2550-3-100R : Starter : 3 phase WRIM(SRIM) Secondary Rheostat
Price: $310 + Freight & handling +GST
This is a 3 phase rheostat used in conjunction with the wound rotor induction motor (71-3-L100) to demonstrate the effect of equalizing the Secondary resistance(R) withe the Rotor Reactance(XL) on the motor torque and speed
- Maximum Starting Torque:
By increasing the resistance of the secondary circuit, by adding extra external resistance into the secondary circuit, so that the secondary resistance in ohms equals the secondary inductive reactance in ohms, the motor can produce it’s maximum torque at start (i.e. R=XL), and by the addition of suitable metering, it can be shown that the Primary starting current is reduced
- Speed Control:
By adjusting the value of added external secondary resistance, under load, the ability to gain speed control at constant torque is achieved.
Again, by the addition of suitable metering, it can be shown that whilst the Primary input power and current remain constant throughout the speed range (at constant torque) the excess secondary energy is dissipated as heat through the external secondary rheostat resistance.