Stuck on solar setup wiring

[Explorenzo]

Greetings everyone! I have been researching solar setups for countless hours and I'm still a bit confused.

I decided to go with a Renogy 300W kit and a Solar Boost 3000i MPPT controller. The panels will be wired in series and mounted to the roof using 3M VHB tape. I will then drill a hole in the roof using a 1.25" metal hole saw, which will be covered by this Cable Entry Box.

I hear a lot of talk about combiner boxes, such as this one from AM Solar. I can't tell whether these are actually necessary or not? I understand that I have to combine the cables from the 3 panels into one in order to be run to the controller. Can't I just splice them instead of using the combiner box?

 

[MikeRuth]

If your doing a series wiring, then you need to bring one the positive lead off one panel down to your controller, then the negative lead needs to run to the next panels positive connection and that panels negative to the last panels positive and then that panels negative back to the controller. You can either use what is provided or scrap all that and wire it your self trimming out a lot of excess wiring.
Personally I have two in parallel and I chose to use my own wire, 8 gauge which suited my system. Don't forget a fuse somewhere along that path back to the controller.

those factory cables supplied are not something I have personal experience with but I'd be willing to bet that yes you can splice and dice as you see fit.

 

[Explorenzo]

If your doing a series wiring, then you need to bring one the positive lead off one panel down to your controller, then the negative lead needs to run to the next panels positive connection and that panels negative to the last panels positive and then that panels negative back to the controller. You can either use what is provided or scrap all that and wire it your self trimming out a lot of excess wiring.
Personally I have two in parallel and I chose to use my own wire, 8 gauge which suited my system. Don't forget a fuse somewhere along that path back to the controller.

those factory cables supplied are not something I have personal experience with but I'd be willing to bet that yes you can splice and dice as you see fit.

Does this mean that since I'm wiring in series there will only be two wires? In other words i don't even need to splice and they can go directly to the controller, assuming I have enough length? I will certainly install a fuse as well.

 

[MikeRuth]

Here is a graphic.
http://www.wattuneed.com/en/content/9-solar-modules-connected-in-serial

 

[Explorenzo]

Here is a graphic.
http://www.wattuneed.com/en/content/9-solar-modules-connected-in-serial

Looks simple enough, thanks!