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difference between them based on the time where time of starting current equal to 2:8sec. & time of locked rotor current equal to 20:25 sec. so it is called also long start time fault.

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What is locked rotor in three phase induction motor?

A motors locked rotor current is the same as the motors starting current. This is the point where the voltage is applied to a non rotating motor, time cycle zero. Because the motor is not rotation and generating a back EMF to oppose the inrush current, the current will go as high as 6 times the running current of the motor.


What is locked rotor current for 3 ton AC?

LRC for 3 ton AC is approximately 5 double the running current (75 A )


What can be done to reduce locked rotor amps?

Reducing the locked rotor amps can be achieved by improving the motor's design or size, ensuring proper maintenance to prevent issues like high friction or misalignment, using soft start technologies or variable frequency drives, and ensuring that the electrical system can handle the motor's starting current requirements.


Why is it that the revolution and rotation of the moon are different?

They aren't different, by earth standards. Luna is tidally locked to the earth's gravitation, so it always keeps the same side facing earth.


What size breaker for a locked rotor motor rated at 54 amps?

For a locked rotor motor rated at 54 amps, it's generally recommended to use a breaker rated at 250% of the full-load current for starting protection. Therefore, you would calculate 250% of 54 amps, which equals 135 amps. However, to comply with electrical code and ensure proper protection, you might choose a breaker size typically available, such as a 150-amp breaker. Always consult local codes and regulations for the final decision.

Related Questions

What is the formula for starting current?

The formula for starting current (Istart) can be calculated by dividing the locked rotor current (ILR) by the motor's starting power factor (PFstart). It can be expressed as: Istart = ILR / PFstart.


What is ip in motor?

I p or current peak sometimes LRA (locked rotor amps) on the nameplate kva class F would mean peak current 7 times the running full load current starting current same thing different names same idea


A particular 3 phase induction motor has a LRA of 100 amps What is its approximate starting current?

LRA (locked rotor amperage) is not considered. Starting current for a motor is usually in the neighbourhood of 300% of the FLA (full load amps). The FLA is taken from the motor's nameplate.


Difference between static and dynamic charercteristic of motor?

I think you are talking about the study of the electrical system for motor starting in ETAP (or any such software). Here are the answers:1. When do we use Static and Dynamic motor starting?If you know the Motor torque characteristics, Load torque characteristics and the inertia information of the motors, bearings and loads, you can do the Dynamic motor starting study. Otherwise, do the Static motor starting study - it simply needs the starting time and the locked rotor current of the motor.2. What is the difference between the two?(1) The Dynamic motor starting develops the motor starting current characteristics based on the motor starting torque, load torque and the inertia, while the starting current remains flat at locked rotor current during the starting time for Static acceleration. (See the previous posting http://cr4.globalspec.com/thread/42981 , comment # 2 for detail how the starting time is calculated for Dynamic acceleration).(2) Dynamic starting acceleration requires additional data than the Static acceleration.(3) The Dynamic acceleration calculates the acceleration time and current from the input data, while the Static acceleration assumes you know the starting time and current.(4) For Dynamic acceleration, the starting current is not 100% flat during the starting time, but in Static acceleration it is flat.(5) Static acceleration is simple, Dynamic acceleration is rather complicated.3. Can we evaluate the system using Static only not dynamic?Yes. Make sure you have the correct information for motor locked rotor current and the stating time for the load.Go the ETAP tutorial site (http://www.etap.com/training/tutorials-training-videos.htm) and see the tutorial #12 (Dynamic Acceleration) and #13 (Static acceleration).curtesy msamd


What is locked rotor?

Locked rotor current is the amount of current a motor would draw if you energize the motor and the rotor (the spinning shaft) doesn't spin.


Do you lose anything if you change your Character Class to a different one anytime after the start of the game in Mass Effect 2?

You can't change your character class after you have created and locked in your character for the game without starting a new one and losing all of your current progress.


When the starter armature is stalled current is?

"Full locked amperage" or "Full locked start-up Amperage" is what I was taught.


What is locked rotor in three phase induction motor?

A motors locked rotor current is the same as the motors starting current. This is the point where the voltage is applied to a non rotating motor, time cycle zero. Because the motor is not rotation and generating a back EMF to oppose the inrush current, the current will go as high as 6 times the running current of the motor.


Is the induction motors running current or its locked rotor current more important in generator selection?

Running current. The locked rotor amps are only seen at initial start up which only lasts a fraction of a second to one or two seconds.


What is the locked rotor current on a 3 ton air conditioner?

You need to first know the wattage of the motor and locked rotor current can be tested at a lab only


Why locked rotor test is performed?

Electrical machines such as motors are designed to withstand a certain maximum rated current (continuous) and a fault condition current for a short duration only. In order to practically verify this capability, a locked rotor test is performed on the motor as part of the final factory acceptance test. The motor rotor is mechanically locked and rated current is applied to the stator winding incrementally, starting from zero, all at rated supply voltage and frequency. Motor stator winding temperature is monitored and also the shaft output torque can also be calculated, if a load cell or strain gauge is connected to the torque arm. Therefore this locked rotor test (which is equivalent of a short circuit test for a generator) is used to verify the maximum current handling capability of the motor. Anush GE


What current would be drawn by a 15KW 400V AC motor with a locked rotor?

yes