ABB RELION REX640 Technical Manual page 817

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