ABB Relion 670 Series Installation And Commissioning Manual page 236

Section 16
Checking the directionality
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• load current > 5% of base current
• Otherwise the settings IMinOpPE and IMinOpPP for ZDRDIR or
ZDMRDIR are available under the HMI menu: Main menu/
Settings/Setting group N/Impedance protection/
DirectionalImpedance(RDIR)
The primary load impedance must have an angle (PHI) between the setting
angles for the directional lines. In case of default settings this means:
• for forward (exported) load: -15 deg < PHI < 115 deg
• for reverse (imported) load: 165 deg < PHI < 295 deg
The settings for forward load: - ArgDir < PHI < ArgNegRes and the settings
for reverse load: 180 deg - ArgDir < PHI < 180 deg + ArgNegRes included in
the directional functions ZDRDIR or ZDMRDIR are available under the HMI
menu:
• Main menu/Settings/Setting group N/Impedance protection/
DirectionalImpedance(RDIR)
3. The directionality of the load current is shown by the directional function
ZDRDIR or ZDMRDIR and it is available under the HMI menu: Main menu/
Test/Function status/Impedance protection/DirectionalImpedance(RDIR)
If the load current flows in forward (exporting) direction there will be shown:
• L1Dir = forward
• L2Dir = forward
• L3Dir = forward
If the load current flows in the reverse direction (importing) there will be shown:
• L1Dir = reverse
• L2Dir = reverse
• L3Dir = reverse
Compare this result with the information given by the external equipment, it
must be the same. If the direction of the three phases is not the same, this is a
sign of incorrect connection of the voltage or current transformers serving the
distance protection function. It is also possible that there is a wrong setting for
the earthing point for one or more of the CTs serving distance protection (the
setting name is: CTStarPoint).
If the directional function shows forward when it should show reverse (or vice-
versa) for all the three phases, this probably means a wrong connection of CTs
and/or VTs serving the distance protection, or it can mean a wrong setting of
earthing point (the setting name is : CTStarPoint) for all the three CTs, or it
could mean a wrong setting for the pre-processing blocks
(3PhaseAnalogGroup) connected to the CTs/VTs and serving the distance
protection (verify that no wrong negation has been set; the setting name is:
Negation).
If the directional function shows "No direction" for all the three phases it can
mean that the load current is below the minimum operating current or that the
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Installation and commissioning manual