why dc series moter is not started at no load?
Answer Posted / abhishekkumar
Motor armature current is decided by the load. On light load or no load, the armature current drawn by the motor is very small.
In case of a d.c. series motor,
Φ α Ia
and on no load as Ia is small hence flux produced is also very small.
According to speed equation,
N α 1/Φ as Eb is almost constant.
So on very light load or no load as flux is very small, the motor tries to run at dangerously high speed which may damage the motor mechanically. This can be seen from the speed-armature current and the speed-torque characteristics that on low armature current and low torque condition motor shows a tendency to rotate with dangerously high speed.
This is the reason why series motor should never be started on light loads or no load conditions. Foe this reason it is not selected for belt drives as breaking or slipping of belt causes to throw the entire load off on the motor and made to run motor with no load which is dangerous.
Is This Answer Correct ? | 5 Yes | 0 No |
Post New Answer View All Answers
Why do we use copper cable for HT Supply and why not Aluminium?
What are the advantages of a three-phase system over a single-phase system?
What are the factors influence the choice of an electrc drive?
Post possible questions for Power Factor Panel FAT / SAT
what is the significance of cabability curve of alternator
comparision between ACB and VCB
how oti and wti connections are different from each other?
what is difference between speed mode and torque mode in motor?? explain in simple words please.
sir& friends i want the collection of recent quetions asked in interview of top most companies please send me on my email san.jsr@hotmail.com
what is the difference between "Rotary bypass isolation switch and Normal bypass switch" pls share indepth techs?
List examples of current sources?
What current flows in the transformer primary when its secondary is open?
WHY DO VOLTAGE TRANSFORMERS FAIL DURING EARTH FAULT IN THE DELTA CONNECTED 6.6KV ELECTRICAL SYSTEM
What is the basic principle of operation of alternators/dc generators?
What is core CT & it's function?