question

Jan Brož avatar image
Jan Brož asked

Et112+anti islanding device

Hi,

I'm in a process of adding a battery and few more solar panwla to my existing grid tie house solar using Easysolar-II GX.

Due to lack of certificate for operation on the Irish grid I need to install an anti-islanding device between the grid and the inverter. Since that is the case, I've decided to build the anti-islanding device in such a way that it will disconnect the whole house in the event of grid failiure. When that happens, I will then use a manual transfer switch to connect the whole house to the EasySolar-II essentially going off-grid while it's down.

This way I don't have to rewire the whole house and still use all the appliances.

What I'm curently not sure about is whether I should put the ET112 meter before or after the anti-islanding device (before meaning between the grid and the anti-islanding device).

Any thoughts?

Multiplus-IIEasySolar All-in-OneAC PV Couplinganti islanding
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
bipedalprimate avatar image
bipedalprimate answered ·

What function does the ET112 perform in your design?

Assuming you are not allowed to feed back to the grid from the Easysolar GX, can't you set the GX device to not allow that? This assumes all PV generation is DC. If so, an ET112 may not be necessary.

If you have PV generation on the AC In side of the Easysolar GX, the ET112 will tell the GX about any surplus PV power and then charge batteries.

A schematic may help answer your question.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Jan Brož avatar image Jan Brož commented ·

I'm allowed to feed in. My current system is 3kWp and is grid tied without battery.

I'm adding EasySolar-II GX in grid parallel configuration where the ET112 (in my case EM112 because it has a screen), should be between the grid and the house and one more (in this case EM111) would be between the Grid tied inverter and fuse board.

1. EM111 would measure PV power from Grid Tie inverter to the fuse board (house).

2. EM112 would measure Grid in/out power.

now that I explain it, it doesn't seem like the second should be necessary, but when I was doing my initial research last year, it was my understanding that I need both, since the CT sensor inside the EasySolar-II wouldn't be used.

Maybe it's just there for information purposes for the GX device, if so I guess it should be behind the contactors.

here's a schematic that kind of shows my situation (missing the EM111).


screenshot-2023-09-30-121750.jpg

0 Likes 0 ·
screenshot-2023-09-30-121750.jpg (115.3 KiB)