Cables from panel size

Coddle4dinner · 10-02-2022 1:16pm #1

Hi,

What size is the cables from the panels to the inverter ?

I want to put panels on the house but the inverter etc in the garage.

I have a change to get some cables in now so would like to be ready as it will be harder (but not impossible...) in future.

Garage is supplied with a 6sq from the main consumer unit .

Jonathan · 10-02-2022 6:42pm

Depending on the length of the run, 6mm2 would be sufficient I'd say. Check with a REC though.

Coddle4dinner · 11-02-2022 8:08am

https://www.boards.ie/discussion/comment/118612183#Comment_118612183

Thanks,

Its not the 6sq I'm worried about but more the link between the panels & the inverter , the DC cables.

graememk · 11-02-2022 8:11am

Solar panel strings are usually on 4mm² (2 per string)

I have a 5 core 6mm² SWA going from the barn to the shed where my panels are (about 50m away)

mun1 · 11-02-2022 8:12am

4mm is used on pv panel tails , less than 10 amps on string

Coddle4dinner · 11-02-2022 8:15am

https://www.boards.ie/discussion/comment/118614283#Comment_118614283

https://www.boards.ie/discussion/comment/118614286#Comment_118614286

Thanks lads,

That's good info.

I think I'll have to do more work to leave room for 4sq.

At the moment I've 2x25mm steel conduits that are already somewhat full.

I'll run a 3rd for future solar .

graememk · 11-02-2022 5:05pm

https://www.boards.ie/discussion/comment/118614294#Comment_118614294

Can you go bigger? 25mm would be a tight fit for 4 solar cables. (Assuming 2 strings)

Then pulling them through is a whole other issue!

irishchris · 12-02-2022 11:26am

100% agree with Graememk as with pulling 2 sets of 4mm solar cable along with am Ethernet cable to my install outdoor it wasn't the easiest and that was with a 50mm ducting. Last thing you want is kinking and damage to cables or worse again getting to that stage and realising you can't get the cable through

Coddle4dinner · 14-02-2022 7:55am

https://www.boards.ie/discussion/comment/118616992#Comment_118616992

Thanks,

Never even considered having 2 strings.

Glad I asked here and I would have left myself short of space.

harderthanf · 15-02-2022 7:19pm

Sounds like you're doing it all yourself but just in case you're not and looking for the grant. The PV cable and power to isolator switch have to be in seperate conduits - at least that's what I was told! It may or may not be useful to you.

graememk · 15-02-2022 8:40pm

https://www.boards.ie/discussion/comment/118636693#Comment_118636693

Good point, ac and DC aren't to be in the same conduit.

spose · 15-02-2022 11:28pm

What’s the max distance you’d consider for 4mm dc cables for say 4-6 panels…50 or 100m be too much? Looking at possibility of small ground mount but would prefer keep inverter indoors

Gant21 · 15-02-2022 11:33pm

leave your ducting, conduit big enough. The longer the run the tighter it gets.

SouthWesterly · 19-02-2022 4:01pm

https://www.boards.ie/discussion/comment/118638283#Comment_118638283

Would you not consider micro inverters for the panels instead of a full size one indoors?

I'm considering doing. Ground system and using them.

spose · 19-02-2022 11:58pm

I’d be open to it but assumed for maybe 4 or 5 panels would end up more expensive to go with the micro inverters

Coddle4dinner · 20-02-2022 8:30am

If you go with micro inverters does that rule out a battery?

graememk · 20-02-2022 10:45am

No, It doesnt, you can get a standalone storage inverters (ie the sofar ME3000) that monitor the grid (in/out) and charge and discharge accordingly.

As there is no grant for batteries now going with a standalone storage inverter or a hybrid inverter it comes out about the same.

Only drawback is that the me3000 limit is 3kw but the solis 5g can do 5kw from batteries

Cables from panel size

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