ac question

Discussion in 'General Electronics Chat' started by shahnawaz, Nov 25, 2010.

  1. shahnawaz

    Thread Starter Active Member

    Dec 30, 2008
    dear friends,

    plz help me regarding the difference between delta and star connections.
    what is the advantage of delta connection based equipments like rectifiers, as compare with the star connection.

    i have a rectifier(48vdc o/p) module of rationg 11kw. but it operates on 03 phase with earth. no neutral connection provided to the module. so what exactly benifet we can get without the neutal connection.

    thanks much
  2. JDT

    Well-Known Member

    Feb 12, 2009
    Delta - 3 wires. Star - 4 wires.

    • The star point is often earthed.
    • Star connection often used when one side of each phase load needs to be at neutral or earth potential.
    • Star connection used when each phase has different loading.
    For example: In a street of houses, each house is connected to a different phase. Although each house will use different amounts of power, over lots of houses the load will be roughly balanced. In a star connection, if all phases have an equal load the neutral (star point) current is zero. So the copper is not efficiently used.

    • Delta - more efficient use of copper.
    • Delta - normally used on balanced loads.
    • Delta - third harmonics cancel out (I think - correct me if wrong!)
    Induction motors usually delta connection.