SPLIT-PHASE MOTORS
TYPE KH 1/60-1/3 hp
Advantages Applications Characteristics
Construction Modifications Ratings
GENERAL & ELECTRIC
1
What Is a Split-phase Motor?
What They Will Drive
A SPLIT-PHASE motor is a single-phase motor that obtains its starting torque from two stator windings of different impedance values which in effect convert the singlephase current to an equivalent two-phase current. The few and simple parts of this motor are shown schematically at the right.
The arrangement and operation of these parts are shown below. The windings are located in different sectors around the stator, and the starting winding is in series with the starting switch. A switch-actuating mechanism is mounted on the rotor and is set to open the switch and open-circuit the starting winding when the motor reaches a predetermined speed.
The phase displacement of the currents in the starting and running windings, together with their physical displacement on the stator, produces a rotating magnetic field that starts the rotor revolving
When the rotor reaches a predetermined speed, the centrifugal switch opens the starting winding Current flows only in the running winding, and the motor operates the same as an ordinary induction motor.
Why Split-phase Motors Are Used
Split-phase motors are admirably suited to applications that require an inexpensive, reliable motor with moderate torque. Inherently simple in construction and operation, the split-phase motor will give many years of satisfactory operation without attention except occasional oiling. Split-phase
motors do not interfere with radio reception they have no brushes or commutators. Split-phase motors have become the accepted drive for domestic washing machines, ironers, fans, and similar devices where long periods of operation without attention are so desirable.
For Washing Machines—"lifetime lubrication," complete interchangeability, and "cushioned-power" mounting
For Oil Burners—flange-mounted type; for compact, streamlined models
For Hair Dryers—has specially designed oiltight bearing housings
APPLICATIONS
ADVERTISING DEVICES
AIR CONDITIONING
DOMESTIC DEVICES
LABORATORY EQUIPMENT
OFFICE DEVICES
POWER TOOLS
PUMPS AND COMPRESSORS
TEXTILE EQUIPMENT
HAIR DRYERS
torque; constant speed.
AND MANY OTHERS
RATINGS
1/8 to 3/4 hp, inclusive; single-phase; 110 or 220 volts: 25, 50, or 60 cycles; high starting
For Low-speed Drives-gear-motors offer unusual economies in installation costs
For Pumps, Small Machine Tools—also well-suited for general use on single-phase lighting circuits
For Ironers—specially designed to give proper characteristics
For Propeller Fans—long-lived, built for quiet operation
For Sump Pumps
WHY THEY GIVE YOU DEPENDABLE SERVICE
G-E motors are built to give you economical operation, and great care is taken to make sure that they are dependable. The materials from which they are made are tested before being used, the motor parts pass exacting tests during manufacture, and every motor is given a two-hour test run, followed by a brake test. An examination of the high-quality construction, shown below, will give a better understanding of why G-E motors stand up under hard service.
ROTOR
This squirrel-cage rotor has a one-piece cast-aluminum winding that has permanent electrical characteristics and is practically indestructible—it will not burn out or become open-circuited. This construction, available in all four-pole motors, gives an inherently well-balanced rotor
without riveted or soldered connections. The ventilating fans are cast integral with the winding and end rings to assure the most direct and effective cooling. This rotor construction has proved its superiority in millions of fractionalhorsepower motors.
BASE
A cradle base for resiliently mounted motors is shown above. The motor is held securely by the two clamps that fit snugly over the resilient rings on the end shields. The motor can be quickly mounted or removed by tightening or loosening the screw on each clamp. Solid bases are welded to the stator frame.
BEARINGS
This sleeve bearing, equipped with a convenient oiler has extra-large oil-storage capacity and requires oiling only at infrequent intervals. Oil is filtered and fed to the bearing surfaces by the wool packing and is circulated by oil throwers and returns. The mirror-like finish of the linings adds to bearing life and makes for quiet operation. Ball bearings can be furnished if desired. They are packed at the factory with sufficient grease to last approximately two years of normal service.
END SHIELDS
These end shields have ventilating openings arranged to protect the windings from falling water and dirt. They give rigid support to the bearings and are accurately machined and aligned to hold the rotor concentric within the stator. Most G-E fractional-horsepower motors have the terminal box built in the end shield; either cord-and-plug or conduit connections are made quickly without soldering or splicing. Other G-E motors have the leads brought out through a conduit box mounted on the stator.
STARTING SWITCH
This durable, positive-acting centrifugal switch is good for the life of the motor. It is equipped with silver contacts and is rustproof, quiet-operating, and long-lived. One part of the switch is mounted in the end shield, and the centrifugal activating device is on the rotor.
STATOR
This construction has proved exceptionally dependable in hundreds of applications and on millions of motors. The welded rolled-steel stator frame combines strength and rigidity with light weight. The windings are made of specially prepared wire and are effectively insulated throughout —they are resistant to moisture, oil, and mild acids and alkalis. The inside metal surfaces are treated to resist rusting
How They Are Mounted
Why They Are Quiet
G-E Split-phase Motors Are Easily and Quickly Installed
These motors are available in a wide variety of mechanical modifications for many methods of mounting. Typical examples are shown below.
All base-mounted motors have slotted bases for ease in mounting and for making belt adjustments quickly. In addition, the Type KH splitphase motor has mounting dimensions interchangeable with those of other G-E motors. Once the mounting-bolt holes have been located on a machine, other types of G-E motors of correspond-
ing ratings for other power supplies can be mounted by using the same bolt holes. The location of the base holes, and of the shaft location with respect to the base holes, are the same for all these motors. Motors with solid bases are also interchangeable, with respect to mounting, with resilient-base motors. Identical mounting dimensions are a valuable feature of G-E motors. They save money on installation costs when machines are to be used on different power supplies.
direct connection to ma
DC 25 CYCLE 50 CYCLE 60 CYCLE
The 1/4-hp, 60-cycle, Type KH motor for washing machines has mounting dimensions identical with those of 1/4-hp G-E washing-machine motors for other power supplies. They all mount in the same space and in the same cradle, as illustrated above. By simply loosening two screws, motors for various power supplies can be quickly interchanged.
Where quiet operation is desirable, the scientifically designed General Electric resilient mounting. available in all split-phase-motor frame sizes, should be used. Large rings of resilient material. close to the axis of vibration, are the cushioning elements. Careful selection of materials and accurate calculation of dimensions give these rings the proper characteristics to absorb torque pulsations, restrain endwise movements, and maintain shaft alignment. The improved resilient material now used in these rings is practically impervious to oil, moisture, and aging These resisting qualities are inherent in the material and are not the result of surface treatment of the rings. General Electric resilient mounting will remain unchanged throughout the life of the motor.
What G-E Research Means to You
Resilient mounting is just one of the many improvements that G-E research has made in fractionalhorsepower-motor performance. The millions of dollars that General Electric has spent and is spending in research for improvements in design, material, and methods give you a longer-lived and better motor at less cost. Continual progress and improvement in G-E motors as a result of research keep their performance record outstanding.
TYPES OF RUBBER MOUNTING
This mercury-pool test shows the effectiveness of the resilient rings-notice that no ripples appear in the cup on the base
This resilient ring, when assembled on the end shield. isolates all torgue pulsations from the motor base
INTERCHANGEABLE MOUNTING DIMENSIONS
with various power supplies
How G-E Motors Help You Sell
They Make the First Sale Easier
In checking over the important features of your machines, prospects naturally examine the electric equipment. They realize that it is important, but a quick external examination of the motor cannot give them a true idea of its worth. They must rely on the manufacturer and his reputation for furnishing high-quality goods. It is here that G-E motors render a real, practical service. General Electric has a widespread reputation for high-quality electric equipment—a reputation which, added to that of your machines, makes it easier to convince your prospect that your equipment is of high quality throughout. It simplifies your selling.
They Give Service that Makes Friends
To keep your business thriving year after year, you must look beyond the initial sale. Installations of your equipment must give years of trouble-free service that will make your customers enthusiastic salesmen for your machines in their communities by telling friends and neighbors how much they like them. G-E motors will give the service that your customers want.
OTHER TYPES OF G-E MOTORS
General Electric can supply other types of motor for applications for which split-phase motors are not suitable—it has a type to meet every requirement. Some of these are illustrated below. Our staff of specialists will be glad to discuss your
motor problems with you. In addition, we can supply you with control and wiring devices for every service condition. Contact the nearest G-E sales office, or write to General Electric, Schenectady, N. Y., for additional information.
Polyphase motor 1/8 hp and larger
Capacitor-motor 1/8 hp and larger
Direct-current motor 1/8 hp and larger
Series motor 1/100 hp and larger
GENERAL 😨 ELECTRIC
SCHENECTADY, N. Y.
9-39 (15M) Filing No. 8260
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