DC rated breaker to be used as a cut off switch

DIY
1

Looking for recommendations for a DC rated breaker to be placed between placed between two (2) 12V 200 Watt 9BB Monocrystalline Solar Panels, and a Victron SmartSolar Charge Controller MPPT 100|50. Wiring will probably be 10AWF from the panels to the charge controller, if the charge controller will accept it. It will be mounted on a wood panel.

2

ABB
Eaton
Kloeckner
Schneider
Siemens

All make 2p DC circuit breakers in good quality.

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3

I get all my DC breakers from Midnite Solar. For that position I used a double pole breaker. Pretty sure it was the MNEPV30-600-2PP.

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4

Thank you for your suggestions.

As an alternative: recommendations for a DC cutoff for the same as the above?

5

I use the Victron Energy Battery Switch for cutting off my system from the battery. A Class T fuse is between the switch and the battery.

6

Good for you, but here it’s about disconnecting both sides of a solar panel.

And, your victron battery switch doesn’t really have a good reputation here, also there seem to be some fakes on the market

7

I’m thinking about one of these:

https://www.midnitesolar.com/productPhoto.php?product_ID=216&productCat_ID=16&sortOrder=7&act=p

Possibly a 40A breaker on a 9AWG PV wire, as 2 200W solar panels will give me > 20A, but if I expand to 3 panels then it’s > 30A.

I’m a newbie, so am I am track here?

8

For solar its safer to take 2-pole breakers.

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9

Yes, I see.

10

Yes, use a dual pole breaker. The reason is that you want to break both legs at the same time in case there an issue with voltage from the PV showing up unexpectedly on one of the legs.

If you use more than two panels in parallel then you need to put a fuse between all three panels. Three panels in series does not require a fuse.

11

Thank you for your responses. My wire is carrying 21.54A so I decided to go with a MidNite Solar MNEPV30 breaker and #10 wire.

12

At what voltage? That is by far more important. Anything over 60V can. Or should I say WILL Arc and you certainly don’t want a cheap breaker for that.

A good double pole DC disconnect is one that offers arc protection and require some serious force to disconnect it. That’s because the springs in it will do its job. Fast.