What is the definition of "decision"?
The second step of a control circuit. Decisions are based on the signals received and the logical functions designed in the circuit.

## Motor Controls Training

Class Information
 Tooling U classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
 Class Name: Logic and Line Diagrams 220 Description: This class will teach you the basic rules for line diagrams and their common elements. You will also learn how line diagrams are put together and how they are referenced. Prerequisites: 550200  550205 Difficulty: Intermediate Number of Lessons: 15 Language: English, Spanish

Below are all the competencies and job programs that contain the class Logic and Line Diagrams 220. Job programs are our traditional class lists organized according to common job functions. Competencies are our latest job-specific curricula that help tie online learning to practical, hands-on tasks.

Click on any title to view its details.

Competencies

Class Outline
• Objectives
• What Is a Line Diagram?
• Rules for Line Diagrams
• Control Devices
• Line Numbers
• Cross-Referencing
• Wire and Terminal Numbers
• Mechanically Connected Contacts
• Control Circuit Steps
• Logic Functions
• AND and OR
• NAND and NOR
• Memory
• Troubleshooting
• Summary

Class Objectives
• Define line diagram.
• Describe the rules for line diagrams.
• Describe control devices.
• Describe line numbers in diagrams.
• Explain how line diagrams cross-reference contacts.
• Identify wire and terminal numbers on a line diagram.
• Describe methods used to show mechanically connected contacts on line diagrams.
• Identify the steps of a control circuit.
• Describe logic functions in control circuits.
• Distinguish between AND and OR circuit logic.
• Distinguish between NAND and NOR circuit logic.
• Describe troubleshooting in control circuits.

Class Vocabulary

Vocabulary TermDefinition
The third step of a control circuit. Actions are the physical work performed as loads are energized.
A type of circuit logic where both normally open control devices must be closed to energize the load. Control devices are connected in series in AND logic.
A type of signal that is sent when an input device detects a change in conditions such as flow, pressure, or temperature.
An additional motor starter contact used to provide memory to control circuits. When energized, the motor starter closes the auxiliary contact, maintaining a closed circuit.
Any input device that controls the flow of current in a circuit. Control devices determine when loads are energized or de-energized.
A device that keeps track of the number of entering inputs and provides an output when a preset count is reached. Counters also usually display the counted value.
The numbers on the right side of a line diagram that reference contacts in other circuit lines that electrically connect the load in the referenced line. Numbers that cross-reference normally closed contacts are underlined.
A method of cross-referencing mechanically connected contacts that operate together but on different lines of the diagram. The dashed line method is used on simple diagrams when the contacts are close together.
The second step of a control circuit. Decisions are based on the signals received and the logical functions designed in the circuit.
A device that can measure voltage, current, or resistance. A multimeter is the most versatile and common meter used today.
Two separate buttons that must be pressed simultaneously in order to power stamping presses. This is an example of AND logic.
Having physical connections that are designed to act the same way over and over.
Another name for a line diagram, due to its resemblance to a ladder. In this sense, each circuit line is a "rung" of the ladder.
A mechanical input that requires physical contact of the object with the switch actuator.
A diagram that shows the logic of an electrical circuit or system using standard symbols. Also known as a ladder diagram because the diagram appears as individual lines or "rungs" connected between two vertical lines.
The sequential numbers running down the left side of a line diagram. Each line, or rung, of the line diagram has its own number.
Any device that converts electrical energy to motion, heat, light, or sound. A motor starter coil and a pilot light are both examples of loads.
The sequence of operations performed by a circuit. Logic functions such as AND and OR follow a set, predictable pattern.
A type of signal that you send to a circuit through physical action. Flipping a light switch or pressing a pushbutton are manual signals.
A type of signal that is sent through the mechanical motion of a machine. A gear contacting a limit switch is an example of a mechanical signal.
The ability of a circuit to store a charge and keep the load energized even after the signal is removed.
A contact that returns to its original position immediately after sending a signal.
An electrically operated switch that uses magnetic induction to provide the startup current for a motor.
A type of circuit logic where both normally closed control devices must be opened to de-energize the load. Control devices are connected in parallel in NAND logic.
A type of circuit logic where only one normally closed control device must be opened to de-energize the load. Control devices are connected in series in NOR logic.
An electrical contact that regularly allows electricity to flow.
An electrical contact that regularly allows electricity to flow until it is signaled to open.
An electrical contact that rarely allows electricity to flow.
A type of circuit logic that uses normally closed contacts.
A method of cross-referencing mechanically connected contacts that operate together but on different lines of the diagram. The numerical cross-reference method is used on complex diagrams when the connected contacts are several lines apart.
A type of circuit logic where only one normally open control device must be closed to energize the load. Control devices are connected in parallel in OR logic.
A normally closed contact placed in series between a load and the neutral line of a circuit. Overload contacts open only when an overload condition is present.
A manual control device that opens or closes a circuit when pressed. Pushbuttons can be normally open or normally closed.
A device that controls one electrical circuit by opening and closing contacts in another circuit.
The first step of a control circuit. Signals are inputs that change the condition of a circuit.
A description of the essential physical and technical properties of a machine. Specs are the principle indicator of machine capability.
A control device that can make or break a circuit by closing or opening. A switch can be either manual, mechanical, or automatic.
A number assigned by a manufacturer to a device's contact points. Terminal numbers help identify the connection points in a circuit.
Connecting one probe of a DMM to the neutral side of a circuit and moving the other probe systematically along the sections of a circuit to find the malfunctioning part.
A device that delays the signal sent by a control device to a load for a preset amount of time.
The systematic elimination of the various parts of a system, circuit, or process to locate a malfunctioning part.
A reference point on a line diagram used to keep track of the different wires that connect the components in the circuit. Wire numbers are circled and start with 1 from the top left of the diagram.