Fundamentals of
circuits with contacts
Workbook
TP 1211
With CD-ROM
24 V
1
1
F1
2
3
4
5
6
7
2
21
F2
22
21
S2
22
13
S1
21
S3
Q1
13
22
14
13
22
Q2
Q1
21
14
14
21
Q1
22
A1
A2
Q2
Q1
Q2
14
K1
21
Q3
22
A1
A2
43
Q2
44
13
Q4
15
16
28
Q4
22
A1
25
K1
21
A2
43
44
Q3
21
22
A1
A2
K1
A1
A2
0V
Festo Didactic
567315 EN
Order number:
Revision level:
Author:
Editor:
Graphics:
Layout:
567315
09/2011
Jürgen Stumpp
Frank Ebel
Doris Schwarzenberger
10/2011, Frank Ebel
© Festo Didactic GmbH & Co. KG, 73770 Denkendorf, Germany, 2011
Internet: www.festo-didactic.com
E-mail: did@de.festo.com
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.
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
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
© Festo Didactic GmbH & Co. KG 567315
III
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.
IV
© Festo Didactic GmbH & Co. KG 567315
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.
© Festo Didactic GmbH & Co. KG 567315
V
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 did@de.festo.com.
The authors and Festo Didactic look forward to your comments.
VI
© Festo Didactic GmbH & Co. KG 567315
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.).
© Festo Didactic GmbH & Co. KG 567315
VII
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.
VIII
© Festo Didactic GmbH & Co. KG 567315
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 readyto-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.
© Festo Didactic GmbH & Co. KG 567315
IX
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





















X
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
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.
•
© Festo Didactic GmbH & Co. KG 567315
XI
Exercise
1
2
3
4
5
6
Learning objectives
XII
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
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
© Festo Didactic GmbH & Co. KG 567315
XIII
Graphic symbols, equipment set
Component
Graphic symbol
Circuit breaker, single pole
1
F1
2
Circuit breaker, 3-pole
1
3
5
2
4
6
F1
R1
Overvoltage limiter
U
1
3
5
13
I>
2
I>
4
I>
6
14
1
3
5
2
4
6
21
Q1
22
STOP
TEST
Motor protection relay (overload relay)
RESET
Motor protection switch with auxiliary switch, 1 NO and
1 NC contact
95
97
F1
Power contactor, 4 kW, with auxiliary switching block,
2 NO and 2 NC contacts
Multi-function time relay
(described function: star-delta)
98
96
A1
1
3
5
13
A2
2
4
6
14
21
31
43
Q1
17
A3
A1
22
32
44
27
K1
18
A2
Relays
A1
13
23
A2
14
24
28
31
41
K1
Operating units
3
S1
1
S2
4
42
32
3
S3
2
4
Indicators
P1
XIV
© Festo Didactic GmbH & Co. KG 567315
Allocation of components per exercise
Exercise
1
2
3
4
5
6
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
1
1
Component
Motor protection switch, 0.35 to 0.5 A
Motor protection relay (overload relay), 0.35 to 0.5 A
Power contactor, 4 kW
1
1
Auxiliary switching block for power contactor, 4 kW
Overvoltage limiter
1
1
2
3
3
4
1
2
3
3
4
1
2
3
3
4
1
1
Multi-function time relay
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, 400/690 V (order number 571875)
or
a MPS transfer line MT AC400 (order number C93104)
© Festo Didactic GmbH & Co. KG 567315
XV
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.
XVI
© Festo Didactic GmbH & Co. KG 567315
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:
Switches/pushbuttons:
Contactors:
Fuses:
Signal devices:
K, K1, K2 etc.
S, S1, S2 etc.
Q, Q1, Q2 etc.
F, F1, F2 etc.
P, P1, P2 etc.
© Festo Didactic GmbH & Co. KG 567315
XVII
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.
XVIII
© Festo Didactic GmbH & Co. KG 567315
Table of contents
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
© Festo Didactic GmbH & Co. KG 567315
1
Table of contents
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
© Festo Didactic GmbH & Co. KG 567315
3
Exercise 1 – Commissioning a stirrer
1.
2.
3.
4.
5.
Assignments
Describe the function of a pushbutton and of a switch.
Describe the setup of a contactor.
Draft a contactor circuit for controlling a 3-phase motor and set it up.
Identify the components in the circuit setup.
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.
4
© Festo Didactic GmbH & Co. KG 567315
Exercise 1 – Commissioning a stirrer
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
1
4
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.
© Festo Didactic GmbH & Co. KG 567315
5
Exercise 1 – Commissioning a stirrer
–
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
1
2
1
3
A1
1
3
5
A2
2
4
6
2
4
7
A2
A1
6
5
Schematic diagram and circuit symbol for a contactor
Designations
 Contactor coil with terminals A1 and A2.
 Fixed iron core – is magnetised when the contactor coil is connected to nominal voltage (230 V, 24 V).
 Moving iron coil – is attracted by the magnetised fixed iron core.
 Moving contact with mechanical connection to the moving iron core.
 Fixed contact to terminals 1 and 2 (NO contact).
 Return spring – pushes moving iron core back to its initial position after magnetisation is deactivated.
 Spring for spring loaded mounting of the moving contact – contact pressure increases when the
contactor is picked up.
6
© Festo Didactic GmbH & Co. KG 567315
Exercise 1 – Commissioning a stirrer
–
Match up the individual components with the correct designations.
Item
Designation
1
Spring for spring loaded mounting of the moving contact – contact pressure increases when the contactor is picked up.
2
Moving contact with mechanical connection to the moving iron core.
3
Fixed contact to terminals 1 and 2 (NO contact).
4
Moving iron core – is attracted by the magnetised fixed iron core.
5
Fixed iron core – is magnetised when the contactor coil is connected to nominal voltage (230 V, 24 V).
6
Contactor coil with terminals A1 and A2.
7
Return spring – pushes moving iron core back to its initial position after magnetisation is deactivated.
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.
© Festo Didactic GmbH & Co. KG 567315
7
Exercise 1 – Commissioning a stirrer
Contactor circuit with inching operation
–
Complete the primary circuit and the control circuit for inching operation.
24 V
F1
L1
L2
L3
1
2
3
4
5
6
1
F2
1
2
13
S1
N
14
PE
A1
Q1
1
3
5
2
4
6
A2
Q1
0V
M1
3
M
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
–
8
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
© Festo Didactic GmbH & Co. KG 567315
Exercise 1 – Commissioning a stirrer
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
Quantity
Identification
Designation
1
F2
Circuit breaker, single pole
1
S1
Pushbutton (NO)
1
Q1
Power contactor, 4 kW
Primary circuit
Control circuit
© Festo Didactic GmbH & Co. KG 567315
9
Exercise 1 – Commissioning a stirrer
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.
L1
L2
L1
L3
L2
L3
V1
U2
V1
V2
U2
W2
U1
U1
W2
W1
Star circuit
–
W1
Delta circuit
Fill in the locations of the jumpers on the terminal board for both star and delta configuration.
Star circuit
10
V2
U1
V1
W1
U1
V1
W1
U1
V1
W1
U1
V1
W1
W2
U2
V2
U2
V2
W2
W2
U2
V2
U2
V2
W2
Delta circuit
© Festo Didactic GmbH & Co. KG 567315
Table of contents
Exercises and work sheets
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
© Festo Didactic GmbH & Co. KG 567315
1
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
© Festo Didactic GmbH & Co. KG 567315
3
Exercise 1 – Commissioning a stirrer
1.
2.
3.
4.
5.
Assignments
Describe the function of a pushbutton and of a switch.
Describe the setup of a contactor.
Draft a contactor circuit for controlling a 3-phase motor and set it up.
Identify the components in the circuit setup.
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.
4
Name: __________________________________ Date: ____________
© Festo Didactic GmbH & Co. KG 567315
Exercise 1 – Commissioning a stirrer
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

Applications
Pushbutton (NC)
 Function

Applications
Switch (NO)
 Function

Applications
© Festo Didactic GmbH & Co. KG 567315
Name: __________________________________ Date: ____________
5
Exercise 1 – Commissioning a stirrer
–
Describe the difference between a pushbutton and a switch.
Layout of a contactor
1
2
1
3
A1
1
3
5
A2
2
4
6
2
4
7
A2
A1
6
5
Schematic diagram and circuit symbol for a contactor
Designations
 Contactor coil with terminals A1 and A2.
 Fixed iron core – is magnetised when the contactor coil is connected to nominal voltage (230 V, 24 V).
 Moving iron coil – is attracted by the magnetised fixed iron core.
 Moving contact with mechanical connection to the moving iron core.
 Fixed contact to terminals 1 and 2 (NO contact).
 Return spring – pushes moving iron core back to its initial position after magnetisation is deactivated.
 Spring for spring loaded mounting of the moving contact – contact pressure increases when the
contactor is picked up.
6
Name: __________________________________ Date: ____________
© Festo Didactic GmbH & Co. KG 567315
Exercise 1 – Commissioning a stirrer
–
Match up the individual components with the correct designations.
Item
Designation
1
2
3
4
5
6
7
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.
© Festo Didactic GmbH & Co. KG 567315
Name: __________________________________ Date: ____________
7
Exercise 1 – Commissioning a stirrer
Contactor circuit with inching operation
–
Complete the primary circuit and the control circuit for inching operation.
24 V
L1
L2
L3
1
2
3
4
5
6
13
N
14
PE
A1
1
3
5
2
4
6
A2
0V
3
M
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
1, 2, 3, 4, 5, 6
S1
PE
F1, F2
A1, A2
8
Name: __________________________________ Date: ____________
© Festo Didactic GmbH & Co. KG 567315
Exercise 1 – Commissioning a stirrer
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
Circuit breaker, 3-pole
Power contactor, 4 kW
3-phase asynchronous motor
Primary circuit
Quantity
Identification
Designation
Circuit breaker, single pole
Pushbutton (NO)
Power contactor, 4 kW
Control circuit
© Festo Didactic GmbH & Co. KG 567315
Name: __________________________________ Date: ____________
9
Exercise 1 – Commissioning a stirrer
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
U2
V1
V2
U2
W2
U1
V2
W2
U1
Star circuit
–
Delta circuit
Fill in the locations of the jumpers on the terminal board for both star and delta configuration.
Star circuit
10
W1
W1
U1
V1
W1
U1
V1
W1
U1
V1
W1
U1
V1
W1
W2
U2
V2
U2
V2
W2
W2
U2
V2
U2
V2
W2
Delta circuit
Name: __________________________________ Date: ____________
© Festo Didactic GmbH & Co. KG 567315