Schweitzer Engineering SEL-351P - Logic; High Current Trip Operation When Reclosing Is Defeated

Date Code 990215 Factory-Set Logic 1-17
SEL-351P Manual Técnico
O PERATIONS TO L OCKOUT , A CTIVATE H IGH C URRENT T RIP , AND A CTIVATE H IGH
C URRENT L OCKOUT L OGIC
Note the symmetry amongst Figure SECTION 1: .8 through Figure SECTION 1: .14. Relay
Word bits SH0 through SH4 assert during different periods of a reclose cycle as the shot
(reclose) counter increments. The shot counter increments just before each reclose. See
Table
SECTION 1: .3 and accompanying note.
An example reclose cycle (from reset to lockout) appears as:
(reset) 1st trip - 1st reclose - 2nd trip - 2nd reclose - 3rd trip - 3rd reclose - 4th trip (lockout)
Per
Table SECTION 1: .3, SH0 = logical 1 during the first trip, SH1 = logical 1 during the
second trip and so forth.
Refer to
Figure SECTION 1: .11. For example, to enable the High current trip - phase for the
third and fourth trip operations, make setting Activate high current trip - phase = 3 (HITRPH =
3). In
Figure SECTION 1: .11, this causes Relay Word bit HTP to be asserted to logical 1 for all
the following conditions:
• shot = 2 (SH2 = logical 1)
• shot = 3 (SH3 = logical 1)
• shot = 4 (SH4 = logical 1)
The note in
Figure SECTION 1: .11 refers to Figure SECTION 1: .17 – the logic that controls
the High current trip - phase (phase definite-time element 67P2T). In this example, High current
trip - phase is enabled for the third trip operation and every following trip operation.
The logic in
Figure SECTION 1: .8, Figure SECTION 1: .9, Figure SECTION 1: .10, Figure
SECTION 1: .12,
Figure SECTION 1: .13, and Figure SECTION 1: .14 operates similarly to
the High current trip - phase just discussed (
Figure SECTION 1: .11).
High Current Trip Operation When Reclosing Is Defeated
If reclosing is defeated via setting (e.g., all Operations to lockout ≤ 1), then all the following
reclosing-related Relay Word bits default to logical 0 (the reclosing relay is nonexistent):
SH0, SH1, SH2, SH3, SH4 (shot counter states)
79RS, 79CY, 79LO (reclosing relay states)
The logic at the top of
Figure SECTION 1: .11 and Figure SECTION 1: .12 enables set phase
and ground high current trips, respectively, when reclosing is defeated.