ABB REL650 series Technical Manual page 107

1MRK 506 335-UUS A
Technical manual
1
7
3
1
1
6
IEC09000308 V2 EN
Figure 32: Characteristic for phase-to-ground measuring
1 RFPG
KNMag |Z|
2
where: KN·Z =ZN
|Z|
3
where Z denotes the positive sequence vector corresponding to the zone reach
LineAng
4
KNAng (negative)
5
R1 + Rn
6
Rn = (R0 - R1) /3
where
7 X1 +Xn
Xn = (X0 - X1) /3
where
X (Ohm/loop)
6
1
*
* Load compensation characteristic
5
is present only for zone 1 phase-to-
ground measurement loops.
2
4
4
R
1
7
1
IEC09000308_2_en.vsd
Section 6
Impedance protection
(Ohm/loop)
101