Thru deck solar wiring advice

[sinnerman]

If your deck has a plywood or balsa core, make sure to seal / fill in the through- hole with fiberglass resin, then drill through the fiberglass.

You do not want water infiltrating the deck's internal wood core.

With the fiberglass sealing, if it leaks, (and it eventually will...) the water will flow directly into the cabin and not damage the core.

Cheers

[TCL]

I did my solar (and wind turbine) thru-deck wiring using a gooseneck made with bilge pump tubing and an inverted thru-hull. You will never get water intrusion. As a bonus, it is cheaper than a cable-clam. Also room for additional wiring when you add things (like more panels).

(Please ignore the need for touch-up painting. It's been raining for a month straight here.)

[MJH]

Originally Posted by djousset

I am in the final stages of my solar build/install and need to decide on wiring entry, (which is feeling like it’s pretty important). Drilling a hole in the deck is completely counter-intuitive, but it appears that's what many do and I'm not sure I see any other way. Panels will be mounted on both port and starboard rails, wires can be run down the stanchions, or aft along the rail. After researching it seems that parallel is best if there is any chance of shading so that’s the direction I am going in.

Better to drill near stanchions? Deck cable glands? Suggestions?

I used cable clams for the four solar panels I mounted, locating them out of the way on the deck.

When installing a new binnacle I elected to drill a hole in one of the stanchions and run the wire inside it...that was problematic. First, drilling s.s. with a hand drill was tough, then I still needed to drill through the cockpit flooring to access power, and lastly I neglected to drill the hole oversize and install a grommet which led to the wire chaffing through and shorting out...so much easier to install wires outside of tubing using wire ties and also for maintenance access when required.

~ ~ _/) ~ ~ MJH

[David B]

Originally Posted by djousset

I am in the final stages of my solar build/install and need to decide on wiring entry, (which is feeling like it’s pretty important). Drilling a hole in the deck is completely counter-intuitive, but it appears that's what many do and I'm not sure I see any other way. Panels will be mounted on both port and starboard rails, wires can be run down the stanchions, or aft along the rail. After researching it seems that parallel is best if there is any chance of shading so that’s the direction I am going in.

Better to drill near stanchions? Deck cable glands? Suggestions?

Our panels are on an arch, and the cables come down through the arch tubes to exit below deck, but if that is not your situation, then these are nice, and can be used on a flat deck, or a bulkhead:
https://www.scanstrut.com/marine/pow...eal/horizontal

[Tomodore]

I am a retired industrial electrician and I did a version of what TCL did I drilled a hole in the fiberglass then used a 1/2 inch pipe tap in the hole. I then screwed in a 1/2 inch liquid tire flex plastic flitting and used nonmetalic flex to the plastic liquid tight junction box. Room enough for multiple wires for my panels to be connected in parallel. Not an installation for everyone but it has been trouble free for a decade.

[djousset]

Thanks for all the input. I am testing the system underway and am pleased with the results so far (one panel installed). Next stop I plan to install the second, wiring in parallel I will use branch connectors to run the line back to the battery. Since my 2 house batteries are wired in series can the connectors go to the + and - of just one battery to charge both? Sorry for the freshman question, I find this stuff a bit confusing.

[David B]

Originally Posted by djousset

Thanks for all the input. I am testing the system underway and am pleased with the results so far (one panel installed). Next stop I plan to install the second, wiring in parallel I will use branch connectors to run the line back to the battery. Since my 2 house batteries are wired in series can the connectors go to the + and - of just one battery to charge both? Sorry for the freshman question, I find this stuff a bit confusing.

Do you mean your service batteries are wired in parallel?
If they are in series, then you must have two 6V, or two 12V batteries to give you either 12V or 24V.
Either way, the solar regulator output then must go across the two batteries to provide charge at the system voltage.

[Wotname]

Originally Posted by djousset

Thanks for all the input. I am testing the system underway and am pleased with the results so far (one panel installed). Next stop I plan to install the second, wiring in parallel I will use branch connectors to run the line back to the battery. Since my 2 house batteries are wired in series can the connectors go to the + and - of just one battery to charge both? Sorry for the freshman question, I find this stuff a bit confusing.

Whoa there... Maybe it is a case of terminology but as written, it is raising some red flags for me.

Normally the solar panel is wired directly to the input of the solar panel charge controller. The output of the solar charge controller is wired to the battery.

Depending on the panels and the charge controllers, you may need one or more charge controllers and the panels may be wired is series or parallel.

Now is a good time to post a diagram or tell us what panels / charge controllers you are using!

[djousset]

@wotname, I was not thorough in my explanation

Two Renogy 100W solar panels, wired in parallel through branch connectors, which go to the charge controller (20A Rover MPPT charge controller), which will them be wired to the battery(ies). From here is the proper connection both + and - to one battery as it is in series with the other, or + to one battery and - to another? Electricity and I have never gotten along well.

[George_SD]

Originally Posted by djousset

@wotname, I was not thorough in my explanation

Two Renogy 100W solar panels, wired in parallel through branch connectors, which go to the charge controller (20A Rover MPPT charge controller), which will them be wired to the battery(ies). From here is the proper connection both + and - to one battery as it is in series with the other, or + to one battery and - to another? Electricity and I have never gotten along well.

Your battery nominal voltage is lower than the the boat's operating voltage? (example: you run 6v batteries in series to make 12v)

Yes, I would connect the leads from the controller to different batteries (you should have one with boat's (-) lead and one with boat's (+) lead. Controller wires should be connected to those form my understanding, but I'll let others chime in and confirm.

[Wotname]

Originally Posted by djousset

@wotname, I was not thorough in my explanation

Two Renogy 100W solar panels, wired in parallel through branch connectors, which go to the charge controller (20A Rover MPPT charge controller), which will them be wired to the battery(ies). From here is the proper connection both + and - to one battery as it is in series with the other,or + to one battery and - to another? Electricity and I have never gotten along well.

OK, thanks for the expanded explanation of your system. Note the 'corrections' I have made to your post!

As George_SD has posted, you have to match the nominal voltages.

In the arrangement you have described, you have two 6V batteries connected in series giving a nominal voltage of 12V. The nominal voltage of the charge controller is 12V so it has to be connected to 12V posts of the series connected 6V batteries. Clear as mud? If you need, I (or someone else) can post a quick sketch.

Please put a fuse between the charge controller and the battery. Locate the fuse near the +ve terminal of the battery and size it according to the wire gauge used.

[djousset]

wotname,

I can see where fuses make sense. Beyond that I am flying BLIND on this.
Two 100W panels, wired in parallel to a 20A charge controller. So a 30A, or a 40 fuse on each line going to the battery? See photo below, end of cable that came with the system goes into fuse, and extender cable goes to battery terminal?

[Wotname]

Originally Posted by djousset

wotname,

I can see where fuses make sense. Beyond that I am flying BLIND on this.
Two 100W panels, wired in parallel to a 20A charge controller. So a 30A, or a 40 fuse on each line going to the battery? See photo below, end of cable that came with the system goes into fuse, and extender cable goes to battery terminal?

One fuse only and only in the +ve wire; connected as you have described.

Another fuse option is the Blue Seas MRBF terminal and fuse. The fuse housing mounts directly onto the battery terminal; very neat and compact.

https://www.outbackmarine.com.au/fus...SABEgLLlfD_BwE

[djousset]

Great, thank you! Do I have the sizing right, a 30A is enough?

[Wotname]

Originally Posted by djousset

Great, thank you! Do I have the sizing right, a 30A is enough?

Yes,

If you opt for a MRBF, 30A is the minimum size available and FWIW, 300A in the maximum size in the MRBF range.