why star point of motor shall not be grounded?
Answers were Sorted based on User's Feedback
Answer / ranjit kumar mallick
In induction motor the rotor movement is due to it's
interaction with the stator resultant rotating magnetic
field flux and the resultant magnetic flux is due to the
three phase closed circuit. Once we ground the star point
the resultant magnetic field will drop and it becomes
extremely dangerous in case of fault as motor will run at
low speed without triping due to the current path available
to ground.So it will draw high current
Is This Answer Correct ? | 6 Yes | 3 No |
Answer / sarwar
Star point of motor is not necessary to ground because a
motor is a balanced load.So,no current will flow through
star point to nutral.
Is This Answer Correct ? | 7 Yes | 4 No |
Answer / vishwanath chothe
Grounding a motor star point will create an earth path for earth leakage current to flow through that motor's star point. If there are 10 motors in a process plant and their star points are all grounded, there are 10 additional paths for earth leakage currents to flow through.
If all the motors' star points are grounded in this way the earth fault current detections by the protection relays will be complicated and likely they will trip at the incorrect locations because earth fault currents are flowing in many directions toward multiple grounded neutral points.
Therefore the electrical consumers (ie the load, including the capacitor banks), even if they are star connected, are not to be grounded.
Is This Answer Correct ? | 1 Yes | 0 No |
Answer / nadeem
Bcoz star point make additinal loop to source volatge and leads to burst the motor...
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / suresh
if unbalance current in motor then motoe burnt due to the
y point earthed
Is This Answer Correct ? | 3 Yes | 5 No |
Answer / raju_
STAR CONNECTED WINDING IS CLOSE LOOP CIRCUIT IT SELF IF
YOU TRY TO GROUNDED THEN CRIRCUIT NOT GOING CLOSE THEN
MOTER WINDING IS NOT GENRETED E M F AND MOTER
CANT'PERFORMING WELL! THATS WHY WE CANT GROUNDED THE STAR
CONNECTED WINDING.
Is This Answer Correct ? | 1 Yes | 5 No |
Answer / rsjendran
The star point of the motor can not be earthed since fault
currents from other systems may enter in to the motor
circuit ....
but normally motors are not protected againest this...
since it is advisable to ground the star point of the motor
thanks
Is This Answer Correct ? | 1 Yes | 6 No |
Answer / sai
In the internal winding of the terminals shorted as a
nutral is Act to as earth.
Is This Answer Correct ? | 2 Yes | 9 No |
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