Star-delta starters are commonly used to start 3-phase induction motors. They connect the motor in star configuration during starting for reduced voltage and current, then switch to delta configuration once the motor reaches operating speed. The starter uses contactors to switch between the star and delta configurations automatically. Star-delta starters are suitable for starting motors that are not heavily loaded during start up, as they provide lower starting torque than direct-on-line starting.

1. Fully Automatic
Star Delta Starter

2. STAR DELTA
A star delta starter is the most commonly used
method for the starting of a 3 phase induction
motor. In star delta starting an induction motor is
connected in through a star connection throughout
the starting period. Then once the motor reaches
the required speed, the motor is connected in
through a delta connection.
Presentation title 2

3. Fully automatic Star delta starter working
principle
There are many different starting methods are used to start a three-phase
induction motor like Star delta starter. One of them, popular and cheapest
is aDirectonlinestarter. But its use limited for smaller HP motor, to start
higher rating 3 phase motors star-delta starter is used. wye-delta starter is
useful where all six terminals of themotorare accessible. In this article, we
will discuss star delta starter working principle with help of power and
control diagram.
Presentation title 3

4. Star-Delta starter is the simplest starting method for reducing the inrush starting current of the Induction motor. The starter can be used with all squirrel-cage induction motors that are
delta-connected for normal operation.
The reduction of the high motor current causes a reduction of the starting torque of the motor. Star-delta starting is therefore especially suitable for drives that are not loaded until after
starting. The starting time is longer than with direct starting, which is especially apparent when driving larger inertial masses. To start a large motor, we need a reduced voltage
starter,to limit starting current. Star delta starter is a reduced voltage starter that applies 1/√3 voltages during the starting time

5. The photographic view of star delta
starter
Presentation title 5

6. Application of Star Delta
Starter
Presentation title 6
• The star-delta method is usually only applied to low to medium voltage and lightstarting
torque motors.
• The received starting current is about 30 % of the starting current during direct on linestart and
the starting torque is reduced to about 25 % of the torque available at a
• D.O.L start.
• This starting method only works when the application is light loaded during the start.
• If the motor is too heavily loaded, there will not be enough torque to accelerate themotor up to
speed before switching over to the delta position

7. Component Details:
Contactor
Contactor Components:
The following three are crucial components of the contactor:
1. Coil or Electromagnet
2. Enclosure
3. Contacts
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8. Contactor Components
Presentation title 8
1. Coil or Electromagnet: This is the most crucial component of a contactor. The driving force that is required to close the contacts is
provided by the coil or electromagnet of the contactor. The coil or electromagnet and contacts are protected by an enclosure.
2. Enclosure: Just like the enclosures used in any other application, contactors also feature an enclosure, which provides insulation
and protection from personnel touching the contacts. The protective enclosure is made from different materials, such as
polycarbonate, polyester,Nylon 6, Bakelite, thermosetting plastics, and others. Generally, the open-frame contactor features an
additional enclosure, which protects the device from bad weather, hazards of explosion, dust, and oil.
3. Contacts: This is yet another important component of this electrical device. The current carrying task of
the contactor is done by the contacts. There are different types of contacts in a contactor namely, contact
springs, auxiliary contacts, and power contacts. Each type of contact has an individual role to play.

9. How the Contactor Operates
Presentation title 9
• Operating Principle of a Contactor:
•The current passing through the contactor excites the electromagnet. The excited
electromagnet produces a magnetic field, causing the contactor core to move the armature. A
normally closed (NC) contact completes the circuit between the fixed contacts and the
moving contacts. This permits the current to pass through these contacts to the load. When
current is removed, the coil is de-energized and opens the circuit. The contacts of the
contactors are known for their rapid open and close action.

10. Contactor Block
The LADN22 is an auxiliary contact block for use with TeSys D and F
series contactors.
• 2NO + 2NC contact configuration
• Rated operational voltage of 690VAC
• Minimum switching current of 5mA at 17V
• Screw clamp terminals
• Compliance to UL and CSA standards
Instantaneous auxiliary contacts operation
APPLICATIONS:-
• Industrial, Power Management,
Automation & Process Control,
Consumer Electronics
Presentation title 10

11. Terminal Blocks
Terminal Blocks are in stock with same-day shipping at Mouser Electronics from
industryleading manufacturers. Mouser is an authorized distributor for many terminal
block manufacturers including Amphenol, Cinch, Eaton, FCI, Molex, Phoenix Contact, TE
Connectivity, Wurth, & more.
A terminal block (terminal strip) is a modular, insulated block which connects one or more
circuits to another. The connections are typically made by a screw or clamp lowering onto a
bare wire in order to complete the connection. Due to this type of connection, terminal
blocksare extremely easy to use and are available in a variety of types across multiple
applications. The most common types are barrier, pluggable, fixed, & DIN rail mount.
Presentation title 11

12. MCB (Miniature Circuit Breaker)
As we all know that, all fuses need to be replaced with them for safety and control
purposes. MCBs are electromechanical devices which are used to protect an electrical circuit
from an overcurrent. It can be reclosed without any hand-operated restoration. MCB is
usedas an option to the fuse switch in most of the circuits. Unlike a fuse, MCB does not have
to be replaced every time after a failure as it can be reused.
Another huge advantage of MCBs is that the detection of a problem is easy. Whenever
thereis a fault in the circuit, the switch comes down automatically and we are hereby
informed that there was a fault. We can then manually go and put the MCB back up and the
electricity will start flowing again.

13. A safety device that protects electrical circuits from the
effects of excessive currents. A fuse commonly consists
of a current-conducting strip or wire of easily fusible
metal that melts,and thus interrupts the circuit of which
it is a part, whenever that circuit is made to carry a
current larger than that for which it is intended. The
screw-plug fuse was once commonlyused in domestic
electrical systems. It contains a short bit of wire (the
fusible element) enclosed in a fireproof container that
has a screw-threaded base; the wire is connected to
metal terminals at both the screw base and at the side,
and the whole is covered with a transparent glass or
mica window for seeing whether the fuse has melted.
The cartridge fuse,a type of fuse widely used in industry
where high currents are involved, has a fusible element
connected between metal terminals at either end of a
cylindrical insulating tube.
Presentation title 13
GLAS
S
FUSE
The photographic view of glass fuse.

14. TIMER
• Time delay relays are simply control relays with a time delay built in. Their purpose is to control an event
based on time. The difference between relays and time delay relays is when the output contacts open & close:
on a control relay, it happens when voltage is applied and removed from the coil; on time delay relays, the
contacts can open or close before or after some time delay.
• Typically, time delay relays are initiated or triggered by one of two methods:
• application of input voltage
• opening or closing of a trigger signal
Presentation title 14

15. The photographic view of timer.
These trigger signals can be one of two designs:
• a control switch (dry contact), i.e., limit switch, push button, float switch, etc.
• voltage (commonly known as a power trigger
To help understand, some definitions are important:
• Input Voltage-control voltage applied to the input terminals. Depending on the function, input
voltage will either initiate the unit or make it ready to initiate when a trigger is applied.
• Trigger Signal-on certain timing functions, a trigger is used to initiate the unit after input voltage
has been applied. As noted above, this trigger can either be a control switch (dry contact switch)
or a power trigger (voltage).
• Output (Load)-every time delay relay has an output (either mechanical relay or solid state) that
will open & close to control the load. Note that the user must provide the voltage to power the
load being switched by the output contacts of the time delay relay.
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16. 2CO
RELAY
DPDT stands for the double-pole double-throw
relay which is an electromagnetic device used to
separate two circuits electrically and connect them
magnetically. They are often used to interface an
electronic circuit, which works at a low voltage to
an electrical circuit which works at a high voltage.
The photographic view of 2CO relay.

17. 4CO
RELAY
4CO Relay generally called 14pin relay. This type
relay having 4 position change contacts generally
called NO, points. In this relay coil voltage is 230V
AC and 30v DC. It having 4 common points
change their position from the initial stage.
Contacts rating depends on the demand by user
The photographic view of 4CO relay.

18. PUSH BUTTON
Push Buttons（Type：Illumination push-button）
Push buttons open and close contacts by force applied by the finger to
the operating component in the vertical axis direction. Push buttons
consist of the operational component that transfers external force to the
switch, the switching component that opens and closes the electrical
circuit, the mounting component that grounds the switch and fixes it
to the panel, the light source that indicates operational status, and the
casing that protects the interior
components. LED illuminated push buttons come with the LED light
source that is built into the operational part and cannot be taken out; push
buttons with incandescent lamp illumination have independent
operational parts and light source that can be separated. Nonilluminated
types do not come with a light source. Button light colours include
green, red, orange, etc. Switch function styles include momentary,
where the pressed button returns to the initial position once it is released,
alternate action, where the first push maintains the operational position,
which is then disengaged with a second push, etc.
Presentation title The photographic view of push button.

19. Thank you