Community Forums

JHinman · 07-20-2021, 09:29 AM

I am planning to add a couple of solar panels to the top of my trailer. I have one Zamp panel already, but will add Renogy. That means I have to transition from MC4 to SAE connectors.

It seems I will have to splice the 10-ga leads from the panels to the combiner box. Those splices will be exposed on the roof top.

What is the best way to get a reliable splice?

I can get water-resistant wire nuts. These apparently are filled with silicone to keep water out.

Should I wrap the splices in water proof tape, like the thick rubber stuff from Gorilla? Maybe just smother the splices with Dicor?

inthepines · 07-20-2021, 09:47 AM

Marine grade butt connectors and heat shrink.
Or do a lineman splice and solder, again heatshrink it.
Throw the wire nuts away, they only belong inside.

BeaverDen · 07-20-2021, 09:54 AM

I have 6 panels on my coach, they are wired in parallel and connect to a fine stranded cable that goes down thru the roof to a marine type rotary power switch SPST. the panel wires feed into a compression type conduit fittings and are using crimp connectors. The + & - are using #8 machine screws and nuts that make each connection (you could use small copper split bolts, Seal them and wrap them. this connection is in a 4"x4" non-metallic electrical box that is mounted and sealed to the roof. The #4 copper stranded pair come out the backside down thru the roof to the switch which is in a closet along with the regulator. everything is sealed outside with DiCore. self leveling sealant

Perryb67 · 07-20-2021, 11:16 AM

You might want to view AM Solar's

Installing the Output Cable video.

Enjoy,

Perry

Pappion · 07-21-2021, 03:06 PM

Quote:

Originally Posted by inthepines

Marine grade butt connectors and heat shrink.
Or do a lineman splice and solder, again heatshrink it.
Throw the wire nuts away, they only belong inside.

I like to stagger the splices. Less chance of a short if pulled apart. Also makes a thinner longer package.
Lineman splice is great for pull strength and does not have an ugly tail. It was used with solid core wire and is useful for stranded if soldered. Clean up all the sharp edges after soldering so it does not poke thru the heat shrink.
https://en.wikipedia.org/wiki/Western_Union_splice

Perryb67 · 07-21-2021, 03:18 PM

Quote:

Originally Posted by Pappion

I like to stagger the splices. Less chance of a short if pulled apart. Also makes a thinner longer package.
Lineman splice is great for pull strength and does not have an ugly tail. It was used with solid core wire and is useful for stranded if soldered. Clean up all the sharp edges after soldering so it does not poke thru the heat shrink.
https://en.wikipedia.org/wiki/Western_Union_splice

We've staggered in the past for the same reasons. I no longer have a soldering gun but use quality connectors with shrink wrap. I definitely want to stagger with connectors. I've used cheap connectors that got hot. I go to an electrical supplier for connectors, not the cheap crap from WalMart. Connectors also make for a neater appearance. TETO!

Enjoy,

Perry

JHinman · 07-21-2021, 04:59 PM

Thanks, people!

I found some waterproof heat shrink butt splices locally. I like the idea of the adhesive-lined heat shrink tube as used in the AM Solar video, but have not found any yet.

TravelSolo · 07-21-2021, 06:19 PM

why? they sell adapters.

cwk · 07-21-2021, 06:20 PM

Quote:

Originally Posted by JHinman

Thanks, people!

I found some waterproof heat shrink butt splices locally. I like the idea of the adhesive-lined heat shrink tube as used in the AM Solar video, but have not found any yet.

I have not watched the video mentioned. But, here is a link to waterproof heat shrink splices. Reading the spec sheet for one of them that I picked at random indicates that they are adhesive-lined as well.

https://www.elecdirect.com/crimp-wir...rink-terminals

I have used this source many times over the years and have never been disappointed.

groswald · 07-21-2021, 06:27 PM

You can get marine heat shrink (thicker and adhesive lined) at Harbor Freight or Amazon.

Regards,

Randy

amosnandy · 07-21-2021, 07:19 PM

Quote:

Originally Posted by inthepines

Marine grade butt connectors and heat shrink.
Or do a lineman splice and solder, again heatshrink it.
Throw the wire nuts away, they only belong inside.

I would agree. Butt connectors and silicone filled shrink tubing. When I do an exposed splice I put shrink tubing on for the size wire I'm using, then I go up one or 2 sizes and slip another shrink tube about an inch longer than the original. Never had a failure even when exposed to salt water.

JHinman · 07-21-2021, 08:34 PM

I will try Harbor Freight for the heat shrink - thanks!

TB673 · 07-21-2021, 09:06 PM

If I was going to have high current (up to 40 amps # 10 wire) splices in an area that isn't accessed regularly, I'm not going with the H.F. heat shrink tube. I'm using a name brand such as 3M, Raychem, Panduit, etc that are available at electrical supply houses. Definitely more expensive, but not going to fail under fault conditions. I can say this as I have used their products in over 35 years in industrial electrical construction.
Good Luck in your install.
p.s. make sure that the heat shrink tube you select is UV rated.

Tim

Terraboat · 01-03-2022, 11:39 AM

For serious weather resistant wiring, you might want to look at what boaters do to deal with the marine environment. A great source of information on wiring, splicing, batteries, solar, etc. from a marine electrician can be found at:
https://marinehowto.com