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, Novotel, Engineering, NINL, RMH Control Systems,     < 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 ?    465 Yes 62 No


 
  prakash
 
View All Answers
 
 
Please Help Members By Posting Answers For Below Questions
 
 Question Views   Select
 
This is urgent!! What is a Thyristor-based 3-ways selector switch with Zero crossing control? how does it operate and where is it mostly found in a system? 375
Block diagram of Power line communication? 547
High voltage test procedure of in swgr board. why should measure millivolt drop on testing time? 447
why any centrifugal blower draw more current in starting. consider id fan and fd fan? 237
how we can do the insulation on secondary of ct explain and so that tan delta will within limit 353
what is ground fault in ACB? 396
Briefing the effects of ASR and ACR of a double closed-loop speed regulating system. 337
how the CT and PT is connected in the circuit during testing of transformer explain with diagram 433
Transformer how to maintaince a check b check c check d check 129
What happens to a line-frequency of high-frequency transformer when it is first energized/ re-energize? 568
with out colour codeing on conductor how can be find what is r,what is b,what is y phases..... 342
What are the main parts of central chiller plant? Explain the function of each stage. 2778
How can we increase the capacity of Energy.? 458
how can we find thae value of capacitor for single phase motor. what is difference between starting capacitor and running capacitor. 816
how to select electronic timer(Star-Delta) setting for diff. rating motors 283
E-Mail New Answers        Answer Selected Questions