How to Wire Solar Panels: Parallel Strings with Branch Connectors

Tips from the truck, This is a great video, Thanks Johnny"

Killing it Johnny!

Ultimately though, paralleling strings (particularly with a branch connector) has numerous problems. For one thing, that means you are putting two strings into one MPPT. If one panel goes bad on one of the strings or you get asymmetric shading between the strings, the MPPT will wind up running both the strings inefficiently. Not just the one with problems, but the other one too. All the strings wind up at non-optimal operating points. So you wind up losing more than just the shaded or failed panel's worth of power. Also, the owner might not notice the failed panel because he has nothing to compare the output against. If each string is given its own MPPT, however, a failed or partially shaded panel only drops that one panel. Both strings are still run optimally by their respective MPPTs. In fact, with one MPPT per string the arrays will often run better than micro-inverter or optimizer arrays in normal lighting conditions. Theoretically you can parallel two strings together but... well think about voltage surges and other protections. You don't want the whole array to fry if lightning strikes nearby. So for large string arrays it is still a good idea to use a combiner box even if only paralleling two strings. The combiner box has series fuses, a breaker to protect the return wiring, and also a surge protector device. Situating the combiner box right there at the array is a good idea. But generally speaking, its an even better idea to not parallelize large strings in the first place. Bring all four wires back, plus a ground wire and give each string its own MPPT. And even in that case I would still put a fuse box at the array (with series fuses and surge protection, but no paralleling). You also get a bit more resiliency as the system ages and test points at the array for checking things without having to disconnect.

I see the electrical connections have O-rings to protect from corrosion and dirt entry... but should you use just a little bit of Dielectric grease to help waterproof the connection and keep the O-ring from drying out? ... love your channel... 👍😎👍

@GainSolarPower So can I please confirm this: Currently I have 6 panels that are facing east to get my batteries charging asap in the mornings with 8 panels facing north for the bulk of the daytime solar. Each string is obviously wired in series currently and my inverter only has input for the two strings. Can I add another series string of 6 panels on the west side to focus on afternoon solar that is then connected in parallel to the east string? Would there be any disadvantage of doing this?

Dude, nice setup but I’m SURE you don’t get much sun in that location 😎😕

Will a 4 awg wire fit on the other end of the branch connector that will run to the inverter?

Is it possible to buy the rack and install it and add the panels little by little a few each month? The county probably wouldn’t allow that. The total cost is so big. I wish I could do it

Is the permit process difficult with the county for a diy ? You need plans?

Sadly I haven't been able to find a branch Y connector that is CSA or cUL rated so we aren't allowed to use them in my jurisdiction.

Dear John. Please provide me with a discreet "shout out" on your next video. It will assist my ego. Also, it would be nice if you could talk bout wiring troughs a bit on your next video during said shout out. Ie; do you have a common go-to trough size, etc? Give us some meat and taters on wiring trays, we the people deserve it. Over and out, solardrew.

The Staubli connectors you are using have a red O ring on the male, I can't seem to find these.

Can I have two separate strings of 5 solar panels one in series and one in parallel, going to different charge controllers but charging the same battery bank?

Question - if I have say 4 hundred watt panels can I hook them to two different batteries. Example - panels in series coming in, then split with one going to a solar controller/battery and the other going to a bluetti 200p.

JOHNNY, THANKS FOR THIS VIDEO! MY GOAL IS TO GET A SOL-ARK 15k & I WAS WONDERING WHY EACH MPPT HAS 2 CONNECTIONS. I WENT ON SOL-ARK’S WEBSITE TO CONFIGURE PANELS & IT SAID 7 PANELS WITH 2 STRINGS. CAN YOU WIRE BACK & USE BOTH MPPT1 CONNECTORS WITHOUT USING THE ‘Y’ CONNECTOR? IF SO, HOW MANY ‘IMO DISCONNECTS’ IS REQUIRED PER MPPT? ALSO, DO YOU RECOMMEND ‘RAPID SHUTDOWN MODULES’?

How many watts in each string?

Can I connect 4 different panels in parallel or do they need to be same

What racking manufacturer is that array?

I have a question that no-one can answer. I have 15 solar panels wired into a dual input inverter? The Panels are a total of 3.3KW. How are they wired?

5:23 wtf lol