What is the purpose of brake test on induction motor?
Aim of the Experiment: To perform blocked rotor test on a three phase induction motor to find out its performance parameters with the help of Equivalent circuit. THEORY: Blocked rotor test is similar to the short circuit test on a transformer.
How do you test a 3 phase induction motor?
Check the motor winding resistance or ohms reading using a multimeter or ohmmeter for phase to phase terminal ( U to V,V to W ,W to U ). The ohms reading for each winding must be the same (or nearly the same). Remember that the three phases have identical windings or nearly so!
What is the purpose of braking in three-phase induction motor?
Dynamic Braking of Induction Motor Dynamic braking of the three-phase induction motor is the slowing down of the motor by converting the kinetic energy stored in the rotating mass to the heat energy in the rotor/stator windings.
How does a 3 phase motor brake work?
Three-phase brakes work similarly to DC brakes in that they are spring-actuate. But, instead of using electro-magnets, they use electric coils for stopping power or braking an engine.
What is no load test of induction motor?
The no-load test of an induction motor is similar to the open-circuit test of a transformer. The motor is not connected from its load, and the rated voltage at the rated frequency is applied to the stator to run the motor without a load. The 2-wattmeter method measures the input power of the system.
How many ohms should a 3 phase motor read?
The reading should be between 0.3 to 2 ohms. If it is 0, there is a short. If it is over 2 ohms or infinite, there is an open. You can also dry the connector and retest to possibly get more accurate results.
What are the braking methods in induction motor?
Plugging induction motor braking is done by reversing the phase sequence of the motor. Plugging braking of induction motor is done by interchanging connections of any two phases of stator with respect of supply terminals. And with that the operation of motoring shifts to plugging braking.
What is plugging and regenerative braking?
Plugging gives greater braking torque as compared to rheostatic braking. This method is generally used in controlling elevators, machine tools, printing presses etc. Regenerative braking is used where, load on the motor has very high inertia (e.g in electric trains).
How do you check a brake coil?
Solution
- Measure the coil resistance with the multimeter or resistance meter.
- Check the housing with coil contacts with the multimeter or resistance meter.
- If there is short circuit in the housing, replace the brake coil.
- Check the brake voltage(if the rectifier is broken, the voltage is too low or there is no voltage).