Table of Contents
- 1 What is the relation between star and delta?
- 2 What is the relationship between resistances connected in Delta and equivalent star systems?
- 3 How do you know if a motor is Star or Delta?
- 4 Why does Delta Start with star and run?
- 5 What is the relationship between line and phase current in star connection?
- 6 What is the relationship between line and phase current in star connection with the positive sequence?
What is the relation between star and delta?
Comparison between Star and Delta Connections
Star Connection (Y or Wye) | Delta Connection (Δ) |
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Line Voltage is root three times phase voltage i.e. VL = √3 VP. Here, VL is Line Voltage and VP is Phase Voltage. | Line Voltage is equal to Phase Voltage i.e. VL = VP. |
What is the relationship between resistances connected in Delta and equivalent star systems?
The equivalent star resistance connected to a given terminal, is equal to the product of the two delta resistances connected to the same terminal divided by the sum of the delta connected resistances.
What is the relation between power in Delta & Power in star?
Delta Connection (Δ): 3 Phase Power, Voltage & Current Values….Comparison between Star and Delta Connections.
STAR Connection (Y) | DELTA Connection (Δ) |
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The speeds of Star connected motors are slow as they receive 1/√3 voltage. | The speeds of Delta connected motors are high because each phase gets the total of line voltage. |
What is the relation between line and phase quantities in both star and delta?
In the case of the Star Connection, the Line Voltage is √ 3 times the Phase Voltage, but the Line and Phase Currents are the same. Whether a Star or Delta Connection is used, the same formula (below) is applied to a 3 phase circuit: P = √ 3 x line voltage x line current times cos ø (power factor).
How do you know if a motor is Star or Delta?
A star only motor has four terminals, three phase terminals and a neutral. A delta only motor has three phase terminals only. A motor designed to be operated either star or delta has each end of each winding brought out, so you have six terminals to work with.
Why does Delta Start with star and run?
After few seconds which already set in the timer motor will connect from the star to the delta connection. So, at starting time star connection helps to reduce the starting current and in the running condition, the delta connection helps to gather enough torque and speed for the motor.
When the star and Delta networks are electrically equal the resistances measured across the pair of terminals?
Explanation: Conversion of given network into delta gives the resistances. After that sum of the resistances equals 122.5Ω. Explanation: The star and delta networks would be electrically equal if a resistance measured between any pair of terminals is same.
How do you know if a motor is Delta or Wye?
If leads are numbered 1-6, the winding can usually be connected wye or delta. On machines rated for two voltages, the wye connection is for the high voltage; the delta connection is for the low voltage.
What is the relationship between line and phase current in star connection?
Relation Between Phase Current and Line Current in Star Connection. The same current flows through phase winding as well as in the line conductor as it is connected in series with the phase winding. Hence, in a 3 Phase system of star connections, the line current is equal to phase current.
What is the relationship between line and phase current in star connection with the positive sequence?
In the balanced star system, magnitude of phase voltage in each phase is Vph. We know in the star connection, line current is same as phase current. The magnitude of this current is same in all three phases and say it is IL.
Why Star Delta is used?
Star/Delta starters are probably the most common reduced voltage starters. They are used in an attempt to reduce the start current applied to the motor during start as a means of reducing the disturbances and interference on the electrical supply.