Chapter 4Chapter 4Electrical Symbols and DiagramsElectrical Symbols and Diagrams

Language of Control • Pictorial Drawings • Electrical Symbols and Abbreviations • Wiring Diagrams • Schematic Diagrams •

Electrical Circuits • Manual Control Circuits • Automatic Control Circuits •

Magnetic Control Circuits • Printreading

Language of Control • Pictorial Drawings • Electrical Symbols and Abbreviations • Wiring Diagrams • Schematic Diagrams •

Electrical Circuits • Manual Control Circuits • Automatic Control Circuits •

Magnetic Control Circuits • Printreading

Chapter 4Chapter 4Electrical Symbols and DiagramsElectrical Symbols and Diagrams

Language of Control • Pictorial Drawings • Electrical Symbols and Abbreviations • Wiring Diagrams • Schematic Diagrams •

Electrical Circuits • Manual Control Circuits • Automatic Control Circuits •

Magnetic Control Circuits • Printreading

Language of Control • Pictorial Drawings • Electrical Symbols and Abbreviations • Wiring Diagrams • Schematic Diagrams •

Electrical Circuits • Manual Control Circuits • Automatic Control Circuits •

Magnetic Control Circuits • Printreading

A pictorial drawing shows the physical details of A pictorial drawing shows the physical details of components as seen by the eye.components as seen by the eye.A pictorial drawing shows the physical details of A pictorial drawing shows the physical details of components as seen by the eye.components as seen by the eye.

Symbols are used to conveniently represent electrical Symbols are used to conveniently represent electrical components in diagrams of most electrical and electronic components in diagrams of most electrical and electronic circuits.circuits.

Symbols are used to conveniently represent electrical Symbols are used to conveniently represent electrical components in diagrams of most electrical and electronic components in diagrams of most electrical and electronic circuits.circuits.

In a wiring diagram, the location of components is generally In a wiring diagram, the location of components is generally shown as close to the actual circuit configuration as possible.shown as close to the actual circuit configuration as possible.In a wiring diagram, the location of components is generally In a wiring diagram, the location of components is generally shown as close to the actual circuit configuration as possible.shown as close to the actual circuit configuration as possible.

In a schematic diagram, components are laid out so the circuit is In a schematic diagram, components are laid out so the circuit is easily read rather than to show the actual position of the easily read rather than to show the actual position of the components.components.

In a schematic diagram, components are laid out so the circuit is In a schematic diagram, components are laid out so the circuit is easily read rather than to show the actual position of the easily read rather than to show the actual position of the components.components.

A line (ladder) diagram consists of a series of symbols A line (ladder) diagram consists of a series of symbols interconnected by lines that are laid out like rungs on a ladder to interconnected by lines that are laid out like rungs on a ladder to indicate the flow of current through the various components of a indicate the flow of current through the various components of a circuit.circuit.

A line (ladder) diagram consists of a series of symbols A line (ladder) diagram consists of a series of symbols interconnected by lines that are laid out like rungs on a ladder to interconnected by lines that are laid out like rungs on a ladder to indicate the flow of current through the various components of a indicate the flow of current through the various components of a circuit.circuit.

A one-line diagram is a diagram that uses single lines and A one-line diagram is a diagram that uses single lines and graphic symbols to indicate the path and components of an graphic symbols to indicate the path and components of an electrical circuit.electrical circuit.

A one-line diagram is a diagram that uses single lines and A one-line diagram is a diagram that uses single lines and graphic symbols to indicate the path and components of an graphic symbols to indicate the path and components of an electrical circuit.electrical circuit.

Care should be taken when using electrical symbols to design or Care should be taken when using electrical symbols to design or communicate electrical circuit operations because electrical circuit communicate electrical circuit operations because electrical circuit operations may be changed. operations may be changed.

Care should be taken when using electrical symbols to design or Care should be taken when using electrical symbols to design or communicate electrical circuit operations because electrical circuit communicate electrical circuit operations because electrical circuit operations may be changed. operations may be changed.

All electrical circuits include the source, load, control device, and All electrical circuits include the source, load, control device, and conductors. Most circuits also include fuses or circuit breakers to conductors. Most circuits also include fuses or circuit breakers to provide protection to the circuit.provide protection to the circuit.

All electrical circuits include the source, load, control device, and All electrical circuits include the source, load, control device, and conductors. Most circuits also include fuses or circuit breakers to conductors. Most circuits also include fuses or circuit breakers to provide protection to the circuit.provide protection to the circuit.

A line diagram may be used to illustrate a manual control circuit of a pushbutton controlling a pilot light.A line diagram may be used to illustrate a manual control circuit of a pushbutton controlling a pilot light.

A line diagram may be used to illustrate the control and protection A line diagram may be used to illustrate the control and protection of a 1of a 1 motor using a manual starter with overload protection. motor using a manual starter with overload protection.A line diagram may be used to illustrate the control and protection A line diagram may be used to illustrate the control and protection of a 1of a 1 motor using a manual starter with overload protection. motor using a manual starter with overload protection.

An electric motor on a sump pump can be turned ON and OFF by An electric motor on a sump pump can be turned ON and OFF by using an automatic control device such as a float switch.using an automatic control device such as a float switch.An electric motor on a sump pump can be turned ON and OFF by An electric motor on a sump pump can be turned ON and OFF by using an automatic control device such as a float switch.using an automatic control device such as a float switch.

The NC contacts of a float switch may be used for a pump operation to The NC contacts of a float switch may be used for a pump operation to maintainmaintaina certain level of water in a livestock water tank.a certain level of water in a livestock water tank.

The NC contacts of a float switch may be used for a pump operation to The NC contacts of a float switch may be used for a pump operation to maintainmaintaina certain level of water in a livestock water tank.a certain level of water in a livestock water tank.

A solenoid is an electric output device that converts electrical energy into a linear mechanical force.A solenoid is an electric output device that converts electrical energy into a linear mechanical force.

A solenoid may be used to control a door lock that is opened only A solenoid may be used to control a door lock that is opened only when a pushbutton is pressed.when a pushbutton is pressed.A solenoid may be used to control a door lock that is opened only A solenoid may be used to control a door lock that is opened only when a pushbutton is pressed.when a pushbutton is pressed.

A contactor is a control device that uses a small control current to A contactor is a control device that uses a small control current to energize or de-energize the load connected to it.energize or de-energize the load connected to it.A contactor is a control device that uses a small control current to A contactor is a control device that uses a small control current to energize or de-energize the load connected to it.energize or de-energize the load connected to it.

The electrical operation of a contactor can be shown using a line The electrical operation of a contactor can be shown using a line diagram, a pictorial drawing, and/or a wiring diagram.diagram, a pictorial drawing, and/or a wiring diagram.The electrical operation of a contactor can be shown using a line The electrical operation of a contactor can be shown using a line diagram, a pictorial drawing, and/or a wiring diagram.diagram, a pictorial drawing, and/or a wiring diagram.

Auxiliary contacts may be added to a contactor to form an Auxiliary contacts may be added to a contactor to form an electrical holding circuit.electrical holding circuit.Auxiliary contacts may be added to a contactor to form an Auxiliary contacts may be added to a contactor to form an electrical holding circuit.electrical holding circuit.

A magnetic motor starter is an electrically operated switch A magnetic motor starter is an electrically operated switch (contactor) that includes motor overload protection.(contactor) that includes motor overload protection.A magnetic motor starter is an electrically operated switch A magnetic motor starter is an electrically operated switch (contactor) that includes motor overload protection.(contactor) that includes motor overload protection.

The electrical operation of a motor starter can be shown using a The electrical operation of a motor starter can be shown using a line diagram, a pictorial drawing, and/or a wiring diagram.line diagram, a pictorial drawing, and/or a wiring diagram.The electrical operation of a motor starter can be shown using a The electrical operation of a motor starter can be shown using a line diagram, a pictorial drawing, and/or a wiring diagram.line diagram, a pictorial drawing, and/or a wiring diagram.

Printreading requires understanding the relationship between a Printreading requires understanding the relationship between a component symbol and the physical shape and location of the component symbol and the physical shape and location of the component.component.

Printreading requires understanding the relationship between a Printreading requires understanding the relationship between a component symbol and the physical shape and location of the component symbol and the physical shape and location of the component.component.

Troubleshooting requires reading a print to determine the location Troubleshooting requires reading a print to determine the location and use of individual components and understanding how to use and use of individual components and understanding how to use test equipment.test equipment.

Troubleshooting requires reading a print to determine the location Troubleshooting requires reading a print to determine the location and use of individual components and understanding how to use and use of individual components and understanding how to use test equipment.test equipment.