IQ aggregator or soladeck for trunk wiring

[joemadsun]

Hey, I ended up going with the IQ Combiner method with a pass-through soladeck on the roof. I figured I need a place to put the envoy anyways so might as well buy a box with the envoy installed in it. Also was leery of putting something that is meant to service(breakers or fuses) some place completely inaccessible(under panels on the roof).

[ChrisBarrett]

Joe,
Which setup did you end up going with? I have a similar conundrum but plan on center feeding from the soladeck. I'm also in Madison WI!

[joemadsun]

Thanks,
That does seem like the safest solution in terms of avoiding any problems that would require removing panels. Also probably results in the fewest junction boxes, since the combiner box will have the envoy in it rather than needing an independent box for the envoy.

[bob-n]

You have three good options. At this point, it's just preference.

If it were me, I'd go with #3, so that the breakers are at ground level. The less you have on the roof exposed to the elements, the better.

Option #3 also helps if you ever have to debug a problem, because you could separate the two strings at ground level. But that's a really tiny advantage. Your Envoy gateway will tell you so much about each panel and each microinverter. Most of the time, you won't have issues. On that 1 in a million chance that you have a problem, the Envoy may tell you all you need without separating branches.

[joemadsun]

Hi,
I'm in the planning stages for a ~18 panel IQ7+ installation. The IQ7+ branch limit is 13 microinverters so I will need two branches. I would like to center-feed the branches as recommended by enphase to minimize losses.

I am looking to get opinions on using an IQ aggregator versus a soladeck versus keeping both branches independent until near the AC disconnect near the meter.

IQ Aggregator
Wire Q cable at center into IQ aggregator. LFMC conduit from IQ aggregator to soladeck, soladeck just acts as a pass-through, 6 gauge wire in 3/4" EMT conduit through attic down to utility room and out to garage(panel in garage, meter outside of garage)
Pros:
The IQ aggregator provides nice Q connectors on the outside so no need to use Q field wireable connectors.
Fuses inside the Q aggregator less likely to blow than breakers?
Only 3 wires(2 current carrying + 1 ground) back to AC disconnect
Cons:
OCPD under panels, if issue comes up, panel has to come off
Still need a soladeck to make rooftop to attic transition

Soladeck with internal breakers
Create two stub cables with field wireable Q connectors that wire through glands in the soladeck. connect these cables to center connectors of each branch. wire to 2x 20A breakers in soladeck and then run 6 Ga cable through 3/4" EMT conduit through attic down to utility room and out to garage(panel in garage, meter outside of garage)
Pros:
Simple solution. Q cables feed into soladeck, soladeck has 2x 20A breakers internal to it
only 3 wires(2 current carrying + 1 ground) back to AC disconnect
Cons:
Circuit breakers more likely to trip than fuses?
OCPD under panels, if issue comes up, panel has to come off
Have to used field wireable Q connectors

Soladeck with combiner box near AC disconnect
Create two stub cables with field wireable Q connectors that wire through glands in the soladeck. connect these cables to center connectors of each branch. wire to DIN pass-through connectors and use 8 gauge cable to run both branches back to combiner box in garage via 3/4" EMT conduit
Pros:
No OCPD on rooftop
Technically lower loss as splitting the branches across 8 gauge wire is lower loss than running both branches on 6 gauge wire
Cons:
Need 5 wires(4 current carrying + 1 ground) back to AC disconnect
Need a juncitonbox somewhere in the garage to do the combining versus using an already availabel junction box(soladeck)



What are your thoughts?
1. My order of preference would be Soladeck with internal breakers seems the most clean, but then I have OCPD devices on the rooftop that could trip. Would you be concerned about that?
2. IQ aggregator is similar to the soladeck with breakers, but enphase designed it so I assume the fuses will never blow unless there is truly an issue.
3. Soladeck with combiner box in garage results in lower loss but its on the order of 0.1% less loss so really insignificant overall.