General dumper wiring question

[Mick-the-fitter]

Or you could use a bit of wire that looked the same thickness

Just don’t hold it!

 

[Shovelhands]

You sound like you know your onions.
I was I told switch gear/ isolators on DC circuits (pv) needs to be rated at twice the amp rating.
Why's that?

DC current will weld the contacts together of undersized switchgear.

 

[Gecko]

I was I told switch gear/ isolators on DC circuits (pv) needs to be rated at twice the amp rating.
Why's that?

As above, but it's because (at 50Hz), the current has a zero volt crossing 100 times a second. This extinguishes the arc as the contacts start to open.
DC contacts must open much wider before the arc collapses. This leads to much hotter contacts and faster erosion.

 

[Russell]

That makes sense, thanks