With rising power costs it is no longer practical to consider the monthly power bill as a fixed base cost that cannot be controlled. Although motors are more efficient than any of the equipment they drive, their operating cost is of vital importance, because they account for a significant amount of the power used by industry. The total annual operating cost for a single motor is based on continuous operation and motor losses. Motor losses can be divided into four categories: stator and rotor losses, stray load, friction and windage, and core losses. All types of motor losses can be adversely affected during a careless or low quality repair. Low quality motor rewinds can definitely increase maintenance costs due to more frequent greasing, premature failures, and additional in-and-out expenses. When selecting a rewind vendor it is important to determine how the old winding will be stripped and what steps will be taken to ensure no increase in core loss.