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Question
What is the d/f between DOL & star delta starter & automatic
star delta starter?
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 11
DOL STARTER MEANS DIRECT ON LINE STARTER WHICH IS USED 2
CONTROLS THE OVER LOADS BUT IN STAR-DELTA STARTER,FIRST WE
WILL CONNECT THE SUPPLY TO STAR.WHEN THE 80% RATED SPEED
OBTAINED,WE WILL CONNETED THE TERMINALS TO DELTA CONNECTION.
 
Is This Answer Correct ?    11 Yes 5 No
Ponnu(the Elite)
 
Answer
# 12
DOL STARTER IS DIRECT ON LINE STATER THIS IS ONLY FOER OVER LOAD PROTECTION BUT THE STAR DELTA STARTER IS MOTOR PROTECTION THAT IS IN START IN STAR WHEN INITIAL LOADING IS DONE THEN IN DELTA. 
Is This Answer Correct ?    10 Yes 8 No
Prashant
 
Answer
# 13
in DOL we are going to connect 3 phase supply directly but
it will capable for less current if more current flows
through it the starter will get damage. while starting the
motor it will take more current, for reducing this start up
current we r going to star-delta connection. in this first
will be in star conection after that it will turn to delta
connection.
 
Is This Answer Correct ?    4 Yes 3 No
H.l.kiran
 
Answer
# 14
in case of dol starter the motor terminals directly to the power supply. & case of star delta the potential speed of motor starts in slowly 
Is This Answer Correct ?    2 Yes 1 No
Varun Machal
 
Answer
# 15
the voltages are reduced in dol and we can use it a proper
manner the lines are connected directly to the motor but in
star delta the voltage is step downed
 
Is This Answer Correct ?    1 Yes 0 No
Bheem Reddy Bhanu Teja Reddy
 
Answer
# 16
When the motor is connected in Delta and started by DOL method, the voltage applied across a coil is the voltage between two phases i.e, 415V approx. Therefore the current inrush is high. In order to minimize the starting current, voltage across the coils should be brought low, which can be done if we connect the coils in star. During star connection the voltage across a coil is 240V (approx) which is 1/(sq root of 3)times that in delta which results in a simultaneous lowering of current also. This eases the stress on relays and conductors.When the motor attains 90% of its rated speed the coils are connected in Delta. therefore generating higher power. 
Is This Answer Correct ?    2 Yes 2 No
Romil Verma
 
Answer
# 17
the d.o.l is 0-5H.P MOTOR,AND STRE DELTA STRTER IS USE
ABOVE 5H.P MOTOR.
THE DOL IS CONNECTED TO DIRECT TO LINE.
THE STARE DELTA IS DO NOT CONNECTED TO LINE USE.
IN AUTOMATIC STARE DELTA STATER IS NO CHANGE OVER SWITCH
THEY CHANGE BY AFTER SOME TIME BY TIMER CKT.
IN STARE DELTA STRTER INITIALLY MOTOR STARTE IN STARE AFTER
SOME TIME THEY RUN IN DELTA.
SOME TEXT.....
 
Is This Answer Correct ?    3 Yes 3 No
Bhavin Makwana
 
Answer
# 18
in dol starter starting torque is high.which is on light load.it is connectrd direct to line and used below 5hp.
in star-delta starter starting torque is 60% and it reduced to 1/3and its then connected to delta.this starter is used above 5hp.
 
Is This Answer Correct ?    1 Yes 1 No
Sanjeev
 
Answer
# 19
star delta ::This is a starting method that reduces the starting current
and starting torque. The components normally consist of three
contactors, an overload relay and a timer for setting the time in
the star-position (starting position). The motor must be delta
connected during a normal run, in order to be able to use this
starting method
dol :: this is also a starting method but some what dangerous for heavy motor who can carry heavy load. because this processes fed direct current to the motor.
 
Is This Answer Correct ?    0 Yes 0 No
Bhavin
 
Answer
# 20
=>dol starte the motor is directly fed from the line and
=>star delta starter ther motor is started initially from
star and later during running from delta
 
Is This Answer Correct ?    5 Yes 6 No
Dhinesh Cipet
 

 
 
 
Other Electrical Engineering Interview Questions
 
  Question Asked @ Answers
 
battery dis charge condition long time condtion?   1
why a single phase motor of same rating takes more amps than the three phase motor? as single phase motor at 230v takes 5amp per HP while 3 p motor takes 2.5amp per hp at 230v.   1
how can we check a fully charged battery? KSEB 2
why rating of motor in HP   2
if i have to use 14 kw what size of power cable can i use and size of earth cable also.   2
We all have seen transmission and Distribution lines In transmission lines the voltage is high and current is low(to reduce I^2r loss) and in distribution lines voltage is low but current is high however the size of transmission wires is bigger than that of distribution wires even though the amount of current carried by the distribution lines is more than that of transmission lines why?   4
Reduction in supply voltage by 10% will change the torque of the motor by ___.   1
what is the function of choke and starter in a tube light?   2
what is ALF and ISF in current transformer?   1
Construction of ac motor?   1
I HAVE CONSUMER WHOSE POWER FACTOR IS 65% I WANT TO INCREASE IT TO 98%.HOW TO CARRY OUT?   7
what is the difference between Resin Cast CT and Oil cooled CT?   1
 
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