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In series motor, At no Load Condition the flow of Armature Current is low, then the Flux is also low. Flux is inversely proportional to speed. If flux is decrease the speed is rapidly increase it spoil the rotor parts...... so SERIES MOTOR is start with LOAD.....
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Why dc series motor cannot be start without any load?
If a DC series motor is started without load, the armature winding (winding that doesn't spin) current will be at a minimum, resulting in the motor going to maximum speed / runaway, which can cause things to fly apart. As Armature current increases, the speed of the motor will decrease. The armature current will be forced to increase / speed of the motor will be forced to decrease as more and more load is applied.
What is the speed of DC series motor at no load?
No load speed is the speed that the motor run when it has no load, i.e., the motor is separated from the engine, that speed is than greater than the rated speed, because the rated speed is the speed whwn the motor are linked to the load and it is the full load.
Why a DC series motor should never be stared without load?
since torque is proportional to flux and armature current . Flux for dc shunt is constant . torque is proportional to armature current only. And initially armature current is very low hence it cannot be started at load .
Why no load-speed of a dc series motor is very high?
high torque
How many times an electric motor can be started in 1 hour?
It depends on the motor's design. One motor I recall could only be started three times in an hour, and then only in exigent circumstances. Others are not so limited. It comes down to the thermal load that is placed on the motor as a result of startup.
Why dc series motor cannot be start without any load?
If a DC series motor is started without load, the armature winding (winding that doesn't spin) current will be at a minimum, resulting in the motor going to maximum speed / runaway, which can cause things to fly apart. As Armature current increases, the speed of the motor will decrease. The armature current will be forced to increase / speed of the motor will be forced to decrease as more and more load is applied.
Why dc series motor is never started on light load?
the speed N is inversely proportional to armature current I. At light loads this current is very small. Hence motor will run at very high speed when started on no load/light load.........
What motor must be never run without a load connected to them?
DC Series motor should never run without load connected to it because starting torque for DC series motor is infinite and running it on no load will damage the motor due to overspeeding.
When did the series circuit started?
dc ckt are only started with load...
What is the speed of DC series motor at no load?
No load speed is the speed that the motor run when it has no load, i.e., the motor is separated from the engine, that speed is than greater than the rated speed, because the rated speed is the speed whwn the motor are linked to the load and it is the full load.
Why dc series motor is always runs at loads?
At no load, the flux is only due to the residual flux, which is very small. the no load speed of dc series motor is very high. so the rotating part of the motor are damaged. hince dc series motor should never be run without motor.
Why a DC series motor should never be stared without load?
since torque is proportional to flux and armature current . Flux for dc shunt is constant . torque is proportional to armature current only. And initially armature current is very low hence it cannot be started at load .
Why the series motor is started with some initial load?
In dc motors Speed is directly proportional to back emf and inversely proportional to flux i.e N∝(Eb/φ) In series motor back emf is practically constant. So if we start motor without any load Flux will be small and so speed will be very high. if we start motor without any load it will gain very high speed and may get damaged due to centrifugal forces. Series motor have very high starting torque and used where high starting torque is required.
Why can we start a shunt motor under no load but why can't a series motor?
The torque on a series motor is determined by the square of the armature current and, so, is very large -much larger than that of a shunt motor. Consequently, on starting, with no back-emf being generated, the torque on a series motor can be dangerously high if the machine has no mechanical load.
Why we apply load during starting a d.c.series motor?
a series motor started without load can go into a condition called runaway. The motor will rapidly accelerate to unsafe speeds literally pulling itself apart. This condition should never be allowed to happen. Consult a professional when installing any electrical equipment.
Why no load-speed of a dc series motor is very high?
high torque
Why a dc series motor should never run at no load condition?
if you run the unloaded motor at max rpm the centrifugal forces will cause the motor to be totally destroyed so it is advisable to not to run it at max rpm it should be okay to run it till 50% of max rpm without loading it
