GE ALPS Instruction Manual page 99

2 CALCULATION OF SETTINGS
If weak infeed tripping is not required, it can be turned off by setting WKINFTRIP = No (Protection Setting 1205).
Three Phase Tripping:
Single Phase Tripping:
1309: TL24DRPOUT - GDOC Blocking Timer
• Step Distance and POTT1 Schemes: Timer TL24 is not used in these schemes. Therefore it is ignored and any set-
ting made is irrelevant.
• Blocking, Hybrid and POTT2 Schemes: Timer TL24 is used to establish transient blocking for the ground directional
overcurrent functions (GDOC). Transient blocking is used to prevent tripping during
1. current reversals that can occur as a result of sequential clearing of faults on a parallel line,
2. voltage reversals that can occur for faults near capacitors on series compensated lines, and
3. transients that can occur for external fault clearing.
The following settings are proposed:
1. Uncompensated Lines: TL24DRPOUT = 30 ms
2. Series Compensated Lines or Lines Adjacent to a Series Compensated Line: TL24DRPOUT = 125 ms
1310: TL25DRPOUT - Distance Blocking Timer
• Step Distance and POTT1 Schemes: Timer TL25 is not used in these schemes, therefore it will be ignored, and any
setting that is made is irrelevant.
• Blocking, Hybrid and POTT2 Schemes: Timer TL25 is used to establish transient blocking for the phase and ground
distance functions (Z4PHASE and Z4GROUND). Transient blocking is used to prevent tripping during:
GE Power Management
52-1A
52-2A
52-1A
b
52-1B
b
52-1C
b
52-2A
b
52-2B
b
52-2C
b
Figure 2–13: TL5PICKUP / TL6PICKUP REPRESENTATION
ALPS Advanced Line Protection System
TL5
b
CC
E
E
5
E = 0 - 200 ms
TL6
b
NUM_BKR = 2
CC
E
6 E
NUM_BKR = 1
(+)
CC
7
CC
E
AND
8 E
CC
E = 0 - 200 ms
9
CC
10
NUM_BKR =2
CC
E
AND
11 E
NUM_BKR =1
CC
(+)
12
2.3 PROTECTION SETTINGS
KEY
AND
XMTR
KEY
AND
XMTR
2-35
2