Deck 9: Dynamic Braking With a Dc Motor-Reversal Control

Question 1

____________________ contacts remain activated (held mechanically) until returned to their original position.

Answer 1

Maintained

Question 2

Magnetic switches used in controllers cannot be used with remote control and are expensive.

Answer 2

False

Question 3

An electrician must know the symbols and terms used in automatic control diagrams to be able to wire, install, troubleshoot, and maintain automatic control equipment.

Answer 3

True

Question 4

Refer to the accompanying figure. What changes occur if the stop button is momentarily pressed?

Question 5

In addition to starting, stopping and controlling the speed of a motor, the controller may be required to respond to a number of conditions. List four examples of these conditions.

Question 6

____________________ are required in automatic controls to transmit varying conditions in one circuit in order to influence the operation of other devices in the same or another electrical circuit.

Question 7

SCADA connections and RTUs and HMIs are increasingly being connected through systems that uses a manufacturer-specific protocol for each component.

Question 8

____________________ is a system that uses input and output data from real-world processes and machinery interfaces.

Question 9

Figure 09-8

Refer to the accompanying figure. Briefly explain the mechanism for keeping the circuit intact after the start button is released.

Question 10

In a typical control circuit, the control contacts provide a(n) ____________________ circuit in parallel to the start momentary contacts.

Question 11

The manufacturing and materials-handling industries can predict maintenance with great certainty and help with failure analysis based on E stop systems.

Question 12

____________________ stations are spring-controlled switches, which, when pushed, are used to complete motor or motor control circuits.

Question 13

In a DC contactor, what provisions help to minimize heavy arcing that burns the contacts?

Question 14

Factors to be considered when selecting motor controllers include the required types of starting, stopping, reversing, running, and controlling speed and sequence. Name two other factors that influence the selection of a controller?

Question 15

Remote control of a controller uses contactors, relays, pushbuttons, sensors, and possibly electronics.