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460/60HZ to 360V/60HZ
- Thread starter place1234
- Start date
Place 1234,
1. "My question is rewind of this motor, is there any difficulty?" : No
2. "there is one batch of these motors, say 1000 numbers, what is the solution?": Perform an economic study to know if is better rewind all motors or Install a new Three phase transformer capable to handle this 1000 Motor load (2.5 MVA??). In the case your choice is a new transformer what happeneed if the transformer fail? this will shut down all motors.By Reliability I think the better choice is rewind all motors because you can have two or three motors like spare parts.
Another alternative is to look the internal winding connection, If the motor is connected for 460 Volts in DELTA you could reconnect the winding for two wyes and the motor will works fine at 380 Volts, then you can use the 360 Volts motors because you will be only 20 Volts below the new voltage rated (380V): 5% less.
Regards
Petronila
1. "My question is rewind of this motor, is there any difficulty?" : No
2. "there is one batch of these motors, say 1000 numbers, what is the solution?": Perform an economic study to know if is better rewind all motors or Install a new Three phase transformer capable to handle this 1000 Motor load (2.5 MVA??). In the case your choice is a new transformer what happeneed if the transformer fail? this will shut down all motors.By Reliability I think the better choice is rewind all motors because you can have two or three motors like spare parts.
Another alternative is to look the internal winding connection, If the motor is connected for 460 Volts in DELTA you could reconnect the winding for two wyes and the motor will works fine at 380 Volts, then you can use the 360 Volts motors because you will be only 20 Volts below the new voltage rated (380V): 5% less.
Regards
Petronila
With such small amperage, is there a way to look at the load and decide that nothing needs to happen? For example, is the load pulling 3 amps at the low voltage at each motor, if so, that is under the limit of the motor. Does the motor have a high service factor? Could you rerate the motor with a smaller service factor?
Place123.
Since the frequency remains 60 HZ, and If the very same orginal connection and circuits are left in the new winding
, the original turns per coil (TPCo) will be reduced and the original conductor cross section area (Acuo)increased.
TPCn = TPCo*(360/460)= 0.7826*TPCo
Acun= Acuo*(460/360)=1.278*Acuo
Since the frequency remains 60 HZ, and If the very same orginal connection and circuits are left in the new winding
, the original turns per coil (TPCo) will be reduced and the original conductor cross section area (Acuo)increased.TPCn = TPCo*(360/460)= 0.7826*TPCo
Acun= Acuo*(460/360)=1.278*Acuo
I agree with the writers that suggest the transformer solution, but only because of the high number of motors.
If it was a single or a few, I would scrap them and install new motors with the correct data, rewinding is much too costly, at lesst in high wage countries.
Greetings Aksel.
If it was a single or a few, I would scrap them and install new motors with the correct data, rewinding is much too costly, at lesst in high wage countries.
Greetings Aksel.
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