induction motor

[Mostafaelec86]

guys am working on 3 phase induction motor in ESP system,,,, phase to phase measurements are 1800 ,1750,1800 V ,PHASE TO GROUND ARE 1000,1000,ZERO V THATS mean that motor is grounded,,,i found amp measurement are 24 A balance,,motor was running with the same ampere before the grounded measurements.

my question is how the motor is grounded and read balanced ampere? and why..

 

[davidbeach]

Those six voltage measurements weren't taken simultaneously and do not represent the same system conditions.

 

[Mostafaelec86]

how mush time does it take before total failure?

 

[LionelHutz]

It's probably a floating power system and if so then something will fail to work when a second ground fault occurs on the system.

 

[Skogsgurra]

Your best option is to wait and see...

Or, if you feel convinced that there's something wrong with the installation - as opposed to your measurements, switch the motor off and let an electrician examine the installation.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[waross]

When one phase of an ungrounded system is grounded, (sometimes done intentionally and called corner grounded) one phase to ground voltage goes to zero and the other two phase to ground voltages rise to the respective phase to phase voltages.
THAT DOESN'T MEAN THAT THE MOTOR IS GROUNDED. It means that there is a ground somewhere in the system. That is; anywhere from the supply transformer to and including the motor.
The ground may be in the motor, but the even amperages suggest that the ground is in the supply wiring.
Disconnect and insulate the motor supply leads at the motor junction box.
Re-check your voltages at the motor starter.
Then do a continuity check of the motor leads to ground.
That should isolate the problem.
You may need a Megger check later but not yet.

Bill
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"Why not the best?"
Jimmy Carter