Zone 2 Trip - ABB REL300 Instruction Manual

I.L. 40-385.7
satisfy AND-2 and provides a high-speed trip (HST) signal from OR-2 to operate the trip output
telephone relay. The trip circuit is monitored by a seal-in reed relay (S), which is in-series with
each trip contact in the tripping circuits. The "S" relay will pick up if the trip current is higher than
0.5 Amp. The operation of the "S" contact will turn-on the breaker trip indicators (with memory),
and feeds back to OR-4 to hold the trip relay in operation until the breaker trips and 52a contact
opens (not shown in Figure 3-5). The TRSL signal plus the output signal from AND-2 turns on
the Zone 1 phase trip indicator (Z1P). The breaker trip and Zone 1 phase trip indicators are
memorized. They can be reset by external RESET voltage or through remote communication.
By pushing the RESET pushbutton, the flashing LED will be reset, but the fault information will
still remain in memory.
NOTE: The operating time of the Trip relay is 2 ms and the BFI relay is between 10 and 15 ms.
The difference of the pickup times should be compensated in the breaker failure
scheme.
The Z1P 3φ trip logic AND-131 is supervised by both the conventional OSB and the FDOPA &
FDOPB & FDOPC, for more security on some special power system applications. (Refer to
section 3.4.12 for detailed FDOP unit.) ZIP logic AND-2 is also supervised by the IM setting,
the medium set phase overcurrent unit.
Similar operations exist for Zone 1 single-phase-to-ground faults. The Z1G unit sees the fault
and operates; the IOM and FDOG units also operate, satisfying AND-3. Tripping occurs via
OR-2 with Zone 1 ground trip indication Z1G. Logic AND-3 is also supervised by the signal of
RDOG (reverse directional overcurrent ground) for security purposes.
The Z1G unit is also supervised by the signal of unequal-pole-closing and RDOG.
A two-out-of-three "leading phase blocking" logic is included for solving the overreach problem
of the single-phase ground distance units, which may respond to a φφG fault.
The high-speed trip (HST) signal also is connected to the reclosing initiation logic.
Either or both Zone 1 phase and Zone 1 ground function(s) can be disabled by setting the Z1P
and/or Z1G to the "OUT" position. Zone 1 trip can be delayed by setting T1 = 0 to 15 cycles.
The delay time is for a non-pilot 3PT backup, with another system operating in SPT mode.
3.3.2

Zone 2 Trip

For Zone 2 phase faults, the Z2P unit will see the faults plus the output of IM and will operate
the Zone 2 phase timer (T2P). AND-4 output plus the T2P timer output satisfy AND-18, as
shown in Figure 3-6 (page 3-31). The AND-18 output provides time delay trip signal TDT via
OR-3. Signal TDT picks up OR-4 (Figure 3-5) and operates the trip relay. The tripping and tar-
geting are similar as described in Zone 1 trip except for Zone 2 phase time delay trip indicator
(Z2P).
Similar operation occurs for Zone 2 single-phase-to-ground faults. The Z2G unit sees the fault
and operates. This, plus the operation of the IOM, FDOG and T2G satisfy AND-19, and provide
the TDT signal via OR-3 with Zone 2 ground time delay trip indicator (Z2G).
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