Electricity Monitoring

[123]

Something isn't making sense in my head too ... like helping someone jury-rig their electrical mains and steering them clear of qualified assistance.

Jim, do yourself a favour and confirm the xfrmrs are approved for use within your breaker-box. If you skip this step, you're putting yourself, and your family, in harm's way.

 

[AnthonyZ]

Not to start any friction here, but I know there isn't any standard electrician in my phone book that has the foggiest idea about integration of electrical and home automation/security. Oh the money it would cost if you could find some people qualified to do it. It still wouldn't be they way I want it anyway.

On the other hand, I do respect electricians when it comes to standard stuff. I use them all the time at work. Leave the control integration to me though.

As far as this post; you should get your hands on one of these - veris 8035 or 8036 - you need a modbus master though. The device does all the calculations for kW/kWH and even more with the 8036. I know there's a 8035 on ebay right now for 159.00. Just search for "veris 8035".

Yeah, this makes a lot of sense...tell a guy not to "waste" money on expert service but evidently it's cool to suggest he spend money on devices when he's OBVIOUSLY already spent $ for what he needs to build his meter. Smart.

 

[Steve]

for what my non-expert opinion is worth, "qualified electrician" is a waste of money you're better off buying a multimeter and a good book I have yet to find an electrician locally who can understand what i've wanted or done in regards to HA. I sent all my NEC questins to an expert forum - no one would touch it with a ten foot pole...
-brad

Yes, my thoughts precisely! Not to start any friction here, but I know there isn't any standard electrician in my phone book that has the foggiest idea about integration of electrical and home automation/security. Oh the money it would cost if you could find some people qualified to do it. It still wouldn't be they way I want it anyway.

On the other hand, I do respect electricians when it comes to standard stuff. I use them all the time at work. Leave the control integration to me though.

As far as this post; you should get your hands on one of these - veris 8035 or 8036 - you need a modbus master though. The device does all the calculations for kW/kWH and even more with the 8036. I know there's a 8035 on ebay right now for 159.00. Just search for "veris 8035".

I agree about most electricians not understanding the HA aspect of things. But your service entrance IS standard and nowhere related to HA. You have probably 200A at 240V live and exposed in there. It can KILL you in a heartbeat if you are not careful. Trust me, I have heard many horror stories about it. Changing switches out and even individual breakers is one thing, the service entrance is not something to fool with if you are not 100% comfortable. It is not worth your safety or your family's. While I do understand how the service entry works and is wired, I would never attempt to give advice to somebody who is a stranger around it. The best course of action is to have a qualified electrician at least be there and instruct you, ask alot of question and get comfortable for possible future work on it on your own.

 

[ckindt]

for what my non-expert opinion is worth, "qualified electrician" is a waste of money you're better off buying a multimeter and a good book I have yet to find an electrician locally who can understand what i've wanted or done in regards to HA. I sent all my NEC questins to an expert forum - no one would touch it with a ten foot pole...
-brad

Yes, my thoughts precisely! Not to start any friction here, but I know there isn't any standard electrician in my phone book that has the foggiest idea about integration of electrical and home automation/security. Oh the money it would cost if you could find some people qualified to do it. It still wouldn't be they way I want it anyway.

On the other hand, I do respect electricians when it comes to standard stuff. I use them all the time at work. Leave the control integration to me though.

As far as this post; you should get your hands on one of these - veris 8035 or 8036 - you need a modbus master though. The device does all the calculations for kW/kWH and even more with the 8036. I know there's a 8035 on ebay right now for 159.00. Just search for "veris 8035".

I agree about most electricians not understanding the HA aspect of things. But your service entrance IS standard and nowhere related to HA. You have probably 200A at 240V live and exposed in there. It can KILL you in a heartbeat if you are not careful. Trust me, I have heard many horror stories about it. Changing switches out and even individual breakers is one thing, the service entrance is not something to fool with if you are not 100% comfortable. It is not worth your safety or your family's. While I do understand how the service entry works and is wired, I would never attempt to give advice to somebody who is a stranger around it. The best course of action is to have a qualified electrician at least be there and instruct you, ask alot of question and get comfortable for possible future work on it on your own.

you're preaching to the choir

 

[ckindt]

Not to start any friction here, but I know there isn't any standard electrician in my phone book that has the foggiest idea about integration of electrical and home automation/security. Oh the money it would cost if you could find some people qualified to do it. It still wouldn't be they way I want it anyway.

On the other hand, I do respect electricians when it comes to standard stuff. I use them all the time at work. Leave the control integration to me though.

As far as this post; you should get your hands on one of these - veris 8035 or 8036 - you need a modbus master though. The device does all the calculations for kW/kWH and even more with the 8036. I know there's a 8035 on ebay right now for 159.00. Just search for "veris 8035".

Yeah, this makes a lot of sense...tell a guy not to "waste" money on expert service but evidently it's cool to suggest he spend money on devices when he's OBVIOUSLY already spent $ for what he needs to build his meter. Smart.

you too - you're preaching to the choir

Sorry to ruffle your feathers, but I bet there isn't one person here that hasn't spent money to upgrade and existing component of their system. It's evolution. My wife hates it. I've bought upgrades to things I haven't even installed yet only because I found a better solution sooner. Maybe using modbus and an intelligent voltage/current sensor isn't practical for this pesrson/application, but it is unequivocally superior to simple analog CTs. I suggested a viable alternative that is smart.

 

[nsisman]

Jim,

Your panel doesn't look standard at all to me (I am for sure not an electrician).

IF YOU GET ON THE WRONG SIDE OF THE MAIN BREAKERS PLAYING WITH SPLIT COIL THINGS AND YOU TOUCH ONE LIVE WIRE EVEN WITH YOUR HAND YOU WILL BE IN GRAVE DANGER !

THAT BEING SAID I WOULD SUGGEST YOU CALL AN ELECTRICIAN TO DO THIS WORK !

THE ONLY SAFE WAY TO DO IT IS TO HAVE YOUR METER PULLED BY A PRO!

Please be safe - 240 is not just an "Oh darn" when messed with

Neil

 

[shenandoah75]

this probably won't surprise anyone but I got zapped by 240 once - backed into a live wire while sweeping up my shop that i was sure was deenergized. We had dropped all the wire but i had't put the twist lock receptacles on yet. Well turns out it wasn't.. tingled a little and I had three little dark dots where my arm had made contact with the end of that orange romex for a couple of weeks.

More recently, I luckily decided to hold back on cutting through some white 14AWG romex which based on its route i was possible was a dead lighting circuit i was removing from the attic. I wisely chose to follow it to be sure and it turns out it supplies my well's pump with 240VAC (and was indeed NOT dead). Based on the last time i cut through a live pair of wires (a plugged in tape deck when i was about seven - i'm sure that would have been interesting to say the least - (the flash of light that 7year old mistake made and the damage it did to the metal in those blue handled scissors - literally put craters in them is one of my most vivid memories)...

That said i'm certainly not advocating snipping these when live to put in your transformers I have a big ole 200A disconnect by my meter which is nice and given my history probably a very very good thing!



edit: actaully when my house was built in 95 all the romex was white. So it's entirely plausible (and i hope) that that white romex was 12AWG (since it's fused at 20amps) and it just looked smaller to me up in in that 120 degree attic

 

[jim3342]

I can appreciate the fact of touching a live wire and I've been really careful about that.

I'm now a little concerned about the CT's near the panel. I've put a CT on line A & B from my diagram and it seems to be giving accurate readings. It will take a few days to know for sure but do I have to worry about something going wrong in that time. What are concerns besides shorting out a 240 line (or even 115) while poking around the panel?

 

[Steve]

What are concerns besides shorting out a 240 line (or even 115) while poking around the panel?

Isn't that enough? As was said, touching the main feed is not like whooops, that was interesting. It can likely be more like, Game over. Remember, there is no upstream breaker that is gonna trip instantly when you are in the service feed.

 

[jim3342]

I'm not saying it should be taken lightly at all.

My point is that I've already done the poking around and it's in place. So is there anyway these CT's can cause other issues?

 

[will40]

I'm not saying it should be taken lightly at all.

My point is that I've already done the poking around and it's in place. So is there anyway these CT's can cause other issues?

Depends what type of CT's they are. If they are current ratio transformers (200:5, 5:1) and the secondary side is open (no shunt) a dangerous voltage will be present and WILL bite you.

What equipment are you using?

 

[AnthonyZ]

Sorry to ruffle your feathers, but I bet there isn't one person here that hasn't spent money to upgrade and existing component of their system. It's evolution. My wife hates it. I've bought upgrades to things I haven't even installed yet only because I found a better solution sooner. Maybe using modbus and an intelligent voltage/current sensor isn't practical for this pesrson/application, but it is unequivocally superior to simple analog CTs. I suggested a viable alternative that is smart.

No need to apologize. Many who've met me will attest to the fact that I'm CRAZY highstrung. No harm. No foul. Not to mention, I've added some approx. 15-20 grand in "upgrades" over the past two years alone. Heck, my wife has to learn a new remote about every 3 to 6 months. I need a twelve step program for electronics...

The product you've recommended is one I'm unfamiliar with. I have spent the last 1/2 hour reading on it and I'm missing where it's unequivocably better than a standard analog CT rig. The Hawkeye piece is only rated to within 1% accurate whereas similar, yet analog, versions are sometimes rated to within .5%. What am I missing?

 

[shenandoah75]

What equipment are you using?

I'd also like to know what you're using to monitor downstream? I looked at TED from the other posting, but all of this stuff is so propritary. I'd like to ultimately tie this into the same inteface i have for everything else (and easily). I think dumping to text or db rather tahn it's own program would be ideal... (maybe directly reading the serial port with TED would be enough if the comm protocol were published?)

 

[linuxha]

Anyway, your original question was where to hook up the CTs. You've established that you have 240 on both A&B and C&D.
I'd put the CTs on the lower C&D cables so they won't interfere with operation of the breaker.

Jim:

From what I've read in the thread (the wires from the meter are on the top - A & B ) I'd stick with A & B, if C & D are a feed to a sub panel then the only current measurements being made will be of that on the sub-panel not the incoming circuit.

Jim the suggestion to get more of the panel in the picture is a good one. It would be helpful to see the entire panels and the feeds. My guess is that you're home has two panels. Mains -> Meter -> Master breaker (split to the panel and the sub panel). Of course this is just a guess on my part. As others have stated be careful electricity is not very forgiving.

And lastly, you do know that the formula P= I * V doesn't apply to AC unless you measure the instantaneous I & V. See Dr. Edward Cheung's Power Line monitor for details.

 

[ckindt]

The product you've recommended is one I'm unfamiliar with. I have spent the last 1/2 hour reading on it and I'm missing where it's unequivocably better than a standard analog CT rig. The Hawkeye piece is only rated to within 1% accurate whereas similar, yet analog, versions are sometimes rated to within .5%. What am I missing?

The 8035 and 8036 (8036 offers a lot more information than the 8035) are superior for power monitoring because they do all the calculations locally. You read the modbus registers to get the values. If you don't have a modbus master than they won't do you any good. They are a standard in industrial power monitoring applications. The 1% accuracy is very good and negligible for their purpose.

Analog CTs can certainly be used in combination with voltage transducers for power calculation, but CTs alone are used more for industrial control applications.

My home control system is centered around an industrial programmable controller and I have a modbus master that I use to read the 8036's registers. I can use the values for any other control function I want.

http://www.veris.com/file_uploads/h8035-36_i0e.pdf