PV Connection before or after master cut off switch

[ff6849]

In looking at most RV solar diagrams the PV system is wired after the master cut off. My question is why wouldn't you want before the Master cut off switch. I would think that you would want kill the 12volt system but maintain your solar for charging. What I am missing?

 

[Supervstech]

In looking at most RV solar diagrams the PV system is wired after the master cut off. My question is why wouldn't you want before the Master cut off switch. I would think that you would want kill the 12volt system but maintain your solar for charging. What I am missing?

Not sure exactly what you are describing, but most solar controllers require a battery connection before solar.

 

[ff6849]

Sorry for the confusion my question is the connection from the solar controller to the battery. Most diagrams have that connection made after master cut switch, so when the switch is closed there would be no charging vs before switch so your able to charge batteries while killing power to the 12 volt system. I am planning on have DC solar disconnect coming off PV before the controller if I need to kill all power to and from batteries.

 

[Charleswgibbs]

Assuming I understand the description correctly having no charge/discharge of the battery is the point of the switch, to isolate the battery from the rest of the system when switched off.

If you only have a means of disconnect between the pv and controller that will stop power coming in from the panels, but the rest of the system (inverter, DC dist, etc) would still be energized.

Usually there is both a pv disconnect and a master switch/battery disconnect

 

[ff6849]

Here is a drawing, of what I am asking, sorry for all the confusion, should have done this first.

 

[12VoltInstalls]

when the switch is closed there would be no charging

It would charge with a closed switch…

Most diagrams have that connection made after master cut switch,

because they saved a couple bucks.

The battery to loads should have a cutoff
The SCC to battery(s) should have its own cutoff/fuse
The panels should have their own disconnect, too

The SCC in pic 2 is on the wrong side of the fuse imho

I’d add a few DC breakers and be happy but the diagram works even if I don’t like it