Blocking Diodes between Series String before combiner box.

[johngalt]

To be absolutely safe I suppose I could put a DC breaker between the PV string and the knife switch.

In order to divert the power in the other direction I could turn the breaker OFF, throw the switch, and then turn the breaker back ON.

I have a few extra 30 amp / 150 volt DC breakers available. The knife switch was to be a convenience item to eliminate having to plug / unplug or rewire anything when I want to divert the string from one CC to the other.

[Naptown]

If you install the switch after the combiner box then you could turn off the breakers in the combiner. Or just wait till dark to throw the switch. Still using an AC switch for a DC load is not advisable.

[johngalt]

I now understand the danger.

Thanks all for your input.

Good video if anybody needs a visual.

[inetdog]

Good video if anybody needs a visual.

Thanks for finding a great link. I would like to see that in a sticky thread somewhere!