Input Circuit Breaker

If you could determine FLA (full load amperage) of the robot controller from Fanuc, then take this information to one of your vendors for breakers, they will size the correct breaker for you. I'm unsure if there is a specific type of breaker, I would assume anything safety rated for robot application will do. Biggest thing will be to find breaker that can withstand 1.25x the FLA of the robot controller. I believe this is the correct # for USA standards, not sure of other countries.

For example, lets say your controller pulls 40 amps on full load, so you will need breaker than can withstand 40 x 1.25 or 50 amps.

In my company, we don't have breakers, just the default on/off rotating switch that comes with the controller on the front of it.

If the incoming power is fused then you shouldn't need a breaker.

He may be adding a breaker for 70E purposes? Even though the switch may be off, there's still 480 on the top side of the switch. Putting a breaker outside the robot controller would eliminate any voltage inside the controller if anyone wanted to work on it, perhaps?

Could just use a fused disconnect in that case.