Electric motors are, by far, the most popular type of prime movers for rotating equipment such as pumps. Compared to other types of drivers such as gasoline engines, diesel engines, steam turbines, gas turbines, etc., electric motors are easy to operate, inexpensive, highly efficient, quiet, available in more horsepower (HP) sizes, and environmentally friendly. They are also available in a variety of enclosures - such as open-drip proof (ODP), weather resistant, totally enclosed fan-cooled (TEFC), or explosion proof - for different environmental conditions. They are also available in standardized frame size so that one brand of electric motor can be replaced easily with another brand. Electric motor-driven equipment are ideal for installation in remotely controlled stations that are located in far-flung areas.
The main disadvantages of using electric motors is their constant speed, and their limited speed availability, which curtail the range of speed by which the driven equipment can operate. They can be used only in places where electricity is available, and sometimes commercial power companies in small communities put a limit to the maximum electric motor size that can draw power from the utility station so as not to affect adversely the power usage of other customers.
Electric motors are available for both horizontal and vertical mounting - in solid or hollow shaft configuration. They can be supplied with extended shaft, or double- extended shaft for special applications.
R: 0210-ELMO C: design, operation F: electric motors