Fundamentals of circuits with contacts...Become familiar with the wiring and function of a self-holding circuit. • Become familiar with the wiring of an ON indicator and an OFF indicator

Workbook

TP 1211

With CD-ROM

Festo Didactic

567315 EN

Fundamentals of circuits with contacts

0 V

Q1

S1

Q2

S2

K1S3

Q1

Q2

Q2 Q1

Q1

Q3 Q4

Q4 Q3 K1

Q2

K1

F222

21

124 V F121

2 3 4 5 6 7

22

21

14

13

14

13

22

21

22

21

A1

A2

22

21

A1

A2

22

21

A1

A2

22

21

A1

A2

A1

A2

22

21

14

13 14

13 44

43

44

43

16

15

28

25

Order number: 567315

Revision level: 11/2009

Author: Jürgen Stumpp

Editor: Frank Ebel

Graphics: Doris Schwarzenberger

Layout: 11/2010, Frank Ebel

© Festo Didactic GmbH & Co. KG, 73770 Denkendorf, Germany, 2010

Internet: www.festo-didactic.com

E-mail: [email protected]

The copying, distribution and utilization of this document as well as the communication of its contents to

others without expressed authorization is prohibited. Offenders will be held liable for the payment of

damages. All rights reserved, in particular the right to carry out patent, utility model or ornamental design

registration.

© Festo Didactic GmbH & Co. KG 567315 III

Table of contents

Use for intended purpose __________________________________________________________________ IV

Preface _________________________________________________________________________________ V

Introduction ____________________________________________________________________________ VII

Work instructions and safety precautions ____________________________________________________ VIII

Training package for fundamentals of circuits with contacts _____________________________________ IX

Learning objective _________________________________________________________________________X

Allocation of learning objectives per exercise __________________________________________________ XI

Equipment set __________________________________________________________________________ XIII

Allocation of components per exercise _______________________________________________________ XV

Notes for the teacher/trainer _______________________________________________________________ XVI

Structure of the exercises ________________________________________________________________ XVII

Component designations _________________________________________________________________ XVII

CD-ROM contents _______________________________________________________________________ XVIII

Exercises and solutions

Exercise 1: Commissioning a stirrer __________________________________________________________ 3

Exercise 2: Operating the stirrer via a self-holding circuit _______________________________________ 11

Exercise 3: Converting a drill press from switch to pushbutton operation for

clockwise/anti-clockwise rotation ________________________________________________ 19

Exercise 4: Connecting a pneumatic compressor via a star-delta contactor circuit ___________________ 29

Exercise 5: Connecting a pneumatic compressor via an automatic star-delta contactor circuit _________ 39

Exercise 6: Connecting a 3-phase drive to a reversing contactor circuit

with automatic star-delta start-up ________________________________________________ 47

Exercises and work sheets









IV © Festo Didactic GmbH & Co. KG 567315

Use for intended purpose

The training package for fundamentals of circuits with contacts may only be used:

• For its intended purpose in teaching and training applications

• When its safety functions are in flawless condition

The components included in the training package are laid out in accordance with the latest technology, as

well as recognised safety rules. Nevertheless, life and limb of the user and third parties may be endangered,

and the components may be impaired, if they are used improperly.

The training system from Festo Didactic has been developed and manufactured exclusively for training and

vocational education in the fields of automation and technology. The respective training companies and/or

trainers must ensure that all trainees observe the safety precautions which are described in this workbook.

Festo Didactic hereby excludes any and all liability for damages suffered by trainees, the training company

and/or any third parties, which occur during use of the equipment set in situations which serve any purpose

other than training and/or vocational education, unless such damages have been caused by Festo Didactic

due to malicious intent or gross negligence.

© Festo Didactic GmbH & Co. KG 567315 V

Preface

Festo Didactic’s training system for automation technology is geared towards various educational

backgrounds and vocational requirements. The training system is therefore broken down as follows:

• Technology oriented training packages

• Mechatronics and factory automation

• Process automation and control technology

• Robotino® – training and research with mobile robots

• Hybrid learning factories

The technology packages deal with various technologies including pneumatics, electropneumatics,

hydraulics, electrohydraulics, proportional hydraulics, programmable logic controllers, sensor technology,

electrical engineering and electric drives.

The modular design of the training system allows for applications which go above and beyond the

limitations of the individual packages. For example, PLC actuation of pneumatic, hydraulic and electric

drives is possible.

VI © Festo Didactic GmbH & Co. KG 567315

All training packages have the same, identical structure:

• Hardware

• Teachware

• Software

• Seminars

The hardware is comprised of industrial components and systems that are specially designed for training

purposes.

The structure of the teachware corresponds to that of the hardware. It includes:

• Textbooks (with exercises and examples)

• Workbooks (with practical exercises, supplementary instructions and solutions)

• Exercise book (with practical exercises and supplementary explanations)

• Transparencies and videos (for dynamic instruction)

The teaching and learning media are available in several languages. They’re intended for use in classroom

instruction, but are also suitable for self-study.

Where software is concerned, computer training programs, as well as simulation, visualisation, project

engineering, design engineering and programming software, are made available.

A wide range of seminar offerings covering the contents of the training packages complete the programme

for training and vocational education.

If you have any suggestions or feedback about this manual,

please send us an e-mail at [email protected].

The authors and Festo Didactic look forward to your comments.

© Festo Didactic GmbH & Co. KG 567315 VII

Introduction

This workbook is part of the training system for automation technology from Festo Didactic GmbH & Co. KG.

The system provides a solid basis for practice-oriented training and vocational education. Training package

TP 1211 deals with the subject of fundamentals of circuits with contacts.

Special emphasis is placed on the setup and function of the components, as well as their wiring and

adjustment.

A permanent workstation equipped with an A4 frame and a 400 V AC power supply are prerequisites for

setting up the circuits.

Each of the circuits for all 6 exercises is set up using the TP 1211 equipment set.

Data sheets for the individual components are also available (contactors, motor protection switches etc.).

VIII © Festo Didactic GmbH & Co. KG 567315

Work instructions and safety precautions

General • Trainees should only work with the circuits under the supervision of a trainer.

• Observe specifications included in the data sheets for the individual components, and in particular all

safety instructions!

• Faults which may impair safety must not be generated in the training environment and must be

eliminated immediately.

Mechanical setup • Mount all components on the A4 frame.

• Adhere to the instructions regarding positioning of the components.

Electrical setup • Electrical connections must only be established and interrupted in the absence of voltage!

• Only use connector cables with safety plugs for electrical connections.

• Only pull the plug when disconnecting connector cables – never pull the cable.

© Festo Didactic GmbH & Co. KG 567315 IX

Training package for fundamentals of circuits with contacts

The TP 1211 training package consists of a multitude of individual training materials. The subject of this

package is the fundamentals of circuits with contacts. Individual components included in the TP 1211

training package can also be included in other packages.

Important components of TP 1211 • Permanent workstation with A4 frame

• Equipment sets or individual components (e.g. contactors, motor protection switches, time relays,

auxiliary switching blocks)

• Complete laboratory setups

Media The teachware for the TP 1211 training package consists of a workbook. The workbook includes exercise

sheets for each of the 6 exercises, the solutions to each individual worksheet and a CD-ROM. A set of ready-

to-use exercise sheets and worksheets is included for each exercise.

Data sheets for the hardware components are made available along with the training package, and on the

CD-ROM.

You’ll find further training materials in our catalogue and on the Internet. The training system for automation

technology is continuously updated and expanded. Transparency sets, videos, CD-ROMs, DVDs and training

programmes as well as additional teachware, are offered in several languages.

X © Festo Didactic GmbH & Co. KG 567315

Learning objectives

Components

• Become familiar with the setup and function of a pushbutton.

• Become familiar with the difference between a pushbutton and a switch.

• Become familiar with the difference between a normally open contact and a normally closed contact.

• Become familiar with the setup and function of a contactor.

• Become familiar with components used in primary circuits and control circuits.

• Be able to connect and test a 3-phase socket.

• Become familiar with the wiring and function of a time relay.

• Become familiar with the wiring and function of an overcurrent trip.

• Become familiar with the wiring and setup of an overcurrent trip in a star-delta contactor circuit.

• Become familiar with the difference between an overcurrent trip and a motor protection switch.

Basic control circuits

• Become familiar with inching operation.

• Become familiar with the wiring and function of a self-holding circuit.

• Become familiar with the wiring of an ON indicator and an OFF indicator.

• Become familiar with the combination of a self-holding circuit with inching operation.

• Become familiar with the wiring of normally open and normally closed contacts at several actuation

points.

• Become familiar with the problems associated with a reversing contactor circuit.

• Become familiar with wiring of the primary circuit for a reversing contactor circuit.

• Become familiar with the reason for interlocking the two contactors (contactor interlocking).

• Become familiar with the reason for a second interlock (pushbutton interlocking).

• Become familiar with reversing the direction of rotation via OFF.

• Become familiar with direct reversal of the direction of rotation.

• Become familiar with the prerequisites for star-delta start-up.

• Become familiar with the layout of a 3-phase motor for star-delta start-up using 230 V/400 V mains

power supply.

• Become familiar with wiring of the primary circuit for a star-delta contactor circuit.

• Become familiar with the designations of the three contactors used.

• Become familiar with the reason for interlocking with star-delta start-up.

• Become familiar with the control circuit for a manually operated star-delta contactor circuit.

• Become familiar with the control circuit for an automatic star-delta contactor circuit.

• Become familiar with the most important disadvantage of star-delta start-up.

• Become familiar with the setup and function of the primary circuit of a reversing contactor circuit with

automatic star-delta start-up.

• Become familiar with the setup and function of the control circuit of a reversing contactor circuit with

automatic star-delta start-up.

© Festo Didactic GmbH & Co. KG 567315 XI

Allocation of learning objectives per exercise

Exercise 1 2 3 4 5 6

Learning objectives

Become familiar with the setup and function of a pushbutton. •

Become familiar with the difference between a pushbutton and a switch. •

Become familiar with the difference between a normally open contact and a normally closed

contact. •

Become familiar with the setup and function of a contactor. •

Become familiar with inching operation. •

Become familiar with components used in primary circuits and control circuits. •

Become familiar with the wiring and function of a self-holding circuit. •

Become familiar with the wiring of an ON indicator and an OFF indicator. •

Become familiar with the combination of a self-holding circuit with inching operation. •

Become familiar with the wiring of normally open and normally closed contacts at several

actuation points. •

Become familiar with the problems associated with a reversing contactor circuit. •

Become familiar with wiring of the primary circuit for a reversing contactor circuit. •

Be able to connect and test a 3-phase socket. •

Become familiar with the reason for interlocking the two contactors (contactor interlocking). •

Become familiar with the reason for a second interlock (pushbutton interlocking). •

Become familiar with reversing the direction of rotation via OFF. •

Become familiar with direct reversal of the direction of rotation. •

Become familiar with the prerequisites for star-delta start-up. •

Become familiar with the layout of a 3-phase motor for star-delta start-up using 230 V/400 V

mains power supply. •

Become familiar with wiring of the primary circuit for a star-delta contactor circuit. •

Become familiar with the designations of the three contactors used. •

Become familiar with the reason for interlocking with star-delta start-up. •

Become familiar with the control circuit for a manually operated star-delta contactor circuit. •

XII © Festo Didactic GmbH & Co. KG 567315


Learning objectives

Become familiar with the wiring and function of a time relay. •

Become familiar with the wiring and function of an overcurrent trip. •

Become familiar with the wiring and setup of an overcurrent trip in a star-delta contactor circuit. •

Become familiar with the difference between an overcurrent trip and a motor protection switch. •

Become familiar with the control circuit for an automatic star-delta contactor circuit. •

Become familiar with the most important disadvantage of star-delta start-up. •

Become familiar with the setup and function of the primary circuit of a reversing contactor

circuit with automatic star-delta start-up. •

Become familiar with the setup of the control circuit of a reversing contactor circuit with

automatic star-delta start-up. •

© Festo Didactic GmbH & Co. KG 567315 XIII

Equipment set

The equipment set for fundamentals of circuits with contacts imparts knowledge about the use of contactors

for controlling electrical machines. The equipment set includes all the components which are necessary for

mastering the specified learning objectives, and can be supplemented with any other equipment sets. A

laboratory workstation, optionally with A4 frame, and 400 V AC electrical supply power are also required in

order to set up functional circuits.

Equipment set for fundamentals of circuits with contacts, order number 571811

Component Order no. Quantity

3-phase power supply 571812 1

24 V power supply unit 571813 1

Contactor board 571814 1

Contactor set for motor technology 571816 1

Operator and signalling unit 571815 1

Overview of contactor set for motor technology, order number 571816

Component Quantity

Circuit breaker, single pole 1

Circuit breaker, 3-pole 1

Motor protection switch, 0.35 to 0.5 A with auxiliary switch, 1 NO and 1 NC contact 1

Motor protection relay (overload relay), 0.35 to 0.5 A 1

Power contactor, 4 kW 4

Auxiliary switching block for power contactor, 4 kW 4

Overvoltage limiter 4

Multi-function time relay 1

Relay including socket 3

XIV © Festo Didactic GmbH & Co. KG 567315

Graphic symbols, equipment set

Component Graphic symbol

Circuit breaker, single pole

2

1

F1

Circuit breaker, 3-pole

6

5

4

3

2

1

F1

Overvoltage limiter

U

R1

Motor protection switch with auxiliary switch, 1 NO and

1 NC contact

22

21

14

13Q1

1 3 5

4 62I> I>I>

Motor protection relay (overload relay)

96

95

98

97

4 62

3 51TE

ST

RES

ET

STO

PF1

Power contactor, 4 kW, with auxiliary switching block,

2 NO and 2 NC contacts A1

A2 2 4

1 3

6

5Q1

22

21

44

43

14

13

32

31

Multi-function time relay

(described function: star-delta) 28

27K1

A3

A2

A1

18

17

Relays

24

23

14

13K1

A1

A2 32

31

42

41

Operating units 3

4

3

4

1

2S1 S2 S3

Indicators

P1

© Festo Didactic GmbH & Co. KG 567315 XV

Allocation of components per exercise


Component

Circuit breaker, single pole, A, 4 A 1 1 1 1 1 1

Circuit breaker, 3-pole, C, 4 A 1 1 1 1 1 1

Motor protection switch, 0.35 to 0.5 A 1 1

Motor protection relay (overload relay), 0.35 to 0.5 A 1

Power contactor, 4 kW 1 1 2 3 3 4

Auxiliary switching block for power contactor, 4 kW 1 2 3 3 4

Overvoltage limiter 1 1 2 3 3 4

Multi-function time relay 1 1

Contactor board 1 1 1 1 1 1

Operator and signalling unit 1 1 1 1 1 1

24 V power supply unit 1 1 1 1 1 1

3-phase power supply 1 1 1 1 1 1

Note

You will need one of the following for use as an electrical machine for all the exercises, for example:

a 3-phase asynchronous motor, 230/400 V (order number 571874)

or

a MPS transfer line MT AC400 (order number C93104)

XVI © Festo Didactic GmbH & Co. KG 567315

Notes for the teacher/trainer

Learning objectives The basic learning objective of this workbook is to become familiar with fundamental control circuits and

their practical setup. The combination of both theory and practice ensures faster progress and longer-lasting

learning. The more specific learning objectives are documented in the matrix. Concrete, individual learning

objectives are assigned to each exercise.

Required time The time required for working through the exercises depends on the learner’s previous knowledge of the

subject matter. For apprentices in the field of electrical installation this is approx. 1 week. For a skilled

worker it is approx. 2 days.

Equipment set components The workbook and the equipment set match each other. Only the components included in one TP 1211

equipment set are required for all 6 exercises.

Standards The following standards are used in this workbook:

EN 60617-2 to

EN 60617-8: Graphical symbols for circuit diagrams

EN 61346-2: Industrial systems, installations and equipment and industrial products –

Structuring principles and reference designations

Identification within the workbook Solutions and supplements in graphics or diagrams appear in red.

Designations in the worksheets Texts which require completion are identified with a grid or grey table cells.

Graphics which require completion include a grid.

Training notes These provide additional information about the individual components and circuits. These notes are not

included in the worksheets.

© Festo Didactic GmbH & Co. KG 567315 XVII

Structure of the exercises

All 6 exercises have the same structure and can be broken down into:

• Title

• Learning objectives

• Presentation of the problem

• Layout

• Project assignment

• Work aides

• Worksheets

The workbook contains the solutions to each worksheet.

Component designations

The components are designated in circuit diagrams in accordance with the EN 61346-2 standard. Letters are

assigned depending on component type. Consecutive numbers are assigned if several components of the

same type are included within a single circuit.

Relays: K, K1, K2 etc.

Switches/pushbuttons: S, S1, S2 etc.

Contactors: Q, Q1, Q2 etc.

Fuses: F, F1, F2 etc.

Signal devices: P, P1, P2 etc.

XVIII © Festo Didactic GmbH & Co. KG 567315

CD-ROM contents

The workbook is included on the CD-ROM as a PDF file. The CD-ROM also provides you with additional

media.

The CD-ROM contains the following folders:

• Operating instructions

• Images

• Data sheets

• Product information

Operating instructions Operating instructions for various components included in the training package are available. These

instructions are helpful when using and commissioning the components.

Images Photos and graphics of components and industrial applications are made available. These can be used to

illustrate individual tasks or to supplement project presentations.

Data sheets The data sheets for the components included in the training package are available as PDF files.

Product information The manufacturer’s product information is provided for selected components. The representations and

descriptions of the components in this format are intended to demonstrate how they are presented in an

industrial catalogue. Additional information regarding the components is also included here.

© Festo Didactic GmbH & Co. KG 567315 1

Table of contents

Exercises and solutions









2 © Festo Didactic GmbH & Co. KG 567315


Exercise 1

Commissioning a stirrer

Learning objectives After completing this exercise:

• You’ll be familiar with the setup and function of a pushbutton.

• You’ll be familiar with the difference between a pushbutton and a switch.

• You’ll be familiar with the difference between a normally open contact and a normally closed contact.

• You’ll be familiar with the setup and function of a contactor.

• You’ll be familiar with inching operation.

• You’ll be able to identify the components used in primary circuits and control circuits.

Presentation of the problem Two liquids are fed into a container and are mixed with the help of a stirrer. The stirrer is powered by a

3-phase motor. The 3-phase motor is run in inching mode operation.

You’ll need to select a suitable pushbutton and a contactor for controlling the motor.

Layout

Stirrer with drive unit

Exercise 1 – Commissioning a stirrer


Assignments 1. Describe the function of a pushbutton and of a switch.

2. Describe the setup of a contactor.

3. Draft a contactor circuit for controlling a 3-phase motor and set it up.

4. Identify the components in the circuit setup.

5. Connect an asynchronous 3-phase motor with squirrel-cage rotor.

Work aides • Technical books, books of tables

• Excerpts from manufacturers’ catalogues

• Data sheets

• Internet

Warning

Electrical connections must only be established and interrupted in the absence of voltage!

Comply with protection against accidental contact during the function test.



Function and circuit symbol of a pushbutton and of a switch

– Describe the function of a pushbutton (NO).

– Describe the function of a pushbutton (NC).

– Describe the function of a switch (NO).

– List typical applications for each component.

3

4

1

2

3

4

Circuit symbols for pushbutton (NO), pushbutton (NC) and switch

Pushbutton (NO) • Function

When the normally open pushbutton is actuated the contacts are closed and they remain closed

until the pushbutton is released. When the pushbutton is released, the contacts return to their

initial position and the circuit is interrupted (neutral position).

• Applications

Actuating contactors, solenoid valves and controllers in general, ON pushbuttons.

Pushbutton (NC) • Function

When the normally closed pushbutton is actuated the contacts are opened, and they remain open

until the pushbutton is released. When the pushbutton is released, the contacts return to their

initial position and the circuit is closed (neutral position).

• Applications

Actuating contactors, solenoid valves and controllers in general, OFF pushbuttons.

Switch (NO) • Function

When the switch is actuated the contacts are closed and they remain closed even after the switch

is released. When the switch is actuated once again, the contacts are opened and they remain

open. ON/OFF switching function.

• Applications

Light switches, ON/OFF switches in general, control switches.



– Describe the difference between a pushbutton and a switch.

The pushbutton changes the status of its contacts when it’s actuated. When released, the pushbutton

returns to its initial position automatically (NO is re-opened, NC is re-closed).

When the switch is actuated, it’s detented in the actuated position and remains there (ON or OFF

position) until it’s actuated once again (ON/OFF switching function).

Layout of a contactor

21

A2A1

36

21

7 4 5 A1

A2 2 4

1 3

6

5

Schematic diagram and circuit symbol for a contactor

Designations Coil terminal, NO switching contact, reset spring, coil, moving iron core, NC switching contact, fixed iron core



– Match up the individual components with the correct designations.

Item Designation

1 Contactor coil with terminals A1 and A2

2 Fixed iron core – is magnetised when the contactor coil is connected to nominal voltage (230 V, 24 V)

3 Moving iron coil – is attracted by the magnetised fixed iron core

4 Moving contact with mechanical connection to the moving iron core

5 Fixed contact to terminals 13 and 14 (NO contact)

6 Spring – pushes moving iron core back to its initial position after magnetisation is deactivated

7 Spring for spring loaded mounting of the moving contact – contact pressure increases when the contactor is picked up

Planning and setting up a primary circuit and a control circuit The 3-phase motor for the stirrer must be commissioned.

– Complete the primary circuit for motor connection and enter the designations as they are specified in

the standards.

– Complete the control circuit for inching operation (motor only runs as long as the pushbutton is pressed

and held).

– Set up the circuit and test it for correct functioning.

Warning

Make sure that the circuit is switched off during setup!

Caution

Make sure that voltages and wiring are correct when connecting the contactor and the motor.



Contactor circuit with inching operation

– Complete the primary circuit and the control circuit for inching operation.

0 V

M

3

2

1

4

3

6

5

A1

A2

14

13

L1

L2

L3

N

PE

6

4

2

5

3

1

24 V

Q1

S1

1F2

21

F1

Q1

M1

Primary circuit for the contactor circuit Control circuit for the contactor circuit

Identification of components in the primary and control circuits Fuses, coil terminals, protective earth conductor, main contacts, pushbutton, contactor

– Match the individual components with the correct designations.

Designation Component

Q1 Contactor

1, 2, 3, 4, 5, 6 Main contacts

S1 Pushbutton

PE Protective conductor

F1, F2 Fuses

A1, A2 Coil terminals



Equipment list

In addition to the circuit diagram, complete project documentation also includes an equipment list.

– Create an equipment list by entering the required number of components and the abbreviations used to

identify them in the circuit diagram in the table below.

Quantity Identification Designation

1 F1 Circuit breaker, 3-pole

1 Q1 Power contactor, 4 kW

1 M1 3-phase asynchronous motor

Primary circuit

Quantity Identification Designation

1 F2 Circuit breaker, single pole

1 S1 Pushbutton (NO)

1 Q1 Power contactor, 4 kW

Control circuit



Connecting a 3-phase asynchronous motor with squirrel-cage rotor A 3-phase asynchronous motor with squirrel-cage rotor can be wired in either star or delta configuration.

– Complete the circuits for the windings in both star and delta configuration.

V1

V2

W1

W2U2

U1

L1 L2 L3

L2 L3

W1W2

U2

U1 V2

V1

L1

Star circuit Delta circuit

– Fill in the locations of the jumpers on the terminal board for both star and delta configuration.

V1

V2

U1

U2

W1

W2

V1

U2

W1

V2

U1

W2

V1

V2

U1

U2

W1

W2

V1

U2

W1

V2

U1

W2

Star circuit Delta circuit

Documents

Fundamentals of circuits with contacts...Become familiar with the wiring and function of a self-holding circuit. • Become familiar with the wiring of an ON indicator and an OFF indicator