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Categories >> Engineering >> Electrical Engineering


Question What is the d/f between DOL & star delta starter & automatic
star delta starter?
 Question Asked In Companies :: ACC, Dalkia, Indeco, Wipro, Novotel, Engineering, NINL, RMH Control Systems,     < I also faced this Question! >
 Question Submitted By :: ravi
  Answer Posted By  
A DOL starter connects the motor terminals directly to the
power supply. Hence, the motor is subjected to the full
voltage of the power supply. Consequently, high starting
current flows through the motor. This type of starting is
suitable for small motors below 5 hp (3.75 kW). Reduced-
voltage starters are employed with motors above 5 hp.
Although DOL motor starters are available for motors less
than 150 kW on 400 V and for motors less than 1 MW on 6.6
kV. Supply reliability and reserve power generation
dictates the use of reduced voltage or not

To reduce the starting current of an induction motor the
voltage across the motor need to be reduced. This can be
done by autotransformer starter, star-delta starter or
resistor starter. Now-a-days VVVF drive used extensively
for speed control serves this purpose also.

Is This Answer Correct ?    465 Yes 62 No

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