Understanding Three Phase Circuits: Direction of Arrows

In summary, the arrows in the given figures denote the sign of voltage induced in the winding when current flows in that direction. The direction of the arrows is not a rule and can be taken in the opposite direction as well. The purpose of this is to indicate the polarity of the voltage in the winding. The line voltages in the third figure are in an anti-clockwise direction, which means that the voltage across the winding is positive when current flows from the terminal Y to R. This direction is determined by the convention of anti-clockwise direction for positive voltage.
  • #1
ranju
223
3
In the given figures , what does the arrows denote , I mean what direction ??
VnR is upward in 1st fig. , VnR is towards left in 2nd fig. ( n is neutral here ) while in 3rd the line voltages are in anti-clockwise direction..!
I wanted to know the pupose of this and why these directions only??
 

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  • #2
ranju said:
In the given figures , what does the arrows denote , I mean what direction ??
VnR is upward in 1st fig. , VnR is towards left in 2nd fig. ( n is neutral here ) while in 3rd the line voltages are in anti-clockwise direction..!
I wanted to know the pupose of this and why these directions only??
The arrow denotes the sign of voltage induced in the winding when current flows in that direction. For example if current flows from terminal n to R, the voltage across the winding denoted by VnR is positive.
 
  • #3
This means it is not a particular rule we can take this in opposite direction too ??
And what about the anti-clockwise direction of line voltages (VYR ,, VBY..) ??
 

Related to Understanding Three Phase Circuits: Direction of Arrows

What is the purpose of arrows in a three phase circuit?

The arrows in a three phase circuit represent the direction of current flow in each phase. This helps to determine the correct phase sequence and ensure proper functioning of the circuit.

How do you determine the direction of arrows in a three phase circuit?

The direction of arrows in a three phase circuit can be determined by using the right-hand rule. Point your right thumb in the direction of the current flow in the first phase, then curl your fingers towards the second phase. The direction your fingers point in is the direction of the arrows in the second phase. Repeat this for the third phase, with your fingers pointing in the direction of the current flow in the second phase.

Why is it important to know the direction of arrows in a three phase circuit?

Knowing the direction of arrows in a three phase circuit is important because it helps to determine the phase sequence, which is crucial for proper functioning of the circuit. Incorrect phase sequence can result in equipment malfunction or damage.

Can the direction of arrows in a three phase circuit be reversed?

Yes, the direction of arrows in a three phase circuit can be reversed by switching the phase sequence. This can be done by swapping any two phases at the source or load end.

What happens if the direction of arrows in a three phase circuit is incorrect?

If the direction of arrows in a three phase circuit is incorrect, it can result in a reversed phase sequence which can cause damage to equipment or incorrect functioning of the circuit. It is important to double check the direction of arrows before connecting a three phase circuit to avoid these issues.

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