What is the formula to calculate the rating of a thermal
over load relay

Answers were Sorted based on User's Feedback



What is the formula to calculate the rating of a thermal over load relay..

Answer / barkha jha

At starting motor draws current 5 to 6 times of the flc so
overload relay setting is done this kept on mind.for e.g
3.7 kw motor the
FLC is 8 amps. we can select the relay 6A-10A range.
tripping setting is 90 % of FLC

Is This Answer Correct ?    38 Yes 7 No

What is the formula to calculate the rating of a thermal over load relay..

Answer / jayakumar.k

There is no General formula .but the general practice is
motor FLC should be the setting . for e.g 3.7 kw motor the
FLC is 8 amps. we can select the relay 6A-10A range. 8Amps
shoud be the trip setting.

Is This Answer Correct ?    25 Yes 17 No

Post New Answer

More Electrical Engineering Interview Questions

what is the difference between the alternator used in hydro and thermal power plants??

2 Answers  


1.Why use in ups in software's,reason,and pls explain. 2.what is the isolation transformer and main use it's functioning and partes.

5 Answers   TATA, Wipro,


what will happen to give a dc supply in transformers?

3 Answers  


if we supply to secondary winding how transformer work?

2 Answers  


list the advantages of RCCB over other circuit breakers?

0 Answers  






why power dissipation is due to low frequency?

1 Answers  


what are all the components required to assemble solar panel other than pv cell?

0 Answers  


Define load factor?

0 Answers  


we have a rewind motor of 2Hp,2800Rpm, 220Volt AC. how can we choose the running capacitor for this motor, any formula for that?

0 Answers  


Why the transformers making noise?

2 Answers   L&T,


what is the difference between squirrel cage & slip ring induction motor by construction & working principle ?

1 Answers   Sail,


What is the difference between eath fault protection & Restricted Earth fault Protection?

2 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)