Example 1 - ABB REL650 Applications Manual

1MRK 506 334-UUS A
4.2.3.1
Application manual
A positive value of current, power, and so on (forward) means that the quantity has a
direction towards the object. - A negative value of current, power, and so on (reverse)
means a direction away from the object. See figure 35.
Definition of direction
for directional functions
Reverse Forward
e.g. P, Q, I
Measured quantity is
positive when flowing
towards the object
Set parameter
CTStarPoint
Correct Setting is
"ToObject"
ANSI05000456 V2 EN
Figure 35: Internal convention of the directionality in the IED
With correct setting of the primary CT direction, CT_WyePoint set to FromObject or
ToObject, a positive quantity always flows towards the protected object and a direction
defined as Forward is always looking towards the protected object. The following
examples show the principle.

Example 1

Two IEDs used for protection of two objects.
Protected Object
Line, transformer, etc
Measured quantity is
positive when flowing
Section 4
Analog inputs
Definition of direction
for directional functions
Forward Reverse
e.g. P, Q, I
towards the object
Set parameter
CTStarPoint
Correct Setting is
"FromObject"
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