Installing Enphase Micro Inverters 

Yup, these are really clever little beasts. The new IQ8 line is even more so as it can run independently (without a battery) when the grid goes down (but as you say, you will need an auto-disconnect to make sure you don't backfeed the grid). At its most basic, all you need is the solar panel, the micro inverter, some wire, an AC disconnect (should be located within 10 feet of the electric meter) and a connection to the grid (usually a breaker in your circuit breaker box). The utility generally supplies you with a bidirectional meter (although you may have to pay for it) so you get credit for power that you send back to the grid. The AC coupled system from Enphase gets a bit more complicated. This allows you to operate when the grid goes down (and manage loads, shift power, etc). With this you add (usually) a combiner box (that included the communication system that allows you to monitor the system), a smart switch (the auto disconnect, place to connect batteries, generators and the like), and then battery packs (if you like). This is a proprietary system, so you have to use Enphase products - you cannot mix and match.

With the IQ7 the system is designed to only connect the two hots (it ignores the neutral and the equipment ground). So it really should not be important as to which hot is connected to which line in the inverter - so it make sense they allow the either or option. With the earlier connectors (for the M series) they connect the neutral as well, so I assume it is important to make sure that one lines up properly.

They do make squirrel barriers just for that purpose (weirdly expensive, however). I have seen some folks use flashing - but I would recommend against that as it creates a solar oven on the roof (no air flow) under the panels. Can cook the shingles and/or the micro inverters.

I was going to suggest Ebay - but sounds like that is a no go. Even though you are mounting the panels in a landscape format, can you run the connections north and south - so the connections between the panels are actually portrait in length?

The disconnect tool for the "M" series of micro inverters is different than the tool used for the newer "IQ" series micro inverters. You can still get them on ebay and other sources. I did a quick search and here is one link to get the tool - but there are others. www.walmart.com/ip/Enphase-Disconnect-Tool-M-and-S-Series/1117348896?wmlspartner=wlpa&selectedSellerId=101067583&adid=222222222271117348896_101067583_14069003552_202077872&wl0=&wl1=g&wl2=c&wl3=42423897272&wl4=pla-295289030566&wl5=9009345&wl6=&wl7=&wl8=&wl9=pla&wl10=377893548&wl11=online&wl12=1117348896_101067583&veh=sem&gad_source=1&gclid=CjwKCAjw15eqBhBZEiwAbDomEnmVgW55_U9JfaqHgG6hLiPaL2JC31cBYhMoHdOpEFayjxBNpUnqchoC4ZEQAvD_BwE

Yes. As long as the panel is compatible with the inverter, each unit works independently. It may look odd - but it should work.

We hold a weekly Zoom session (Solar Noon Tuesday) at noon Eastern time every (logically) Tuesday. I would encourage you to join in and ask questions. Normally a number of installers and owners of similar systems are on hand and we can answer any questions as you work your way through the process. All are welcome and the login info is: Topic: Solar Noon Tuesdays Time: This is a recurring meeting Meet anytime Join Zoom Meeting us06web.zoom.us/j/91067004366?pwd=b1dvcVZKYXQvSlk0a2Qvc0RqTi9VQT09 Meeting ID: 910 6700 4366 Passcode: 625623

The micro inverters give off an AC signal, so no DC in the system. You can certainly put in an AC surge protector, however.

With the older micro inverters (M250) the connectors would only allow one way to connect. The trunk cable had four wires (two hots, a neutral, and an equipment ground). It would therefore matter how they connected. The newer connectors (for the IQ6 through IQ8) have only two wires rather than four. Only the two hots (the ground is done through the metal case of the micro inverter and apparently it does not need a neutral). So I suspect it doesn't matter which hot connects to which as they each perform the same function with the same output.

Probably depends on the size of the panel (in watts). I suspect you could still find some old Enphase 215 units that would work. I don't think the positive or negative grounding much matters in a micro inverter system (as everything from the panel is AC.

I did hear of concerns with the M215 models. Haven't heard the same with IQ7 units. I have installed a number of the older units without problems - so take it for what it is worth.

@@bluerockstation thanks for your reply !

I just had my first M215 unit fail - I plan to post a video on the ease or trials involved in getting it replaced. Should be interesting...

Yes, Enphase makes three phase micro inverters as well.