Advice for a 11.7kw DIY system in Florida

[Tooncinator]

So I have been pretty busy and obsessing about going solar for a few years and am finally in a position to (hopefully) get it done. I have been doing as much reading and research as I can but there are a few "holes" in my understanding that I hope you guys could help with. As much as I have gone round and round I am fairly certain I want to do IQ7 micros with 325 watt Hanwha q cells. Seems to be great pricing on these locally. I do have a small amount of shading and will likely have a bit more over the next few years from regrowth of some large Oaks ( we got hit bad by hurricane Michael).

Q1: I can't seem to find a whole lot about info on bringing the Enphase q cable into the J-Box and what those connections look like. Does anybody have pics or links to what that looks like? I intend to hire an electrician to do the more technical parts but am wanting to know for my own understanding.

Q2: I will have three arrays on two different roof levels. I was wanting to know if I could bring a home run cable from arrays B & C (see attached pictures) to a j box in the attic under array A. Then bring The q cable/conductor from Array A to that same J Box and combine it there for a single line back to the electrical panel. Is this advisable and best practice or should I run as second separate conductor and ground wire in the same conduit to the combiner/Envoy? I really want a clean look and don't want to run exterior conduit if I don't have to.

Q3: I have two main electrical panels with a 200 amp main breakers on each. How do I know if I have the available room for 3 branches with the 20 amp breakers required? I've attached pics. Not sure how this quite works because there are open "slots" for extra breakers but when I add up the total amount of amperage on the existing breakers it comes out to 280 +/- on each panel. I would also like to know if I could potentially add a NEMA 14-50 in the future if we were to go electric.

I welcome any other thoughts/advice based on my pics too.

Thanks so much, I know I have others but those are some of the most nagging.

[NewBostonConst]

Q1....yes the Enphase manual sucks on this. Pretty much you buy the cable and tell them how many connections you are going to have. The cable will come with connectors for each inverter installed. The ends of the cable will not have connectors so you can add one Q connector on the last one usually. Then you connect the other end of the cable to your junction box to feed into your disconnect and then into your house breaker. (cable length could be short but mine haven't been. It will be half the length of the distance between the panels cable length)

You can only put like a max of 14 panels in a row so you could order a cable with 13 connectors if you did it this way and install an extra connector at the one end.

Or if you wanted 14 you could order a 14 connector cable and put their end cap plug on to seal off the extra pigtail. Or you could connect the extra pigtail back to the same junction box to minimize voltage drop by giving the power to directions to go. If you do this last idea you will have to match the wire colors in the junction box and may want to verify the cable was made correctly if you do this with a ohm meter.

[NewBostonConst]

Q2...Yes but there are some issues you could have.....you will need to use breaker or fuse if you change wire sizes. If your sum of panel currents goes over 20 amps you will need to up your cable size and use a combiner box with breakers/fuses.

[NewBostonConst]

Q3....yes you have the room.....breakers protect the wire so when you are summing the amps it is ok because your are protecting the wire with a main breaker. If you were to turn everything on and run all circuits at full power it would trip your main breaker but that is very rare and rarely worried about.....

[emartin00]

Q3: You have to follow what is referred to as the 120% rule. Since you now will have two sources of power feeding your panel, you have to ensure they cannot provide more than 120% of the rated capacity of the bus bar. With a 200A panel, you can add up to 40A of solar breakers.
I believe since you have 2 main panels, you can add 40A to each, but you wouldn't be allowed to add 60A to a single panel.

[ButchDeal]

You should be looking at the IQ7+ with your 325W PV modules.
Max string size of the IQ7 is 16, max string size of the IQ7+ is 13.

You have Array A 10 PV modules
Array B 18 pv modules
Array C 8 PV modules

You want bring modules from B & C together under A. That is fine but you will have to have a string of 16 with IQ7 (clipping) or a string of 13 IQ7+ from B and the rest of B strung with C

[Tooncinator]

Q2...Yes but there are some issues you could have.....you will need to use breaker or fuse if you change wire sizes. If your sum of panel currents goes over 20 amps you will need to up your cable size and use a combiner box with breakers/fuses.

Ok, I think there is only one size of Q cable that I can see 12 awg. is there a reason I would use different size wire? Are you supposed to only run one cable for each maxed branch circuit of 13 +/- panels in the conduit back to the panel. Enpahse has that aggregator that looks like it combines several branches and combines it into a single homerun. I like the idea of simplicity but is a bit spendy. It looks like if you aggregate 2 branches you would run a single conductor and maybe use a single 40 amp breaker instead of two 20's.

Q3....yes you have the room.....breakers protect the wire so when you are summing the amps it is ok because your are protecting the wire with a main breaker. If you were to turn everything on and run all circuits at full power it would trip your main breaker but that is very rare and rarely worried about.....

Excellent. Thank you.

Q3: You have to follow what is referred to as the 120% rule. Since you now will have two sources of power feeding your panel, you have to ensure they cannot provide more than 120% of the rated capacity of the bus bar. With a 200A panel, you can add up to 40A of solar breakers.
I believe since you have 2 main panels, you can add 40A to each, but you wouldn't be allowed to add 60A to a single panel.

Perfect this is in line with what I have read too.

You should be looking at the IQ7+ with your 325W PV modules.
Max string size of the IQ7 is 16, max string size of the IQ7+ is 13.

This is interesting and I have been hazy on this. What is the advantage of bumping up to the plus model? I like the idea that I could run a few more on a branch with the iq7 to make installation a bit more flexible. Would I harvest more energy by bumping up?

Thanks!

You have Array A 10 PV modules
Array B 18 pv modules
Array C 8 PV modules

You want bring modules from B & C together under A. That is fine but you will have to have a string of 16 with IQ7 (clipping) or a string of 13 IQ7+ from B and the rest of B strung with C

In my mind I thought I would run a short exterior conduit from Array C (8 PV modules) over the ridge to the j box under array B. I could combine those 8 with 5 of the 18 from Array B and then maybe use the Q aggregator or ????? lol

[NewBostonConst]

You should only change the wire size if you were using circuit breakers/fuses and wanting to combine multiple circuits in a box to minimize your circuit going all the way back.

If you are required (likely are) to have a disconnect you will have to put in a combiner box or sub panel with this size of system.

You could use just a junction box and combine 2 circuits/arrays if the sum of the panels is under 20 amps.

You are definitely going to need at least 2 circuits if not 3.

[ButchDeal]

This is interesting and I have been hazy on this. What is the advantage of bumping up to the plus model? I like the idea that I could run a few more on a branch with the iq7 to make installation a bit more flexible. Would I harvest more energy by bumping up?

Have you looked at the specs for the IQ7 and IQ7plus? The IQ7 is only rated to inverter 240w continuous and the IQ7Plus is rated to inverter 290 continuous.
You are planning to attache them to 325 watt Hanwha q cell PV modules. The 240W IQ7 would be clipping much of the time with those PV modules. The 290W IQ7plus would clip much less often.

https://enphase.com/sites/default/files/downloads/support/IQ7-IQ7plus-DS-EN-US.pdf

In my mind I thought I would run a short exterior conduit from Array C (8 PV modules) over the ridge to the j box under array B. I could combine those 8 with 5 of the 18 from Array B and then maybe use the Q aggregator or ????? lol

you might want to take a look at SolaDeck options to clean up the look and penetrate the roof.

[NewBostonConst]

I agree with the SolaDeck option....you can connect all strings to one place and have one home run.

The SolaDeck with breakers you can have on larger home run. You can also use mn-b cable (aka romex) so you don't have to run conduit. You can get 2 conductor plus ground 8 awg MN-B cable.

[Tooncinator]

Have you looked at the specs for the IQ7 and IQ7plus? The IQ7 is only rated to inverter 240w continuous and the IQ7Plus is rated to inverter 290 continuous.
You are planning to attache them to 325 watt Hanwha q cell PV modules. The 240W IQ7 would be clipping much of the time with those PV modules. The 290W IQ7plus would clip much less often.

https://enphase.com/sites/default/files/downloads/support/IQ7-IQ7plus-DS-EN-US.pdf

you might want to take a look at SolaDeck options to clean up the look and penetrate the roof.

I think I am getting more confused now. I guess I dont understand why the iq7 would be "commonly paired" according to their spec sheet with 235-350w panels if it was going to clip/waste everything above 240. I mean the iq7+ would be a little better but still unable to harvest the max potential. Are the enphase micros basically not caught up to the high efficiency panels?

[Tooncinator]

I agree with the SolaDeck option....you can connect all strings to one place and have one home run.

The SolaDeck with breakers you can have on larger home run. You can also use mn-b cable (aka romex) so you don't have to run conduit. You can get 2 conductor plus ground 8 awg MN-B cable.

I wish i could pay you guys to design this for me. haha. So I'm trying to imagine how I would integrate the soladeck. Would I bring the circuit from arrays A & C down through the roof, then run them back up through the roof under Array B where I imagine I would place the Soladeck, then combine it and run back down through and back to the panel?

[ButchDeal]

I think I am getting more confused now. I guess I dont understand why the iq7 would be "commonly paired" according to their spec sheet with 235-350w panels if it was going to clip/waste everything above 240. I mean the iq7+ would be a little better but still unable to harvest the max potential. Are the enphase micros basically not caught up to the high efficiency panels?

It is marketting speak that they are commonly paired.

[NewBostonConst]

I wish i could pay you guys to design this for me. haha. So I'm trying to imagine how I would integrate the soladeck. Would I bring the circuit from arrays A & C down through the roof, then run them back up through the roof under Array B where I imagine I would place the Soladeck, then combine it and run back down through and back to the panel?

Yes...guessing you would need a disconnect so a 8 awg cable would be run from the Soladeck to the disconnect and then from the disconnnect to the breaker in your box. You will need this inspected from city inspector and from the questions you are asking should have a electrician look it over at the least. You will have to figure out the grounding also.

You will need to run conduit between each array group to the Soladeck unless in a junction box that you are going to need anyway you switch from the 12 awg wire to NM-B type cable.

I hold no responsibility in what I am telling you. I can not see your house or your installation. I am currently not a cert electrician, just someone that try's to help. This is very close to the last install I did.

This post might help you understand the inverter sizing Butch is trying to explain to you.

https://www.solarpaneltalk.com/forum...f-solar-panels

[ButchDeal]

Yes...guessing you would need a disconnect so a 8 awg cable would be run from the Soladeck to the disconnect and then from the disconnnect to the breaker in your box. You will need this inspected from city inspector and from the questions you are asking should have a electrician look it over at the least. You will have to figure out the grounding also.

You will need to run conduit between each array group to the Soladeck unless in a junction box that you are going to need anyway you switch from the 12 awg wire to NM-B type cable.

I would get 3 soladecks and put one under each array to penetrate into the attic, a bit cleaner. You can also put a small AC panel on the inside back to one of the soladecks to do the combining in the attic. This leaves the breakers in the attic where they can be more easily reset if needed, instead of under a PV module.

Run conduit down to a disconnect and paint it to match the siding

OP should check as a locking disconnect is commonly required.