Solar cable routing behind front cap

[epfd217]

I'm looking to finally begin my solar install and I'm trying to plan the best route for my solar cables.

Batts are on the tongue, front pass through area houses the inverter and is where I will mount the charge controller, fuses etc.

I've got a 2017 Salem Hemisphere 312QBUD. My plan is to drill into the front cap from the roof and just drop wires down behind the hollow front cap. There is a 2-3" gap and its the route in from the bottom that the battery wires go to the inverter.

I'm curious if anyone has done this routing or is familiar with the front cap and if the air gap behind the cap continues to the roof? I can't seem to get any confirmation from anyone.

Anyone tried this route?

[TUCQUALA]

My son was easily able to run down the front cap of his Wind River. F/glass sticks did the job from the inside connections in the front cabinet.

You could use this for the input on the top of cap, if fits:

https://www.zampsolar.com/solar-ports

Or just for one pair of wires:

https://www.amazon.com/Winegard-CE2000-Cable-Entry-Plate/dp/B009LX1HFO/ref=pd_sim_263_4?_encoding=UTF8&pd_rd_i=B009LX1HFO&pd_rd_r=EA61G4F5RCPCG48VZK98&pd_rd_w=EKdQu&pd_rd_wg=dYIDp&psc=1&refRID=EA61G4F5RCPCG48VZK98

I used the second one, with liberal Dicor and have no leaks!!!

[Almot]

CA Traveler wrote:
But no need for unnecessary losses either. I have 61' of 10 gauge wire at 92V and 8.2A for 0.5% loss. And with flat mounted panels the maximum amps and loss is less.

Why didn't you install 8 gauge MC4 wire then, to reduce unnecessary losses 🙂 ?

But, thanks for illustrating my point. People trying to make the shortest run possible no matter what, sometimes don't do their math.
With 24V panels in series, losses up to 70ft are negligible. If this makes for easier or more aesthetically pleasing install, it makes sense.

[epfd217]

Thank you for all the great suggestions. I'll have to make a trip to the rv to check that front cap. I have a lightweight, non-metallic probe I never considered using. If that doesn't get me where I want to be, I guess a fish tape is in order.

As I've said, I still plan on drilling a hole, I was just hoping to do it through the front cap instead of going into the rig and then creating a route through the interior. I prefer making one hole over two (or more) new holes. It sucks how much the electrical is hidden in the newer rigs. SO little room to work and even less room to expand or reconfigure devices.

[CA_Traveler]

One of the biggest taboos on these boards is drilling a hole in the roof. Many roofs have hundreds of holes from the factory. Secure the wire, seal it correctly and it won't leak. For my roof I don't spare the Dicor and it doesn't leak - if you've every gotten Dicor on your hands you'll understand.

[CA_Traveler]

Almot wrote:

RasMouSein wrote:
The MPPT don't care, you don't care...

THINK. Then - post.

At 65V*8A, V drop results in less than 1.5% drop at max wattage, at this length.

Less than 1% loss in daily harvest, or ~1AH out of 140-160 AH (max wattage is only a part of the day, if at all).

You may run #8 MC4 to cut loses lower yet, but I didn't find this necessary.

But no need for unnecessary losses either. I have 61' of 10 gauge wire at 92V and 8.2A for 0.5% loss. And with flat mounted panels the maximum amps and loss is less.

[CA_Traveler]

MrWizard wrote:
goto harbor freight or home depot or lowes etc..

buy a fish tape, that thing we electricians use to pull wire

push it in the hollow from the bottom and see how far you can extend it

if it goes all the way and bumps up against the roof, you are good

it it only goes part way and stops, then you know to find another way

the thing is very handy tool to have around and NOT expensive

Plus if there are any light switches, lights, etc on the inside wall pull them and use the hole for probing.

I use a 1/8" flexible fiberglass wire puller that also serves me well for probing. I also have a 4' long flexible drill bit that has served me well. No exposed wires covered or not for me.

[fpresto]

I agree with Mr. Wizard. Verify that the gap goes all the way to the roof with no ribs in the way. If it is open then your idea should work perfectly.

[MrWizard]

goto harbor freight or home depot or lowes etc..

buy a fish tape, that thing we electricians use to pull wire

push it in the hollow from the bottom and see how far you can extend it

if it goes all the way and bumps up against the roof, you are good

it it only goes part way and stops, then you know to find another way

the thing is very handy tool to have around and NOT expensive

[RasMouSein]

THINK. Then - post.


Hehe that's why you had to edit your post...

[grizzzman]

epfd217 wrote:
The front cap area is already accessible from below. Thats how I know its hollow from the bottom.

My rig has a residential fridge (no I don't plan to run using solar), so there is no fridge vent. I could use a vent path to the underside of camper, but I'm hoping so see if anyone knows if the front caps remain hollow to the top.

I would still have to drill a hole and use a combiner box or glandat the front lip of the rig, but it would provide an unobstructed route to the front pass-through if my presumption is correct. Also, the entire front of my rig is wide open and perfect for panels.

I don't know if this helps but I ran 4 6awg wires down the awning mount then to the pass through.
Find some bailing wire , drill a small hole and see if it goes through.

[westend]

epfd217 wrote:
The front cap area is already accessible from below. Thats how I know its hollow from the bottom.

My rig has a residential fridge (no I don't plan to run using solar), so there is no fridge vent. I could use a vent path to the underside of camper, but I'm hoping so see if anyone knows if the front caps remain hollow to the top.

I would still have to drill a hole and use a combiner box or glandat the front lip of the rig, but it would provide an unobstructed route to the front pass-through if my presumption is correct. Also, the entire front of my rig is wide open and perfect for panels.

If you have some fish sticks or a fish wire, run it up from the bottom and measure length to the top of the cap. Total fish length should be within 1 1/2" of the cap height, if open all the way, inside.

[Almot]

RasMouSein wrote:
The MPPT don't care, you don't care...

THINK. Then - post.

At 65V*8A, V drop results in less than 1.5% drop at max wattage, at this length.

Less than 1% loss in daily harvest, or ~1AH out of 140-160 AH (max wattage is only a part of the day, if at all).

You may run #8 MC4 to cut loses lower yet, but I didn't find this necessary.

[RasMouSein]

The MPPT don't care, you don't care...
I do and people that want the better scenarios for their setup, care.
And A big rule in solar is to keep runs a short as possible.
eh! If you don't care ... feeling as nothing to do with voltage drop !! hahah

[Almot]

MPPT controllers don't care about 50-70ft cable run, if you detour through the fridge vent. With PWM this could be a problem, yes.

My 2*245W solar in series, #10 cable, goes through the fridge, then behind the cabinets and along the ceiling/wall corner, down to controller which is mounted inside in front bedroom. Don't want to expose +$300 device to elements.

I used Wiremold cover to hide the cable on the wall where it was not hidden in cabinets.

Battery cables are routed through the floor to Baby breakers box in front storage, then to controller.