Question 1

It is necessary to restart a motor after it has been stopped by a three-wire control circuit with protection.&#10;A)high-voltage&#10;B)high-temperature&#10;C)low-resistance&#10;D)low-voltage

Accepted Answer

The only necessary protection mentioned for restarting a motor is for it to have low-voltage protection. This ensures that the motor will not restart if there is a voltage drop and potential damage to the motor. Low-voltage protection is designed to prevent the motor from starting or running if the voltage drops below a certain level. Once the voltage is restored to normal, the motor can be safely restarted.

Question 2

What is the first action when the start button of a three-wire control circuit is pushed?&#10;A)The circuit is completed through the coil.&#10;B)The contacts close.&#10;C)The power circuit contacts to the motor close.&#10;D)The holding contact remains off.

Accepted Answer

When the start button of a three-wire control circuit is pushed, the circuit is completed through the coil. This energizes the coil, which then causes the contacts to close and start the motor.

Question 3

It is sometimes desirable to operate push buttons or other control devices at some voltage higher than the motor voltage.

Accepted Answer

False

Question 4

Sirens, horns, and loud buzzers may be used in production systems to call attention to malfunctions.

Accepted Answer

Sirens, horns, and loud buzzers are commonly used in production systems to notify workers of malfunctions and encourage quick responses to resolve them. Sirens, horns, and loud buzzers are known as audio alarms and are commonly used in production systems to alert operators and maintenance staff of equipment malfunctions or unsafe conditions.

Question 5

Pilot lights are tested frequently to ensure operation.

Accepted Answer

Pilot lights should be tested frequently to ensure they are operating properly, as a faulty pilot light can be a safety hazard. Pilot lights should be tested frequently to ensure that they are functioning properly and to prevent any potential safety hazards.

Question 6

In a three-wire control circuit, when the supply voltage returns after a failure, the circuit is re-energized.

Accepted Answer

In a three-wire control circuit, typically used for motor control, the circuit is designed to require a manual restart after a power failure to ensure safety. This prevents the motor or device from automatically starting unexpectedly when power is restored.

Question 7

When configuring separate control wiring, the maintenance technician must ensure that the proper connections are made.

Accepted Answer

This is true because if the proper connections are not made in the control wiring, it can result in malfunctions and potentially dangerous situations. The maintenance technician needs to make sure that the wiring is connected correctly to ensure proper control of the equipment or system. Failure to do so can result in malfunction or damage to the equipment, or even safety hazards for personnel.

Question 8

A three-wire control circuit uses momentary contact, start-stop stations, and a holding circuit interlock connected with the start button to maintain the circuit.&#10;A)in tandem&#10;B)in parallel&#10;C)alternately&#10;D)in series

Accepted Answer

In a three-wire control circuit, the holding circuit interlock is connected in parallel with the start button. This allows the circuit to maintain power after the start button is released, as the holding circuit will "hold" the circuit closed even when the start button is no longer being pressed.

Question 9

No-voltage protection protects .&#10;A)only the operator&#10;B)either the operator or the equipment&#10;C)both the operator and the equipment&#10;D)only the equipment

Accepted Answer

No-voltage protection is designed to protect both the operator and the equipment from accidental or unintended start-up of machinery or equipment due to power failure or other electrical malfunctions. Therefore, the correct choice is C as it indicates that both the operator and equipment are protected. No-voltage protection is designed to protect both the operator and the equipment from unintentional energization or damage due to power failure.

Question 10

The operation of the overload protection the control circuit.&#10;A)opens&#10;B)cancels&#10;C)closes&#10;D)verifies

Accepted Answer

The purpose of overload protection is to open the control circuit in the event of an overload or fault, which will stop the equipment from operating and prevent damage or injury. Overload protection is used to protect electrical components from being damaged due to overcurrent. When an overload occurs, the overload protection mechanism opens the circuit, preventing the flow of current. Therefore, it "opens" the control circuit.

Deck 18: Three-Wire and Separate Controls