Help me pick an INVERTER

[Blue Grouse]

Hello, we originally designed this set of 3 Arrays to utilize 3 Inverters but, now are wondering if just 1 Inverter will do. It is a roof mounted, grid-tie13.2kW.

The panels are already mounted to the roof and would be very difficult to move/alter. Again, we originally planned to use an Inverter for each row of 11 panels (and may still go that route) but we're considering utilizing 1 Inverter to handle the 13.2kW

Thoughts? THNX

[SunEagle]

Whatever inverter you get make sure it can handle 3 inputs and you have the correct circuit breaker rating to input your electrical panel. Also make sure your electric panel has the capacity to handle the inverter kw rating.

Selecting the proper inverter and circuit breaker is part of understanding a DIY install.

[Blue Grouse]

SunEagle, THNX. So far, I'm only finding Inverters that only handle 2 inputs. What manufacturers would you suggest for 3 input models?

[SunEagle]

SunEagle, THNX. So far, I'm only finding Inverters that only handle 2 inputs. What manufacturers would you suggest for 3 input models?

I would look at high quality type maybe SMA or Solaredge. No specific ones come to mind but I would imagine that an inverter rated in the 13 to 15kw range probably has 3 inputs. Remember you can go with a smaller inverter depending on how the panels are mounted. If they are all pointing to the same place then your inverter needs to be big enough to handle the entire wattage.

[Blue Grouse]

SunEagle, could we just go with our original plan and use 3 Inverters (one for each array of 11 panels)? that was our original thought...then I tried to talk myself into one Inverter. So far, the Fronius Inverters (11.4 and 12.5) have only 2 inputs and we would have to somehow break down the arrays into: 3 - 8 panel arrays (24 total) and 1 - 9 panel array.

I it would be quite the hassle to get back on roof and uninstall panels to rewire series

YES, all panel arrays are all 'stacked' and pointed in same direction

[SunEagle]

SunEagle, could we just go with our original plan and use 3 Inverters (one for each array of 11 panels)? that was our original thought...then I tried to talk myself into one Inverter. So far, the Fronius Inverters (11.4 and 12.5) have only 2 inputs and we would have to somehow break down the arrays into: 3 - 8 panel arrays (24 total) and 1 - 9 panel array.

I it would be quite the hassle to get back on roof and uninstall panels to rewire series

YES, all panel arrays are all 'stacked' and pointed in same direction

I am not sure how you get the 3 inverters to work together. Maybe someone else can provide some guidance on that part.

Again I have stated in the past that a DIY can sometimes be a problem if the system doesn't work properly. If you do the install then you are responsible for all the fixes. Sometimes that ends up costing more then having a professional company do the install for you with a warranty on all equipment.

[solarix]

There are no inverters in the 13 to 15kW range that I'm aware of.
The 20% backfeed rule in the Code pretty much makes it hard to do inverters greater than 7.7kW - so manufacturers don't do it. I would use three 3.8kW inverters combined together with a 100amp load panel with a 20A breaker on each one. The load panel would then feed a 60A breaker in your main panel which needs its main breaker reduced from 200A to 175 to give you 65A of backfeed allowance.

[Blue Grouse]

THNX for the info. I'm finding that these online solar retailers are...well, flaky at best. Poor communication and when the try to sell you something that you don't need, poof they gone!

[foo1bar]

I would use three 3.8kW inverters combined together with a 100amp load panel with a 20A breaker on each one.

Wouldn't it be cheaper and just as effective to do a 7.6kW and a 3.8kW, putting two strings on the 7.6 and the 3rd on the 3.8?
It'd mean a 40A breaker for the 7.6kW and a 20A for the 3.8 - and appropriate wire sizes for each.
But I think a 7.6kW is usually 75% the cost of a pair of 3.8s


There are 11.4kw solaredge inveters - and that might be an option, except the OP already has the panels on the roof, so adding the optimizers would be a PITA.
If he's in somewhere that requires the rapid-shutdown, he may be pulling up the panels anyhow to put either optimizers or some other device in there. In which case solaredge may be a good option.
I think 11.4kW AC inverter with a 13.4kW DC array is likely to have only a little clipping and maybe none - depending on where you live and how the panels are angled.

BTW - I used renvu for most of my DIY project components - and they were pretty good at communicating at that time. And the person I dealt with was knowledgable enough to ask about some of my choices to make sure I was thinking things through.

[nerdralph]

If those panels are on a house, you'll be exceeding the 600V maximum (temperature-compensated) allowed by the NEC (and CEC).
A single Growatt 11400TL-XH-US would likely do the trick with minimal (<1%) clipping. They are relatively inexpensive compared to Fronius & SMA.