Schweitzer Engineering Laboratories SEL-421-4 - Page 1001

6.25
Date Code 20171006 Instruction Manual SEL-400 Series Relays
Autoreclosing
Two-Circuit-Breaker Autoreclosing
Trip Logic and Reclose Sources for Single-Pole Breaker Applications
Internal Recloser
Program the recloser function to drive the trip logic with Relay Word bits R3PTE
(Recloser Three-Pole Trip Enable), R3PTE1 (Circuit Breaker BK1 Recloser
Three-Pole Trip Enable) and R3PTE2 (Circuit Breaker BK2 Recloser Three-Pole
Trip Enable) as follows:
E3PT := R3PTE Three-Pole Trip Enable (SEL
OGIC Equation)
E3PT1 := R3PTE1 Breaker 1 Three-Pole Trip (SEL
OGIC Equation)
E3PT2 := R3PTE2 Breaker 2 Three-Pole Trip (SEL
OGIC Equation)
These settings connect the internal recloser for both three-pole reclosing and sin-
gle-pole reclosing.
Enter enable settings ESPR1 and E3PR1 as appropriate for your application. By
default, the relay is a single-pole tripping relay; that is, if E3PT is logical 0 and
E3PT1 equals logical 0, the relay can single-pole trip Circuit Breaker BK1. If
E3PT1 equals logical 1, the relay can only three-pole trip Circuit Breaker BK1.
The same conditions apply to setting E3PT2 and Circuit Breaker BK2.
Table 6.23 summarizes the relay trip logic enable options.
Relay Word bits R3PTE1 and R3PTE2 both equal logical 1 for any of the follow-
ing conditions when Global setting NUMBK (Number of Breakers in Scheme) is
2 and SPLSHT (Single-Pole Last Shot) is asserted (see Figure 6.9):
➤ BK1TYP and BK2TYP equal 3 (Circuit Breaker 1 and Circuit
Breaker 2 Trip Type)
➤ NSPSHOT := N (Number of Single-Pole Reclosures)
Example 6.1 Conditional Three-Pole Tripping for Circuit Breaker BK2
Your system reclosing requirement is that Circuit Breaker BK2 always three-
pole trips, unless Circuit Breaker BK2 is the leader. (This occurs when Cir-
cuit Breaker BK1 is out of service.) Program SEL
OGIC control equation
ESPR2 as follows:
ESPR2 := LEADBK2 AND BK1LO Single-Pole Reclose Enable—BK2
(SEL
OGIC Equation)
Table 6.23 Trip Logic Enable Options
Enable Condition Circuit Breaker BK1 Circuit Breaker BK2
E3PT E3PT1 E3PT2
Single-
Pole Trip
Three-
Pole Trip
Single-
Pole Trip
Three-Pole
Trip
000x x
001x x
010 xx
011 x x
100 x x
101 x x
110 x x
111 x x