The problem may be easy to fix or it may not be. So a breaker or fuse going off is often a sign that something else is wrong: a symptom, not a cause of your problem.
The converter uses the higher-voltage AC power that comes in from the campground or generator through the 115-volt AC breaker panel and converts it to 12-volt DC. Whenever the power stored in the batteries gets low, the converter charges it up. Your DC power comes from a battery or batteries (like in the picture above). The campground supplies AC power on two different wires: a 240-volt supply is split into two "legs" of 115 volts or so. The AC power control panel distributes this power to the appliances and outlets that use AC power, for example the air conditioner.