Keeping the main breaker from tripping

[Aren_Hill]

Originally Posted by Cory

Generally breakers have 2 methods of protection. If you have a slow increase of current until you get to a continuous amount that will trip the breaker, the trip occurs via a piece of metal bending as it heats up until it no longer makes contact with the circuit.

If you were to have a short you'd see a huge sudden surge of current, which would cause a solenoid to pull the contacts apart.

I assume the one we use features both methods, but I've never looked inside one before.

The internal construction is actually a spring steel plate slightly warped to naturally press against a contact point. The off button springs this up (the plate bending is the resistance you feel), and lets the lever you flip to close the breaker swing between the plate and its contact.

So its performance is entirely thermal, warm that plate up and it will trip, do it fast or slow, doesn't matter, hit a certain temp and it pops (buckles) and when it buckles the "on" lever isolates the plate and its contact, leaving your robot off.

(Opened one up a few weeks ago to satisfy my curiosity...)

-Aren