Variations in 2022 Jay Feather Micro 166FBS builds

[TomC_AZ]

That is a thought. Those wires run through the roof/ceiling over to the bathroom wall where they run down. Maybe on the ceiling in the cabinet there next to the refrigerator. The refrigerator space, at least mine with the gas/120 fridge, is too tight.

[Forester2]

Not sure with the 12volt dc. As Ive said, I believe at least the positive solar wire, was run down to the area near the power center where they spliced in the converter wire.

[DonBr]

Originally Posted by TomC_AZ

you have to cut both neg and pos off at the same time from panels. It can cause great heat and big sparks etc.

What? How? Why?

Is your solar negative not run to common chassis ground? If not, why not? If it is, why would you want to let it float?

[TomC_AZ]

The MPPT and other equipment are grounded. The neg from the panels to the charge controller does NOT go to the ground on the trailer. After the controller, yes , but not before it. And before the controller is where these switches are installed. It isolates the controller and system so you can work on them if needed.
Here is a bit on the dyi solar group about it
https://diysolarforum.com/threads/so...uestion.42651/

Here is a good video explaining it all
https://youtu.be/HOXnWXvLXko

[Forester2]

I know you guys have changed out your controllers too, as have many pthers. My factory GoPower seem to work OK. What are the benifits to upgrading?

[Forester2]

Never mind: reread previous posts and now get the MPPT.

[DonBr]

Originally Posted by TomC_AZ

The neg from the panels to the charge controller does NOT go to the ground on the trailer.

The link is in reference to residential, NEC, which is very conservative. A house is not grounded. An RV has a chassis ground. From what I've read, most controllers designed for the 12V and 24V market have hard connections internally for the two negative poles. Victron says this, direct quote from their MPPT FAQ: "The MPPT is non isolated, meaning that the minus of the PV input is at the same potential as the minus of the battery output."

If in doubt, disconnect all wiring from the MPPT and measure resistance between the two grounds. Note: I have not done that, but I'm betting it will be 0, or as close to zero as a typical multimeter can measure.

[Forester2]

With the costs being so similar I think I will err on the side of safety and do the double pole disconnecting + & - .

[DonBr]

No argument about getting what you want. I just don't buy the "causing arcing" argument.

[Forester2]

Believe I've also read thing about not having solar going to controller when batteries are removed. Don't know if that's factual or not but if true, another good reason for a disconnect.

[Forester2]

Also see the Renogy 40 amp controller is only $111 on Amazon. Seems like a pretty inexpensive upgrade!

[DonBr]

Originally Posted by Forester2

Believe I've also read thing about not having solar going to controller when batteries are removed. Don't know if that's factual or not but if true, another good reason for a disconnect.

I've read that also, but it begs the question of why the controller has a display that tells you when the battery is disconnected! In this case, though, Tom at least is talking about a disconnect on the PV lines, which would leave the controller still connected to the batteries.

[Yooper906]

Originally Posted by Forester2

Believe I've also read thing about not having solar going to controller when batteries are removed. Don't know if that's factual or not but if true, another good reason for a disconnect.

It's factual alright. On a 2022 28.5 RSTS there is NO solar disconnect without digging into the wiring. Unplug from the 7 way, unplug from shore power, completely disconnect batteries and there is still solar voltage. Enough to use lighting, gas detectors and usb outlets. You can turn off the main circuit breaker by the battery box, batteries disconnected and makes no difference. Still solar power. Different situation, different story.

[TomC_AZ]

The RV is my home when I use it and thus will be very conservative especially when dealing with things that can burn it down. One exception is we do drive with the propane fridge on. A 12v might be in the future this coming 2023 season, we will see. Also I do have a separate battery disconnect that would totally cutoff from everything to isolate. This is actually secondary to the OE RV battery disconnect that is still installed and functional. (At least as functional as they made it)

Yooper - that solar behavior is why I upgraded everything solar wise. Allowed me to control what I wanted and when I wanted to. Most (not all) RV manufactures unfortunately build their systems like Jayco and do not add items like the PV switch.

[Forester2]

To Dons point, what think I read was power from the solar panels to controller could damage it. The disconnect location would solve that. Dont recall seeing anyrhing about batteries without panel damaging controller which kind of makes sense considering no power co?es from there every night.

[DonBr]

I don't know why controller makers say to not connect the solar unless the battery is connected, but it could be because in an install situation there would be no ground until the battery ground is connected. So far, everybody is finding their solar works with battery positive disconnected. The screenshots are 2 minutes apart, 10 minutes ago, first with battery connected, and second with battery positive disconnected (I have a full disconnect at the battery as Tom does). I could disconnect the negative, but that would remove ground from the controller, which I'm not interested in doing.

[Forester2]

Don, I think you have of Renogy controller I was just looking at.

What is the routeing for the 12v feed into the power center? The solar must get there before going to the battery??

[TomC_AZ]

Yeah I agree, and not sure why some say that. I have read a couple places that you should “start/boot” the controller off the battery first then enable the PV. But have not found any definitive about that from any source. Either way I set it up so I can turn both ends off fully if wanted/needed.

[DonBr]

Originally Posted by Forester2

Don, I think you have of Renogy controller I was just looking at.

What is the routeing for the 12v feed into the power center? The solar must get there before going to the battery??

Yes, same one. I bought as part of a package with 2 100W panels. I also added the BT-1 bluetooth module, since i would rarely see the display.

I don't believe the solar goes to the power center. On mine, the plus wire goes to the bus behind the water heater, and I removed that to put it into the controller. The power center also connects to that bus, so that is how they would be connected.