we have pvc pipe plant due to low voltage and low connected load we want to use 15 HP 3 compressor on single vfd. compressor will never stop and start we have max 10 kg pressure cut off for com but from 9kg pressure we reduce rpm of com and when it reach to 6 rpm incrise

Are you going to start all the compressor altogether. If yes get VFD at least 50 HP and connect all compressor together otherwise it is not possible to drive compressor with only one vfd. I am considering 3 phase motor.

thank we are using 3 phase motor on lg compressor all run at a time. which vfd i sgood in terms of cost ,after sales service, spare part.we are base at dehradun haridawar.we have vfd on pvc extruder yaskkawa japan and vacon finland

Go for Siemens vfd.. They might be costly but serves well.and service its also good.

maybe you'll have to connect a filter between your VFD and motors. This is described in the datasheet of the VFD.
Danfoss or Siemens are the best

In a machine i need to do oscillation.Using micromaster420 should i do?I have planed to use limit switch and reversing the motor rotation when i get feed back from LS.I have doubt that the frequency of oscillation should be very less.any one should any idea about this.

We made a big transporter system with 12 motors and have had big problems with heating of motors protections.

Dear Amit das

try a servo motor for oscillation ,it is the best

Dear Suresh

always find out the load current of the output and then decide since VFD is selected based on Load Current