Sel 551 - Table 3.6 Shot Counter Correspondence to Relay Word Bits and Open Interval Times

3.27
Date Code 20110408 Instruction Manual SEL-551 Relay
Relay Elements and Logic
Reclosing Relay
When the shot counter is at a particular shot value (e.g., shot = 2), the
corresponding Relay Word bit asserts to logical 1 (e.g., SH2 = logical 1).
The shot counter also increments for sequence coordination operation. The
shot counter can increment beyond the last shot for sequence coordination
[see Sequence Coordination (79SEQ)].
Reclosing Relay
SELOGIC Control
Equation Settings
Overview
These settings are discussed in detail in the following text.
Reclose Initiate and
Reclose Initiate
Supervision Settings
(79RI and 79RIS,
Respectively)
The reclose initiate setting 79RI is a rising-edge detect setting. The reclose
initiate supervision setting 79RIS supervises setting 79RI. When setting 79RI
senses a rising edge (logical 0 to logical 1 transition), setting 79RIS has to be
at logical 1 (79RIS = logical 1) in order for open interval timing to be initiated.
If 79RIS = logical 0 when setting 79RI senses a rising edge (logical 0 to
logical 1 transition), the relay goes to the Lockout State.
Factory Settings Example
With factory settings:
79RI = TRIP
79RIS = IN1
the transition of the TRIP Relay Word bit from logical 0 to logical 1 initiates
open interval timing only if the IN1 Relay Word bit is at logical 1 (IN1 =
logical 1). Input IN1 is connected to a 52a breaker auxiliary contact and, thus,
the circuit breaker has to be closed when the TRIP Relay Word bit asserts in
order to initiate open interval timing.
Table 3.6 Shot Counter Correspondence to Relay Word Bits and Open
Interval Times
Shot
Corresponding
Relay Word Bit
Corresponding
Open Interval
0 SH0 79OI1
1 SH1 79OI2
2 SH2 79OI3
3 SH3 79OI4
4SH4
SELOGIC Control
Equation Setting
Factory Setting Definition
79RI TRIP reclose initiate
79RIS IN1 reclose initiate supervision
79DTL !LB1+LB3 drive-to-lockout
79DLS 79LO drive-to-last shot
79SKP 50P2*SH0 skip shot
79STL TRIP stall open interval timing
79BRS (51P1+51G1)*(79RS+79CY) block reset timing
79SEQ 0 sequence coordination