A.4 Connection Examples
489
7UM62 Manual
C53000-G1176-C149-3
Figure A-27 Busbar System with Low-Ohmic, Switchable Starpoint Resistors
Connection on each side to three current transformers and three voltage transformers (phase-to-ground volt-
ages) –earth fault detection as differential current measuring by two CT sets; detection of displacement volt-
age at broken delta winding (e–n).
I
A(L1)S2
I
B(L2)S2
I
C(L3)S2
V
E
V
A(L1)
V
B(L2)
V
C(L3)
I
A(L1)S1
I
B(L2)S1
I
C(L3)S1
A (L1)
B (L2)
C (L3)
I
EE2
R18
R16
R17
R15
Q8
Q7
R13
R14
Q1
Q2
Q3
Q4
Q5
Q6
7UM62
low resistance
if necessary
(for protection of resistor
do not earth
here
R
E
J1
J2
J3
J4
J5
J6
I
EE1
J8
J7
TD3
K18
K17 +
TD1
K14
K13 +
TD2
K16
K15 +
Measuring transducer:
- Temperature
injection
- or DC voltage
injection
Excitation voltage
injection
n
e
ANSI
52