Rotation units and control systems having rotational direction control and methods of controlling the same

A method of controlling a direction of rotation for a rotation unit of an apparatus for manufacturing semiconductor devices using a three-phase power supply having a plurality of power lines to power the rotation unit, the method comprising:

• automatically sensing a current rotational direction of the rotation unit;
• automatically determining whether the current rotational direction is a desired direction;
• and
• automatically switching connections of the plurality of power lines to respective corresponding power supply lines of the rotation unit responsive to determining that the current rotational direction is not the desired direction.

A rotation system for an apparatus of manufacturing semiconductor devices, the system comprising:

• a rotation unit;
• a rotational direction sensing unit that senses an actual direction of rotation of the rotation unit and generates an output signal based on the sensing result;
• a rotational direction determining unit that determines the actual direction of rotation of the rotation unit in response to the output signal of the rotational direction sensing unit;
• and
• a power controlling unit that controls a power connection supplied to the rotation unit such that the rotation unit rotates in a desired direction based on the determined actual direction of rotation.