Solar Wires Into Bus Bar?

[LongIslandCamper]

My camper is not solar ready.

Let’s say I mount two 100w panels on my roof and run the wires down my fridge vent. My water heater and breaker panel are under the fridge. The solar wires then go into my controller. From the controller I run wires into a shut off switch and then from the shut off switch I run into a bus bar.

I then remove the wires that run from my converter to my batteries and plug that into my bud bar.

Finally I run new wires from my converter to the bus bar.

This would allow me to turn off the solar input when on shore power and then allow me to flip the solar on with the shut off switch when I dry camp to charge my batteries.

Would that work? Do you see any issues?

[colby]

You will need a solar charge controller between the solar panels and the bus bar. Most solar panels are a higher voltage than 12v, so the charge controller will step it down for you. For example, a Renogy 100W panel is pushing 20v, two in series is 40v. That will fry things pretty quickly. If you are doing 2x100 in series (or parallel), you could get away with a smaller solar charge controller like the Victron 100 20amp (which covers you at 16amps for 200 watts of solar), and it's $90 on Amazon (https://www.amazon.com/Victron-Smart...s%2C123&sr=8-8). You could output that to the bus bar. Personally I would put a solar isolator switch in also, but that's just me being really cautious.

[LongIslandCamper]

Thanks. I already have a Bluetooth capable 20a controller. I was wondering if my posted setup would work.

[colby]

Originally Posted by LongIslandCamper

Thanks. I already have a Bluetooth capable 20a controller. I was wondering if my posted setup would work.

That's what I get for replying late at night, I completely missed the part where you said that you had a controller, and I see that you have a shut off switch after the controller. What you are planning should work fine, and is generally how it is done. If you look at the really fancy setups, the Victron Lynx Distributor is really a fancy bus bar.

Any way to put the shut off switch between the solar panels and the controller? That way you would cut the power from getting to the controller which is a little cleaner and potentially safer as the controller wouldn't have the high voltage going to it when not being used.

[dvspl]

Originally Posted by colby

Any way to put the shut off switch between the solar panels and the controller? That way you would cut the power from getting to the controller which is a little cleaner and potentially safer as the controller wouldn't have the high voltage going to it when not being used.

Connecting the output from solar controller and the converter to bus bars is the same as connecting them to the battery. Just make sure you have a large enough wire between the bus bar and battery to carry the combined current. Also, I think the solar shut off switch should be between the panels and the controller. You can put another one between the controller and the bus bar if you like but most controllers want to be connected to the battery before they're connected to the panels. They use the battery to power themselves up and also need somewhere to send the power once the panels are connected.

[LongIslandCamper]

Originally Posted by dvspl

Connecting the output from solar controller and the converter to bus bars is the same as connecting them to the battery. Just make sure you have a large enough wire between the bus bar and battery to carry the combined current. Also, I think the solar shut off switch should be between the panels and the controller. You can put another one between the controller and the bus bar if you like but most controllers want to be connected to the battery before they're connected to the panels. They use the battery to power themselves up and also need somewhere to send the power once the panels are connected.

Thanks. My reasoning for the shut off switch was also to limit the charge going to the batteries and not having to run a bigger line. I have no need to run solar when on shore power so why bother running a larger cable?

My converter is 45a and the solar controller is only 20a so there should be no problems with too amps on the existing wire.

[RogerR]

Renogy told me that you always shut off the solar going into the MPPT before detaching the battery from the MPPT. Not sure of why but I assume that failure might damage the MPPT.
I pulled the fuse and now only use solar to keep my battery charged as my older model is not Lithium capable.

[colby]

Originally Posted by dvspl

Connecting the output from solar controller and the converter to bus bars is the same as connecting them to the battery. Just make sure you have a large enough wire between the bus bar and battery to carry the combined current. Also, I think the solar shut off switch should be between the panels and the controller. You can put another one between the controller and the bus bar if you like but most controllers want to be connected to the battery before they're connected to the panels. They use the battery to power themselves up and also need somewhere to send the power once the panels are connected.

That's actually what I was saying (it was an addendum to my first post), that the solar isolator should be between the panels and the controller.

[JKyle]

Considering you're gong through the entire effort and solar panels being more powerful these days, for the same footprint, I'd go with the 200 watt panels vs 100's. Unless you already own the 100s.

[waynehead99]

Just an FYI as I just put solar on my camper last month... the campers that are pre-wired for the Go Power solar, they are wired exactly as you are planning to do.

The positive is on the positive bus bar and the negative is on the negative bus bar (all inside the nose and not exactly easy to get to).

All I did was tie the wires together inside the camper where they have the sticker for the Go Power controller (negative wasn't cut, but positive was) and then toned out to make sure the wires from the roof were in fact the wires I was suspecting on the bus bars.