Fitting a Switch For Solar Panels

[Dougal]

I'd like to fit an isolation switch in the solar charging circuit, but don't know where to place it... There's one panel and a 'dual' charge controller for the two separate banks. If the switch has to be downstream of the regulator, then I guess it needs two?

Is it ok to put in a simple single switch between panel and controller?

 

[longjohnsilver]

Hi Phil, can't see any problem in turning off the power from the panel, that's what I'd do.
PS hope you're both keeping well, John and Debs (& Buster and Pip) off mobo Eos.

 

[xeitosaphil]

I would have thought that if you put a duble pole switch between the panel and the controller that would be fine as the panel would think it was open circuit. I think it depends on how big your panel is?
Mine is a 100w panel but the controller is a Morningstar Prostar 15 which has the facility to turn the panel of with a switch anyway, it does have a heat sink though to get rid of any charge generated. I think if the panel is small enough there should be no problems with it.

Others may think differently?

 

[Dougal]

Hello guys! There's a coincidence... we were only talking about you yesterday. We're good. Hope you are all good too.

Hi Phil, can't see any problem in turning off the power from the panel, that's what I'd do.
PS hope you're both keeping well, John and Debs (& Buster and Pip) off mobo Eos.

 

[JumbleDuck]

I'd like to fit an isolation switch in the solar charging circuit, but don't know where to place it...

Why, as a matter of interest?

Is it ok to put in a simple single switch between panel and controller?

Yup.

 

[Dougal]

Mostly because I like to be able to isolate each of the four separate charging sources. Also, so I can stop ALL charging whenever I need to, enabling me to get at least a semi accurate reading on the voltmeter. Is that ok for you;-)))

Why, as a matter of interest?



Yup.

 

[SiteSurfer]

On the instructions on my little solar panel it says that you shouldnt disconnect the solar panel with load on it (in the sunlight/daylight I guess) - wouldnt the switch removing it from the circuit cause damage to the panel or is the damage very very negligble?

 

[William_H]

I can't imagine any way that disconecting a load on a working solar panel will damage the panel. Unless there was a highly inductive load causing large back EMF which might cause switch to arc when switched off.
If OP only wants to stop charge perhaps an old blanket would do to throw over the panel. A switch in the panel wiring would do the job. However for leaving off long term the controllers may soak some power from batteries (check) so making it desirable to disconnect from battery side 2 lines.
good luck olewill

 

[JumbleDuck]

Mostly because I like to be able to isolate each of the four separate charging sources. Also, so I can stop ALL charging whenever I need to, enabling me to get at least a semi accurate reading on the voltmeter. Is that ok for you;-)))

Sure, just wondered.

 

[aquaplane]

Just picking up on the "get a semi accurate reading on the voltmeter".
Another boater always used a hydrometer to test state of charge.
I have always used a voltmeter but since the sun gets up before me the battery has usually gone from a long overnight rest to being charged by the panel.
How accurate is a hydrometer? Will it give a better guestimate of % charge than a voltmeter when there is +ve or -ve load?

 

[homer]

Make sure you put the switch between the panels and the regulator (assuming you have one). If you disconnect the regulator from the battery, but leave the panels connected, you could blow the regulator. Some have over-voltage protection, some don't. (Learned the hard way!)

 

[rogerthebodger]

If you disconnect the regulator from the battery, but leave the panels connected, you could blow the regulator. Some have over-voltage protection, some don't. (Learned the hard way!)

That is surprising as you should have a fuse between the battery and the regulator, as close to the battery as possible, to protect the cables. If the fuse should blow of cause it will disconnect the regulator from the battery.

I have circuit breakers between the battery and solar regulators and my main bank of solar panels have my main isolator switch between the battery and regulators.

Even in the African sun I have had no problems.

If your regulator failed due to the open circuit voltage, IMHO your regulator is not fit for purpose.