1PH8 with no drive

Hello,

I have a customer with many 1PH8 installed in your plant with papers machines (Perrini and other brands). The install base is around 300 servomotors and they have a lot of experience with these motors.

Last week they sent me a question regarding connect 1PH8 without servodrive (Sinamics), directly with contactors in line supply (R,S,T). Off course  I answered them that our motor was assembled to work with drives to be a special motor different from standard asynchronous motor AC.

But, they didn't accept my answer and they need to understand WHY NOT use this motor without servodrive.

I have been tried to find some manual or explanation to send to them. Can you help me with some technical  answer or manual? Explaining that is impossible to connect this motor without Servodrives.

Thanks,

Marcelo Udo

Hello M.UDO,

1PH8 series asynchronous as well as synchronous motors are designed to work at rated voltage with rated frequncy which needs to be operated with drive. 1PH8 series motors are not standard induction motors which are designe to work on direct supply voltage at standard frequency 50/60Hz. 

Please refer the attached sheet extracted from Siemens manual for more detail.

You may also ask your customer to check the name plate details of 1PH8 series motor, which will give details about motor rated voltage & rated frequncy specifications. So it needs AC drive to supply the motor its rated voltage, rated current at rated frequnecy so that motor would deliver the rated power.

HTH.