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?

Not familiar with your rig, but the norm is to bring rooftop wiring down to charge controller via fridge vent or even grey vent. Then wires go from charge controller forward to the batts. Im not sure I would want to drill into the top then bottom of the cap. Having shorter wire runs is tempting, but using properly sized wires will minimize loss and allow less invasive hole cutting. Hopefully other TT owners will give some advice as my solar was done on a 5er

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.

When we had a TT I ran the panel wires in Cord Mate II then in through the floor to the CC to avoid holes in the roof.

I'll will be doing something similar, as going trough the fridge vent is way to much of a detour for my setup.I will be going on the wall and use a "hide wire system", to achieve shortest run as possible.

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.

Solar cable routing behind front cap | Good Sam Community

18 Replies

westend
Explorer
Feb 14, 2018
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
Explorer III
Feb 14, 2018
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
Explorer
Feb 14, 2018
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
Explorer III
Feb 14, 2018
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.
RasMouSein
Explorer
Feb 14, 2018
I'll will be doing something similar, as going trough the fridge vent is way to much of a detour for my setup.
I will be going on the wall and use a "hide wire system", to achieve shortest run as possible.
scrubjaysnest
Explorer
Feb 14, 2018
When we had a TT I ran the panel wires in Cord Mate II then in through the floor to the CC to avoid holes in the roof.
epfd217
Explorer
Feb 14, 2018
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.
FLY_4_FUN
Explorer
Feb 14, 2018
Not familiar with your rig, but the norm is to bring rooftop wiring down to charge controller via fridge vent or even grey vent. Then wires go from charge controller forward to the batts. Im not sure I would want to drill into the top then bottom of the cap. Having shorter wire runs is tempting, but using properly sized wires will minimize loss and allow less invasive hole cutting. Hopefully other TT owners will give some advice as my solar was done on a 5er

Forum Discussion

Solar cable routing behind front cap

18 Replies

About Technical Issues

Related Content

Another solar question.

Montana Route 200S

Solar wiring route?

Route tips

Solar