I am planning my AE upgrade and starting to get the permits/approvals. It will basically be a major replacement of the current 20+ y.o. system with a new inverter, more PVs and new battery. Fairly straight forward, but there is one thing which has been troubling me. The placement of the CT's. This system will be grid tied, with a sell back agreement with the PoCo (hopefully). Most of the inverters I have been looking at utilize CT's (current transformers) on the L1 and L2 lines, ideally right after the PoCo's meter. Not a big deal, and on many installs, there is nothing other than wire (and a CB) between the inverter and the meter, so one could place the CT's relatively close to the inverter in the main breaker panel.
HOWEVER, my wiring setup is a bit unconventional. The PoCo meter is on the outside of my barn/shop. It feeds a small breaker panel with a 200A main breaker and a few 20A breakers for the shop, then continues underground 150' to a 200A breaker outside the main house which feeds the main house breaker panel in the garage. The inverter, battery and sub-panel are all in the garage close to the house main breaker panel.
Ideally one would place the inverter's CTs at or before that first 200A CB by the meter, but while accessible, that would require running the CT connection wiring 150' or more as well as digging a trench, etc. I could place the CT's towards the meter side of the main breaker panel, or at the house 200A CB, but that would leave the barn/shop loads on the wrong side of the CTs. Meaning the shop loads would end up coming out of what the inverter thought it was feeding to the grid, sometimes.
So I am wondering what, if anything, to do about this. I don't plan to use the CTs to limit any grid feedback so it may not be important to get them on the other side of the barn loads for that reason. But it would be "nice" to have the inverter able to accurately track how much power is going back to the grid (just to keep the PoCo honest). Any good solutions folks can think of here?
HOWEVER, my wiring setup is a bit unconventional. The PoCo meter is on the outside of my barn/shop. It feeds a small breaker panel with a 200A main breaker and a few 20A breakers for the shop, then continues underground 150' to a 200A breaker outside the main house which feeds the main house breaker panel in the garage. The inverter, battery and sub-panel are all in the garage close to the house main breaker panel.
Ideally one would place the inverter's CTs at or before that first 200A CB by the meter, but while accessible, that would require running the CT connection wiring 150' or more as well as digging a trench, etc. I could place the CT's towards the meter side of the main breaker panel, or at the house 200A CB, but that would leave the barn/shop loads on the wrong side of the CTs. Meaning the shop loads would end up coming out of what the inverter thought it was feeding to the grid, sometimes.
So I am wondering what, if anything, to do about this. I don't plan to use the CTs to limit any grid feedback so it may not be important to get them on the other side of the barn loads for that reason. But it would be "nice" to have the inverter able to accurately track how much power is going back to the grid (just to keep the PoCo honest). Any good solutions folks can think of here?
