• Forward means direction into the object.
• Reverse means direction out from the object.
Protected Object
Line , transformer, etc
ForwardReverse
Definition of direction
for directional functions
Measured quantity is
positive when flowing
towards the object
e.g . P , Q , I
ReverseForward
Definition of direction
for directional functions
e.g . P , Q , I
Measured quantity is
positive when flowing
towards the object
Set parameter
CT_ WyePoint
Correct Setting is
" ToObject"
Set parameter
CT_ WyePoint
Correct Setting is
" FromObject"
ANSI11000275-1.vsd
ANSI11000275 V1 EN
Figure 2: Internal convention of the directionality in the IED
If the settings of the primary CT is right, that is CTStarPoint set as FromObject or
ToObject according to the plant condition, then a positive quantity always flows
towards the protected object, and a Forward direction always looks towards the
protected object.
The settings of the IED is performed in primary values. The ratios of the main CTs and
VTs are therefore basic data for the IED. The user has to set the rated secondary and
primary currents and voltages of the CTs and VTs to provide the IED with their rated
ratios.
The CT and VT ratio and the name on respective channel is done under Main menu/
Hardware/Analog modules in the Parameter Settings tool.
3.3 Settings
Dependent on ordered IED type.
Section 3 1MRK 505 277-UUS C
Analog inputs
36
Technical Manual
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