Solar cable thru fridge vent

I had to go through a screen on the fridge flu to gain access when I ran two RG cables down through for SAT TV...

I guess I didn't seal it too good as now I get the LADY BUGS in the fall part of the season in my air conditioner ducts that run thru the ceiling area...

Everything works fine just be sure to seal up any holes you make good...

Roy Ken

An alternative: fridge vent combiner box

Open the vent - remove that big plastic cover. Then you will have a better picture. There is no "shaft" in my trailer. Under the cover you will find a plastic coaming with mesh on top, about 2" tall. Under this coaming there is a fridge cabinet.

It's difficult to use a normal strain-relief fitting without having access to both sides of the fitting. I had to cut the mesh a little, to access the fitting on the inner side of the coaming. Some other people cut the fitting flash with the coaming and glued it to the coaming from outside. If you you attach the cable to the roof with a caulk before the vent, and then with a spray foam or caulk on the other side - where it exits through the fridge cabinet wall - you don't need to worry about fixing it in the coaming.

Once inside the coaming, my cable exits right through the fridge cabinet wall to kitchen (there was some wigging with a coat hanger wire to route the cable through that wall, while sitting on the roof). I used a spray foam in that hole in the wall. On the other side of the wall there is (usually) some cabinet.

I didn't use fridge vent combiner box for these reasons:
1) This box is expensive and bulky, it doesn't fit under the plastic cover well.
2) I didn't need all those many fittings because I used series wired panels, so there was no cables to "combine" and therefore no need in "Combiner box".

Fisherguy made a neat job of his with a photo if it can be found.

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28531332/srt/pa/pging/1/page/1.cfm

Because I have so many panels, I installed a J Box on the roof in a pool of Dicor, then drilled a diagonal hole into the left, non flu side of the fridge cavity. This was an early pic with only two panels installed.

BFL13 wrote:
Fisherguy made a neat job of his with a photo if it can be found.

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28531332/srt/pa/pging/1/page/1.cfm

Ah, those parallel panels... A lot of wiring with not too much wattage. And he still had to cut the vent mesh, as I see.

Get 24V in series, 250-300W each, 2 or 3 of them, #10 or #8 MC4 cable, a single hole in the vent, no combiner box or posts. Plug and play all the way. Easy. This is what SMK here did, I did the same only with fewer panels and smaller controller.

MC4 cable enters the vent and then exits through the fridge cabinet wall into kitchen cabinet, no connections around the vent or in the fridge cabinet, uninterrupted cable run all the way to controller.

I ran two each #10 romex wires down from the roof to the controller. I used a coat hanger to help assist me in hooking the romex and pulling it into the space behind my refrigerator. Then I was able to push it into a hole that I drilled below the refrigerator into the space below it, by removing the drawer inside, I was able to drill a hole into the basement. I put the controller under the refrigerator in the basement compartment.

I ran #8 wire from the controller output to the battery about 4 feet away.

Good luck,

Fred.

I probably should've mentioned that did not fall for a "simple" install with 80-pound piece of 2*250W panels bolted together as per SMK ;)... Instead I mounted panels separately on aluminum angles like Fred here posted a few times.

Yes, #10 Romex cable can be used with series wiring, but most panels come with MC4 pigtail anyway. MC4 cables are cheap at Unlimited Solar, locally made and of good copper. You can get MC4 extension as thick as #8, though #10 is sufficient for arrays up to 500-600W.

My 60 feet of solar extension cable 10 awg came today with MC4 connectors. My plan was to cut in half and attach each to the panel. Then run 5 feet to the vent maybe drilling 1 or 2 holes in thru the side of the vent. Run them down the vent shaft on the opposite side of the flue where I can drill an exit hole on the shaft side. This would allow me to poke the cables thru to a wiring shaft dropping down next to the water heater tank area. This is accessible by removing the screws on cabinet wood cover below the fridge. Then it's a simple fishing the cable around to the other side via cabinets and raised flooring. I say it's simple as I have already fished cord all the way around to make it a simple pull. From there it runs under the stove and sink cabinet where I have my old Xantrex Battery Monitor and where I will place the controller. The cabinet opens in the entry step area. On the outside of the cabinet in the entry door area I will mount a cut-off switch like the one for the battery. From there it's accessible to the house batteries.
So since it's just one panel, I don't need a box and buss bars. Maybe I'll try what was suggested and glue on the fittings to the side of the vent. If I want to add another panel, I have the branch connectors. Not going over 200 watts and getting a 30 amp controller.

NOW I think my cable is too thin and I should only run the 10 AWG to the vent and then go with heavier awg to the controller

DAS26miles wrote:
My 60 feet of solar extension cable 10 awg came today with MC4 connectors. My plan was to cut in half and attach each to the panel.

Yes, this is how it's done - order 2 times longer and cut in half.

DAS26miles wrote:
So since it's just one panel, I don't need a box and buss bars.

Yes. But It's good to have a Baby box from Midnite Solar (or Big Baby Box), and install breakers and buss bars in there. I have Pos bus, Neg bus, Load breaker, Controller breaker - all housed in the Big Baby, and there is one vacant slot left (planned for panel breaker but it's not much necessary).

DAS26miles wrote:
Maybe I'll try what was suggested and glue on the fittings to the side of the vent. If I want to add another panel, I have the branch connectors. Not going over 200 watts and getting a 30 amp controller.

You may get away with no fittings at all. Fix cable to the roof with a blob of Dicor, and then with a caulk or Dicor where it exits the fridge cabinet.

Yes, another panel with PWM controller means getting MC4 Y-splitter.

DAS26miles wrote:
NOW I think my cable is too thin and I should only run the 10 AWG to the vent and then go with heavier awg to the controller

I don't think it's too thin for 200W with PWM, but there is no need to guess. Run the numbers through Voltage drop calculator. Allow 3% V-drop and use one-way length, i.e. if you use 60ft cable cut in half, put 30ft in calculations.

With MPPT I wouldn't worry even with 5% drop because controller would boost the voltage automatically, but with PWM let others speak. Me thinks that with PWM V-drop is not important as long as you're getting at least 15V to controller, because stupid PWM will cut everything else off :)