In star the voltage from line to neutral is 1/sqrt(3) times the nominal voltage, while the load current equals the line current.
In delta the voltage between lines is the nominal voltage, while the load current is 1/sqrt(3) times the line current (for a balanced load).
So a delta load needs 3 times the resistance compared to a star load of the same power.
normally delta connection wired in 3 phase induction motor. during starting wiring is in Star and after running normal speed changeover to delta .beacause starting time its phase voltage equals less root3 times of line voltage ,line current and phase current equals. in Delta phase voltage and line voltage equals, and phase current equals root3 times line current
The current is the same in the three live wires. The voltage can be described as the line voltage (phase to neutral) or the phase voltage (phase to phase) which is larger by a factor of sqrt(3). So a line voltage of 230 v corresponds to a phase voltage of 400 v.
On a three phase system with a line to line voltage of 13800, a wye connection will give you a voltage of, 13800/1.73 = 7977 volts to ground.
For the same amount of power, a star or delta connection will use the same line current. However a delta connection supplies sqrt(3) times less current to the device on each of its connections because the voltage is sqrt(3) times more. The apparent contradiction comes about because in a delta connection each connection to the line is shared between two connections to the device (Historikeren 20-07-2015).
1.73 (the square-root of 3) is the ratio of line voltage to phase voltage in a star (wye) three-phase connection, and is the ratio of line to phase current ratio in a delta three-phase connection supplying a balanced load. In each case, it is derived from the phasor addition of two values displaced from each other by 120 electrical degrees.
(a) voltage and current readings vary with position along the transmission line, (b) voltage and current are difficult to define in non-TEM transmission lines.
An accidental ground is the extra path for a current to flow. If a tree touches the high voltage line, it provides a connection to the ground and may allow for a shock current through a person.
In a high voltage installation, with the same power, current drawn is small compared to those in low voltage. However it requires a thicker insulation, thus cost of insulation is significant compared to the conductor cost. By using a star connected winding, the insulation voltage required is equal to line to neutral connection, otherwise if it is connected in delta the insulation rating has to be provided for a line to line connection. Despite having a higher current, the total cost is still lower compared to using a higher insulation rating.
In a 3 phase system, the voltage measured between any two phase is called line to line voltage.And the voltage measured between line to neutral is called phase to neutral (line to neutral) voltage.AnswerThere is no such thing as a 'phase-to-phase' or a 'phase-to-neutral' voltage. The correct terms are 'line-to-line' and 'line-to-neutral'.The voltage between any two line conductors is called a line voltage.In a three-phase, three-wire, system, the line voltage is numerically equal to the phase voltage.In a three-phase, four-wire, system, the voltage between any line conductor and the neutral conductor is called a phase voltage. The line voltage is 1.732 times larger than the phase voltage.
Devide the wattage by the voltage
maximum current will flow in that line
Because it is the same current, as you can determine by examining a circuit diagram of a star connection.