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
My question is abt backlog.I had dropped one subject in my second year, and completed this subject in the 3rd attempt, so how many backlogs i have got?1 or 3?plz sujjest the answer as soon as possible
what is package substation.how many types they have
Actuality I have at home electrical panel with 220v 50hz, and I want to converter from there to 110v 60hz, to wiring on the half of my house. Also I like to keep another half of my house with the original 220v 50hz. What is the best and safety way to do?
What is EHT tariff or Power factor Tariff ????
What is the tube exial fan?
what kvrah y we need to take the readind of that
Transmission voltage is kept 11KV,33KV,66KV,132KV,220KV due to form factor. What happen to 400KV and 765KV transmission voltage?
What is the formula to calculate the no load current of a single & three phase induction motor
Dear all, how we select the cable size according to current with or without including different correction factor , is there any direct method for sizing of cable...
what is booster? and how it is connected in a circuit?
acb(AIR CIRCUIT BREAKER)NOT CHARGING AUTO
What shall be the secondary output voltage if the primary winding of a 220/6V, 50 Hz transformer is energized by an 110V, 60 Hz supply?
Brushes are placed at magnetically neutral axis,when brushes reach that point,the armature conductor gets shorted,but it can be seen that the dc supply is also shorted,wont that get damage? help me plz
What does the kvar means?
How to select circuit breakers rating eg. if i select a circuit breakers of capacity 40 amps DC with operating voltage 28 volts and if i what to use same circuit breakers for 300 Volts DC application what is the current rating of this circuit breakers.