Solar install question

[Chef_Tim]

Hi all.
I am wanting to install a solar panel on top of my Aspen Trail 1700db TT. I know enough about how solar works to understand the BASIC relationship between panel, charge controller, and battery, and how to connect them in the most simple terms.
Here's the equipment I want to install:
- Kyocera 150W panel
- 30A MPPT charge controller + MT-50 meter (I will add another panel later)
- 40ft solar cable, 10awg
- 2x12 volt deep cycle batts (wet)

Planned install: Mount panel atop slightly curved rubber roof; run solar down through fridge vent to charge controller mounted in a cabinet next to the fridge.
This is doable for me. But here's my problem: due to the configuration of the TT, it would be very difficult to connect directly to the batteries, located outside the coach on the tongue.
I'd like to connect the charge controller to the batteries via the converter, a WFCO 8955. Apparently this is how the rv dealership where i purchased my trailer adds solar, for which they charge about $500 bucks + the cost of (overpriced) GO Power panel (160W).

The dist. panel board has 2 white wires on the DC side (1 going to converter and the other (battery?) going to a buss behind the converter. it then leaves the buss and drops into a hole in the floor, so i assume this goes out to the batteries. For the positive, there's a black cable connected at the board, plugged into 1 of 2 lugs. the other lug on the board is open.
I have seen a video here: https://www.youtube.com/watch?v=oqfIjfF5eGQ&list=PL_8gRzheasijMxKqQ30cP_4QGoYZeSnPB. At the 9 minute mark the video demonstrates what I want to accomplish. However, my unit doesn't have wire nuts, only the negative going into the buss, and then just the positive disappearing into the floor.
I am wondering if I can do the following:
- plug the neg charge controller cable into the buss
- plug the pos charge controller cable into the open lug on the board. I'd also like to install a kill switch.

Any reason I SHOULD NOT do this? Again, this is up for consideration only because after going under the trailer and seeing how everything is hidden behind either darco or coroplast, i'm looking for an easier way to accomplish my goal.

Thanks for reading this very long post.

Tim

[westend]

Forum member's solar installations, A compilation

[Calkidd]

This is a good read if not a must. He's not a favorite of all but extremity knowledgeable when it comes to solar.

https://handybobsolar.wordpress.com

[Chef_Tim]

thanks to all for the really helpful advice. i will pay it forward!

[Chef_Tim]

corvettekent: yes, thank you. wish i could go a shorter route to batts, and i realize i will lose some wattage. however, it's my only option. in the future i'll add another 150w panel and at that point i might try to re-route the charge controller closer to the front of the coach.

Tim

[corvettekent]

Try to find a shorter route to run your wire and mount your charge controller close to the batteries. You should also step the wire to 8 awg. I agree that you need a switch or fuse between the panel and controller.

[Boon_Docker]

Chef Tim wrote:
Boon Docker,
Can you tell me exactly what your disconnect is? On/Off switch?

Thank you!
Tim

I used an inline circuit breaker.

[time2roll]

I would go 40 amp fuse with a 30 amp controller connected with #6 wire.

Maxi fuse holder with #6 leader

Nothing special about a "solar panel switch". Just needs to be rated for the DC voltage and Isc (short circuit amps) panel rating.

Trouble is I don't know a great low cost solution. I used a high voltage cut off switch since I have series panels that can go over 100 volts. A bit bulky. For simplicity two of those fuse holders might do fine. Something like Blue Sea rotary battery switch might work. For mine I like having both wires disconnected but one should be fine.

Here is a two pole battery switch. Not sure if this is best or how you will mount it.
DPST Master Disconnect Switch


I like this one better:
Blue Sea 2 circuit surface mount $41
Should be able to mount it in the fridge compartment just above the controller.

[Chef_Tim]

Boon Docker,
Can you tell me exactly what your disconnect is? On/Off switch?

Thank you!
Tim

[Chef_Tim]

smkettner:
What is a solar panel switch?
What size inline fuse?

Thanks for the information!
Tim

[Boon_Docker]

As "smkettner" says, that will work just fine. That is the way my solar is connected to the batteries plus a disconnect between the panel and charge controller.

[time2roll]

https://www.youtube.com/watch?v=oqfIjfF5eGQ&list=PL_8gRzheasijMxKqQ30cP_4QGoYZeSnPB

Chef Tim wrote:

I am wondering if I can do the following:
- plug the neg charge controller cable into the buss
- plug the pos charge controller cable into the open lug on the board. I'd also like to install a kill switch.

The plan seems fine to me. I would skip the kill switch (controller to RV) but add a fuse close to the positive lug since the wire would seem to be tucked into a blind area. Can always remove the fuse for service.

What you do need is a solar panel switch as most controllers need the power source disconnected before you disconnect the battery.

[Shadow_Catcher]

Check voltage drop from the panel 10 AWG at 40' may not be enough.