Solar load isolation / disconnect question.

[SoMoney]

Hi everyone I just finished my 1st DIY solar project and installed a 50W Battery maintainer Solar System on the the roof (wiring down the refer vent) of my 350DS (more pictures to come).

The MPPT Charge controller I purchased also has a 12VDC/10Amp load pass through so I connected it to the fridge 12VDC. As you can see in this diagram the +Load lines also inadvertantly send 12VDC back through the entire coach bypassing my battery disconnect.

Ideally, I would like the option to keep the fridge running but not sure if thats even possible (I believe the propane tank needs 12VDC to keep the line open).

Question: I need a way to "Remotely" disconnect the 10A Load line when I'm in storage as not to risk battery drain.

[Buzzard616]

The setup shown in your post should work fairly well. These controllers are designed to run a load on solar all day and battery at night. They will, however shut off before the battery gets too low so your fridge might shut off before dawn and come back on once the sun hits the panel. You might even replace the cutoff switch with an appropriate size diode so you don't have to remember to flip the switch.

Stu

[SoMoney]

Unfortunately these Chinese solar controllers lack technical support. I'm confident the MPPT controller will stop charging the battery when full, but I'm not convinced that it will "shut off" the load lines to the coach at all.

But I'm not sure if adding a Diode behind the fridge will be of much use. Doesn't the disconnect switch also turn off the propane? There are two wires going to some type of relay on the inlet hose of the propane tank and it gets hot when the house is on.

[Fire Instructor]

What I wa told was that most of the disconnect switches on the market aren't designed to be thrown when under high load (unless you buy an expensive switch designed for that). So what I have is covers that I keep in my garage. The panels are made of styrofoam insulation panels, and have a wood rim that fits over the panel edges. If I'm going to be working on ths system, or if I want to kill panel output while at peak outputs, I toss the lightweight covers over the panels.

I use these panels during winter storage, to protect the panels from any damage, as well.... They are held in-place with a single ratchet strap around the panel and the cover.

[SoMoney]

Since this Charging/Load Controller has an LED display it also allows me to see that the coach pulls 1.75AMPS with everything off. I Assume its from
1. Propane detector in cabin.
2. Propane Solenoid (12VDC Shutoff) on tank itself (gets hot so Biggest draw I bet).
3. Misc power indicator LED's on devices in standby mode. (DVD player, Water/Sewage level panel, power indecator on disconnect switch, etc.)

With all my lights on (mostly LED), Overhead DVD PLayer, I doubt the coach will draw more than 5AMPS.

I saw one of these Wireless 12VDC Relays on ebay:
Universal 12V DC on Off Remote Control Wireless 12V Output Relay Switch RM100 | eBay
Can I use one of these you think?

[SoMoney]

More photos of the Controller installed behind the refer & the inside volt meter showing great voltage at 13.2v.

[RPAspey]

that remote switch is only rated at 8 amps. I don't think I'd use it.

[SoMoney]

I dont know why I didnt think of this earler. With mostly LED lighting through the coach I doubt I'll ever exceed 5amps. I think the prudent issue here is inserting a 5-8amp fuse with physical 12V/15amp SPST Switch instead (see image).

I'll save the wireless option for some undercarriage/front porch lighting.