Hi Guest
Find Projects

Star or Delta starters are probably the most common reduced voltage starters in the50 Hz industrial motor world (known as Wye / Delta starters) in the 60Hz, in USA.They are used in an attempt to reduce the starting current applied to the motor during start as a means of reducing the disturbances and interference on the electrical supply besides limiting the starting current.

 The Star/Delta starter is generally manufactured using three contactors, an Electromechanical timer and a thermal overload for operating a 3-phase motor at 440 volt at AC mains supply of 50 Hz. The interlocking arrangement of all the contactor coils is traditionally wired in 440 volt AC. However, in our project we have taken up the same to Operate a 3-phase motor at 440 volt AC mains supply 50 Hz with a set of 12 volt DC relays,an electronically adjustable timer and a set of miniature circuit breakers. The interlocking arrangement of the relay coils and the electronic timer are all wired in low-voltage DC of 12 Volt fed from an in-built DC power supply for safe handling of the starter during the study,still retaining its application for a 3-phase motor starting with a single phasing prevention.

The project would be expensive if it uses a 3-phase induction motor. Therefore, the project shall be tested with a set of lamps in each phase. During star operation, the lamps will glow dim indicating the supply voltage across the coils  to be around 440/sqrt(3), and while in delta condition after the timer operates, the lamps will glow with full intensity indicating full supply Voltage of about 440volts across the coils. The timer comprises of a 555 in mono-stable mode – the output of which is fed to a relay for changing the mains supply from 3-phase star to delta. The project also has the provision of single phasing protection since the 3-phase motors may get burnt if any one phase goes missing during operation. The output to the lamps shall be completely cutoff in the event of any phase failure.

Furthermore, the project can be enhanced by using thyristors in a firing angle control principle for soft start of the induction motor that would overcome all the drawbacks of the star delta starter.

Non-Microcontroller Project.
Low Cost Relay Star-Delta Starter.
Call/mail for Tech Support from 10 am - 7 pm IST.
Easy to use, Self-explanatory kit.
All-inclusive solution kit.
Extensive audio-visuals available.
Branding-free material.
Pre-programmed Microcontroller.
Hardware Requirements
  • 3CO Relays
  • 1CO Relay
  • 555 Timers
  • Transistors
  • Transformers
  • Capacitors
  • Resistors
  • Diodes
  • LEDs
Software Requirements
  • None
Q & A
Q:  What is the three phase induction motor rating to be used?
A:  Three phase induction motor can be used, but limited up to 1 HP only as it uses a relay of 6A contact rating only. For higher HP just use a contactor of appropriate rating. The 230 AC coil of the contactor is powered in series from one of the contacts of the relay.
Q:  What is automatic star-delta starting?
A:  Automatic star delta starting means to switch on a 3 phase load in star connection for a set time and then automatically changing over to delta connection.
Q:  Why is the star-delta starter needed?
A:  The star delta starter is needed to extend the life of the motorand protect itfrom drawing high current at the start
Q:  What is the rating of motor to be used in this project?
A:  3 phase, ¼- ½ HP motor rating is used in this project.
Average Rating
Please enter security code
Showing 2 of 2 reviews
POOJA LIMBANI, Gujrat on 28th January, 2015, 01:20 PM

fantastic idea of project.....

salman, on 24th April, 2013, 04:59 AM

nice project

Rating Breakdown (2 Reviews)

Edgefx Technologies,
1001 Bayhill Drive, 2nd Floor,San Bruno,
CA - 94066, United States of America.
© 2012 Edgefx Technologies Pvt Ltd. All Rights Reserved