ABB Relion REG670, Technical Manual, Page: 451 / 1298

When the maximum phase-to-phase voltage is larger than DisarmU> for the period
tDisarm , it is ensured generator is on line. During this state, undervoltage operation is
disarmed, blocking the overcurrent operation and thus the function becomes
inoperative.
BLOCK input can be used to block AEGPVOC . In addition, the BLKTR input that
blocks the TRIP signal is also present. The input BLKTR can be used if AEGPVOC
is to be used only for monitoring purposes.
I>
Operation = ON
a
a>b
b
Imax_DFT
AND
BLOCK
TRIP
tOC
START
ARMED
S
R NOUT
OUT
ArmU<
a
a<b
b
Uph-ph_max_DFT
t
tArm
ON - Delay
DisarmU>
a
a>b
b
t
tDisarm
ON - Delay
OR
AND
IEC09000784-2-en.vsd
t
IEC09000784 V2 EN
Figure 206: AEGPVOC logic diagram
8.13.1.7 Technical data
Table 240: AEGPVOC technical data
Function Range or value Accuracy
Operate value,
overcurrent
(5-900)% of IBase ±1.0% of I
r
at I≤I
r
±1.0% of I at I>I
r
Reset ratio, overcurrent >95% at (20–900)% of IBase -
Transient overreach,
overcurrent function
<10% at τ = 100 ms -
Critical impulse time,
overcurrent
10 ms typically at 0 to 2 x I
set
-
Impulse margin time,
overcurrent
15 ms typically -
Operate value,
undervoltage
(2-150)% of UBase ±0.5% of U
r
at U ≤ U
r
±0.5% of U at U > U
r
Critical impulse time,
undervoltage
10 ms typically at 2 to 0 x U
set
-
Table continues on next page
1MRK502052-UEN B
Section 8
Current protection
445
Technical manual