ABB RELION 670 Series Technical Manual page 238

Section 7
Impedance protection
The input signal DIRCND is used to give condition for directionality for the distance measuring
zones. The signal contains binary coded information for both forward and reverse direction. The
zone measurement function filters out the relevant signals depending on the setting of the
parameter
ZDMRDIR (21D) function.
OffsetMhoDir=
Non-directional
DirMode=Offset
PHSEL
LoadEnchMode=
On/Off
LDCND
DIRCND
OffsetMhoDir=
Forward/Reverse
DirMode=
Forward/Reverse
BLKZ
BLOCK
ANSI11000216 V1 EN-US
Figure 107: Simplified logic for release start signal
When load encroachment mode is switched on (
checked against LDCND signal.
Results of the directional measurement enter the logic circuits when the zone operates in
directional (forward or reverse) mode, as shown in figure 107.
Composition of the phase pickup signals is presented in figure 108.
232
DirMode . Input signal DIRCND must be configured to the STDIRCND output signal on
AND
T
True
F
AND
AND
T
AND
F
AND
OR
LoadEnchMode=On ), start signal PHSEL is also
1MRK 502 066-UUS B
Release
AND
ANSI11000216-1-en.vsd
Technical manual