AC Motors

Question 1

What are the 2 AC types that motors can be available in?

Answer 1

1. Single phase
2. 3 phase

Question 2

Different voltages like 115, 208, 230 etc just depend on what?

Answer 2

The transformer being used

Question 3

What do more poles in the motor do?

Answer 3

Lower the rpm and raise torque

Question 4

What are some factors that can make a motor overheat?

Answer 4

Clogged fins, voltage fluctuation, overloading, high ambient Temps, repeated starts and stops

Question 5

Because of motors being manufactured by nema what are is some information you can give when ordering a new one if you don’t have a motor data plate?

Answer 5

Shaft center line and bolt pattern

Question 6

What on the data plate would give you the insulation value?

Answer 6

Motor class

Question 7

What is the definition of service factor?

Answer 7

The amount of overload a motor can take before overheating

Question 8

What is the most common service factor for a motor?

Answer 8

1.0

Question 9

What the service factor goes up what has to go up with it?

Answer 9

Motor class

Question 10

If rpms are low what are torque and current?

Answer 10

High

Question 11

2 types of mounting styles ?

Answer 11

1. C-face
2. D-flange

Question 12

How to know if it is a c-frame mount?

Answer 12

Driven unit is bolted to the motor

Question 13

How to know if it’s a D-flange mount?

Answer 13

Motor is bolted to driven

Question 14

What protects a motor?

Answer 14

Overloads

Question 15

What does mto and ato stand for?

Answer 15

Manual and automatic thermal overloads

Question 16

What are the parts of an ac motor?

Answer 16

Rotor, stator, end bells, fan, fan shroud and shaft

Question 17

Why are ac motors the go to of the industry?

Answer 17

High efficiency, cheaper cost and start up torque

Question 18

What is the slip in a motor?

Answer 18

The difference between synchronous speed and actual speed?

Question 19

Biggest downside of a single phase motor?

Answer 19

There is no start up torque

Question 20

What do we know about shaded pole motors?

Answer 20

The motor rotates in the direction of the shading ring

Question 21

What do we know about split phase motors?

Answer 21

Once it reaches the full rpm a switches kicks out the starting windings

Question 22

Most common single phase motor used in industrial applications?

Answer 22

Capacitor start motor

Question 23

Permanent split capacitor motors are common for what?

Answer 23

Changing speed and direction of a fan