By monitoring some parameters like voltage, current, temperature, and vibration problem could be diagnosed and by correcting these faults the overall efficiency of the machine can be improved. This will reduce the energy consumption and operational costs.
What is the purpose of induction motor?
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor.
What is the purpose of no load test?
No Load Test is an indirect method used for determining the efficiency and also to determine the circuit parameters of the equivalent circuit of the three-phase induction motors. The open circuit test performed on the transformer.
What is Type test of induction motor?
The purpose of the test in the motor routine testing is to calculate power factor, starting current and starting torque. The test is done on the locked rotor condition. The starting current might be high, and the test normally is done at lower voltage and result of the test extrapolated to the rated voltage.
Which test is not performed on induction motor?
As the name suggest no load test is performed when rotor rotates with synchronous speed and there is no load torque. This test is similar to the open circuit test on transformer. Actually, to achieve synchronous speed in an induction motor is impossible.
Which motor is used in fan?
How does an induction motor start?
When the supply is connected to the stator of a three-phase induction motor, a rotating magnetic field is produced, and the rotor starts rotating and the induction motor starts. … At the time of starting, the motor slip is unity, and the starting current is very large.
Why blocked rotor test is done?
A blocked rotor test is normally performed on an induction motor to find out the leakage impedance. Apart from it, other parameters such as torque, motor, short-circuit current at normal voltage, and many more could be found from this test. Blocked rotor test is analogous to the short circuit test of transformer.
What is synchronous speed?
Synchronous speed is a significant parameter for the rotating magnetic field-type AC motor. It is determined by the frequency and the number of magnetic poles. Synchronous speed No = [rps, revolutions per second] f = Frequency [Hz]
What is the no load current of a motor?
The no-load current is the current required just to turn the motor shaft with nothing connected. It is the current required to overcome the bearing and brush friction plus the aerodynamic drag caused by the rotor moving in the air and moving air through the motor for cooling purposes.23 мая 2017 г.
What is Type test of motor?
As the name suggests, this type of motor testing is done when the machine is stopped. Static testing assesses things like resistance/insulation resistance, high-potential (HiPot) tests, polarization, surge tests and more.
How do you calculate engine load?
When calculating motor loads, you need to know how to convert a motor’s current rating (given in amps) to a VA rating. To do this, multiply the motor’s nameplate amperage by the supply voltage.
How do you check motor windings?
Start by completely disconnecting the spindle motor from all power sources. Check each wire, including T1, T2, T3 and the ground wire. If the reading is infinite, your motor should be fine. If you get a zero reading or any continuity reading, you have either a motor problem or a cable problem.
What is cogging and crawling in induction motor?
A.Cogging can also be reduced by using skewed rotor. Q.What is Crawling? A: It has been observed that squirrel cage type induction motor has a tendency to run at very low speed compared to its synchronous speed, this phenomenon is known as crawling. The resultant speed is nearly 1/7th of its synchronous speed.
Why the synchronous motor is not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. … Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
Why LPF wattmeter is used in no load test of induction motor?
Answer: LPF wattmeter is used to measure power in inductive circuits. … In open circuit test the secondary winding of transformer is kept open.As the secondary side is open, the entire coil will be purely inductive in nature.So the power will be lagging due to inductive property of the circuit.