Deck 6: Motor Nameplates

Question 1

_______________ horsepower is the horsepower output the motor is designed to deliver on a continuous basis, when the motor is energized with its rated voltage and frequency.

Answer 1

Rated

Question 2

North America is standardized to operated on _______________ Hz rated frequency.

Answer 2

60
sixty

Question 3

A good rule of thumb to remember is that for every ____ degrees C the operating temperature of a motor increases over rated temperature, the motor life will be cut in half, because excessive heat will cause the type of electrical insulation used in motors to fail.

A)10
B)20
C)30
D)40

Answer 3

A

Question 4

A ____ type of motor shaft has threads on the end of the shaft, and is used on uni-directional motors for special applications such as driving impeller of jet pumps.

A)flat
B)key
C)round
D)threaded

Question 5

____ is the maximum twisting force supplied by the motor at its rated horsepower.

A)Max torque
B)High torque
C)Rated torque
D)Ranked torque

Question 6

A ____ type of motor shaft is found on very small shaded pole C-frame motors.This type of shaft design is limited to only very low torque requirement applications, because only the friction of the setscrew of the coupling device with the mechanical load is preventing the shaft from slipping.

A)flat
B)key
C)round
D)threaded

Question 7

A ____ type of motor shaft is found on motors with 5/8" and larger shaft diameters.Its purpose is to prevent the shaft from slipping on the coupling device with the mechanical load.

A)flat
B)key
C)round
D)threaded

Question 8

An example of a standards agency is _____.

A)NAMEPLATE
B)CODE
C)NEMA
D)DCG

Question 9

The rated voltage of a motor listed on the nameplate is called the _______________ voltage.

Question 10

The ____ of a locked-rotor current is calculated with the motor's design code letter.

A)color
B)size
C)shape
D)intensity

Question 11

A ____ is found on motors up to 1/2" diameter shaft.The portion of the shaft provides an area for a setscrew on the sheave, coupler, or whatever other device is connecting the motor to the mechanical load, to seat and prevent the shaft from slipping.

A)flat
B)key
C)round
D)threaded

Question 12

____ indicates how well a motor converts electrical energy into mechanical energy.

A)Efficiency
B)Work
C)Power
D)Torque

Question 13

Automatic protection usually contains a temperature-sensing device in the stator coil windings that ____ the power supply if the internal temperature of the motor becomes too high due to failure to start or overload.

A)disconnects
B)engages
C)turns on
D)starts

Question 14

Full-load speed is measured in _______________ and indicates the rotor speed when the motor is producing its full rated horsepower.

Question 15

____ voltage is the design or configuration voltage of the electrical distribution system.

A)Nominal
B)Terminal
C)High
D)Magnetic

Question 16

_______________ specifies the maximum length of time the motor can operate at its rated horsepower and be able to effectively dissipate the heat generated inside the motor, without exceeding the motor's temperature rise.

Question 17

Motor terminal voltages are rated ____ than the nominal system voltages to compensate for the electrical distribution system voltage drops.

A)slightly less
B)slightly more
C)equal
D)much more

Question 18

Motor service _______________ is the percentage of overloading above the rated horsepower the motor can handle for short periods of time, such as a mechanical load surge.

Question 19

When a motor design is tested by the manufacturer, it is loaded to the full-load horsepower using the motor's rated frequency and voltage, and the measured current becomes the nameplate ____ for that motor.

A)HLA
B)FLA
C)FLP
D)NEC

Question 20

The ____ bearings are the physical connection between the stationary stator, and the rotating rotor, and the only wear point on three-phase induction motors.

A)torque
B)motor
C)stator
D)power

Question 21

What is the difference between nominal voltage and terminal voltage?

Question 22

Why is terminal voltage lower than nominal voltage?

Question 23

_______________ protection is found on only small motors, and is designed so that the motor will not burn out under locked rotor conditions.