I am finishing my basement. The previous owner had ran a MWBC to the area that will be the bathroom. In the panel it is two 1-pole 20amp breakers. My questions are:
First to confirm, it seems I should split/fork the MWBC into two circuits. One for the lights and exhaust fan, and the other for receptacles. On the receptacles circuit the first outlet should be GFCI. Correct?
I am very unclear on if the two 1-pole breakers is considered safe or even to code. Should I be replacing the breakers with one that is combined, simply add a handle tie, or just leave it as is?
Relating to the last question, my understanding is its best to have two separate circuits in a bathroom. This way if the receptacle circuit blows when using a hair dryer, the lights also do not go out. For example, by using a handle tie don't I loose this — won't both circuits go out? Should I instead split the MWBC and use one circuit for the bathroom receptacles, and the other for lights in the other part of the basement? (This way if the breaker trips you aren't left in the dark in the bathroom.)