FAQs

Q2. Why one has to buy higher frame size motor if it is to be used with frequency inverter applications?

Q3. What is the significance of using only a particular speed motor with a particular application?
        What are the consequences if 3000 RPM motor is used in place of 1500 RPM motor or vice versa?

Q4. What is the full load current of the motor?

Q5. What is the starting current of the motor?

Q6. What is the size of starter and overload relay range required for a particular motor?

Q7. What is the full load torque of the motor?

Q8. What is the starting torque of the motor?

Q9. What is the method of starting for a particular motor.- DOL, Star-Delta, Rotor Resistance

Q10. How many times a motor can be started in an hour without any harmful effect on the winding?

• Q1. Can a 1500 RPM motor be run at 3000 RPM by frequency inverter application?

  No. It will have mechanical problems like bearing failure.

• Q2. Why one has to buy higher frame size motor if it is to be used with frequency inverter applications?

  If the motor is run at lower speed, cooling will be insufficient. With a higher frame motor more surface area for cooling will be available.

• Q3. What is the significance of using only a particular speed motor with a particular application?
          What are the consequences if 3000 RPM motor is used in place of 1500 RPM motor or vice versa?

  Driven equipment is designed to run at particular speed only. If it is run at higher speed, mechanical damage and accident may occur. If it is run at lower speed, output will be less than rated.

• Q4. What is the full load current of the motor?

  Please refer the performance chart for the motor in the relevant section on this website.

• Q5. What is the starting current of the motor?

  Please refer the performance chart for the motor in the relevant section on this website.

• Q6. What is the size of starter and overload relay range required for a particular motor?

  This has to be obtained from the starter supplier.

• Q7. What is the full load torque of the motor?

  Please refer the performance chart for the motor in the relevant section on this website.

• Q8. What is the starting torque of the motor?

  Please refer the performance chart for the motor in the relevant section on this website.

• Q9. What is the method of starting for a particular motor.- DOL, Star-Delta, Rotor Resistance

  Normally for small motors upto 10 HP – DOL, for 10 HP and above ratings star-delta and for slipring motors – Rotor resistance.

• Q10. How many times a motor can be started in an hour without any harmful effect on the winding?

  2 Hot, 3 Cold and 4 Equally spaced starts for S1 duty motors.