Motors and generators must be installed, operated, and maintained correctly. Motors and generator are referred to as rotating machines or rotating apparatus. The rotating apparatus ranges from very small to very large machines. Consequently, the attention and care provided in the selection, installation, operation, and maintenance varies for different units. Many precautions must be taken, especially for large rotating apparatus, to avoid damage because most of this equipment is expensive and hard to replace. The scheduled maintenance, overhauls, or repair of large rotating apparatus may require partial or extensive disassembly. Therefore, maintenance personnel assigned to perform the work should be familiar and knowledgeable with all aspects of the apparatus. This chapter discusses the selection, application, mechanics, maintenance, troubleshooting and testing of motors and generators.
The rotating apparatus is an energy-conversion device. That is, it converts mechanical energy into electrical energy, or vice versa. It can be designed precisely to perform the service expected. But to perform best, it must be correctly installed, protected, ventilated, and maintained. The objective in applying a motor or generator is to select rating and features so that it can carry the load without exceeding its temperature limits. Since many motor and generator applications will have a bearing on other equipment, it is important to review the engineering information on it. The National Electrical Manufacturers Association (NEMA) has published standards titled MG1-2006, Motors and Generators, that list all the pertinent details of this equipment.