CHAPTER 1ELECTRICAL CONTROLLER
EQUIPMENT
BY:Salsabila Ahmad
ELECTRICAL CIRCUIT BASIC
4 ELECTRICAL BASICS POWER SUPPLY INPUT DEVICE
Input Controller Equipment CONDUCTOR OUTPUT DEVICE
Output Controller Equipment
POWER SUPPLY
Definition: A device which supplies energy needed
to create an electrical current
INPUT DEVICE DEFINITION 2 TYPES OF INPUT DEVICE
Mechanical input device Solid state proximity device
ELECTRICAL SWITCHING Basic Principle of Electrical Switching Types of Contacts How do These Contacts Work?
DEFINITION: A device which allows/ controls the flow
of current in a circuit These devices are known as“ELECTRICAL CONTROLLER EQUIPMENTS” Provides Electrical Switching
MECHANICAL INPUT DEVICES
Definition: An input device with a
mechanical contact
SOLID STATE PROXIMITY DEVICES
Definition: An electronic input device which
needs power to be able to operate
EG Various types of sensors
EXAMPLE OF MECHANICAL INPUT DEVICES Contact Relay Push button Limit Switch Selector Switch Toggle Switch Temperature Switch Pressure Switch Solenoid Switch Induction Motor Controller
PROXIMITY SENSORS CATEGORY
Proximity sensors inductive
capacitive dielectric type
conductive type
ultrasonic
optical diffuse reflective type
retro reflective type
thru beam
fiber optic sensor
color mark sensor
encoder sensor
RELAY
2 TYPES OF RELAY: EMR SSR
ELECTROMAGNETIC RELAY (EMR)
Definition: An EMR is an electromagnetic
device composed of a frame/core, electromagnet coil and contacts (move and fixed)
Based on simple electromagnetic principle
SOLID STATE RELAY (SSR)
HOW IT OPERATES? Operates similarly to EMR, but
with no mechanical contact. Employ semiconductor switching
elements such as thryristors, triacs, diodes and transistors.
Employ optical semiconductors called photo couplers to isolate input and output signals.
Photo couplers change electrical to optical signals and relay the signal through space.
CHARACTERISTICS OF EMR AND SSR
EMR SSR
slow speedwears out easilyNoisyCheap
high speed, high frequency for switching operationsno failure due to wear out, since no mechanical contactslittle noiseExpensive
Most common relay symbols used in electrical machine diagram
Normally open (NO)
Normally close (NC)
Coil
RELAY SYMBOLS
BASIC PRINCIPLE OF ELECTRICAL SWITCHING
A situation of breaking and open an electrical circuit
Or to direct current from one conductor to another.
The PLC is the solution to today’s electrical switching requirements where it is able to solve
complex switching requirements.
2 TYPES OF CONTACT
NO NC
HOW DO THESE CONTACTS WORK?
Once coil is energized, the contact will change state NO NC NC NO
SOLENOID SWITCH
Use concept of magnetic flux for armature/plunger to move
Produces linear mechanical motion
DEFINITION pushbutton-type operator Have one set or more contact/spring Mostly have a set of normally open
(NO) and normally closed (NC) contact
PUSH BUTTON
CONCEPTS OF OPERATION
Pushing the operator causes the contacts to change state
Spring causes switch operator to automatically return to it’s natural state when it is released.
NO NC NONC NO NC
natural state change state automatic return
a switch with this return spring action, is called a momentary switch.
APPLICATIONS
Frequently used in industrial applications to control functions such as starting and stopping
the machine’s operation With a safety nature. Why?
SCHEMATIC SYMBOLS FOR PUSH BUTTON
Normally Open Contact
Normally Closed Contact
Similarly to pushbutton, but instead of pushing, you rotate a knob
may be designed to stay in a selected position or may have a momentary action
selector switch that stays in a certain position is called a maintained switch.
SELECTOR SWITCH
APPLICATION Widely used in industrial applications
for switching mode of operation to turn the main power on and off to select between AC or DC output.
Some requires key (authorized person) to turn on for safety reason.
SCHEMATIC SYMBOLS FOR SELECTOR SWITCH
Normally open contact
Normally close contact
Selector switch with two contacts
TOGGLE SWITCH
Toggle switch is a maintained switch
INDUCTION MOTOR CONTROLLER Commonly used micro-controllers
PROXIMITY SENSORS
INDUCTIVE PROXIMITY SENSOR
Sense only metallic objects e.g. steel, iron, aluminum, tin,
copper etc Has limited sensing range
range affected by the type of metal sense
CAPACITIVE PROXIMITY SENSOR
sense all material with mass. operation for both dielectric and
conductive type are the same The dielectric type works best for
high density material Low density material (e.g. paper,
foam etc) do not cause a detectable change in dielectric.
The conductive type works best on electrically conductive material e.g. metal or water-based
material)
ULTRASONIC SENSOR
Use ultrasonic technology How does it works?
CONCEPTS OF ULTRASONIC SENSOR Use an ultrasonic “ping” sent from
sensor to target Sensing area is a funnel shape area Therefore, target must be located directly in
front of sensor
When echo is returned, sensor detects target by measuring time delay between transmitted ping and returned echo sensor calculate distance between
sensor and target
Do not work well on cloth, foam rubber
since good absorber of sound waves
Works best on high density material
where sound waves reflects best
DIFFUSE REFLECTIVE
Emitter and receiver located in same housing
Light emitted is received when the object is present
Works well on glossy target but not transparent
Emitter and receiver
Emitter and receiver located in same housing.
Light emitted is received when the object is absent.
Does not work well with glossy target. Why?
Because glossy target acts like a reflector
Emitter and receiver
reflector
RETRO-REFLECTIVE
Emitter and receiver is located in different housing
Sense the object’s present when it passes through between emitter and receiver
where it stops the light from hitting receiver
emitter receiver
THRU-BEAM
Use plastic and glass fibers to carry lights
Available in both thru beam and reflective
Thru-beam
Reflectorobject
FIBER OPTIC
A special type of diffuse reflective optical sensor that can differentiate between colors
some can detect contrast between colors.
Typically used to check labels and sort packages by color mark.
COLOR MARK
ENCODER
Used for position feedback and some for velocity feedback
Two main types Incremental absolute
CONDUCTOR
Definition: A medium that connects all the
components and allows current to flow.
Examples: copper wire bread board
OUTPUT DEVICE
DEFINITION A component that will produce a
desired output. It is also referred to as a load.
COIL Can represents various forms of
output including Motor Light Pump Counter Timer Relay
TIMER most common symbol for
displaying timer function is in block diagram uses a box shape to display the
timer function Sometimes, timer is displayed
in coil format symbol
CHARACTERISTICS OF TIMER
Timers typically have one or two input
Timer with one input has functions as a timer enable input. When input ‘high’, the timer begins timing
A timer with 2 inputs has additional functions which is used to reset the timer accumulated time to zero when the second input is ‘high’
Every timer has a time base Typically; 1 sec, 0.1 sec and
0.01sec.
HOW TIMERS ARE IDENTIFIED? Each timer will have number to
identify it There are two parameters for timer
timer number Used to identify timer e.g. Timer
0, Timer 2. Preset value
Is the delay time set for the timer
TIMER’S PROGRAM
There are still many similarities in the way the timers are programmed even when PLC are different brand
Let say the time base of a timer is 0.1 second
Therefore, if a programmer entered 50 for the number of delay increments
What is the timer’s delay? the timer would have a 5-second
delay. 50 x 0.1 sec = 5 sec
Has one input Timer enabled if the
input logic is ON Timer reset if the input
logic is OFF Maximum value 9999
TMR TIMER0
T0
K40
INPUT
TMR
TMRA Has two inputs Timer starts timing
when ENABLE is ON Timer stops when
ENABLE is OFF without resetting the current value to 0
TMRA TIMER2
T2
K50
ENABLE
RESET
The timer resets when RESET is ON The timer is enabled to start when
RESET is OFF
What is it? What is it characteristics? How does it works? Testing your understanding….. Testing your imagination…..
used to capture and store number of occurrence
COUNTER
CHARACTERISTICS
set to some preset number value when this value of input pulses has
been received, it will operate its contacts
Let say the counter is set for 10 pulses, then when 10 pulse impulses have been received, the counter contacts will close
When there is a input transition for X0 from OFF to ON, counter starts counting
When the RESET is ON, the counter resets to 0
COUNTER PROGRAM
CNT COUNTER0
CT0
K5
INPUT
RESET
X0=sensor/ toggle switch
CT0
X1
OUT1 Counter starts counting when there is
an input transition X0 from OFF to ON
When the RESET is ON the counter resets to 0
MOTOR In PLC, motor can only be
controlled for power (ON/OFF) direction (CCW/CW) preset speed
TYPES OF MOTOR
DC motor type wound fieldpermanent magnetelectronics commutation
dc motors
AC motor type induction motorssynchronous motor