Which motor should not be started at no load?
When the DC series motor is connected to the load at the time of starting of the motor, the motor draws the more armature current compared to the starting current with motor operation at no load and the speed of the motor increases in the controlled way. The DC series motor must not be tested on no load condition.
Why does series motor always run with load?
But practically the motor will accelerate to very high speed , which will damage the motor. But if you start the motor with the load, you are actually reducing the starting speed hence the motor runs safely. Since series motors has this property it is used in trains to pull high load.
Can a series generator be operated on no load?
When the series field is connected in reverse so that its field flux opposes the shunt field flux, the generator is then differential compound. … At no load, only the shunt field is effective. When no-load voltage build up is achieved, the generator is loaded.
Which DC motor has maximum self loading property?
Which DC motor has got maximum self-loading property? Explanation: A differentially compound DC motor, flux reduces so sharply at small increase in load at higher values of load.
Which motor has highest no load speed?
Explanation: At no load, armature current tends to zero, flux φ tends to zero, where speed is inversely proportional to the flux, speed will tend to infinity. Thus, no load speed of DC series motor is highest.
Should always be started with load because?
When the motor is connected across the supply mains without load, it draws small current from the supply mains. … The increase in back emf weakens the armature current and hence the field current. This cause again increases the speed so the back emf.
Is advised not to run DC series motor with no load why?
It is advised not to run dc series motor with no load. … Explanation: If the torque is zero in dc series motor then the speed will be infinite causing the damage of the machine permanently. 6.
What is the main disadvantage of a series motor?
The series motor has poor speed regulation. When the load speed of the machine increases, the DC shunt motor keeps its constant speed from no load to full load. The dc series motor’s Torque drops sharply when the speed increases.
What is the DC series motor?
Series DC motors are a group of self-excited DC motors in which the field coil is connected in series to the armature winding and thus a higher current passes through it. A series DC motor mission is to turn the electrical energy into mechanical one based on electromagnetic law.
Which DC motor has self relieving property?
Which DC motor has got maximum self-relieving property? Explanation: DC series motor develops large starting torque initially and slow down with increase in load and so get automatically relived from heavy excessive load. Thus, DC series motor is called as self-reliving machine.
Which DC motor is preferred for constant speed?
DC Shunt-wound motor: This is an almost constant speed motor and its torque varies nearly as the current.