FWC Wiring Question

[Jon R]

I have a new Grandby arriving in May, and I'm doing a LiFePO battery and solar installation immediately. I've bought most of my parts at this point, but need to buy crimp lugs for the FWC-installed solar wiring and for the main load wiring that I assume will be a single pair going from the battery to the main cutoff switch (pos) and a negative bus bar.

I'm wondering if someone can tell me the gage of those wires. I've read the solar panel wires are 10AWG, but I've never seen anything about the size of the other wires.

Thanks

 

[ri-f]

My 2020 Hawk had 10 AWG for the wires you're referring to. The 10 AWG is okay for the solar to the controller (even if you use two panels in parallel), but if you're using something like a Victron 100/30 mppt controller I would use the biggest wire that those terminals can take, which if I recall is 6 or 8 AWG. I'd run that from the controller to the battery because you will have more current converted by the controller running outbound to the battery and 6 or 8 AWG can handle it with no degradtion through the wires. The inbound wire to the controller can be 10 AWG if you like. That's what I did with two 160W panels in parallel. Works great.Wherever I installed new wires (solar, dc-dc charger) I used 6 AWG wire. For the 30 amp dc-dc charger run from the truck battery to Lithium in camper I used 4 AWG.

Rich

 

[Fishyhead]

For my camper, I used 4 AWG wire from the battery to the cut off switch then to the positive bus bar and the same from the negative post to the shunt then to the negative bus. 8 AWG from the bus bars to fuse blocks or boxes. The pv panel feeds to a breaker box then a controller then fuse via 10 AWG.

 

[Jon R]

Thanks for the responses. I am planning to run 6awg from the truck engine compartment to the DC-DC converter, and for the short wires from the DC-DC converter (Victron Orion 12/12-30) to the battery and from the solar controller (Victron MPPT 100/30) to the battery. My wife and granddaughter will be impatient to go on the first camping trip while I do the initial battery and solar panel installation, so I was not planning to change any of the load wiring. That's why I wanted to know the gage of the existing load wires connected to the battery. While I may change out those wires later, initially I want to just install 5/16 ring terminals on those existing FWC wires and connect them to my new large bus bars in the in the battery compartment.

 

[Fishyhead]

FYI, I ended up with an assortment of #10, 1/4, 5/16, 3/8, and 1/2 ring terminal for the various wire gauges because there doesn't seem to be a standard size post.

 

[ri-f]

Thanks for the responses. I am planning to run 6awg from the truck engine compartment to the DC-DC converter, and for the short wires from the DC-DC converter (Victron Orion 12/12-30) to the battery and from the solar controller (Victron MPPT 100/30) to the battery. My wife and granddaughter will be impatient to go on the first camping trip while I do the initial battery and solar panel installation, so I was not planning to change any of the load wiring. That's why I wanted to know the gage of the existing load wires connected to the battery. While I may change out those wires later, initially I want to just install 5/16 ring terminals on those existing FWC wires and connect them to my new large bus bars in the in the battery compartment.

I'm always tempted to rewire every wire and butt connector and ring terminal that came stock with the camper when I compare it to the wire and connectors that I buy to install or upgrade new components. You can get spoiled using real marine-grade tinned wire. It's pliable and just looks and feels good. And it's expensive, which I suppose is why you don't see it in your camper unless you install it there yourself. When I strip some of the original 10 guage wire running through the camper it always feels stiff as a board and has no tin in the wires. Hard to work with. I don't envy the electrical crew who had to run all that cheap wire throughout the campers. Aside from going up a size in the places where it might be important, I can also imagine that you might want to simply run some quality wire.

Rich

 

[Jon R]

I agree about using quality wire. I don't have my camper yet so I haven't experienced the factory wire. I have bought 6awg Ancor Type 3 marine tinned wire for my modification, which I suspect is just what you are suggesting. I will also install Blue Sea 250 amp 4x5/16 post bus bars and a Blue Sea 300 amp battery fuse block (with 80 amp fuse). My initial modification will be to just get the lithium and solar up and running for a first camping trip, so as I said I don't plan to immediately get into replacing load wiring beyond the battery compartment if I don't need to. Once I no longer have the wife and granddaughter asking "is it ready yet," I may get further into replacing the runs to the factory individual circuit fuse block and negative bus bar. I want to make sure the wiring up to the factory fuse block is all adequate for the fault current allowed by the sizing of the fuse I'm installing at the battery, so I'll eventually run 6awg Ancor wiring all the way to the fuse block. If it looks easy to do I may do it as part of the initial modification, but if it involves significant cabinet disassembly I'll do it later in the summer and just put a smaller fuse in the battery fuse block based on assessing the factory wire size.

 

[ri-f]

Yes, I did use Ancor wire, which has a higher temp rating than some of the other marine-grade tinned wire. I also used Blue Seas circuit breakers and bus bars, etc.. Sounds like you're completely on top of all this. Good luck with the pressure of "Is it ready yet?" As soon as it is ready, the next guestion will be "Are we there yet?"

Rich

 

[Jon R]

I don't know about completely on top of this, but I've done a lot of research and sought lots of advice. Thanks for the help and advice.