Archive for June 13th, 2017

Motor Generator Sets

A Motor Generator Set is a combination of and electric motor driving a generator. The purchase is to convert one type or value of voltage to another. Usually an AC, 3 Phase, 60 Cycle motor is used to drive a generator to produce DC Motor or AC Power with a different Voltage or Cycle output.

DC Mill Motors

DC Mill Motor are a special class of DC Motor that are built in a clam shell style frame. This type of DC Motors is predominately used in the Steel and Mining Industries. DC Mill motors can be serviced while in place rather than having to be removed from the application to service. DC Mill Motors were manufactured by General Electric, Westinghouse Electric, P&H Electric, and Crocker Wheeler.

DC Generators

DC Generators, when driven produce DC Electric Power. DC Generators have all of the same characteristics as DC Motors.

Vertical Motors

Vertical Motors are motors that are vertically oriented, have the letter “P” in the frame size, and are used in all types of pump applications. There are two primary types of vertical motors: Vertical Hollowshaft and Vertical Solid Shaft. The most common manufacturers of vertical hollowshaft motors are US Electric, General Electric and Teco/Westinghouse. They were also produced by Westinghouse Electric, Newman Electric, and Marathon Electric, Allis-Chalmers, Siemens-Allis, and Siemens. Vertical solid shaft motors are produced by US Electric, General Electric, Reliance Electric, Baldor Electric, Allis-Chalmers, Siemens-Allis, and Siemens. Vertical motors are often configured with non-reversing ratchets which allow the motor to be operated in one direction only. Vertical motor frame sizes have the following suffixes at the end of their frame numbers: P, HP, LP, VP, and TP. These suffixes represent different thrust characteristics and bearing arrangements.

Variable Speed Motors

Variable Speed Motors are AC motors that can operate within a range of different speeds. The most common type of Variable Speed Motors have a combination of an AC motor and an Eddy Current (DC) Clutch. Dynamatic is the largest manufacturer of AC Eddy Current motors. Variable Speed motors are used on punch presses, air handling equipment, mixers, etc. This type of motor is manufactured by General Electric, Louis-Allis, US Electric, and Westinghouse. Variable Speed motors are very expensive and are being obsoleted by Variable Frequency Drives.

Synchronous Motors

Synchronous motors are designed to run exactly at their Synchronous speed with no slip. Synchronous motors have AC windings in the stator and DC windings in the rotor, the rotating part of the motor. Synchronous motors typical are 500 HP and above. The most common manufacturer of Synchronous Motors are Allis-Chalmers, Electric Machinery, General Electric, Ideal Electric, and Westinghouse.

Slip Ring Motors

Slip Ring motors are motors that have a winding in the stator of the motor, like regular motors, and a winding on the rotor, the rotating part of the motor. Slip Ring motors were used in applications where the application required varying the speed of the motor. Slip Ring motors are used on conveyors, cranes, and mixers. Slip Ring motors are being obsoleted by variable frequency drives. The most common manufacturers of Slip Ring Motors are: Allis-Chalmers, General Electric, Louis-Allis, P&H, Reuland, and Westinghouse.

Multi-Speed Motors

Multi-Speed motors are AC motors that can run at two or more speeds. The most common multi-speed motor utilizes one winding that can be connected for two different speeds. The leads on one winding, two speed motors have 6 leads and are numbered 1-6. Multi-Speed motors can also have two separate windings. Multi-Speed motors with two windings have 6 leads and are numbered 1-3, 11-13. It is also possible to have Multi-Speed motors that operate at 3 or 4 speeds. Both require a two winding configuration. Multi-Speed motors are commonly used in mixer, crane, and cooling tower pump applications. Multi-Speed motors are being obsoleted by variable frequency drives. Multi-Speed motors are made by most manufacturers including: Allis-Chalmers, Baldor Electric, General Electric, Lincoln Electric, Leeson Electric, Louis-Allis Electric, Marathon Electric, Reliance Electric, Siemens, Siemens-Allis, Teco/Westinghouse Electric, US Electric, and Westinghouse Electric.

Gear Motors

Gear motors are a gear reducer with an electric motor mounted directly to it. The purpose of a gear motor is to reduce the speed of the motor, through the gearbox, to the speed the application requires. Gear motors come in parallel and right-angle configurations.

Design D Motors

Design D Motors have high starting torque and higher than normal slip characteristics. Slip is the difference between the synchronous speed of the motor and the actual running speed. Design D motors are rated 5-8% Slip or 8-13% Slip. Design D motors are commonly used in punch press and oil pump jack applications. Design D motors have been produced by Delco Electric, General Electric, Louis-Allis Electric, Reuland Electric, Toshiba Electric, Teco/Westinghouse Electric, and Westinghouse Electric.