1MRS759142 F
I
prim
The power of the stabilizing resistor is calculated as follows.
P
≥
The need for voltage dependent resistor is checked with equations
U
max
˘
u
=
The voltage dependent resistor, one for each phase, is needed in this case because
the voltage during the fault is much higher than 2 kV.
The leakage current through the varistor at the stabilizing voltage can be available
from the varistor manual, assuming that to be approximately 2 mA at stabilizing
voltage.
Iu
≈ 0 002
The sensitivity of the protection can be re-calculated taking into account the
leakage current through the varistor as per equation
I
prim
4.3.8.9
Signals
MHZPDIF Input signals
Table 727: MHZPDIF Input signals
Name
I3P
BLOCK
REX640
Technical Manual
(
1000 0 020
.
A
2 0 0085
.
=
⋅
+ ⋅
2
(
)
323
V
W
≈
27
3900
Ω
12 770
A
⋅
(
=
⋅
3900
Ω
+
1000
(
2 2 323
V
36200
V
323
⋅
⋅
−
.
A
(
1000 0 020
.
A
2 0 0085
.
=
⋅
+ ⋅
Type
SIGNAL
BOOLEAN
)
A
0
A
37
A
+
≈
15 3
.
Ω
+
1 73
.
Ω
+
0 10
.
Ω
)
V
9 6
.
kV
≈
)
A
0 002
.
A
39
A
+
≈
Default
-
0=False
Protection functions
)
kV
≈
36 2
.
Description
Three-phase currents
Block signal for acti-
vating the blocking
mode
(Equation 229)
(Equation 230)
(Equation 231)
(Equation 232)
(Equation 233)
(Equation 234)
817