0
Squirrel cage induction motors.
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
Why field winding work as stator and armature winding as rotor?
No, these can be switched depending on the requirements of the application. It is more practical to have the armature windings (since they will carry the full load current) as the stator for this will require larger wires and is also easier to cool if kept stationary. The field windings do not carry the full load current of the load so this requires smaller wires and smaller slip rings since this is the piece that will rotate.
What cause earth fault in a motor?
The Rotor Protection relay is used in synchronous motors and generators to identify the presence of an earth fault in the rotor winding. While the winding in the rotor is insulated from the ground during normal operation, the Rotor is subjected to stresses due to vibration, heat, etc. These stresses can cause the winding to give way in a particular place and the winding can get earthed. While a single earthing in the winding is not immediately damaging. It sets the stage for damage if a second failure should occur. The second earthing can cause a short-circuit through the rotor causing extensive damage to the rotor and the winding. The currents produced during a rotor earth fault can cause excessive vibration and disturb the magnetic balance inside the alternator. These forces can cause the rotor shaft to become eccentric and in extreme cases cause bearing failure. Hence, it is necessary that any earthing in the rotor is detected at the earliest. In slip ring rotors, carbon deposits on the slip rings may compromise the insulation resistance of the rotor. Hence, the slip rings need to be inspected for any deposits. The Rotor Earth Fault Protection Device consists of a current injection device which applies an AC voltage to the rotor winding by means of a slip ring fitted on the rotor. The current is applied to the rotor through a coupling capacitor. In the normal condition, the system is floating and the current flowing through the device is zero as the resistance is high. When a fault occurs, the current increases causing the relay to operate. The relay can be configured for alarm or trip depending on the criticality.
Need of changing current direction in 3 phase motor?
Your question is confusing. Are you asking how to reverse the direction of a three-phase motor? If so, then the answer is that you simply interchange any two of the line conductors. This will cause the naturally-rotating magnetic field in the motor's air gap to reverse direction, causing the rotor to reverse direction.
Can you change the direction on an ac motor?
A series DC motor can be thought of as having two components, the rotor and the stator. The rotor has windings which rotate and the stator's windings stay stationary. In a series DC motor these windings are connected in series. To make the motor turn backwards you must reverse the current through either the rotor or stator windings, but not both.
How do you reverse the rotation of a 110 volt motor?
As long as it is an induction 110 volt motor it can be reversed; if it is any other type of motor it cannot be reversed. You will have to get into the windings to bring both leads to the start in order to make it go in reverse. <<>> A split 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.
Why field winding work as stator and armature winding as rotor?
No, these can be switched depending on the requirements of the application. It is more practical to have the armature windings (since they will carry the full load current) as the stator for this will require larger wires and is also easier to cool if kept stationary. The field windings do not carry the full load current of the load so this requires smaller wires and smaller slip rings since this is the piece that will rotate.
What is the difference between a field winding and an armature winding in any machine?
simply saying u that field winding is a winding present at the stator of the motor and is used to produce the magnetic field and the armature winding is the winding present in the rotor and is used to rotate the shaft of the motor. there are some machines with permanent magnets, those permanent magnets are used as the major source of magnetic flux in the machine instead of the field winding .
What cause earth fault in a motor?
The Rotor Protection relay is used in synchronous motors and generators to identify the presence of an earth fault in the rotor winding. While the winding in the rotor is insulated from the ground during normal operation, the Rotor is subjected to stresses due to vibration, heat, etc. These stresses can cause the winding to give way in a particular place and the winding can get earthed. While a single earthing in the winding is not immediately damaging. It sets the stage for damage if a second failure should occur. The second earthing can cause a short-circuit through the rotor causing extensive damage to the rotor and the winding. The currents produced during a rotor earth fault can cause excessive vibration and disturb the magnetic balance inside the alternator. These forces can cause the rotor shaft to become eccentric and in extreme cases cause bearing failure. Hence, it is necessary that any earthing in the rotor is detected at the earliest. In slip ring rotors, carbon deposits on the slip rings may compromise the insulation resistance of the rotor. Hence, the slip rings need to be inspected for any deposits. The Rotor Earth Fault Protection Device consists of a current injection device which applies an AC voltage to the rotor winding by means of a slip ring fitted on the rotor. The current is applied to the rotor through a coupling capacitor. In the normal condition, the system is floating and the current flowing through the device is zero as the resistance is high. When a fault occurs, the current increases causing the relay to operate. The relay can be configured for alarm or trip depending on the criticality.
Why the capacitor motor will not develop any starting torque without capacitor?
The start winding needs a capacitor in series with it in order to produce a phase shifted magnetic field that will develop the torque necessary to bring the rotor up to operating speed. Once operating speed it obtained, a centrifugal switch opens and disconnects the start winding - the rotor's inertia can then keep it going as needed.
Need of changing current direction in 3 phase motor?
Your question is confusing. Are you asking how to reverse the direction of a three-phase motor? If so, then the answer is that you simply interchange any two of the line conductors. This will cause the naturally-rotating magnetic field in the motor's air gap to reverse direction, causing the rotor to reverse direction.
How do you reverse a three phase air conditioning unit?
Any three phase motor can be reversed in rotation by inter changing any two of the motor's incoming feed conductors. For example connect the motor winding wires to L1, L2, L3 and the rotor turns clockwise in rotation. Connect the same motor to L3, L2, L1 or L2, L1, L3 or L1, L3, L2 and the rotor turns counter clockwise. As you can see any combination of the two wires will reverse the rotors rotation.
What are the three key parts of any electric motor?
The Stator, the Rotor and the Windings.
Can you change the direction on an ac motor?
A series DC motor can be thought of as having two components, the rotor and the stator. The rotor has windings which rotate and the stator's windings stay stationary. In a series DC motor these windings are connected in series. To make the motor turn backwards you must reverse the current through either the rotor or stator windings, but not both.
How do you make an AC motor go in forward and reverse?
If it is a three phase motor just interchange any two of the three wires. If it is a single phase motor, which is also known as a split phase induction motor, it 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.
How do you reverse the rotation of a 110 volt motor?
As long as it is an induction 110 volt motor it can be reversed; if it is any other type of motor it cannot be reversed. You will have to get into the windings to bring both leads to the start in order to make it go in reverse. <<>> A split 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.
What is mean by rotor in machines?
a ROTOR is basically any part of a machine that rotates. eg the armature in a motor a STATOR is the part of a machine that is stationary. ie the ROTOR revolves within the STATOR
What is the principle of 3 phase induction motor?
When three phase supply is given to the three phase stator winding of the induction motor,a rotating magnetic field is developed around the stator which rotates at synchronous speed.This rotating magnetic field passes through the air gap and cuts the rotor conductors which were stationary.Due to the relative speed between the stationary rotor conductors and the rotating magnetic field,an emf is induced in the rotor conductors.As the rotor conductors are short circuited, current starts flowing through it.And as these current carrying rotor conductors are placed in the magnetic field produced by the stator, they experiences a mechanical force i.e. torque which moves the rotor in the same direction as that of the rotating magnetic field. the induction motor can't run at the synchronous speed because at synchronous speed the induction motor can not develop any torque to move the rotor from its stationary position.
