Yes!
It should be connected to circuit breaker. Circuit breaker will automatically discontinue the flow of electricity if it detects faulty condition.
A circuit breaker is designed to 'break' in a circuit if a short circuit (or other malfunction) occurs. This prevents overheating (or burn-out) of the circuit wires. In older systems, you would need to find which fuse wire has fused and replace it. In a circuit breaker, once the fault has been found and corrected, the breaker is simply switched back on.
Use a 30 amp breaker.
AWG 12/2 requires the use of a 20 amp single pole breaker.
Yes!
If it was two wires under one screw on a single-pole breaker, that would not be proper, and most probably against electrical code.If it was two wires, each under their own screw on a double-pole breaker, then that would be a 220 volt circuit; each wire going to its own "leg" of the breaker panel.
4 wires. 2 hot legs, 1 neutral leg, and 1 ground wire.
Hopefully just the black wires are on the breaker. Two circuits on one breaker. Shouldn't be a problem. It would depend on how many outlets or lights were on the breaker in total. Even then, there is very little chance of something drawing current from every outlet at the same time. The only thing is you can't put two wires under one breaker (by code). You would have to wire nut them with a pig-tail then just put the one wire under the breaker.
It should be connected to circuit breaker. Circuit breaker will automatically discontinue the flow of electricity if it detects faulty condition.
Your ballast should show two wires for supply side of ballast. Make sure that neither side of this is grounded to the light and connect the 220 V from your breaker to these two wires and then connect a ground to the chassis of the light from the panel.
Overcurrent current protection is for the wires
Your only hope is that someone wired the box not to code and that there are two wires going into the offending breaker. If you can't separate wires you can't distribute the load.
Remove the breaker in main panel and either remove wires from main panel or cap off wires with wirenuts and label for possible future application. Put a breaker filler strip in hole left by missing breaker. At outlet you can just leave outlet or remove from wall and repair hole in wall. If you remove outlet and leave wires in wall it is best to totally remove wire from main panel.
a breaker or a fuses
A circuit breaker is designed to 'break' in a circuit if a short circuit (or other malfunction) occurs. This prevents overheating (or burn-out) of the circuit wires. In older systems, you would need to find which fuse wire has fused and replace it. In a circuit breaker, once the fault has been found and corrected, the breaker is simply switched back on.
A breaker is a device that is used to connect and disconnect the buss bars of an electrical panel to the feed end of wires that feed an electrical load. The function of a breaker is to protect the wires from an overload by the use of an internal thermal trip, and to protect the load and wires from a short circuit by use of an internal magnetic trip.