Combiner box...

[Sunking]

Actually Most/all? din rail DC Breakers are polarized (magnetic) and need to be setup with the + toward the greatest potential. I believe the NEC is moving to make these no longer acceptable, likely, like the dead front combiners boxes, when they become available... https://www.youtube.com/watch?featur...&v=Mtq3cs9GuccI'll agree with this if you include the solar panel as part of the 'wiring' I think it's confusing to people to say the breaker is there to protect the wiring, I've had arrays set up with 10 gauge wire where the combined strings didn't total 30amps the capacity of 10 gauge, but require a 15 amp breaker to not over load the 'wire' in the panel it's self.

Magnetic breakers are one of many types available for DC. They are not the only type. Code makes no requirement for Magnetic to be used. NEC does Permit as of now polarity sensitive devices may be used, but is not required.

What is important for everyone to understand is this code requirement?

690.9 Overcurrent Protection


(A) Circuits and Equipment. Photovoltaic source circuit,
photovoltaic output circuit, inverter output circuit, and storage
battery circuit conductors and equipment shall be protected
in accordance with the requirements of Article 240.
Circuits connected to more than one electrical source shall
have overcurrent devices located so as to provide overcurrent
protection from all sources.

So with that said a single string OCPD must be able to protect the panels from even the batteries in the event your controller fails shorted input to output. That is the bottom line and what the pros know. So does the Inspector.

No problem using a #6 AWG conductor on a 20 amp breaker, but a violation to use a 20 amp breaker with 14AWG connected somewhere along the path. Breakers or any over current devices only job is to protect the wiring unless otherwise noted in the code, nothing else. Anything else is just a beneficiary.

[photowhit]

Their only job is to protect the wire, and nothing moreWhat is important for everyone to understand is this code requirement?

.... Breakers or any over current devices only job is to protect the wiring unless otherwise noted in the code, nothing else. Anything else is just a beneficiary.

Okay, a little better, would still be confusing to a beginner, who many of the people here are...

.... Magnetic breakers are one of many types available for DC. They are not the only type. Code makes no requirement for Magnetic to be used. NEC does Permit as of now polarity sensitive devices may be used, but is not required.

Most combiner boxes using breakers use din rail breakers, the reason for the explanation of polarized breakers. vs your statement that;

The breakers are not there to keep current from flowing, and they do not care what direction the current is flowing

We are in the 'off grid' section, doubt many are using anything but, din rail breakers.

[Sunking]

Most combiner boxes using breakers use din rail breakers, the reason for the explanation of polarized breakers. vs your statement that;



We are in the 'off grid' section, doubt many are using anything but, din rail breakers.

I don't use them or know of many pros that do use them. We use Eaton DC Thermal/Magnetic Breakers Poin tis it does not matyter if they are DIN or not as it has nothing to do with what size or type is used.

[photowhit]

I don't use them or know of many pros that do use them. We use Eaton DC Thermal/Magnetic Breakers Poin tis it does not matyter if they are DIN or not as it has nothing to do with what size or type is used.

You still miss the points...

This is what will likely be used by the majority of the people reading this post, hence my correction. I have no desire other than to make it clear that they do have a current direction, something you told them they don't have.

It's kinda' like being in a room with a 'window shaker' running off a minimal off grid system and being told it doesn't work, or that 'net metering' doesn't exist when it's law of the land, or that solar is only 90% reliable... sometimes I wish you would try... I have a long memory, and tend to provide links...

FWIW-My minimal cabin system kept me cool for 4 years, total of 5 years life, out of my 4 golf cart batteries, I lived it, don't tell me I didn't, or that it's not possible...

[inetdog]

... I lived it, don't tell me I didn't, or that it's not possible...

I think that you are just a clever computer simulation, so there.