edweather
New Member
At most I'll have three 365W panels in series. The lsc of each panel is 11.07A. Do I need a breaker between the panels and the inverter, and if so, could you please recommend one if possible. Thanks.
Do I need a breaker between solar panels and AIO inverter?
- Thread starter edweather
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littleharbor2
Solar Addict
While not required if you series wire the 3 panels, it is desirable to have a breaker for system maintenance and shut down/startup . Be sure it is a DC rated breaker and also rated for switching under load. Midnite Solar make this type of breaker.
PreppenWolf
Solar Addict
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- Oct 10, 2022
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My system is fused for overcurrent protection and breakered (in my combiner box), and I have a PV disconnect inside next to the AIO. So I can isolate panels from inside or outside the house.
edweather
New Member
littleharbor2
Solar Addict
Those baby boxes are pretty pricey for what they are. If you can get some DIN Rail you can get creative and avoid needing the box.
littleharbor2
Solar Addict
I have added Din Rail to these Square D boxes for those type of breakers.
edweather
New Member
Would a piece of this work? Or this box, it has a piece if DIN rail in it. The box is only like $7.
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littleharbor2
Solar Addict
That's the Din rail. You can simply screw it to the wall alongside the inverter. Kind of rough looking application but it will work to hold the breaker but not the most substantial support.
Certainly a solar panel DC disconnect switch is needed in my opinion.
IMO DC Disconnect Rooftop Isolator Switch
IEC 60364-7-712, dc disconnect, imo, ul listed, DC AC, DC DISC
signaturesolar.com
An ANL fuse on the positive is also a good idea.
A little more pricey, but gets the job done well. I like the combination of the switch and fuse vs breaker.
Noooo... that ANL fuse is only rated at 32V ????
It's for low voltage battery to inverter not PV to inverter.
Good catch. Need to research further.
SignatureSolarJames
Try Solar, the Grid will always take you back
you do not, the breaker is no good for solar, you would need breakers if you had 3 or more strings combined in parallel
@edweather
Looks like this fuse is the way to go if one is desired between the solar panels and solar charge controller.
Combine it with the solar disconnect switch which is needed IMO.
IMO DC Disconnect Rooftop Isolator Switch
IEC 60364-7-712, dc disconnect, imo, ul listed, DC AC, DC DISC
signaturesolar.com
Some say the fuse is optional in your configuration for various reasons, but with my electrical - electronic background when wiring any electrical circuit a fuse is used. It certainly will not hurt. Just need to make sure it is properly rated.
littleharbor2
Solar Addict
This is because a solar panel, or string of panels will not ever put out more current than it is rated at. Even two panels, or strings in parallel won't put out enough current to damage the wiring. Only when you get three panels or strings in parallel will you get more current than the wiring is rated to handle. This is code. Therefore, a disconnect, switch, CB or whatever is purely for convenience.
HalfBaked
Ever the student
Any suggestions for a 60a version?
If looking for 60 amp the MidNite Solar 60 amp breaker with the MidNite MNBabybox would be the way to go. @littleharbor2 pointed this out in a previous post.
Something like this
IMO DC Isolator 16A 2 Pole 800V (Single String)
The voltage matters for a DC switch, not just the amperage. Very useful to be able to switch the solar off, you can't turn off the sun.:
littleharbor2
Solar Addict
Midnite Solar has a 300 Vdc version also.
]https://www.solar-electric.com/midnite-solar-mnepv30-300-1pp-breaker.html
edweather
New Member
We've almost come full circle. This is the one I originally looked at. According to my math, this would be the correct breaker.
https://www.amazon.com/MidNite-Solar-Photovoltaic-Circuit-Breaker/dp/B004EQK8SA
That 30A breaker looks nice, but do I need it? If it would help, I just as soon get that one.
littleharbor2
Solar Addict
What is your anticipated Voc and current coming into this breaker? I'm showing a 300 Vdc breaker and you, a 150 Vdc breaker.
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