QUESTION The purpose of an interpole in the DC motor design is to ____. reduce heat generated under load increase torque when running under heavy load conditions reduce rpm when under exceptional mechanical loads reduce sparking at the commutator

Delmar's Standard Textbook Of Electricity
7th Edition
ISBN:9781337900348
Author:Stephen L. Herman
Publisher:Stephen L. Herman
Chapter33: Single-phase Motors
Section: Chapter Questions
Problem 16RQ: When a repulsion-start induction-run motor reaches about 75% of rated full-load speed, it stops...
icon
Related questions
Question

QUESTION 

  1. The purpose of an interpole in the DC motor design is to ____.

       

    reduce heat generated under load

       

    increase torque when running under heavy load conditions

       

    reduce rpm when under exceptional mechanical loads

       

    reduce sparking at the commutator

    QUESTION 

    1. One of the dangers of Series motors is : _______________

         

      They are inherantly unstable and should never be used.

         

      The motor can reach dangerous RPM if there is no load.

         

      The motor overheats quickly when loaded at 100%

         

      The CEMF will stop the motor too quickly when the load is suddenly reduced.

      QUESTION 

      1. As a motor increases in rotational velocity to 100%  of the rated RPM, the CEMF induced in the motor:

           

        increases upto 7 to 10x the source voltage.

           

        almost zero.

           

        increases to the point where it is almost the same as the source voltage.

           

        stays the same

        QUESTION 

        1. The size of the conductor feeding the motor should be able to carry at least ____ of the full-load current.

             

          125%

             

          200%

             

          150%

             

          100%

          QUESTION 

          1. The proper way to determine the required over-current protection is to:

               

            determine the FLA based on the nameplate.

               

            Use the standard rule of thumb that the over-current protection shall be 7 to 10x the locked rotor amps.

               

            determine the watts by converting the HP rating on the nameplate to watts.

               

            to determine the FLC by looking up the value in the appropriate table(s) in the NEC as they relate to the horsepower of the motor.

            QUESTION

            1. The resistance of the Armature's conductor coil(s) in most motors is: _________.

                 

              quite high, usually a few thousand ohms or more depending on the size of the motor.

                 

              Typically an open circuit value on most multimeters

                 

              quite low, usually a few ohms or less depending on the size of the motor.

                 

              very high, usually in the megaohms.

Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps

Blurred answer
Knowledge Booster
DC Generator
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Delmar's Standard Textbook Of Electricity
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:
9781337900348
Author:
Stephen L. Herman
Publisher:
Cengage Learning