Thanks for the reply @overeasy. My comment to yours about not understanding is this.
If I measure on the line side (before my 2 way meter, in the area that is locked by the energy company, I was trying to say that any measurement there would measure energy that is either imported or exported from or to the grid, respectively. My goals of measuring electricity are:
Measure production of Solar PV system (Solar Edge Inverters). I do get the measurements from their platform and there is an API directly to the Inverters I can query if I want to.
I want to measure the consumption of all electrical power (to my comments about this panel and the 4 lines needing to put a CT around – impossible due to space and size. I have installed a Rogowski type coils (qty 2) that are looped in a figure 8 around L1 and L2 respectively that is connected to a Solar Edge monitoring device (Mobibus I think, rebranded).
This data is transmitted to the SE web portal to view on mobile app/website. I also am know getting detailed data from the Energy company on import/export data as well.
I want to measure independently the consumption of:
3a. Consumption of all home electricity
3b. Many circuits, e.g. AC units, pool equipment, larger appliances, office, refrigerators, etc.
I have purchased the iotawatt system, perhaps too early, as I did not know that the new panel they would install was this Siemens panel – good panel, but just short on space. I will be able to measure the usage with the iotawatt system as noted in 3b, but am struggling to see, using CTs, how I can measure the overall usage with the limited space, without figuring out a way to interface a Rogowski type coil to interface to the iotawatt system – as these are very flexible and I have one in there now and can see that there is room for another.
But, my point was if I put the CTs on the Main lines before the meter, it will measure the “net” energy (import + export). Options I see are:
Rogowski coil around mains. But appears this is not a feasible option (not sure I fully understand why yet, perhaps the output voltage translation?
I could measure, as you suggest and if I can get into that part of the panel “legally”, and then measure the Solar PV circuit independently and do the math
Measure all circuits, use sum and compare to Solar PV circuit (production) measurement. Do the math.
I don’t see any difference between measuring the mains before the meter or between the meter and the mains CBs. They are the same, and yes, the measurement is the net power.
That about sums it up. Rogowski coil not supported.
Measuring all the circuits should give you a good picture using the IoTaWatt calculator scripting capability to do the math.
I’m glad I looked here @brgr before responding to your original post. I was wondering how you ended up finalizing your job. So you had the utility come out and remove the meter and you were able to put the CT’s on the line side? I have a similar panel but with the solar breaker on its own bus. I’m assuming when you say the lower left is because your utility lines come in from the bottom? In my case the my lines come from overhead so they come in from the top. I’m glad I got this solved. I can call my utility and they’ll unlock the meter and I can put the CT’s on there without them causing a fuss. They’ll come back a week later and lock it backup. IMG_20210223_135204001_HDR~2|375x500
Can you post a picture of your utility side if you happen to have taken one? So you only used two CT’s for the main since you originally were contemplating using four for each load side connection. Thanks!!!
Here in Los Angeles, I can call the utility and request to have the meter removed for maintenance. They come out, remove the lock and come back about a week later to relock it. Try giving the utility a call. I can even do the request online and it’s handled by the meter spot folks.
Tried looking to find a picture, was unable to locate one. I did only use the 2 for the mains, no way I could have gotten 4 in with the space in the panel.
Correct, my power feed comes from underground, so it comes up into the panel in the lower left corner. I had some additional work done and so it was installed at the time when the utility side was unlocked.
That really helps! No worries on the picture since I see what your describing. Really appreciate it. I’m glad you were able to get the CTs on there without having to deal with the utility. I wish my electrician didn’t flip the lugs to the top side so my service lines could have bent down like @bkgeig’s panel which gives access under that lower panel. Oh well. I’ll just schedule a meter unlock and install them soon.
