Originally Posted by P-J
Please keep in mind that fuses and circuit breakers are placed to protect the wiring. I place that fuse in the circuit for that exact purpose - to protect the wiring. It allows you to run a relatively small wiring set to the E-Stop switch and a low surrent switch as well. If you are not comfortable with that, do it your way.
Are we worried about protecting the wire when our brewery is melting down around us? I do not believe that a fuse belongs in a critical circuit. You seem knowledgeable. Have you ever wired a fire pump? Protecting the wire is the last concern.
As far as "design the circuit to be capable ..." - that already exists within the GFCI breaker. One only needs to walk to the power panel and press the test button when an emergency presents itself. Hey, it could be a long walk, but, what the heck.
So a GFCI will never fail? It will never require more than a millisecond to trip? What if it takes just a fraction of a second longer to trip than the resistors take to burn up? Why build in a fail?
Let's say we put 4 1k 1W resistors in series. 30mA fault current should be plenty. You can hold the button all day and not fry the resistors.
Here's a scenario you may not have thought of...say your a safe brewer and you test your GFI before each brew session. This time it doesn't work. Now replace the breaker and the resistors you just fried.
I dunno, makes sense to me.
Edit...sorry I typed in the middle of your quote...stupid phones...