Section 8
Current protection
8.8.8
264
is larger than IPickup for the period tOC then the TRIP signal becomes activated. Also
PICKUP signal becomes activated when overcurrent is detected.
When the maximum phase-to-phase voltage is larger than 59_Drop_out for a period
longer than 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 AEGGAPC (50AE). In addition, the BLKTR input
that blocks the TRIP signal is also present. The input BLKTR can be used if AEGGAPC
(50AE) is to be used only for monitoring purposes.
Imax_DFT
a
a>b
b
IPickup
Operation = Enabled
BLOCK
Uph-ph_max_DFT
a
b
27_pick_up
a
a>b
b
59_Drop_out
ANSI09000784 V2 EN
Figure 120:
AEGGAPC (50AE) logic diagram
Technical data
Table 140:
AEGGAPC (50AE) technical data
Function
Operate value,
overcurrent
Reset ratio, overcurrent
Transient overreach,
overcurrent function
Critical impulse time,
overcurrent
Table continues on next page
AND
0-tOC
0
0-tArm
a<b
0
ON - Delay
OR
0-tDisarm
0
ON - Delay
Range or value
(5-900)% of IBase
>95%
<20% at τ = 100 ms
10 ms typically at 0 to 2 x I
set
1MRK 502 048-UUS A
TRIP
RI
Enabled
AND
S
OUT
R
NOUT
ANSI09000784-2-en.vsd
Accuracy
± 1,0% of I
at I<I
n
n
± 1.0% of I at I>I
n
-
-
-
Technical manual