Deck 41: Developing Control Circuits

Question 1

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

Answer 1

False

Question 2

Figure 41-4

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

Answer 2

When the pressure switch opens, coil 1M will deenergize, permitting all 1M contacts to return to their normal positions.

Question 3

Figure 41-1

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

Answer 3

It must be connected as normally closed because the pressure switch must close when the pressure drops.

Question 4

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 5

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 6

Figure 41-5

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

Question 7

Figure 41-7

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

Question 8

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.

Question 9

Figure 41-1

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

Question 10

Figure 41-5

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

Question 11

Figure 41-7

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

Question 12

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

Question 13

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

Question 14

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 15

Figure 41-3

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