Zero Grid feed back with long run CT'S

Q&A and troubleshooting
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1

System info.

6050 watts solar coming into Victron MPPT 250/100-Tr going to Victron Lynx Power in (no shunt) out to two Multiplus 2’s 48/3000/35-50 120v and a Cerbo GX MK2 as a data/commination center at my garage sub panel, the main panel is about 100ft away

This will power my split phase 240v house system though I do need to limit Solar/Battery output to 25amps do to 10awg wire size, any extra power needed will come from grid

I will can not feed power back to the grid,

I believe I need to install to Victron CT sensor’s at the main and send info to Multiplus’s for each leg so when not using much home power the batteries /PV panels will not send power back to grid.

Will I be ok if I run 100+ feet of shielded & twisted 18awg wire to extend the Victron CT’s?

I have no main power coming to my Multiplus’s, the batteries will charge by solar only.

So can I and should I still program a ESS based on what the house always uses a for say a 100watts to insure that the house is always pulling a little power from the grid to over come any errors in my ct readings do to the long run?

My goal is to use grid power for heavy loads, solar during the day for lighter loads and my batteries at night until they reach 40% charge so I always have a little reserve for power outages, should this happen all heavy loads will be turned off like, electric dryer, AC etc.

2

It has been discussed a few times, it can be done but accuracy becomes an issue because of the way the CTs work.
Signal noise as well adds to the issue so use cat6 or twisted pair wire. And not running the signal wires close to any other wiring.

3

Just remember that when large loads shut off, there will be a 1-2 second interval where power is fed back to the grid, regardless of the 100W offset. No device can react instantaneously fast, so the power has to go somewhere. If you have other loads in the house to cover for it, you may be fine. If this will cause you problems, you should reconsider your approach.

This is true for any hybrid inverter that runs parallel to the grid, including Victron’s ESS implementation.

1 Like
4

Can I set the multiplus’s to say send only 1Kilowatt per hour max back to the main panel, my two high load items a AC & Electric dryer and those only during the daylight mostly. This would cut my power bill by about 3/4 which is what I’m after

5

As you intend to design your system, i would advise research / learning system design / principles ect.
All available for free on Victron Professional