Rapid shutdown switch question

Hedges said:

For GT PV, simply opening AC connection with safety switch triggers RSD.

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What would be the difference then between an AC Isolator and a Rapid Shutdown Switch? Or are they the same thing?

That switch provides isolation and can be locked off for work on the circuit. I see rated for 690V or 1000V circuits, up to 125A, don't see a rating for stand-off or test voltage.

Rapid shutdown switch may be for small signal current telling other electronics what to do. Might be a mushroom pushbutton. I think it is more what the switch goes to than type of switch.

I understand "Isolator" to be something like 1" gap between contacts, safely isolating grid from wires humans are going to touch (or isolating grid lineman will work on from your generator/inverter.)

A break is an isolator. A supplemental protector (looks a lot like a breaker) is not.

Utility may require a visible blade disconnect, not just an isolator like a breaker.

The issue for us is how to trigger RSD for rooftop PV panels, disable AC from our inverter, and isolate our system from the grid. I plan to accomplish all with the knife switch, making use of a 3rd contact (3rd knife blade or handle position microswitch.)

Hedges said:

Utility may require a visible blade disconnect, not just an isolator like a breaker.

The issue for us is how to trigger RSD for rooftop PV panels, disable AC from our inverter, and isolate our system from the grid. I plan to accomplish all with the knife switch, making use of a 3rd contact (3rd knife blade or handle position microswitch.)

Click to expand...

Like something like this correct? https://www.eaton.com/us/en-us/skuPage.DG222NRB.html My plans are to have M215 MI. My understanding is that turning the AC off would then start the Rapid shutdown process. I have the isolator on my pergola structure as the additional gap for when work needs to be done.

That one is 2 pole. Good enough for GT PV, it isolates from grid and because power goes away, inverters with RSD function turn off the keep-alive.

If you had a hybrid with battery that continued to operate when grid went down, it couldn't distinguish grid failure from switch being pulled. For that, I would use a 3-pole switch, or add accessory handle position microswitch.

My existing system has 100A 2-pole switch, so I bought the add-on to support RSD if I put additional panels on the roof.
New place I've mounted a 3-pole.