5 meters, or would It have to be 5 minutes of each meter?

for the Dash software... I see there is a $30 registration key, Personally, I feel this is reasonable, and I'm also happy to see there are no upgrade fees or anything involved here as well... Those kinds of things DO make a big difference to your customers, and it is appreciated! My question about this is.... Is the registration key a per computer license or per person license? could I install it on my desktop computer, my laptop, and something to be a datalogging server all at the same time with this, or would I need 3 registration keys?

Too bad it won't run on the RPi... I've been using them for file and media servers with 128GB SD cards for a while now... the reason I like them.. very very low power usage! I think that would be an ideal datalogging server. I like low power for datalogging as I can keep it running during a blackout for a much longer amount of time for a lot less battery backup.. that and I like lower power bills too... however, there are other options, I can probably get something like an inexpensive netbook to do the job with low power consumption... what are your thoughts on that? would it be a fast enough processor, enough ram.. etc? It would be used for only this purpose, no other applications would be running on it at all. Would it work with an Intel Atom processor?

Jameson
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Joined: Fri Nov 04, 2011 7:42 pm
Location: Santa Cruz, CA
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Re: Questions for a new installation

Post by Jameson » Tue Oct 27, 2015 3:40 pm

I'm really impressed with the quick and detailed responses here on this forum
Thanks Zaaphod, we try to be as responsive as possible. Many of your questions others may find pertinent to their own needs, so hopefully others will read what is written here.
I'm very happy to hear that there are no ongoing fees for data access
Yes, this was a conscious decision on our part, we try to put ourselves in our customers shoes, and build the kind of system that we would want to install in our buildings. I dont like recurring fees myself, so I think offering FREE data is a huge advantage that we offer. It also adds tremendous value to the metering hardware that we sell. Of course there are those that would say we are crazy to give up on recurring revenue, but we think it is better to encourage more use, more awareness, and more water and energy savings by giving a lot away. Our model is to give our data to others that can then choose to make money by offering their own software solutions via our Open API: http://www.ekmmetering.com/developer-portal/
is the once per minute... per meter or per account?
If you were to buy 20 meters and connect them to 2 EKM Pushes. We would set each meter to be read once per minute. So if you were looking at a single meter you would be getting a full meter read once per minute.
Is the registration key a per computer license or per person license?
If you buy 1 EKM Dash license you can use it on an unlimited number of computers reading an unlimited number of meters.
would it be a fast enough processor, enough ram.. etc? Would it work with an Intel Atom processor?
Yes you can run Dash on something like a netbook. You can try it before you buy just to make sure it will work for you, we offer a 30 day free trial, it then goes to a "deprecated" version. From what I am reading online, it should work with an Intel Atom processor: https://forum.xojo.com/9241-arm-procesor/0 We use Xojo to write the EKM Dash, so that is where the Raspi/ARM Processor restriction comes from. If you are really interested in the Raspberry Pi, search this forum, as there are others that are reading our meters using RasPi, Arduino, BeagleBone, etc.
Jameson
EKM METERING
http://www.ekmmetering.com
831.425.7371

Zaaphod
Posts: 20
Joined: Fri Oct 23, 2015 2:04 pm

Re: Questions for a new installation

Post by Zaaphod » Sun Nov 01, 2015 3:29 pm

Thanks for taking the time to answer all my questions, I realize the answers are probably already in various places if I took the time to look for them, but it's so much better in my opinion to have a dialog going and to be able to just ask what I am wondering about instead of digging around to find it.

I really like everything I am finding out about your products, and I've placed an initial order late last friday that will get me started with my development. I'm glad you have decided on an Open API setup and I'm sure I'll find your developer portal invaluable in getting things to work. I could spend hours muddling around myself, or just ask a few questions and someone who already knows how it all works can get me on the right path much quicker.

I initially was just looking for something to install in my own home, however given the flexibility of your products and the Open API to allow me to develop my own product, using your devices as components of the entire project, opens up the possibility that I could develop the system I have in mind into something I could also market to my customers. I'm looking forward to working with your products!

Zaaphod
Posts: 20
Joined: Fri Oct 23, 2015 2:04 pm

Re: Questions for a new installation

Post by Zaaphod » Mon Nov 16, 2015 2:56 am

I have a few more questions about your omnimeters, I'm basically just wondering about the capabilities so I can make a total system plan.

First, is it possible to use two current transformers on a single input of an omnimeter to read the total of the two lines? I realize both CTs would have to be on the same phase and polarity matched, but I'm wondering if doing this would read as accurately as running both primary wires through one CT. The reason for this is I would like to monitor my A/C split system separately, but combine both the air handler and compressor units, however the wires in the panel come in on opposite sides are not long enough to go through the same CT.

Next, can I use one omnimeter to monitor three lines on the same phase? or are the three inputs strictly for three phase power? If so, could I monitor three separate 220v 2 wire single phase sources?

and last, for an installation with no internet, If I were to write a program to log data on my Raspberry Pi, Is the database format available for your dash software? If so, I could format the logged data correctly so that I could use dash to read my logged data when the windows computer is turned on.

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