Are Circuit Breakers Interchangeable

Different types of circuit breakers and how to lock them out two breakers in one slot Yes this is a tandem breaker It's designed to be used when you start running out space in your breaker box I would recommend an electrician as two slot Yes, breakers are moved around all the time The slots are all identical so the breakers don't care which one they are mounted to

two breakers in one slot Remove one of the small 2 pole circuit breakers and put in a 30a or 40a 2 pole breaker and feed a sub-panel next to the current panel