Electrical panel question
I have a inside electrical panel with the following info. It is a Challenger, Model#3, 125 A. Max., Type 1 Enclosure, Indoor.
I have one 15 amp breaker that runs my entire garge plugs and lights. If my air compressor kicks in while I am running my drill press it will kick the breaker.
I want to put the air compressor on its own line with its own breaker. The air compressor pulls 15 amps according to the motor label.
My inside box has down one side, a double 20 amp, a double 15 amp, a double 15 amp (with one of those marked as a spare), a 20 amp breaker with a knock out that has not been removed below that.
Down the other side is a double 30 amp w/bar, a double 25 amp w/bar, a double 20 amp, a double 20 amp.
So the question is how do they figure available amperage for this box? Can I add another breaker without overloading the box?
Can I put the compressor on the 15 amp marked as spare and it will handle the compressor only without a problem?
Or should I remove the knock out and add another breaker to handle the compressor? What size can I use?
Or should I pair up another breaker with the available 15 amp spare to get enough amperage to run the compressor?