Solar panel DC breaker for DIN mounting

DIY
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1

Between the solar panels and the MPPT charger I want to put a DC breaker in between in case I need to do maintenance on the system. I found many breakers but I could find one that can be DIN mounted. Any suggestion for a 500V/16A DIN breaker? Thanks.

2

I found the following from brand Beny: PV DC schakelaar | LithiumAccus.nl

Any experiences with this product?

3

That brand is pretty good. Just make sure you get a non-polarised one. I have used FEEO they are green in colour and good quality. I don’t think Noark will have that voltage they only go to 450V. There are formulas to help select the size so you can break the DC arc. They end up around 1.6 x the isc. So if you have 10amps need at least a 16A if that makes sense.

4

Thanks for the quick feedback. Regarding the formula you are referring to. I’ve 2x 5 panels in one string, short circuit Amps 11.58 (open circuit voltage 41,78) per panel. I still want to add one extra panel in each string.

So a 16Amp/350V should be enough for the breaker, correct? Or do I need to multiply with 1.6? If so, for what reason?

5

Check if there are local regulations. You need a higher amp rating so the breaker can break the DC arc and extinguish it. 11.58A I would go for the 20A version. It is quite concerning when you flick that breaker and you can hear it crackle.

1 Like
6

Hello Rene,

You do not actually need a breaker, but a disconnect switch. Breakers on PV installations are only if you put more than two strings in parallel to stop the combined Isc of all strings combined backfeeding their energy into one string and frying that when a fault occurs.

I would recommend the Eaton P-SOL20, one for each of your strings. This one is not polarized. These are also prepared for an emergency shutdown with one of the add-on modules. I do expect rules like that to come in NL within 5 years.

7

Thanks for the feedback, appreciated. Indeed I was more talking about disconnect switch rather than a breaker, you are right. For now I’ve selected and purchased the Beny switches after talking to the company who also use them in their own PV installations. Lets see how the switches behave in the future :slight_smile: