You have a TWO pole motor. The speed on the nameplate is the giveaway. Theoretically, a 2-pole motor would run at 1800RPM, but since an AC motor has to 'slip' to develop torque, it runs at 1750RPM.
"Repulsion Start" is explained here:
Repulsion Start - Induction Motors. The repulsion start induction motor is a single phase motor consisting of a stator winding connected to the power source and a rotor winding connected to a commutator. The motor starts as a series motor and at a predetermined speed, all the commutator bars are electrically shorted by a device called a "necklace" to give the equivalent of a squirrel cage winding. This type of motor starts as a repulsion motor but operated as an induction motor with constant speed characteristics. It does require more maintenance and has therefore been almost entirely replaced by capacitor start motors, although the repulsion start induction motor can develop more locked-rotor torque with much less locked rotor current.
Courtesy of: »
www.sdp-si.com/D220/HTML ··· T145.htmThis is very similar to a "Wound Rotor" motor, only instead of using the rotor windings to control the speed, they're used as a starting winding, and then shorted together once the motor reaches its "Base Speed", identical to what the controller of a Wound Rotor motor would do when running at full speed.
And yes, if it's Repulsion Start, it
is quite old!