October 21, 20241 yr Author Hi All, I am new to the whole solar game and I am sure this has been asked and debated countless times before but please humor me. I am in discussion with my installer of a Sunsync 12kw Hybrid Inverter solution about where they have chosen to place the CT coil, which is inside the inverter as shown in the pic. This is because the DB board and meter are 30m from the inverter. My understanding (based on a lot of information on both here and elsewhere) is that if installed like this then: a) no excess PV can be used by non-essential loads b) no excess PV can be exported to the grid. The response from SunSync support is as follows: Me: Thank you Monisha, I am most concerned with the pushback to non essential loads and not the grid, can I still pushback to non essential when CT is between DB and inverter? Monisha : Yes, you can still push back power to non-essential loads when using a CT (current transformer) between the DB (distribution board) and the inverter. The CT placement monitors the flow of power, and as long as your inverter is configured correctly, it can prioritize supplying non-essential loads before drawing from the grid or sending excess power back to the grid. Can anyone else please confirm that PV can be pushed back to non essential loads with this installation and why there may be a difference in understanding. Thank you.
October 21, 20241 yr 9 minutes ago, JustMojo said: Can anyone else please confirm that PV can be pushed back to non essential loads with this installation and why there may be a difference in understanding. Unless you have power from commercial power coming into your DB, then to inverter with this same source running back to DB feeding your non-essential side and another run from the UPS side of the inverter going back to feed essentials, there is no way to determine whether you are feeding the grid or the essentials. Thus, you should have the main CB feeding the inverter only (5 wires from DB to inverter) onto which you can clamp the current transformers, then another 5 wires from the input of the inverter back to DB for non-essential side and finally another 5 wires from the UPS side of the inverter back to the DB/wherever you are connecting your essential loads... In the photo I can only see 5 pairs from DB, no return wires and 5 wires from the UPS end, thus your current transformers will only measure the power you are providing to the grid side, whether that goes to the grid or you own non-essential devices is anyones guess...
October 21, 20241 yr @JustMojo, No, the Non-Essentials will not be using PV to power them, because you have your CT coils in the wrong place. As per diagram, (freely available), you/ your electrician has installed the CT coils in the Yellow marked position. They should be installed in the Blue marked box location i.e. after your non-essential in your DB. Yes, sometimes getting from the Inverter to DB is a schlepp (30m in your case). Better that trying to install 5 core cable all that distance. Just use a good quality Shielded Ethernet Cable (like Cat 6), and try keep the Ethernet wires from running parallel to any AC wires, to minimize any interference. In this pic, " Home Loads" = Non Essentials Also, If you run this inverter above it's limit on the AC side, the built-in CB for the Grid trips, and you need to open the inverter to reset. Quite annoying. Edited October 21, 20241 yr by Sidewinder
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