Basic electrical comp
Post on 28-Nov-2014
1553 Views
Preview:
DESCRIPTION
Transcript
HCLT Confidential
ELECTRICAL COMPONENTS
Ganesh Kumar.M
HCLT Confidential
Agenda
VIISTA
HCLT Confidential
FUSE
A safety device that protects an electric circuit from becoming overloaded.
HCLT Confidential
FUSE
� Fuse - is a type of over current protection device.
� Its essential component is a metal wire or strip that
melts when too much current flows, which interrupts the
circuit in which it is connected.
� Short circuit, overload or device failure is often the
reason for excessive current
� A fuse interrupts excessive current (blows) so that
further damage by overheating or fire is prevented.
HCLT Confidential
MINIATURE CIRCUIT BREAKER (MCB)
An automatic switch that stops the flow of electric current in a suddenly overloaded or otherwise abnormally stressed electric circuit
HCLT Confidential
� when excessive current develops, a circuit breaker opens to protect
equipment .
� These abnormal currents are usually the result of short circuits
created by lightning, accidents, deterioration of equipment.
� A protective device that opens a circuit upon sensing a current
overload. Unlike a fuse, it can be reset.
MINIATURE CIRCUIT BREAKER (MCB)
HCLT Confidential
MCB WORKING
� Able to protect the wiring and the loads of electrical circuits.
� MCB’s are a Thermal-Magnetic type circuit breaker.
� Thermal part loads (motors, heaters, power supplies, etc.)
� will be protected from short circuits by its magnetic parts.
HCLT Confidential
MCB APPLN
� These are manufactured for fault level of up to 10KA.
� Only with operating current range of 0.5 to 63 Amps.
� Available types are single, double and three pole version.
� Mainly used for control voltage protection.
� Machine Lighting.
� Cooling unit.
HCLT Confidential
Type B devices are generally suitable for domestic applications. They may also
be used in light commercial applications where switching surges are low or
non-existent.
Type C devices are the normal choice for commercial and industrial
applications where fluorescent lighting, motors etc. are in use.
Type D devices have more limited applications, normally in industrial use
where high inrush currents may be expected. Examples include large battery
charging systems, winding motors, transformers, X-ray machines and some
types of discharge lighting.
Type B devices are designed to trip at fault currents of 3-5 times rated current
(In). For example a 10A device will trip at 30-50A.
Type C devices are designed to trip at 5-10 times In (50-100A for a 10A
device).
Type D devices are designed to trip at 10-20 times In (100-200A for a 10A
device).
MCB TRIPPING
HCLT Confidential
Curve Graph
HCLT Confidential
MOULDED CASE CIRCUIT BREAKER (MCCB)
An automatic switch that stops the flow of electric current in a suddenly overloaded or otherwise abnormally stressed electric circuit for high SC production.
HCLT Confidential
MCCB (Mould case circuit breakers)
� MCCB’s are Moulded case Circuit breakers, with
protection facilities of over current, earth fault.
� They are manufactured for fault levels of 16KA
to 50KA and operating current range of 25A to
630Amps.
� They are used for application related with larger
power flow requirement.
� In machines it is used for main supply
connection.
HCLT Confidential
MOTOR PROTECTION CIRCUIT BREAKER (MPCB)
An automatic switch that stops the flow of electric current in a suddenly overloaded or Short circuit protection.
HCLT Confidential
MPCB (MOTOR PROTECTION CIRCUIT BREAKER)
Motor Protection Circuit Breakers may
provide the following protective and
control functions.
� Disconnect for Motor Branch Circuit
� Branch-Circuit, Short-Circuit Protection
(Magnetic Protection)
� Overload Protection (Thermal Protection)
� High Current Limiting
� High Switching Capacity
� Current Range 0.1…630 A
HCLT ConfidentialSlide 15
A relay is an electrically operated switch.
Relay
TYPES OF RELAY:
• Latching relay.
• Solid state relay.
• Over load protection relay.
HCLT ConfidentialSlide 16
� Electrical device such that current flowing through it in one circuit can switch
on and off a current in a second circuit.
� Many relays use an electromagnet to operate a switching mechanism
mechanically.
� A relay is used to isolate one electrical circuit from another.
� It allows a low current control circuit to make or break an electrically
isolated high current circuit path.
� Normally-open (NO) contacts connect the circuit when the relay is
activated; the circuit is disconnected when the relay is inactive.
� Normally-closed (NC) contacts disconnect the circuit when the relay is
activated; the circuit is connected when the relay is inactive
Relay Operation
HCLT Confidential
CONTACTOR
A contactor is an electrically controlled switch used for switching a power circuit, similar to a relay except with higher current ratings.
HCLT Confidential
CONTACTOR
� A contactor is controlled by a circuit which has a much lower power level than the
switched circuit
� Unlike a circuit breaker, a contactor is not intended to interrupt a short circuit
current.
� A type of relay that can handle the high power required to directly control an electric
motor is called a contactor.
� Contactors typically have multiple contacts, and those contacts are usually
normally-open, so that power to the load is shut off when the coil is de-energized.
� The most common industrial use for contactors is the control of electric motors.
HCLT Confidential
PUSH BUTTONS
Actuating any function in the
machine can be done by Push Buttons.
HCLT Confidential
� It is a simple switch mechanism for controlling some aspect of a
machine or a process.
� Buttons are typically made out of hard material, usually plastic or
metal
� Pushbuttons are often color-coded to associate them with their
function so that the operator will not push the wrong button in error.
� Commonly used colors are RED for stopping the machine or
process and GREEN for starting the machine or process.
� Secured operations can be done by Key Switch.
PUSH BUTTON
HCLT Confidential
EMO Switch
Emergency Machine Off.
HCLT Confidential
EMO Switch
HCLT Confidential
CONNECTORS & CRIMPS
Connector is an Electro-Mechanical device for joining Electrical Circuits as an interface using a mechanical assembly.
HCLT Confidential
� A D-sub contains two or more parallel rows of pins or sockets
usually surrounded by a D-shaped metal shield that provides
mechanical support .
� The part containing pin contacts is called the male connector or
plug, while that containing socket contacts is called the female
connector or socket .
D-Sub CONNECTORS
Click
HCLT Confidential
� Communications Ports (RS-232 serial communications )
� Network Ports. (Ethernet, network interface cards, )
� Computer Video Port. (VGA Adapters)
� Game Controller Port.
D-Sub CONNECTORS Appln
Click
HCLT Confidential
� Circular Plastic Connectors (CPC).
� Lightweight, all-plastic connectors and metal-shell versions
available.
� CPC connectors are UL 94V-0 rated stabilized, heat resistant, self-
extinguishing thermoplastic material .
� Operating temperature range: -55°C - 105°C
� Unique contact pattern for each position size helps prevent
accidental mating with other position sizes
CPC CONNECTORS
Click
HCLT Confidential
CABLES
A device for connecting electrical devices together.
HCLT Confidential
CABLES
Cable Basics
� Conductor is a material which contains movable electric charges.
� Of the metals commonly used for conductors, copper has a high conductivity. Silver
is more conductive, but due to cost it is not practical in most cases. Aluminum has
been used as a conductor in housing applications for cost reasons.
� Electrical Wires are either solid or stranded Conductors. "Solid Conductors" are
exactly that, one solid Wire. "Stranded Conductors" consist of a Wire made of a
number of smaller Wire strands wrapped around each other.
� The choice between solid or stranded depends on the need for flexibility in handling
and working with the Wire. Smaller electrical Wire Sizes are generally made of solid
Conductors; while Wires larger than Number 6 AWG are generally stranded.
HCLT Confidential
CABLES
� Insulation separates conductors electrically and physically within a cable.
� The jacket physically protects the internal components of a cable, improves the
cable’s appearance and provides flame redundancy.
� Protects from the environment
� Drain Wire Metallic conductor frequently used in contact with foil-type signal-cable
shielding to provide a low-resistance ground return at any point along the shield.
� Twisted pair cabling is a type of wiring in which two conductors (the forward and
return conductors of a single circuit) are twisted together for the purposes of
canceling out electromagnetic interference (EMI) from external sources; for instance,
electromagnetic radiation from unshielded twisted pair (UTP) cables, and crosstalk
between neighboring pairs.
.
HCLT Confidential
AMERICAN WIRE GAUGE(AWG)
American wire gauge (AWG) is a standardized wire gauge system
used predominantly in the United States and Canada for the
diameters of round, solid, nonferrous, electrically conducting wire.
The cross-sectional area of each gauge is an important factor for
determining its current-carrying capacity
HCLT Confidential
AWG TABLE
HCLT Confidential
SHRINK TUBING
Shrink tubing - is a sleeve ordinarily made of nylon or polyolefin, which shrinks in diameter when heated.
HCLT ConfidentialSlide 33
� Its diameter and thickness can vary. Heat shrink tubing is rated by its
expansion ratio, a comparative of the differences in expansion and recovery
rate.
� Heat shrink is used to insulate wires offering abrasion resistance and
environmental protection for stranded and solid wire conductors,
connections, joints and terminals in electrical engineering.
� To protect wires or small parts from minor abrasion, and to create cable
entry seals.
� Common shrink ratio is 2:1, while high-grade polyolefin heat shrink is
available in 3:1
� Heat shrink tubing is available in a variety of colors to allow easier color
coding of wires and connections
Heat Shrink Tubing
HCLT Confidential
Heat Shrink Tubing
HCLT Confidential
SHIELDING
Shielding - Contains electrical energy so that the signal on the cable does not radiate and interfere with signals in other nearby cables and circuitry.
HCLT Confidential
� It is the process of reducing the electromagnetic field in a space by
blocking the field with barriers made of conductive and/or magnetic
materials .
� Shielding is typically applied
� 1) to enclosures to isolate electrical devices from the 'outside world' and
� 2) to cables to isolate wires from the environment through which the
cable runs
� The cable shielding and its termination must provide a low-
impedance path to ground. .
� A shielded cable that is not grounded does not work effectively.
� Make sure the equipment that the cable is connected is properly
grounded.
SHIELDING
HCLT Confidential
SHIELDING
•Protects the signal from external interference.
Shielding materials-
� Metallic foil
� Braid
� French braid™
� Spiral (serve)
� Semi-conductive
HCLT Confidential
GROUNDING
Ground or Earth may be the reference point in an electrical circuit from which other voltages are measured
HCLT Confidential
� In mains powered equipment, exposed metal parts are connected to
ground to prevent contact with a dangerous voltage if electrical
insulation fails.
� An electrical ground system should have an appropriate current-
carrying capability in order to serve as an adequate zero-voltage
reference level.
� Signal Ground is a reference point from which that
signal is measured.
� Chassis ground is the box or frame in which
a circuit is built.
GROUNDING
HCLT Confidential
TERMINALS
A device for joining electrical circuits together
HCLT Confidential
� A terminal is the point at which a conductor from an electrical
component, device or network comes to an end and provides a point
of connection to external circuits .
� A screw terminal is a type of electrical connector where a wire is
clamped down to metal by a screw .
TERMINALS
HCLT Confidential
BusBar
A device used for Making Multi- Connection
HCLT Confidential
� In electrical power distribution, a busbar is a thick strip of copper or
aluminum that conducts electricity within a switchboard, distribution board,
substation or other electrical apparatus.
� Busbars are used to carry very large currents, or to distribute current to
multiple devices within switchgear or equipment.
� Busbars are typically either flat strips or hollow tubes as these shapes allow
heat to dissipate more efficiently due to their high surface area to cross-
sectional area ratio.
BusBar
HCLT Confidential
PD overview
HCLT Confidential
HCLT Confidential
HCLT Confidential
top related