Hello

Just did a lab involving induction motors. I am just wondering about variables and parameter that affect the speed of the rotor. Are the variables current and voltage and parameter is the torque? Thanks

 

Primary function is frequency. For 60Hz, it is not uncommon to see motors rated at 1750 RPM. Synchronous speed would be 1800 for that motor so the 50RPM drop is called slip resulting from load. If you think about how an induction motor is made, the slip allows the synchronous speed rotation of the field to cut through the shorting bars of the rotor which in turn, generate the armature field and torque. Others will clarify and correct my attempt to explain.

 

BillB - that is true in the case of a four pole motor, but other numbers of poles have other "base" speeds. Two pole motors are higher RPM, and more than four pole motors have lower RPM. Then you get into changing speed by changing AC frequency.

 

Right, Shortbus! I should have included the base design of the motor. My primary focus was on the external influences.