Transformers 3-Phase Flashcards
3-phase fundamentals
What are the 6 3-phase transformer connections?
open-delta/open-delta open-wye/open-delta delta/wye wye/wye delta/delta wye/delta
What is the percentage of AC electricity generated in the world?
Almost 95%
How many voltages are available on a delta system?
Only one voltage between any two wires.
What electrical system is a 3 wire system?
A delta system.
The line voltage and the phase voltage are the same in a delta system.
True
The line current and the phase current are different in a delta system by a factor of what?
The line current is 1.73 (the square root of 3) times higher than the phase current. The line current on any single line is fed from the two coils that share the same connection as that line. The two phase currents converge at a point to form the line current.
What is the most commonly used three phase system?
The wye or star system.
The coils in a wye system share a common point forming a Y. What is the voltage from tip to tip?
The tip to tip voltage is called the line voltage which is 1.73 times the phase voltage or coil voltage.
How many voltages are available on a wye system?
2
How many wires are on a wye system?
A wye system is a 4 wire system.
How much can the load be increased by switching a 3-wire delta system to a 4-wire wye system?
73%
