DIY Field Ground Mount Arrays - Multiple Inverters - Battery DC distance - CU Wiring

bunderoon

Hey all,

To give you an idea. Assumptions that an RECI would check, certify, NC6 etc.

Shed in field directly behind house, 35m away from house's consumer unit. ~5Kw Array 1 location's edge (last panel) is about 20m to the left of the shed. ~2Kw Array 2 to the right of the shed would be 30m away from shed.

Aim is to use the shed as the central mini consumer unit AC junction (AC switches & RCBOs) and then run a single 16sq armored cable between shed and house.

Q1 - If the array 1 (left) had a hybrid inverter, outside due to 20m from shed, how would a battery setup work? Or would it work well since its going to be 20m distance for DC from inverter to charge the batteries. Alternatively it would mean placing the Hybrid inverter inside the shed and having the + and - tails running 20m from the array to the shed. Is either feasible?

Q2 - I assume that each AC feed in the shed's CU would have its own sized RCBO. And then another larger rated RCBO in the House CU.

Q3 - How does Exporting and FIT work with multiple Inverters using one 16sq line to the house's CU?

ELM327

I'll allow more knowledgeable folks than I answer the rest... but 20m is too long for DC without significant voltage drop

slave1

Q3 - How does Exporting and FIT work with multiple Inverters using one 16sq line to the house's CU?

No issue, you will export from your house as a whole, beit one inverter or three. If you wish to measure you simple clamp the live tails cable, this is done to allow your inverter divert export into your battery in any case

graememk

Batteries go beside the inverter, as short as possible.

you also will need a way for the CT for the hybrid inverter to get from the main consumer unit/meter box, usually a cat 6 cable.

But the DC from the solar panels can be taken a long distance. As the voltage is much higher. Eg mine is a good ,50+m away from my inverter.

They are on a 5 core 6mm2 swa though, from the fireman switch to the isolator beside the inverter.

Q2, you will either have an rcbo in the house and a mcbs in the shed or a mcb in the house and rcbos in the shed, (eg only 1 rcd on each line.)

bunderoon

https://www.boards.ie/discussion/comment/120183184#Comment_120183184

you also will need a way for the CT for the hybrid inverter to get from the main consumer unit/meter box, usually a cat 6 cable.

Yep, will plan on running a few Cat6 runs between the house and shed also. Forgot to mention that in the OP.

But the DC from the solar panels can be taken a long distance. As the voltage is much higher. Eg mine is a good ,50+m away from my inverter. They are on a 5 core 6mm2 swa though, from the fireman switch to the isolator beside the inverter.

Brilliant, that solves that then. Hybrid inverter and batteries in shed! Understood. Any reason for 5 cores in particular?

Q2, you will either have an rcbo in the house and a mcbs in the shed or a mcb in the house and rcbos in the shed, (eg only 1 rcd on each line.)

Perfect, thanks.

graememk

https://www.boards.ie/discussion/comment/120183344#Comment_120183344

5 core for 2 (2 Pairs) strings + earth.

irishchris

https://www.boards.ie/discussion/2058282236/diy-field-ground-mount-arrays-multiple-inverters-battery-dc-distance-cu-wiring

Also if having a hybrid you should consider ruining a second swa cable from backup connection on inverter in shed to your house to either provide power to a socket or to a changeover switch for power outages. Nothing worse than having to re dig the trench 😀

bunderoon

https://www.boards.ie/discussion/comment/120184050#Comment_120184050

https://www.boards.ie/discussion/comment/120182964#Comment_120182964

@graememk Ah, of course. Yes.

@slave1 Valid point. I'll be running two 2x 2" ducts between the house and shed (actually its a 20' shipping container) so I should be well covered then.

Thanks guys.

graememk

https://www.boards.ie/discussion/comment/120191266#Comment_120191266

If you can go bigger, go bigger. Especially if you have bends in it.