Hello Robert,
You replied first! 
. I am verifying if the circuits have a neutral or not. In any case, I think want to use a CT per power line. I was going to ask the question…thanks for clarifying.
Jorge.
Understood. I called Enphase. They do not have the info readily available, for customer at least. However, I called Falco directly (to their Mexico office) and I think I got what we need. They were very nice and helpful.
Below is a picture of the CTs I got (the Falco CTs sold as Enphase CTs):
Below is the info from Falco:
Some physical dimensions below:
If these work, I will get them for the main lines. I will probably get the smaller ones from OEM for the individual circuits, as the Falco unit might be a little big for individual circuits wiring.
Thanks again Robert!
Jorge.
There’s no content there! Can you upload the information to this site please. This is so that the data stays here and does not get lost, and it is available to anyone reading this the in future.
Hello Robert,
You can’t see it? I can see it. I thought you could see it as well. I am sorry about that.
I did not know I could upload files. Good stuff!
CT tech specs:
CT physical dimensions:
CT picture:
-Jorge
Bummer, it’s a Milivolt CT. 
An oddball though. 400 mV vice the usual 333 mV.
Either way, not what you want for use with an emonTx or EmonPi.
Wrong 
- read the spec and the notes!
It says 0.4 V with 5 Ω burden (not supplied).
So if you wired those in series each with their own burden, and sacrificed a bit of (waveform) accuracy for voltage, you could use a 6.8 Ω burden and get the exact voltage that the emonTx needs.
It might be worth asking the supplier what will happen with a 6.8 Ω burden. I would expect the wave shape to suffer some distortion, and the phase error would increase. However, if you’re not going to hit 200 A very often - if at all - it’s likely to be OK.
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So it’s only good for the envoy-S but not for the OEM…Correct?
Its ok. I will use them for the envoy-s only, and have my parallel OEM based system.
I will go here to check my options. Any suggestions? solid vs. split (I guess split are easier to install)? any brand in specific?
Thanks again Bill.
Regards,
-Jorge
No. My mistake.
You will be able to use them. 
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Very well. Thanks for the insight Robert.
-Jorge
Hello Bill,
I only got two of these Enphase CTs to complete my envoy-s consumption monitoring setup. I will have to use them for my envoy anyways. I will get CTs from the recommended CTs list in the North America section of the guide…to move forward. It is easier that way.
I will look at each circuit and determine the wire gauge and breaker amp rating, and select a CT model that works. I am thinking about using solid core for the house circuits as it is easy to disconnect the wires from breakers and slide the solid core CT. Split core CTs seem easier for the mains as I don’t want to mess with the main lines.
I will post back sometime during the weekend with info and my preliminary selections before I start buying components.
Anything else I should verify before selecting CTs?
Thanks!
-Jorge
That makes a lot of sense. Ring core c.t’s will be more accurate, and most likely cheaper, and definitely smaller. But you don’t want to be disconnecting the main incomers, or any circuit you cannot isolate, so you need split core for those.
The main thing to watch for is don’t get a high secondary current - up to 100 mA is OK, above that you start to think about the power rating of the burden resistor. Decide now how you are going to combine the c.t. outputs (if that’s what you intend) because that might influence your choice.
Also, I’ve mentioned the maximum voltage ( = VA rating) shouldn’t be exceeded, otherwise errors and distortion start to build up.
It would be a good idea to calculate the burden resistor values just to check that they look sensible.
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Standard wire size for a 20 Amp breaker is AWG 12. For a 30 Amp breaker it’s AWG 10 and a 50 Amp breaker will use AWG 6. You may or may not have 15 Amp breakers, and they could be wired with AWG 14, or AWG 12.
15, 20, 30 and 50 Amps are the most commonly used breakers in a US 200 Amp load center. (circuit breaker panel)
Wise choice as you wouldn’t be able to disconnect the SEWs without pulling your meter out of its can. Something your electrical utility would not be too happy about, as you’d have to break the meter seal to do it. And that definitely gets their attention.
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Sounds like a plan. I will get to work during the weekend.
Thanks for the guidance.
Regards,
Jorge.
Roger that. Thank you for the guidance as well Bill.
Regards,
Jorge.
Good. One last thought…is it possible to, instead of connecting two CTs to one input port, connect CTs to individual ports and add them via software? I am thinking the only drawback is buying 2 or 3 emonTx’s. I get to keep CTs in their stock form, and minimize failure modes due to additional wire junctions / connections. In another thread I read having a few emonTxs is not a problem until I get too many and wireless data collision becomes likely. Am I way off or missing something?
Thanks again.
Jorge.
Yes, you can add (subtract, multiply…) in software, but remember in addition to extra emonTx’s, you need power and the a.c. reference voltage also. So you’re trading connections on the c.t. inputs with extra hardware and extra connections there. Your decision, but it looks to me as if the failure modes count is roughly the same, the material cost is somewhat greater.
I don’t think you’ll have significant problems with collisions in the ether with just a few emonTx’s, but the possibility exists nevertheless.
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Excellent. Understood. I will get to it then.
Thank You Robert.
Jorge.
I have a question Bill,. I Googled overall OD’s of AWG sizes (conductor + insulation). I found this WW-WASG03 Electrical Wire Sizes-WEB 7-7-11.pdf (69.1 KB)
Are ODs standardized like conductor gauge size, or is the insulation vendor specific?
Regards,
Jorge.
In the UK, you get slight variations in thickness of the cable insulation and sheath, but not major differences. But you could always put a pair of calipers over the sheath and measure it. In any case, the c.t. must be a free fit on the cable, never forced on nor clamped, because if it is a split-core one with a ferrite core, the slightest pressure on the core can snap it and render the c.t. useless.
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Very well. Thank You Robert.
Regards,
Jorge.