Document k97E9yv65kkOdZxrxgQqnvJ3n

632 CHAPTER 35 1948 Guide Typical Specifications for Single Phase Motors ` ------------------ Hp,------------------ RPM, |gg| Cycles, {230} Volts,-Single Phase Motor of the----------------- !----------- ----Type for Driving--_______ ___________ Motor Shall (Capacitor, Split Phase, etc.) - .'(Application) . , y. Be Arranged for |VcrLca1k1^} Mounting And Shall Be Provided With -Type of Enclosure, NEMA {ciaS b} Insu!ation- And (Open, Splashproof, etc.) Kve} Bearings- Typical Specifications for Squirrel-Cage Motor Control Control for Squirrel-Cage--------------------------------- Motors Shall Consist of An Enclosed (Fan, Pump, etc.) {Magnetic} Voltage} Starter Providing Overload Protection And Low Voltage |p^^`on|. Control Shall Include A Safety Disconnect Switch Typical Specifications for Wound Rotor Motor Control Control for Wound Rotor Motor Control for____ Applications Shall Consist of a Safety (Fan, Pump, etc.) Disconnect Switch, a {c^^on^} Mounted Across the Line Starter Providing Over load Protection, Low Voltage {gggf?"}. and a Secondary {l^ngRegulating} Controller for {MSng^&tm^Endosure}- Primary and &*ondary Control Shall Be Interlocked so as to Provide Complete Control from the Rheostat Handle. the commutator when the motor., comes up to speed. These motors are suitable for applications such as" industrial compressors where high break-away torque is required and where commutator and brush noise are not factors. ' , Split Phase motors have a high, resistance auxiliary winding'which is in the circuit during starting but is disconnected through the action of a centrifugal switch as the motor comes up to speed. Under running con ditions it operates as a single phase induction motor with one winding in the circuit. These units: are available for the small horsepower ratings and when equipped with a high slip rotor may be used for adjustable PER CENT OF FULL LOAD. TORQUE Fig. 9. Performance Characteristics of A Wound Rotor Motorwith External Resistance varying speeds through line voltage control.! The motors are ideally suited for fan duty. Speed-torque characteristics of.single phase motors are shown in Fig. 10. Typical specifications for single phase motors are shown on page 632. CONTROL FOR ALTERNATING CURRENT MOTORS Squirrel-Cage motors are usually linestarted where power company limitations permit. In sizes up to 2 hp the motors are started by means of manual switches with an overload current element for motor protection. rt-r i, 1 1 1 sSwWrITrCoH OPERATING SPEEDS w -Ay % % > 55at Am O STARTING WINDINGS ^ cc * 3r t m too 200 300 400 PER CENT OF FULL LOAD TORQUE Fig. 10. Speed-Torque Characteristics of Single Phase Motors