The standard power panel in the US is divided into 2 power busses, if that is the correct word. An incoming 220 line is split into two to make 2 110 sides. A 110 breaker connects from one side of a 220 line to the central ground. A 220 breaker connects from one line of the 220 to the other line of the 220. So it is not split. The panel can produce 220 this way but the 110 breakers are only using half of the 220 line. It is usually balanced in the box by having breakers on alternating sides. A panel is designed to have both 110 and 220 voltages but a 220 breaker will always be 220 volts. You can't reduce it down because it is drawing from both sides of the incoming line.