Solar to replace broken generator, can I use its wiring?

[Cyruszs]

Hi guys,

I just purchased the first few elements of my solar system (100w panel, wiring and mppt 40amp charge controller), I'm planning to upgrade it gradually to a more powerful system with more panels and batteries.

My generator at the same time is done for, so I wanted to see if I could use the wiring that used to go into the generator to get it into the new charge controller and call it a day so everything would be connected just like before with my generator especially it would avoid for me to set up all the wiring to get to the auxiliary deep cycle battery.

I have different wires that were connected to the generator:

3 wires (one black, one white, one nude which I'm guessing is one hot, one neutral and ground) that go into a transfer switch box. And then separately 2 other wires a little thicker, one with a little metal loop at the end and one with a bolt at its end. I'm not exactly sure where these go, I tried to follow those cords but it ends up being a complex set of connections underneath the RV so I'm not sure.

Let me know your thoughts on this, I hope I'm clear enough explaining the situation but if not I'll be happy to give more details.

Thank you!

Cyrus

[MrWizard]

One more thing, charging the engine battery from solar will not charge the house battery
The engine and the house connect thru a battery isolater or relay
Connecting directly at the engine battery does Not feed back to the house
That battery is separated and isolated from the house battery

you have to connect to WIRE that is GOING TO THE BATTERY to be charged by the controller

[MrWizard]

Cyzrus
i'm not sure what you are thinking

the output power wires from the generator are for 120vac the go the transfer switch or manual plug in and from there to the circuit breaker panel

they are not useable for the solar controller

BUT IF you are talking about the 12v wire from the batteries for the generator starter, then 'MAYBE' they can be used for the charge controller
it depends on wheter that wire connects to the house battery or to chassis-engine battery ?
it can be wired either way, depends on what the builder did

if wired to the house batteries then yes you could use that for the charge controller connection to the house batteries 'maybe'

you see the the generator is probably grounded to the frame, NO negative wire going to the batteries

solar controllers are usually wired directly to the batteries with both the positive and negative wires, going direct
not using frame ground for negative
your controller may or may not work to charge the batteries using a frame ground instead of a direct run

MOST seem like an easy idea tricks
do not work to well with solar wiring in RV's

[mike-s]

Well, the solar really wants to connect to the house battery - that's what the solar needs to recharge. You'd normally connect the batteries with the switch when going down the road so they all get charged, then open the disconnect when camping so the starting battery doesn't get discharged to where it won't start the engine.

The wires are there for the generator electric start and are connected to the starting battery so you can still start the gen and recover if you've drained the house battery. They're probably reasonably heavy gauge, but better check and there may be a need to run heavier ones as your system grows.

Generally, you want the inverter as close to the battery as possible - a 400W one is going to pull over 30 A DC. Without knowing the wire gauge, not much can be said about what to expect.

[Cyruszs]

Ok! Just updated my profile, I have a Ford Chinook 1990.

Yes, it's connected to the vehicle battery. I'm really thinking that for a solid long term solution I should just get a 1000w inverter in between the solar system and the transfer switch box, then I would be connected to the house battery.

I'm not sure about the disconnect switch I could unscrew it to take a look, but the generator is not an option anymore, I'm getting rid of it. It's broken and repairs on it ,with the high cost of labor at the shop, would not be worth it. I might just sell it on eBay for super cheap for someone who would want to take the time and make it a project of repairing it themselves (or if anyone on here is interested).

I have a 400w inverter and I'm thinking of starting with that, connecting it in between solar system and transfer switch. Is that a good idea?

[dave17352]

hum I wonder if that disconnect switch connects your vehicle starting battery with your house battery so you could use its power to start your generator. Is it a spring loaded switch? The little loops are called ring connectors or ring terminals. 🙂 If this is the case and the two wires run to your house battery you are good. If the two wires run to your vehicle battery you are not. Also right now you only have one 100 watt panel, as things grow you will have to be checking your wire gauge and length of run etc. Also it would be good to fill out your profile as the other poster said. May be someone on here that has been there and done that on your exact rig. JMHO

[1995brave]

Fill out your profile with Make, Model, and year of your RV. Then people will understand what you are dealing with and someone with the same RV can chime in and help you better.

[Cyruszs]

Thanks a lot for your response. I figured out a bit more by myself too in the meantime.

The wires with the little loops are linked to the main car battery, the chassis battery, just did a test, you were right on that. So for now I can just connect the charge controller to that battery (same way you did if I understood right) because it is also indirectly connected to the auxiliary battery anyway. Now I'm wondering typically are the batteries of an RV connected in parallel or series? I'm guessing they would be in parallel to keep the system at 12V.

Those two batteries came with the RV and are both under the hood and there is a "battery disconnect" switch on the dashboard that connects or disconnects them.

Also about the other wires that used to pump AC power from the generator into the transfer switch, I agree, this seems like a more risky operation. If anyone has a better knowledge about that I'd be happy to hear. Otherwise I could connect an inverter in between the charge controller and the transfer switch. The reason I want to be able to use the transfer switch is that it is connected to a series of AC outlets in the RV.

[Lwiddis]

I wouldn't. Run new wire from panels to controller and controller to batteries. Eventually you'll buy a new generator.

[dave17352]

I don't see any reason why you could not use your generator wires that run to your 12 volt battery. I use 2 12 volt batteries. One is located in the existing battery location on my TC. The other I put in my former generator compartment. My solar goes to the controller, then the generator compartment into the first battery. From there I use the existing 4 gauge wire that runs to the battery compartment. Works just fine. In a perfect world I would have my two 12 volt batteries in the same location but with the heavy gauge wire between them and the small loads I am not too concerned. The two heaver gauge wires I assume are running to your house batteries for starting you generator. That is/was how mine was wired. Those are the wires I used to run to my existing battery. You will need to make sure that is how yours is wired. The solid wire romex type wire is what supplied 120 to your transfer switch. I am no electrician so make sure you can verify before doing any damage to yourself or your rig. 🙂 Also you need to make sure those romex wires are not hot when plugged to shore power. If so they need to be capped off. But you could actually take the transfer switch out if you are not going use it anymore. JMHO

[sch911]

Solar controller creates a DC output, generator is an AC output, so how's that going to work?

My solar charge controller is connected directly to the house batteries.