What is load test on DC series motor?
In load test on dc series motor, the motor should be activated on load condition because if the motor can be activated on no load, then it will achieve an extremely high speed.
Why is a DC series motor used to start heavy loads?
The starting torque of the DC series motor is proportional to the square of the armature current. … That is why DC series motor is capable to produce high starting torque, and it is preferred for driving heavy loads.
What are the advantages of DC series motor?
Advantages of DC Series Motor
Dc series motor have good accelerating torque. Dc series motor have a relatively huge starting torques. Dc series motor delivers high torque during an overload. The dc series motor draws less current and power from the source compared to a shunt or compound motor.
What are the applications of DC series motor?
In portable applications using battery power, DC motors are a natural choice. DC machines are also used in applications where high starting torque and accurate speed control over a wide range are important. Major applications for DC motors are: elevators, steel mills, rolling mills, locomotives, and excavators.
What is no load current in DC motor?
The no-load current is the current required just to turn the motor shaft with nothing connected. It is the current required to overcome the bearing and brush friction plus the aerodynamic drag caused by the rotor moving in the air and moving air through the motor for cooling purposes.
What polarity do Interpoles take in a DC motor?
Interpoles are narrow poles placed at the GNA and fitted to the Yoke and also known as Commutating Poles or Compoles. For generator, the polarity of Interpoles must be same as that of main Pole ahead of it in the direction of rotation. For Motor, the polarity of Interpole must be same as that of Main Pole behind it.
What is the speed of DC motor?
DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors.
Which power is mentioned on a name plate of a motor?
Which power is mentioned on a name plate of a motor? Explanation: Name plate of the motor shows rated values i.e. rated speed, rated current, rated voltage. It also shows output power available at shaft when all other quantities are set to rated values.
Which DC motor is preferred for the constant speed?
Explanation: Rotary compressor generally demand constant speed operation throughout the load. Sometimes, DC machines are not able to produce constant speed throughout the process hence, synchronous machine is used. 4.