Disconnecting Solar Panel Under Load

[Triton318]

I recently purchased a solar panel and solar charge controller. Although I won't be installing them for a couple of months, I wanted to make sure I understood everything correctly before attempting to do so.

On the negative cable on the panel, there is a tag that says to not connect or disconnect while under load. Does this mean while the panel is generating current (in the sun) or while there is something in the system that is turned on and drawing current?

I hope it's the latter, because I was planning to have two mounting poles, one each stern quarter, so I could move the panel when needed to avoid having shadows cast on the panel. (As I know that drastically reduces the efficiency of the panel.) I was hoping to be able to disconnect the panel's wire leads at one pole, move the panel, and plug the leads in at the other location.

Thanks.

[Nemo55]

Cover your panel with a dark cloth or plastic sheet to stop it generating, then make sure all your breakers fed by the panel and inverter are in the off position,then move the panel.

Originally Posted by Triton318

I recently purchased a solar panel and solar charge controller. Although I won't be installing them for a couple of months, I wanted to make sure I understood everything correctly before attempting to do so.

On the negative cable on the panel, there is a tag that says to not connect or disconnect while under load. Does this mean while the panel is generating current (in the sun) or while there is something in the system that is turned on and drawing current?

I hope it's the latter, because I was planning to have two mounting poles, one each stern quarter, so I could move the panel when needed to avoid having shadows cast on the panel. (As I know that drastically reduces the efficiency of the panel.) I was hoping to be able to disconnect the panel's wire leads at one pole, move the panel, and plug the leads in at the other location.

Thanks.

[donradcliffe]

This is the first time I've heard of such a warning--I would get in touch with the supplier and ask why, and avoid any panels which had such a restriction.

Solar cells are idiot proof--you can short them, you can connect them, disconnect them, load, no load--they don't care. The only reason for such a notice is if some designer put in electronic circuitry downstream which can't take the standard transients. Or maybe some idiot lawyer is worried about you getting zapped and falling off your roof...

[Nemo55]

The man could have a Pacemaker like me,, i definately would not want any stray DC current,or in case of explosive fumes aboard,,it just makes Logical sense to take precautions don't ya think???

Originally Posted by donradcliffe

This is the first time I've heard of such a warning--I would get in touch with the supplier and ask why, and avoid any panels which had such a restriction.

Solar cells are idiot proof--you can short them, you can connect them, disconnect them, load, no load--they don't care. The only reason for such a notice is if some designer put in electronic circuitry downstream which can't take the standard transients. Or maybe some idiot lawyer is worried about you getting zapped and falling off your roof...

[Sailmonkey]

Originally Posted by donradcliffe

Or maybe some idiot lawyer is worried about you getting zapped and falling off your roof...

Bingo!! I've seen this label on a handful of newer panels, Nothing internal is different from older panels, same diodes etc.......it's the exposed pin on the mc4 connectors that cause this label to exist.

[Sailmonkey]

Originally Posted by Triton318

I hope it's the latter, because I was planning to have two mounting poles, one each stern quarter, so I could move the panel when needed to avoid having shadows cast on the panel. (As I know that drastically reduces the efficiency of the panel.) I was hoping to be able to disconnect the panel's wire leads at one pole, move the panel, and plug the leads in at the other location.

Thanks.

I think if it was me I'd just use a longer cable that you don't have to disconnect, the connectors are not what I'd call "easy" to disconnect.

[JonathanSail]

You shouldn't have trouble disconnecting the panel upstream of the controller but just in case I'll point out that disconnecting the controller from the battery with the panel charging can fry some controllers. You'll want to mount the controller close to the batteries so I doubt this would be a risk with the setup you have in mind anyway.

I also agree that I'd try to set it up in a way where it doesn't have to be unplugged at all, for a number of reasons. The plugs will be less vulnerable to corrosion/issues if you can seal them up and leave them. You won't need the extra wiring to each side, etc. etc.

Jonathan

[sularis]

Aside from possible electrical shock, one major concern is the arc created at connector contact. Arc can cause "damage" to the contact surface, resulting higher resistance.

[Singleprop]

Some controllers have a warning that says: do not disconnect battery while charging......so the input cables has to be opened instead...

[newhaul]

The reason for the warning is to protect the manufacturer from lawsuit if you get a shock from the panels when not hooked up however as stated don't in hook the battery from the controer with the panels still powering the controller it will fry the controller

[MarkJ]

I have heard such warnings and I believe them to the extent that we need to invent a thing called

A switch.


It works on every other bit of electical kit known to man. It disconnects the wires. Click. So what is the difference between disconnecting a solar panel and a switch? None.

[newhaul]

Originally Posted by MarkJ

I have heard such warnings and I believe them to the extent that we need to invent a thing called

A switch.


It works on every other bit of electical kit known to man. It disconnects the wires. Click. So what is the difference between disconnecting a solar panel and a switch? None.

Technically three extra connections to corrode and or fail and it won't accomplish what the op wants o do

[Opie91]

Originally Posted by newhaul

Technically three extra connections to corrode and or fail and it won't accomplish what the op wants o do

With that attitude you might as well stay home...

A switch will accomplish what the op is trying to do. He said "under load". If it is not connected to a load (via open switch) than its not under a load.

[Singleprop]

Originally Posted by JonathanSail

You shouldn't have trouble disconnecting the panel upstream of the controller but just in case I'll point out that disconnecting the controller from the battery with the panel charging can fry some controllers. You'll want to mount the controller close to the batteries so I doubt this would be a risk with the setup you have in mind anyway.

Jonathan

The sticker on my controller states exactly that: do not disconnect controller from batteries while under load....

[newhaul]

Originally Posted by Opie91

With that attitude you might as well stay home...

A switch will accomplish what the op is trying to do. He said "under load". If it is not connected to a load (via open switch) than its not under a load.

Yes the lines would still be under load from the power the panel is producing. As I stated before and the controller manufacturers say don't disconnect the battery from the controller when the panels are producing power to the controller id: the controller is under load disconnect the panels first just don't cross the panel wires you will get a shock out of life