Difference Between Star and Delta Connection

The main key difference between star and delta connection on the basis of several important factors as their configuration, voltage, current, power. motor speed, number of turns, insulation level, application. Here this article gives the basic difference between star and delta connection considering this factor.

The main key difference between star and delta connection are listed below:


  • In star connection, the line current is equal to the phase of the current. While in delta connection the line current is equal to the root three times of the phase current.
  • Star connection is mainly required for the power transmission network for the use of the longer distance, whereas in delta connection mainly in the distribution network and is used for a shorter distance.
  • The amount of insulation required in star connection is low while in delta connection, a high insulation level is required.
  • Instar connecting, each winding receives 230 volts and dealt with a connection each winding receives 415 volts.
  • In star connection, the line voltage is equal to root three times of the phase voltage, whereas in delta connection line voltage is equal to the phase voltage. 
  • Both 3 phase, 4 wire, and 3 phase 3 wire system can be derived in the star connection, while in delta connection only 3 phase 4 wire system can be derived.
  • The speed of the star-connected motor is slow as they receive for 1/√3 of the voltage but the speed of the delta connected motors is high because in each phase gets the total of the line voltage.
  • In star connection, phase voltage is low 1/√3 times of the considering line voltage, but in delta connection phase voltage is equal to the line voltage.
  • The terminals of point of the three branches are connected to a common point. The network formed is known as a star connection. The three branches of the network are connected in such a way that it forms a full of closed-loop known as delta connection.
  • In a star connection, the starting and the finishing point ends of the three coil are connected together to a common point known as the neutral point. While in delta connection, there is no neutral point. The end of each coil connected to the starting point of the other coil that means the opposite terminal of the coils is connected together.
  • In star connection line current is equal to the phase of the current, while in delta connection line current is equal to the root three times of the phase current.
  • In star connection, line current requires fewer turns, while in delta current requires a large number of turns.
  • In star connection insulation required is low, While in delta connection high insulation is required.

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