Is there any advantage to having a fuse/breaker between solar panels and solar charge controllers?

[carboncontext]

Is there any advantage to having a fuse/breaker between solar panels and solar charge controllers?

From my understanding, a malfunctioning panel will only produce less current than its closed circuit current and so there should be no need for a fuse/breaker to protect the components.

 

[Texas-Mark]

If for no other reason, you would want a disconnect for the panels to the CC. Might as well use a breaker.

 

[Alphacarina]

I wouldn't want to be without one. Anytime you need to work on the system, it's really handy to have a quick and easy way to shut the system down and since you cannot remove DC power from the SCC while it's connected to the panels without damaging it, step one is always to disconnect the solar input. There are other ways to do it, but flipping a breaker is just do handy

Don

 

[nicorellius]

I use XT60 or XT90 connectors to easily disconnect solar. Install a tail from the charge controller and then the panels can be plugged/unplugged rather easily. I've heard of people using MC4 tails for the same purpose.

 

[boondox]

I use XT60 or XT90 connectors to easily disconnect solar. Install a tail from the charge controller and then the panels can be plugged/unplugged rather easily. I've heard of people using MC4 tails for the same purpose.

Wait 'til you pull a fat arc that way one day. If the system is under load and the voltage of your string is high enough you'll wish you were wearing Depends. A long time ago when I used fuses that would happen and I hated it. You can also damage connectors that way.

 

[nicorellius]

Wait 'til you pull a fat arc that way one day. If the system is under load and the voltage of your string is high enough you'll wish you were wearing Depends. A long time ago when I used fuses that would happen and I hated it. You can also damage connectors that way.

Ha! Very good imagery ;-)

That's a very good point. I'm very new to this so I am in no way an expert. I saw Will Prowse use XT60s on a small system he built in one of his videos. My system is rather small, so I thought it was a good idea (plus I had lots of these in my RC gear). And thus far, I've restricted when I disconnect to when the sun was low or down, so PV input was minimal. That said, I'll seriously consider a breaker for the future, especially if I expand my system or build larger ones. I don't want to add Depends to my solar toolbox...

 

[OffGridInTheCity]

I have a breaker box right near my controllers. The panel combiner boxes near the PV arrays are 100ft+ away.
I use these breakers to turn off the incoming PV array power instead of the tedious walk out to 2 different array locations when I want to work on things. Also, the ease of having them right in the solar control area promotes safety because I avoid temptation to do 'live' work instead of doing the long walks.

 

[HOU_Castle]

Ha! Very good imagery ;-)

That's a very good point. I'm very new to this so I am in no way an expert. I saw Will Prowse use XT60s on a small system he built in one of his videos. My system is rather small, so I thought it was a good idea (plus I had lots of these in my RC gear). And thus far, I've restricted when I disconnect to when the sun was low or down, so PV input was minimal. That said, I'll seriously consider a breaker for the future, especially if I expand my system or build larger ones. I don't want to add Depends to my solar toolbox...

For an additional safety, you also need to cover the PV panel with tarp or blanket (small system) when plan to disconnect MC4 at the panel.

 

[boondox]

For an additional safety, you also need to cover the PV panel with tarp or blanket (small system) when plan to disconnect MC4 at the panel.

For my array I would need to get out the extension ladder to get to the top to tarp. That is also a possible accident. For me I shut down the AC side of the system so that there are no loads. Then flip the panel breakers. Then disconnect panels. Honestly I have never needed to disconnect the panels, in the 10 years this system has been up there has been no need. (knocks on wood!)

 

[nicorellius]

If for no other reason, you would want a disconnect for the panels to the CC. Might as well use a breaker.

What do people recommend for a DC cutoff/breaker? There seems to be plenty of options, with a variety of prices. My solar array is about 100 V, 16 A.

@OffGridInTheCity I recall your reply here. I've been considering this setup but might want something simpler to start.

What do people recommend for a DC cutoff/breaker? There seems to be plenty of options, with a variety of prices.

 

[mrzed001]

What do people recommend for a DC cutoff/breaker? There seems to be plenty of options, with a variety of prices. My solar array is about 100 V, 16 A. Is there an affordable option for this that anyone might recommend? Something simple to start would be preferable.

I think Andy's solution is what I would suggest:

 

[time2roll]

Yes a switch for service is convenient. Especially for higher voltage. Make sure the switch is rated for DC at the proper voltage. Breaker is an expensive switch.
If the solar voltage is nominal 24v or less maybe just skip it and pull a wire off for service.

 

[boondox]

Voltage is as always only one part of the equation. Even at 24 volts if you have enough amps you will pull an arc. Trouble with switches is that while they may be rated for the voltage and current it is often unknown what current level they will break without arcing. And if you ever need to shut down in a hurry you won't know if you will break the current or not. And it is not only electrical issues that can cause a need for a rapid shut down.

Myself, I don't go cheap on gear like that. I like the Midnite breakers.