Linepickup - GE ALPS Instruction Manual

2.3 PROTECTION SETTINGS 2 CALCULATION OF SETTINGS
805: Z2TIMETRIP - Block For Zone 2 Time-Delayed Trip
Set Z2TIMETRIP = YES if reclosing is to be blocked following a Zone 2 time-delayed trip.
806: Z3TIMETRIP - Block For Zone 3 Time-Delayed Trip
Set Z3TIMETRIP = YES if reclosing is to be blocked following a Zone 3 time-delayed trip.
807: Z4TIMETRIP - Block For Zone 4 Time-Delayed Trip
2
Set Z4TIMETRIP = YES if reclosing is to be blocked following a Zone 4 time-delayed trip.
808: Z1PHASTRIP - Block For Zone 1 Phase Trip
Set Z1PHASTRIP = YES if reclosing is to be blocked following a Zone 1 instantaneous trip.
809: ANYZ2PHASE - Block For Any Zone 2 Phase Fault
Set ANYZ2PHASE = YES if reclosing is to be blocked for following any trip in which any Zone 2 phase distance function
operates.
810: CONFGTRIP - Block For Configurable Trip Logic
The ALPS logic can be configured so that tripping can be initiated via an external contact input. Set CONFGTRIP = YES if
reclosing is to be blocked following a configurable trip.

2.3.11 LINEPICKUP

Line Pickup provides tripping in the event that the breaker is closed into a zero-voltage bolted three-phase fault, such as
occurs if the grounding chains are left on the line following maintenance. Figure 1–4: LINE PICKUP LOGIC DIAGRAM
(THREE PHASE TRIPPING) on page 1–12 and Figure 1–5: LINE PICKUP LOGIC DIAGRAM (SINGLE PHASE TRIP-
PING) on page 1–13 show the functional logic for Line Pickup.
When the line is de-energized, the open breaker detector (formed by IB and the positive-sequence voltage detector V1)
produces an output indicating that the line is dead. The resulting output from AND4 causes timer TL2 to operate 150 ms
later.
If the line is energized and no fault exists, V1 picks up and timer TL1 will begin timing; 25 ms later the output of TL1 resets
timer TL2 via the fast reset input. AND1 and AND2 have the lower inputs removed at that time to take Line Pickup out of
service.
If the line is energized and a fault exists, current detector I1 or one of the Zone 2 distance functions will operate and AND1
and/or AND2 will produce an output.
If BYPASSTL3 = YES, then the bottom input of AND3 is connected to (+), and AND3 immediately produces an output to
initiate tripping of the breaker. If BYPASSTL3 = NO then the bottom input of AND3 is connected to reference (REF), and
tripping will occur after the 45 ms pickup delay of timer TL3.
Timer TL3 is provided where simultaneous high-speed reclosing is employed at both ends of the line, and where the I1
function must be set to pick up below the maximum load current that can occur at that time. TL3 then allows time for the
voltage to return to normal and take Line Pickup out of service before it can trip on load current. If simultaneous high-speed
reclosing is not used, timer TL3 can be permanently bypassed.
Line Pickup via the I1 function is intended primarily to trip for zero-voltage bolted faults wherein the distance functions con-
nected to line-side potential will not operate. As an additional feature, operation of any one of the Zone 2 distance functions
will also initiate a line pickup trip. This is accomplished by routing the Zone 2 phase-distance or ground-distance function
outputs to the upper input of AND1. The other input to AND1 comes from the normal line-pickup-enable output of timer TL2
as previously described. Operating time for the distance functions will be slower than normal since the pre-fault voltage is
zero (assuming line-side potential) and it takes the relay several cycles to establish a memory polarizing voltage. However,
this feature still results in faster tripping for permanent faults past the Zone 1 reach, and below the pickup of the I1 function.
901: LINEPICKUP - Select Line Pickup
Set LINEPICKUP = YES if the line pickup logic is to be used, otherwise set LINEPICKUP = NO.
2-30 ALPS Advanced Line Protection System GE Power Management