Break Pos or Neg on Solar Panel wire to controller

[OrangeCrush]

I am installing solar right now and based on what seemed like good advice in another thread I am putting a Bluesea Series 285 breaker (which is also a switch) on the positive lead between the battery bank and solar controllers. (3 controllers on one 25amp breaker). I didn't do this for lightning protection as much as in the unlikely event of a short in the solar controller, that it wouldn't also short the battery and start a fire.

[rom]

Originally Posted by OrangeCrush

I am installing solar right now and based on what seemed like good advice in another thread I am putting a Bluesea Series 285 breaker (which is also a switch) on the positive lead between the battery bank and solar controllers. (3 controllers on one 25amp breaker). I didn't do this for lightning protection as much as in the unlikely event of a short in the solar controller, that it wouldn't also short the battery and start a fire.

And you are right to do so, however this thread is about the switch that shall be installed between the panels and the controller, not between the controller and the battery.

[john61ct]

https://www.bluesea.com/products/cat...ttery_Switches

Plain ON-OFF version, sized for the max total Amps.

[rom]

Originally Posted by john61ct

https://www.bluesea.com/products/cat...ttery_Switches

Plain ON-OFF version, sized for the max total Amps.

John, this is totally overkill as there are usually only very few amps (but often higher voltages) at the ouput of the panels. You might install those high amps switches between the controller and the batts though, maybe that is what you meant.

Oh, and I just realized that the OP has already purchased the bluesea breaker 285. jbinbi, you might install it in between the controler & the batt as OrangeCrush and a few other are doing. After making sure the specs are fine of course.

[OrangeCrush]

Originally Posted by rom

And you are right to do so, however this thread is about the switch that shall be installed between the panels and the controller, not between the controller and the battery.

Fair enough, I should read things a bit more carefully before I post. My panels all came with MC4 connectors. When I (infrequently) need to disconnect them, I plan on first turning off the breaker between controllers and battery, then throwing something over the panels to darken them before disconnecting the MC4s. Not sure if this is ideal but I'd rather replace a MC4 connector or two down the line than buy three more switches right now.

[jcapo]

I have toggle switches in the solar plus side. No issues after shutting off solar input hundreds of times is 6 years.

OrangeCrush: Check your manual re: solar connected with no battery connection. My Morningstar MPPT controllers don't like that case at all.

[rom]

Originally Posted by OrangeCrush

Fair enough, I should read things a bit more carefully before I post. My panels all came with MC4 connectors. When I (infrequently) need to disconnect them, I plan on first turning off the breaker between controllers and battery, then throwing something over the panels to darken them before disconnecting the MC4s. Not sure if this is ideal but I'd rather replace a MC4 connector or two down the line than buy three more switches right now.

I think it is common practice to disconnect the panels first, and then to disconnect the controller from the batts.
As for MC4 disconnect, well, I like the ease & security of dedicated switch and it is not a very expensive item.

[OrangeCrush]

Originally Posted by jcapo

OrangeCrush: Check your manual re: solar connected with no battery connection. My Morningstar MPPT controllers don't like that case at all.

Thanks for the heads up, but I think I'm good on that issue. As per my Genasun GV-10 manual: While connecting the battery first will not damage the GV-10, we recommend connecting the panel first. This eliminates the risk of shortcircuiting the panel while the GV-10 is operating, which can cause damage.

[thinwater]

Originally Posted by smac999

Your best option is to cover the panels. Or work at night... I don't think you want to break that connection from panel to controller while they are producing.

^^ This. What could be simpler? It's typically right in the instructions. I either throw a heavy towel or flip them over, depending on what I'm doing. Why add more bits?

[DotDun]

Originally Posted by thinwater

^^ This. What could be simpler? It's typically right in the instructions. I either throw a heavy towel or flip them over, depending on what I'm doing. Why add more bits?

Depends on where and how big your panels are. I don't have a 50sq.ft. towel and not about to climb the arch to get to the panels.

[john61ct]

Originally Posted by rom

John, this is totally overkill as there are usually only very few amps (but often higher voltages) at the ouput of the panels.

Sure, but for those with higher amps, they're very solid, basically failsafe, last forever.

I would appreciate specific recommendations for switches at a similar level of quality designed for DC at the smaller amperages.

[jbinbi]

For what I am trying to do, which is just to break the line from the panel to the controller, I have actually thought of just using a standard light switch from HD. I need to use this switch maybe a few x a year. I bet this would work fine for $0.99. I know it's not marine rated etc., but this is inside under the berth out of the way.

[PacificGreen]

Did some posts here get removed dealing with spst switch for lsc testing breaking positive? There was even a picture accompanying the post.

[rom]

Originally Posted by john61ct

Sure, but for those with higher amps, they're very solid, basically failsafe, last forever.

I would appreciate specific recommendations for switches at a similar level of quality designed for DC at the smaller amperages.

I am no expert but I would certainly install on my own boat the DC switch that DotDun showed in a previous post..

To jbinbi: I would not install anything that is not clearly rated for this application. But then again, I am no expert, this is your call.

[Teknishn]

Originally Posted by jbinbi

Then an electrical person at the yard said to break the NEG? I know about electron flow etc., but doesn't it make more sense to break the POS in this case.

Breaking the NEG lead is a good idea...when removing leads from batteries. On a battery, your NEG wiring will most likely be common throughout the boat. If removing the POS lead first and an accidental short to ground (i.e. NEG) occurs, then you could possibly damage other systems/equipment.

For solar panels: First, only use breakers and/or switches rated for DC usage at the appropriate rating (as mentioned previously, or for any DC system). My preference for which side to break? Both....a complete disconnect. Going on 40 years now working with electricity, 38 of those in the marine environment. Best advice is to completely disconnect everything when and where possible prior to working on a circuit. This is for both yours, and the equipment/system's sake.

Concerning which breakers or switches to install? Won't give advice on that. Previous posts have pretty much got that covered. Good Luck!