Calculating current requirements for this motor

Discussion in 'General Electronics Chat' started by vijaybala85, Jul 14, 2010.

  1. vijaybala85

    Thread Starter Member

    Jan 7, 2010
    Hi everyone,

    This is the information I have regarding a single phase motor that will run at 120VAC. I would like to know how to calculate the current the motor would source from the supply. I have limited experience dealing with motors but this is interesting to know nonetheless.
    Here are the details

    1 off assembly part number: P1-008-XXX-XXX-XXX-C03
    P1 axial piston water pump @ 0.8l/min
    0.37kw, single phase, 4 pole, 71 frame, foot/flange mount in permanent cap style electric motor
    Bell housing
    Relief, check and unload C03 valve assembly

    This statement was sent to me as well..

    It is 120 volt of course and would have a current draw similar to a ½ hp capacitor motor that we would source locally.

    How to know what value it sources from supply? Please let me know. I am trying to control this motor from a Data acquisition card that would control a relay which switches on/off the motor. Any help would be greatly appreciated. Calculations, circuit setup, diagrams, explanation... etc.. Thanks!

  2. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    CEC lists a 1/2 hp - 120v motor as 9.8 FLA
  3. vijaybala85

    Thread Starter Member

    Jan 7, 2010
    Also, can you point out the difference between a solid state relay/switch and a mechanical relay?

  4. hspalm

    Active Member

    Feb 17, 2010
    Why cant he just divide the 370 watts and the 120 voltage to get amps while running at full throttle? Is this because of the stall-current when starting the motor will exceed this 3 amps?

    A solid state relay is like a mechanical relay in its usage. The load and the control signal is optically isolated from the latching circuit by a diode and a phototransistor, which in turn "latches" a thyristor or power transistor for the load. This means you have no moving mechanical parts.