Shunt trip for 20A branch CBs?

Dale001289

Senior Member
Location
Georgia
The client wants a shunt trip on all 20A molded case circuit breakers for panelboard. This seems very unusual to me - not sure what the typical application would be for this?
 
Thanks.
This is an industrial plant—waste water treatment—and I don’t see the need for rapid shutdown of any equipment here.
Since this is a very old plant and specification maybe it’s something they liked 70 years ago? But not very applicable today.
 
And what are they using to control these shunt trips? A separate control for every circuit breaker?
 
I am very rural and bout the only time I have seen them is connected to Ansul. One on the man would shut the coolers and the music off too.
 
The OP said, "The client wants a shunt trip on all 20A molded case circuit breakers for panelboard."

Only later did we find out that there are exceptions, so individual circuits, not all.

Just how many, and should they all trip for the same single cause, which is what?

We ask for these details so we can answer you as closely to the situation as we can.
 
Usually with the gas pumps and canopies, they have an auxiliary contact on the breaker to disconnect the neutral too.
I don't believe a E-stop operation would be required to open the grounded conductor. You could still have a "fuel panel" with shunt trip main or feeder breaker and still have switched neutral breakers on branch circuits where needed. I think many fuel control systems have input leads for an E-stop button and it just locks out the controls if stop is pushed and never shuts off any branch circuit breakers.
 
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