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Why does a single phase synchronous motor need a capacitor but for a three phase motor it is not required?
Wiki User
∙ 9y ago
A three-phase motor has a rotating magnetic field inside that is set up by the supply, so the armature always rotates in the correct direction. A single-phase motor can in principle start either way so it has a starting winding supplied through a capacitor to provide a small component of rotating field to get it started the right way. After it has picked up speed the starting winding can be switched out.
Wiki User
∙ 9y ago
Wiki User
∙ 11y agoA capacitor is a two-terminal device. Its value (in Farads) and its maximum voltage rating are the two main specifications. There is no such thing as a three-phase capacitor. Associating "three-phase" with a capacitor implies that it has been specified for use in a three phase circuit for some particular application. If that application changes, the value may have to be changed.
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Does a induction motor need excitation?
The induction motor is the special kind of motor which runs below and above the synchronous speed. which the synchronous motor runs nearly equal the synchronous speed. The operation of synchronous motor runs with dc field excited hence separate dc field current is given to the field circuit. where as the induction motor the field and main field is drawn from the same supply hence no excitation is required. But due to this separate starting mechanism has to be required in case of the single phase induction motor.
What are the types of single phase ac motor?
capacitor start motor
Drawing block diagram of single phase capacitor start motor?
Drawing block diagram of single phase capasitor start motor?
What is run capacitor in single phase motor starter with three wire?
A run capacitor and a starter capacitor are not the same thing. A run capacitor is energized the entire time the motor is running, and a start capacitor is not. A run capacitor is one that changes the current on the windings of a single phase AC induction motor to create a rotating magnetic field to energize a second-phase winding. A start capacitor increases starting torque, allowing a motor to be turned on rapidly. It stays in the circuit only long enough to bring the motor to 3/4 of full speed. Some motors then continue to run with a run capacitor.
Cause of single phase capacitor start motor burning?
mainly due to undervoltage.
Does a induction motor need excitation?
The induction motor is the special kind of motor which runs below and above the synchronous speed. which the synchronous motor runs nearly equal the synchronous speed. The operation of synchronous motor runs with dc field excited hence separate dc field current is given to the field circuit. where as the induction motor the field and main field is drawn from the same supply hence no excitation is required. But due to this separate starting mechanism has to be required in case of the single phase induction motor.
What is synchronus capacitor?
A synchronous condenser (also known as a synchronous capacitor or synchronous compensator) is a DC-excited synchronous computer (large rotating generators) whose shaft is now not connected to any using equipment.
Why can a run capacitor with a single phase motor remain in circuit after the motor starts?
Because from the capacitor characteristics at first it will charge and then it will stsrt to run so when the motor get power from single phase capacitor take time for charging. Amit.
What are the types of single phase ac motor?
capacitor start motor
Why A synchronous motor is sometimes called a synchronous capacitor Explain?
A synchronous motor can operate as either a Generator or a Motor.When a synchronous motor has current applied to the windings on its rotor and the stator is energized with say a 50hz line supply (with little or no physical load) then the exact amount of excitation provided by the rotor can determine whether the stator displays inductive or capacitive properties.If the rotor is under excited (too Little rotor current) the Synchronous Motor will behave as an Inductor, however if the rotor is over excited then the Synchronous Motor will behave like a Capacitor.Hope this helps
What is synchronous machein?
mainly alternator,synchronous motor comes under the synchronous machine.a synchronous motor is not a self starting motor.if a synchronous motor moves with more than synchronous speed then it acts as a synchronous generator.
What are four types of single phase motors?
zma da ghan mata sa razeEven if I do not understand the language used above I still believe that the answe above is very irrelevant, to say the least.Answer:1. Resistance start single phase motor2. Capacitor start single phase motor3. Capacitor start and run single phase motor4. Capacitor start capacitor run single phase motor
What is difference between synchronous motor and synchronous condenser?
a synchronous condenser is over excited synchronous motor under no load
Why is a capacitor NOT used in a single phase motor?
Very often a capacitor IS used in a single-phase motor. It provides a phase-shifted current to the starting winding to ensure that the motor runs in the right direction, e.g. clockwise if that is the requirement.
How to rate capacitor in single phase motor?
above 20 Rs/-
What is the purpose of capacitor in a single phase motor?
the purpose of the capacitor is to create a phase difference between main winding current and axillary winding. this would produce a rotating constant magnetic field which is required to produce the torque.
What is slip of synchronous motor?
A synchronous motor runs at synchronous speed, so there is no slip, or zero slip.
