ABSTRACT
The control of electrical power is a very important part of electrical power system operation. Control is the most complex part of electrical systems. It is, therefore, necessary to limit the discussion in this chapter primarily to some of the common types of electromechanical equipment used for electrical power control. Two well-known organizations publish standards that are of importance to industry. These organizations are the American National Standards Institute and the Institute of Electrical and Electronic Engineers. The standards published by these organizations are for the use of the manufacturing industries as well as power consumers and, in some cases, the general public. Limit switches are made in a variety of sizes. Limit switches are merely on/off switches that use a mechanical movement to cause a change in the operation of the electrical control circuit of a motor or other load device.
