ALLInterview.com :: Home Page
 Advertise your Business Here     
Browse  |   Placement Papers  |   Company  |   Code Snippets  |   Certifications  |   Visa Questions
Post Question  |   Post Answer  |   My Panel  |   Search  |   Articles  |   Topics  |   Errors
   Testimonials Refer this Site  Refer This Site to Your Friends  Site Map  Contact Us      
   
 
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,     < I also faced this Question! >
 Question Submitted By :: ravi
  Answer Posted By  
 
Answer
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 ?    436 Yes 59 No


 
  prakash
 
View All Answers
 
 
Please Help Members By Posting Answers For Below Questions
 
 Question Views   Select
 
How to test IR testing &amp; magnetic balance test 5
to hook up ten 50 amp rv pedastels at a lenth of 600 feet from the service what size will my service need to be and the size of wire will I have to run to each pedastel in series?????? 258
How to calculate total harmonic distortion level(THD) in VFD? and how can we reduce harmonics? 1788
Why are the cores of large transformers built up of circular transactions ? 302
what is the function of anti pumping relays? what is KVAR? How it is generated in alternator? What is 3rd Harmonics? What is IDMT relay? 315
what is the difference between circular wdg & ractangular wdg? 325
Following test should be conducted to find out relative polarity of transformenr terminals A no load test B back to back test C phasing out test D none of above 264
what will be d.g. capacity to cater together for 14hp A.C. load & 3kw lighting load 395
Advantages/Disadvantages of earthing of neutral bus on MSB instead of separate neutral earthing for transformer/DG sets feeding to MSB 606
what do you mean by type zero control sytem ?Give an practical example of type zero contol sytem? 286
10 tube light connect in mcb breaker.one tube light is fault.so breaker is tribe.how fault is rectified.(using 3wire phase,earth,neutral) 462
what is mean by restructuring power system? 216
how to find out difference between ELCB, MCB and RCB on looking on it 798
what is the purpose of silicon dropper used in battery charger? 1435
Frequency of rotor emf in induction motor is around A same as stator frequency B 50% C 5 % or below D 30% 249
E-Mail New Answers        Answer Selected Questions