1
1
1
L
L
L
U
Z
I
(uncompensated)
2
2
2
2
L
L
L
U
Z
I
(uncompensated)
3
3
3
L
L
L
U
Z
I
(uncompensated)
All uncompensated impedances Z
L1
, Z
L2
and Z
L3
are compared with the starting characteristic
and temporarily set the logical signals Ph and E (no display). An impedance loop is selected on
the basis of these signals (loop = selected phase).
Phase-ground-loop
For a phase-ground-loop, the impedance is calculated with a compensation factor k
0
= 1:
Ph 0
Ph 0
Ph
E
U
Z
I
1 I
For example:
L
L
1
L10
1
E
U
Z
I
1 I
Phase-to-phase loop
For a phase-to-phase loop, the impedance is calculated using phase-to-phase variables:
Ph Ph
Ph Ph
Ph Ph
U
Z
I
For example:
1MRK 505 406-UEN B
Section 5
Bay protection functions
Bay protection functions REB500
55
Technical manual
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