What is single phasing,causes and effects.

Single phasing is said to be occur when one of the phase is broken in a three phase line. This will cause no current passing through one of the line and 2.4 times more current in other two lines for normal load.

Cause
     One of the fuse may blown off.
     Line wore broken.
     Relay contacts damaged.

Effects
      High current passing through other two lines which will gradually damage them.
       Due to single phasing uneven torque will be produced which will result in vibration of motor.
        It is impossible to start a motor wiit single phasing.
        Motor speed may get reduced.
        Motor winding will melt due to overheat.
 
Protection   
      Overload relay
       Thermostats which will indicate an alarm by temperature change due to single phasing.  

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