Deck 41: Developing Control Circuits

Question 1

In the accompanying figure, what happens when power is applied to the stator?

Answer 1

When power is applied to the stator, all resistance is connected in the rotor circuit and the motor will operate in its lowest or first speed.

Question 2

Figure 41-7
 


In the accompanying figure, speed control for a wound rotor motor is obtained by placing resistance in the secondary or rotor circuit.

Answer 2

True

Question 3

Figure 41-5



In the accompanying figure, what does the selector switch permit?

Answer 3

The selector switch permits the circuit to alternate operation of the two pumps, or permits the operation of one pump .

Question 4

Figure 41-7
 


In the accompanying figure, second speed is obtained by closing ____________________ and shorting out the first three-phase resistor bank.

Question 5

Figure 41-08



In the accompanying diagram, when the FIRST SPEED button is pressed, motor starter coil 1M will close and connect the stator of the motor to the power line.

Question 6

Figure 41-1



In the accompanying figure, why must the pressure switch be connected as normally closed?

Question 7

Figure 41-5



In the accompanying figure, a(n) ____________________ switch is connected to the output of the pressure switch.

Question 8

Figure 41-7
 


In the accompanying figure, what is the function of load contacts 1M?

Question 9

The best method of designing a motor control circuit is to solve one requirement at a time.

Question 10

In the accompanying figure, auxiliary contact 1M cannot be used as a holding contact.

Question 11

Figure 41-3
 


In the accompanying figure, each motor starter coil is protected by a separate overload contact.

Question 12

Figure 41-02


In the accompanying figure, because control relay CR is used as a(n) ____________________, it must be permitted to remain energized when either or both of the motor starters are not energized.

Question 13

Figure 41-4


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In the accompanying figure, what happens when the pressure switch opens?

Question 14

In the accompanying figure, a(n) ____________________ has been used to step down the 480-volt  supply line voltage to 120 volts for use by the control circuit.

Question 15

Figure 41-1



In the accompanying figure, a(n) ____________________ is used as short-circuit protection for the control wiring.