HOW to select VFD drive

Discussion in 'General Electronics Chat' started by nandha_vikram, Nov 11, 2010.

  1. nandha_vikram

    Thread Starter New Member

    Aug 14, 2010
    4
    0
    sir.. now i m using a 10HP 1500 RPM 3 phase AC induction motor as a primemover for my pump which is operating 50 bar pressure (constant) ...

    i like 2 change flow rate of pump by adjusting the frequency or voltage of input supply to the motor...

    suggest me ur best opinion to select the VFD drive to my motor.....
     
  2. JDT

    Well-Known Member

    Feb 12, 2009
    658
    85
    10HP approximately = 7.5kW. See the motor plate for its rated current.

    VFD must be able to handle power and current.

    For this power, the VFD will have 3-phase input (probably 400V).

    What is the pressure when the motor is started? The motor will need to be unloaded at start.
     
  3. nandha_vikram

    Thread Starter New Member

    Aug 14, 2010
    4
    0
    sir. that motor rating is 15HP (not a 10 HP) and name plate current is 50A..
    frequency is 50Hz. three phase induction motor...

    my requirement is want to change flow rate at constant pressure....

    in starting condition motor may be unloaded.....
     
  4. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    1,571
    230
    How would you be controlling this drive. Manual interface (speed pot), PLC networked, Feedback with Internal PID?

    Is your motor inverter duty?

    Is the pump capable of providing what you ask, and at what speed/torque range are you likely to operate?

    The best bet would be to contact your current drive suppliers to review the lines they carry. There are many offerings in a wide price range, but service and availability add to the value.
     
  5. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    I've picked up very expensive VFDs from eBay at remarkable savings and never regretted it, the size you're needing is going to be necessary but expensive.

    HOWEVER - before you spend a dime you better make sure your pump motor is "inverter rated" meaning it will safely operate off of a VFD. Inverter rated motors have higher insulation ratings than regular motors do.
     
  6. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
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