Fundamentals of circuits with contacts

Transcription

1 Fundamentals of circuits with contacts Workbook TP 1211 With CD-ROM 24 V F F S2 22 S Q1 43 Q2 S Q Q K1 K Q2 Q1 Q3 Q A1 A1 A1 A1 A1 Q1 Q2 Q4 Q3 K1 A2 A2 A2 A2 A2 0 V Festo Didactic EN

2 Order number: Revision level: 11/2009 Author: Jürgen Stumpp Editor: Frank Ebel Graphics: Doris Schwarzenberger Layout: 11/2010, Frank Ebel Festo Didactic GmbH & Co. KG, Denkendorf, Germany, 2010 Internet: 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.

3 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 III

4 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

5 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 V

6 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 at did@de.festo.com. The authors and Festo Didactic look forward to your comments. VI Festo Didactic GmbH & Co. KG

7 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 VII

8 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

9 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 IX

10 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. X Festo Didactic GmbH & Co. KG

11 Allocation of learning objectives per exercise Exercise 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 XI

12 Exercise 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. XII Festo Didactic GmbH & Co. KG

13 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 Component Order no. Quantity 3-phase power supply V power supply unit Contactor board Contactor set for motor technology Operator and signalling unit Overview of contactor set for motor technology, order number 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 XIII

14 Graphic symbols, equipment set Component Graphic symbol Circuit breaker, single pole 1 F1 2 Circuit breaker, 3-pole F Overvoltage limiter R1 U Motor protection switch with auxiliary switch, 1 NO and 1 NC contact Q I> I> I> Motor protection relay (overload relay) TEST RESET STOP F Power contactor, 4 kw, with auxiliary switching block, 2 NO and 2 NC contacts Q1 A1 1 3 A Multi-function time relay (described function: star-delta) A1 K1 A2 A Relays K1 A A Operating units 3 1 S1 S2 S Indicators P1 XIV Festo Didactic GmbH & Co. KG

15 Allocation of components per exercise Exercise Component Circuit breaker, single pole, A, 4 A Circuit breaker, 3-pole, C, 4 A 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 Auxiliary switching block for power contactor, 4 kw Overvoltage limiter Multi-function time relay 1 1 Contactor board Operator and signalling unit V power supply unit phase power supply 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 ) or a MPS transfer line MT AC400 (order number C93104) Festo Didactic GmbH & Co. KG XV

16 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 to EN : Graphical symbols for circuit diagrams EN : 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

17 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 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 XVII

18 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

19 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

20 2 Festo Didactic GmbH & Co. KG

21 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

22 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. 4 Festo Didactic GmbH & Co. KG

23 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 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

24 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 A A A1 A2 1 2 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 6 Festo Didactic GmbH & Co. KG

25 Exercise 1 Commissioning a stirrer 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. Festo Didactic GmbH & Co. KG

26 Exercise 1 Commissioning a stirrer Contactor circuit with inching operation Complete the primary circuit and the control circuit for inching operation. L1 1 F V 1 F2 2 1 L2 3 4 L3 N 5 6 S PE Q Q1 A1 A2 0V M1 M 3 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 8 Festo Didactic GmbH & Co. KG

27 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 Primary circuit Quantity Identification Designation 1 F2 Circuit breaker, single pole 1 S1 Pushbutton (NO) 1 Q1 Power contactor, 4 kw Control circuit Festo Didactic GmbH & Co. KG

28 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 L3 L1 L2 L3 V1 U2 V1 V2 U2 W2 U1 V2 U1 W1 W2 W1 Star circuit Delta circuit Fill in the locations of the jumpers on the terminal board for both star and delta configuration. U1 V1 W1 U1 V1 W1 U1 V1 W1 U1 V1 W1 W2 U2 V2 U2 V2 W2 W2 U2 V2 U2 V2 W2 Star circuit Delta circuit 10 Festo Didactic GmbH & Co. KG