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Resistance of stator winding is the resistance of the copper conductors being used for building the windings of three separate phases, i.e. R-Y-B. These windings are marked like U1-U2, V1-V2 & W1-W2 at the motor terminals (6 nos.) for the three phases, i.e. R-Y-B respectively. We have simply to measure the resistance of each winding by using a multimeter by connecting the terminals (2 no.) to U1 & U2 and so on.
The resistance should be in ohms not milliamps [amps is form of measuring current not resistance] milliamps to microamps in case of large motors, it may be in amps in case of small sized motors. But resistance of each winding should be nearly same to each other. This shows the electrical balance among windings & also proves the healthiness of the winding.
What else can I help you with?
How can you reverse the direction of rotation in an induction motor?
A single phase induction motor has two sets of coils and a centrifugal start switch. The start winding is in series with the start switch. The start winding provides a rotating magnetic field in one direction enabling the motor to start. The motor can be reversed by reversing the connections of either the start winding or the run winding but not both.
Speed of the stator field of an Induction motor is?
synchronous speed
What are the constructional features of a 3 phase induction motor?
stator,roto
What is the useful of open end winding of induction motor?
Standard induction motor has a closed squirrel cage rotor, where as open ended induction motor has split phase rotor.
Why field producing winding of 3 phase induction motor made stationary?
Because the motor is much simpler and easier to design when the electrical power is supplied to the stator, while the rotor is a short-circuited copper cage. It allows the motor to work with no commutator or slip rings, so induction motors are quiet and have a very long life.
Does induction motor has rotor winding?
Yes, the induction motor has a rotor winding. It is usually one turn, shorted. This is how the magnetic fields generated in the stator induce a current in the rotor, which subsequently generates a torque from the opposing magnetic fields, stator to rotor.
What is the similarity between an AC induction motor and an AC synchronous motor?
Only Stator winding is similar in both the cases.
Why induction motor is also called short circuit transformer?
Like transformer induction motor has stator winding(Primary winding) and rotor winding(Secondary winding) separated by an airgap.Rotor winding(generally Al bars) are short circuited at the end to produce torque for the rotation.Hence the name short circuited transformer.
What do you understand about the stator of an AC motor?
AC motor has two main winding components - stator and a rotor. Stator winding is stationary where as rotor winding is on rotating part.
What happen if we do the 3 phase winding in rotor of induction motor and give the 3 phase supply only stator winding?
This is how an induction motor normally works, hence the name. The supply voltage is connected to the stator winding(s) and a current is induced in the rotor. A synchronous motor, on the other hand, will have current supplied to the rotor through slip rings and brushes. The rotor current is generally supplied as DC though, or else rectified in the rotor.
What is induction motor in physics?
An induction motor consists of a rotor winding and stator winding. Rotor windings are short circuited and stator winding are given electrical AC supply .Now lets do the physics behind it . As the current starts to flow in the stator winding , magnetic flux start to produce around it . due to it's alternating nature that flux varies and according to farady law emf is induced in the rotor winding .Since the rotor winding is short circuited the current circulates in it .And when a current carrying conductor is placed in magnetic field it experiances a force and hence if start to rotate.
What is the meaning of open end winding induction motor?
Normally the machine is supplied from one side of the stator winding only and the other side is isolated connected in star or delta. Open-end winding means the neutral point of the machine is opened and now the supply is possible from both side of the stator winding of the machine.
How is the resistance of a motor winding expressed?
The resistance of a motor winding is expressed in
How is the synchronous motor made self starting?
The synchronous motor is made self starting by providing a special winding on the rotor poles, known as damper winding or squirrel cage winding. AC supply given to the stator produces a rotating magnetic field which causes the rotor to rotate, therefore, in the beginning synchronous motor provided with damper winding starts as a squirrel cage induction motor. The exciter moves along the rotor. When the motor attains about 95%of synchronous speed, the rotor winding is connected to exciter terminals and the rotor is magnetically locked by the rotating field of the stator and the motor runs as a synchronous motor. While starting a synchronous motor, the field winding must be shorted through a suitable resistance so that the induced voltage is distributed throughout the whole winding and no part is subjected to the high voltage induced in the entire winding.
Why a single phase induction motor have two winding on stator?
Single phase motor will not start automatically unless it has a start and run winding.
Difference between squirrel cage and wound rotor induction motor?
Both have 3 a phase stator winding, the squirrel cage has a rotor with bars arranged around it's periphery, these bars are joined at both ends by a continuous ring. This forms a closed circuit of low resistance which is fixed. The wound rotor (slip ring motor) is similar in construction but the bars are replaced by copper windings, similar to those in the stator. They are star connected and the three ends are brought out to slip rings which allow an electrical connection to be made to the outside world. When no connection is made between these ends and the stator is energised, little current flows in the stator which does not turn, but when some resistance is inserted, current flows in the stator windings and the rotor rotates. As the rotor gains speed the resistance is taken out of circuit and the slip rings shorted together. The motor runs as a cage induction motor.
How can you reverse the direction of rotation in an induction motor?
A single phase induction motor has two sets of coils and a centrifugal start switch. The start winding is in series with the start switch. The start winding provides a rotating magnetic field in one direction enabling the motor to start. The motor can be reversed by reversing the connections of either the start winding or the run winding but not both.
