INTRODUCTION TO AUTOMATION SYSTEMPrepared by: Aftas Azman jke/psa/jun2010

INTRODUCTIONControl system now converge a lot to Automation Control System. Now are days, we were surrounded by this system for example at home, in vehicle and buildings. In industry Automation Control System are used to improve quality and increase productivity. Automation Control System are influence our future lifestyle.

Automation Control System needs in IndustryAutomation Control System are able to control a process with or without manual help.

Automation Control System had capacity to start, posting, act present or measure variable in process and stop process for product output.

Automation Control System needs in Industry

Main purpose Automation Control System used in industry is to increase productivity of :- Increase output quantity. Improve production's quality. Control the expenditure cost.

Fixed Automation / Hard-Wire ControlThis control system designed to do a specific task. The control circuit function is still and remain.

Work would be complicated if we wish to do next job other than present for this control system.

Flexible Automation / Programmable Control System Flexible Automation is a complex control system that can do various task. Function of control circuit are programmed by consumer and can be modified.

When doing modification at the machine we can only change the control program to meet new task.

COMPARISON BETWEEN FIXED WITH FLEXIBLE AUTOMATION

Exp 1Fixed controllerFlexible controllerPLCIN OP

Exp 2Fixed controllerFlexible controller

SUIS16432135914121181071615123Fixed Automation

Fixed Automation

Fixed Automation

Fixed Automation

Fixed Automation

Fixed Automation

PLCOUTPUTINPUTFlexible Automation

PLCOUTPUTINPUTPROGRAMWhen switch no 1 ON, lamp 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 will ON

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

PLCOUTPUTINPUTPROGRAMWhen Switch no 1 ON, lamp 1 3 5 10 will ON

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

PLCOUTPUTINPUTPROGRAMWhen switch no 3 ON, lamp 1 3 5 10 will ON

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

PLCOUTPUTINPUTAutomasi Boleh AturcaraFlexible Automation

INTRODUCTION of RELAYS

IntroductionRelays open and close electrical contacts to operate other devices.

They are often used because they cost less than corresponding electronic switches.

But some relay qualities are superior to solid-state devices. For example, input and output circuits in relays are electrically isolated unlike those of most solid-state devices.

IntroductionRelays can have numerous contacts electrically isolated one from another.

In addition, electromechanical relays are becoming smaller, now available in PCB-mount and surface-mount packages that are suitable for automated soldering.

Basic electro magnetic relay

Relay schematic diagram

Principle Functionally, armature and a relay is a solenoid operated switch, it consists of a coil of wire, one or more contacts. Figure bellow shows the principle.

How relay works

Basic relay Structure

Relay functionsThe main function of relays is:-changing from a normally closed to a normally open contact (Inversion)

Multiplying contacts from one (to energize the coil) to any reasonable number of contacts.

Power amplification

Voltage change

Memory function

Relay functionsThe latter function is realized with the most important basic relay circuit is called a holding Circuit. Methods that are used are shown bellow:-

Types of RelayThere are several type of relay that used nowadays, some of its are:-

Plug-in RelaysPrint RelaysSpecial Function Relays

Plug-in Relays

There are various types of relays. A distinction can be made according to the mounting method: plug-in type or print type.

Print RelaysPrint Relays are designed to be soldered on circuit boards. They have terminals in the form of small strips or pins to be inserted in the holes of print plates and are to be soldered in the same process as electronic components.

Special Function RelaysLatching RelaysAnother distinction can be made according to the function. A bistable device, made of two relays with a latch on the moving armature.

Relays POLE and ThrowThere are many type of pole and throw of relay, such as:Single pole double throw SPDT, Double pole double throw DPDT, Four pole double throw 4PDT and others.

*Figure : Relay Contact Configuration

*This is a Single Pole Single Throw (SPST) relay. Current will only flow through the contacts when the relay coil is energized.

*This is a Single Pole Double Throw (SPDT) relay. Current will flow between the movable contact and one fixed contact when the coil is D-energized and between the movable contact and the alternate fixed contact when the relay coil is energized. The most commonly used relay in car audio, the Bosch relay, is a SPDT relay.

*This is a Double Pole Single Throw (DPST) relay. When the relay coil is energized, two separate and electrically isolated sets of contacts are pulled down to make contact with their stationary counterparts. There is no complete circuit path when the relay is D-energized.

*This relay is a Double Pole Double Throw (DPDT) relay. It operates like the SPDT relay but has twice as many contacts. There are two completely isolated sets of contacts.

SBO/ PMM/ EJ501/ Jun2011 *This is a 4 Pole Double Throw (4PDT) relay. It operates like the SPDT relay but it has 4 sets of isolated contacts.

*Figure : Wiring of relay

RatingsRelay is rated firstly by the voltage requirements of its coil that is 12Vdc, 24Vdc and 110Vac. Secondly the switch contacts are rated for maximum voltage and current flow, for use in both AC and DC circuits.

Maintenance

Service life will very with loads placed upon them, but most breakdowns occur due to open circuit. Coil bum out, when switch contacts weld due to excessive current or voltage.

Maintenance

The relay is an electromechanical device. The relay offers a simple ON/OFF switching action and response to a control signal.

INTRODUCTION of CONTACTOR

ContactorsA contactor works on exactly the same principle as a control relay but s usually much larger, built to control the larger currents drawn by electric motors. A contactor can be fitted with overload protection, and this is not usually available for control relays.

ContactorsRelays can be used to directly control small motors only if the current required by the motor, is within the operating range of the relay.

Contactors Symbols

Contactors Connection

Building Diagram

OperationWhen a relay is used to switch a large amount of electrical power through its contacts, it is designated by a special name: contactor.

OperationContactors typically have multiple contacts, and those contacts are usually (but not always) normally-open, so that power to the load is shut off when the coil is de-energized.

Perhaps the most common industrial use for contactors is the control of electric motors.

OperationThe top three contacts switch the respective phases of the incoming 3-phase AC power, typically at least 415 Volts for motors 1 horsepower or greater.

OperationThe lowest contact is an "auxiliary" contact which has a current rating much lower than that of the large motor power contacts, but is actuated by the same armature as the power contacts.

OperationThe auxiliary contact is often used in a relay logic circuit, or for some other part of the motor control scheme, typically switching 120/240 Volt AC power instead of the motor voltage.

OperationOne contactor may have several auxiliary contacts, either normally-open or normally-closed, if required.

INTRODUCTION of Electromechanical Timer

Electromechanical timerSymbol of Electromechanical timerContact symbols determine the time of timer action:-On-delay action - TR energized, contacts change state after set time intervalOff-delay action - TR de-energized, contacts change state after set time interval

Electromechanical timerDefineElectromechanical timers are used to start or stop a machine or other device at preset or delayed intervals.

They consist of both electrical and mechanical components, andoften feature an electric motor that drives one or more gears.

They typically accept electric or electronic inputs to operate a mechanical output such as rotating wheels or knobs.

Electromechanical timerA timer is a specialized type of clock for measuring time intervals Short-period bimetallic electromechanical timers use a thermal mechanism, with a metal finger made of strips of two metals with different rates of thermal expansion sandwiched together; steel and bronze are common.An electric current flowing through this finger causes heating of the metals, one side expands less than the other, and an electrical contact on the end of the finger moves away from or towards an electrical switch contact. The most common use of this type is in the "flasher" units that flash turn signals in automobiles, and sometimes in Christmas lights. This is a non-electronic type of multivibrator.

Electromechanical timerA category of timers that operate through a combination of electricity and mechanical motion. Electromechnical timers are gradually being replaced by solid state technology

INTRODUCTION of Electromechanical Counter

Electromechanical counterA category of counters that operate through a combination of electricity and mechanical motion.

Electromechanical counters receive an electrical input signal and convert it to mechanical action to output a count, stop a count, or reset the counter to zero.

Electromechanical counterElectromechanical counters are used to detect, totalize, and indicate a sequence of events. They typically accept electric or electronic inputs to operate mechanical outputs such as rotating wheels or knobs. These devices may count UP and/or DOWN, support multiple functions, and provide reset capabilities.

Electromechanical counterSymbol Electromechanical Counter

Electromechanical counterSimple Logical Control/ Automation Sequence

Application of relay and contactor

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