star delta motor calcs

Discussion in 'General Electronics Chat' started by slama01902, Nov 12, 2007.

  1. slama01902

    Thread Starter New Member

    Nov 12, 2007
    2
    0
    whats the formula for working out the full load current of a star delta motor
    i think its P/V X 0.58
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Star, or Delta?

    For Star (also called "Wye"):
    Eline = \sqrt{3}Ephase
    and
    Iline = Iphase

    But for Delta:
    Eline = Ephase
    and
    Iline = \sqrt{3}Iphase
     
  3. slama01902

    Thread Starter New Member

    Nov 12, 2007
    2
    0
    i need the calculation for the amps for a star delta started motor, terminal box has 6 terminals so you are using 6 wires U1 V1 W1 / U2 V2 W2
    eg if you have a 550 kw 400 volts wired in star delta what amps is that???
     
  4. recca02

    Senior Member

    Apr 2, 2007
    1,211
    0
    in star
    current is
    power(input)/(sqrt(3)*line voltage)--line voltage is voltage across two phases.

    for delta:
    there are two currents
    current in each phase and current thru the supply lines,
    power/(sqrt(3)*line voltage)
    gives line current,
    line current=sqrt(3)*phase current
     
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