At site, we have 30Kw motor (3 phase, 400V,50Hz) and FLC
54A as per the nameplate. At the time of starting it draws
840A instead of 390A (7.2%). As per the data sheet also its
390A starting current. it thru a dol starter from the MCC.
can anyone tell what is the problem in the motor

Answers were Sorted based on User's Feedback



At site, we have 30Kw motor (3 phase, 400V,50Hz) and FLC 54A as per the nameplate. At the time of ..

Answer / ranjan prasad

From the question motor terminal connection is not known.
However this problem may arise if you will connect the
motor in delta instead of star. First check the terminal
connection of motor, if it is in star, connect in the same
manner.

Is This Answer Correct ?    7 Yes 3 No

At site, we have 30Kw motor (3 phase, 400V,50Hz) and FLC 54A as per the nameplate. At the time of ..

Answer / kannapa

do not use dol starer above 2.2kw rated motors

use star to delta starter it can withstand.

check also connections.

Is This Answer Correct ?    1 Yes 0 No

At site, we have 30Kw motor (3 phase, 400V,50Hz) and FLC 54A as per the nameplate. At the time of ..

Answer / r.v.giribabu

First Check the healthyness of the motor.

1. Check the winding resistence
2. Check insulation resistance using megger.
3. Check the bearing and apply the lubricant as applicable.
4. Check the healthyness of connected load.
Follow above steps adn yoiu will identify the problem.

Is This Answer Correct ?    0 Yes 0 No

At site, we have 30Kw motor (3 phase, 400V,50Hz) and FLC 54A as per the nameplate. At the time of ..

Answer / wani y.s.

First Check the healthyness of the motor -

1. Check the winding resistence
2. Check insulation resistance using megger.
3. Check the bearing and apply the lubricant as applicable.
4. Check the healthyness of connected load.( It should not
locked etc.)
5. If all above is OK. Then remove the motor from load &
ensure it is starting in ideal condition.( Hope connections
you are following up as given on the nameplate)
If it is starting in no load that means load GD squre is
high. Motor is taking longer time to start.You have to
select proper heavy duty DOL starter to withstand the
longer starting time. But ensure that motor is having
thermal time capacity to withstand this time.
7. You can also go for VFD as a starter this will definetly
will solve your problem no need to take care of thermal
time of the motor. Only select proper VFD to suit starting
torque of your application.

Is This Answer Correct ?    0 Yes 1 No

At site, we have 30Kw motor (3 phase, 400V,50Hz) and FLC 54A as per the nameplate. At the time of ..

Answer / atul pradhan

pl. check motors connection in terminal box if it is
connected in star then current may increased.

Is This Answer Correct ?    5 Yes 13 No

Post New Answer

More Electrical Engineering Interview Questions

how to calclate fault level

2 Answers  


Why the underground cables will Punchar? or what is the reason to burst the underground cables?

1 Answers  


what is mean Boost voltage and what is working principle of Tube light

2 Answers   Trimax,


What was the Dg set radiator and lube oil temperatures trip in ACB

0 Answers   Gland Pharma,


why we use post insulators in no ofstacks at substation for supporting equipment ? why we not use single post insulator

3 Answers  






is dc transformer is possible ?

4 Answers   Jyona Power,


Whats the minimum value for I.R. that can be allowed for HT & LT alternators for operation?

1 Answers  


how to set the transformer differential relay

1 Answers   Divis Laboratories,


what are the things that can cause a three phase motor to crawl?

1 Answers  


what is the current law ?

4 Answers   Aster, TCS,


Is it legal of using 3 phase motors in 2 phase in Tamilnadu?

2 Answers  


write a program that prints prime numbers from 1-20 in digonal form

0 Answers  


Categories
  • Civil Engineering Interview Questions Civil Engineering (5085)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4451)
  • Electrical Engineering Interview Questions Electrical Engineering (16632)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)