good morning;



I am electrical engineer, I have a question about thermal protection of HV motors, concerning the importance of winding temperature detedtors in this protection; anyway in case wherever these detectors are defected can we dispense of them and count upon the electrical protection as [ANSI 49,46,51LR and 66]?

[49] thermal overload protection
[46] unbalance protection
[51LR] locked rotor protection
[66] number of starts limitation


Best regards.

 

The more expensive the motor the more layers of protection you should have. While you can risk it and run without the RTD, you really should plan to have it repaired during planned maintenance. Hopefully the cost of repairing the RTD is cheaper than replacing the whole motor.

 

Djaba...
Welcome to Control Automation.
As GMcc pointed out, the more expensive the motor, then more layers of protection should be provided.
I presume you consider Protection, to mean shutdown the motor! But, RTD's should never be used for protection!
However, you have mentioned 4 of the 13 electrical conditions that can negatively affect Induction Motors (15 for Synchronous-Motors).
Statistics indicate that the most likely, and costly, are stator-winding ground-faults.
My advice is that you consider Stator-Winding Ground-Fault protection. This forum has covered many methods. If you want additional information, just ask!
Regards, Phil Corso
BTW, you can use the Magnifying Glass in the heading of this discussion for additional information.

 

good morning Sir;
is the exploded view of motors can be delivered by the manufacturer free?
regards.

 

Djaba...
Welcome to Control Automation.
As GMcc pointed out, the more expensive the motor, then more layers of protection should be provided.
I presume you consider Protection, to mean shutdown the motor! But, RTD's should never be used for protection!
However, you have mentioned 4 of the 13 electrical conditions that can negatively affect Induction Motors (15 for Synchronous-Motors).
Statistics indicate that the most likely, and costly, are stator-winding ground-faults.
My advice is that you consider Stator-Winding Ground-Fault protection. This forum has covered many methods. If you want additional information, just ask!
Regards, Phil Corso
BTW, you can use the Magnifying Glass in the heading of this discussion for additional information.

thanks

 

good morning Sir;
is the exploded view of motors can be delivered by the manufacturer free?
regards.

 

@Djaba
What do you mean by "Exploded view of motor"?
Regards, Phil Corso (PE, Semi-Retired)
[email protected]

 

@Djaba
What do you mean by "Exploded view of motor"?
Regards, Phil Corso (PE, Semi-Retired)
[email protected]

a view showing the general assembly of motor like rotor, stator bearing ..etc.

 

@Djab...
Thank you for the information. The motor manufacturer may have proprietary information related to a patent! How much money is in question?
Phil Corso