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Why does the direct start up is used with low rated asynchronous motor?
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How are motor start capacitors rated?
Motor start capacitors are rated with two main values. One is capacitance in micro farads and the other is in voltage.
Why induction motor should not start by direct switching?
because IM draws 4 to 5 times the rated current when it is connected to the supply directly in order to start the IM smoothly we need starters 1.star delta starter 2.auto transformer starter DOL starter for direct starting for smaller capacity IM (upto 1HP) Note:IM means Induction motor
Why are no starting components needed on three-phase motors?
Yes, by using a DOL Starter, which gives a controlled "soft-start" for the motor even though it is always connected in delta configuration.In this type of starting a 3-phase motor, full voltage is applied to the motor through relays and contactors. Its is the most common type of 3-phase motor starter used.DOL means Direct On-Line starter.
When does a motor draw current more than its rated current?
This is a good indication that the motor is being overloaded. If the motor load is belt driven, remove the belt and then check the motor amps. If it goes back to normal FLA then there is a problem with the driven load. If the motor amperage stays high check the motor bearings for the problem.
How do you start single phase induction motor?
capacitive start motors start by themselves however a normal single phase induction motor requires a starter motor to 'kick-start' the motor into action.
How are motor start capacitors rated?
Motor start capacitors are rated with two main values. One is capacitance in micro farads and the other is in voltage.
Why induction motor should not start by direct switching?
because IM draws 4 to 5 times the rated current when it is connected to the supply directly in order to start the IM smoothly we need starters 1.star delta starter 2.auto transformer starter DOL starter for direct starting for smaller capacity IM (upto 1HP) Note:IM means Induction motor
Which type of bit synchronization utilizes start and stop bits?
asynchronous
Why is Dc series motor used to start at heavy load?
due to its high initial torque value. the DC series motor is a Constant power motor, equal to the RATED POWER if it has at rated value of the U and I. Angular velocity=Rated Power/Torque, so Torque =Rated Power/Angular Velocity thus, in the start the velocity is zero or near, so, the Torque is infinit or very higt
Why is dc series motor used to start heavy loads?
due to its high initial torque value. the DC series motor is a Constant power motor, equal to the RATED POWER if it has at rated value of the U and I. Angular velocity=Rated Power/Torque, so Torque =Rated Power/Angular Velocity thus, in the start the velocity is zero or near, so, the Torque is infinit or very higt
Why are no starting components needed on three-phase motors?
Yes, by using a DOL Starter, which gives a controlled "soft-start" for the motor even though it is always connected in delta configuration.In this type of starting a 3-phase motor, full voltage is applied to the motor through relays and contactors. Its is the most common type of 3-phase motor starter used.DOL means Direct On-Line starter.
Can 3 phase induction motor start and run rated speed by 2 phase?
yes, It would run as long as the motor was not coupled to a load. Coupled to a load the motor would have no torque and would stall.
When does a motor draw current more than its rated current?
This is a good indication that the motor is being overloaded. If the motor load is belt driven, remove the belt and then check the motor amps. If it goes back to normal FLA then there is a problem with the driven load. If the motor amperage stays high check the motor bearings for the problem.
How use start and stop bit in asynchronous transmission?
Register two times the async input. Use it in your sync system
Why use star delta gether for motor?
In a large power motor the starting current is too high if connected 'direct on line'. If you start a motor on 'star' connection it uses less current to get it going before the 'delta' connection takes over.
What happens when start and stop buttons of direct on line method starter of induction motor pressed at same time?
The stop button is connected in series so will effectively override the start button.
What size breaker is needed for a 125 hp motor?
It depends on what the amperage of the motor is. The motors amperage depends on the voltage of the motor. The higher the voltage the motor operates on the lower the amperage. So unless the amperage from the motor's nameplate is stated an answer can not be given.Just remember that the feeder capacity to the motor has to be 125% of the motors full load amperage and the breaker protecting the conductors to the motor has to be rated at 250% of the motors FLA. This higher breaker size allows the motor to start without tripping a normal size breaker that is rated for the lower conductor size.
