Overcurrent protection

[adobejoe]

With the newer all-in-one inverters they can often take high voltage of up near 600 volt. Typically Pv breakers may be sized at 20 or 30 amp.  The MS breakers are rated for 150 volt, or you can stack two for 300 volt.  It might be questionable whether breakers are necessary here? What to use

Curious.

[tanner0441]

Hi

DC breakers are rated for a specific voltage because unlike AC there is no zero voltage point to suppress the posibility of arcing. Cascading two switches still means the switched gap will not be any greater.

Any breaker used on DC needs to be DC rated for the voltage specified. There are examples on YouTube of solar switch gear failures,

Brian

[XeonPony]

As tanner said,  ideally you want a rated voltage higher then system nominal other wise it arcs till it is converted to magic smoke.

[tanner0441]

Hi

Yes I had a breaker that looked like an MCB suposedly Solar rated. then I saw a video on YouTube of a sytem in Australia where the guy tried to switch under load, It was done as a test but within 5 seconds of switching off the switch was on fire.

So I bought a switch with a rotory action rated at 800V at 45A although I only have just over 2Kw of solar which off load produces a little over 200V.

Brian

[XeonPony]

https://www.youtube.com/watch?v=B-xInEewI_U

https://www.youtube.com/watch?v=PRT6lv8RKvA

https://www.youtube.com/watch?v=EJC6wKir_Lo