8-58
Application
BE1-951
V O X
VOX=IN1*/INX
SL-62=1,VOX
S<g>-62=500,0
S L - V O Y = 6 2
INI
B L K
62 TIMER
62
V O Y
P I C K U P
T I M E
D R O P O U T
T I M E
INX
( C L O S E C K T )
IN1
(52B)
0 = C L O S E C K T O P E N
1 = C L O S E C K T O K A Y
D2587-02
07-22-99
0 = B R E A K E R C L O S E D
1 = B R E A K E R O P E N
Figure 8-19. Close Circuit Monitor Logic
1 0 1
B R E A K E R
C O N T R O L
S W I T C H
7 9
R E C L O S E R
B F
P R O T E C T I V E
T R I P
E X P R E S S I O N
V O 1 1
B F P U
B F T
1 0 1 T
1 0 1 C
1 0 1 S C
7 9 C
7 9 R N G
7 9 F
7 9 L O
7 9 S C B
V O 1
V O 2
T R I P
C L O S E
D 2 5 8 2 - 0 2
07-22-99
Figure 8-20. High-Speed Reclose Interlock Logic
High-Speed Reclose
Each reclose time delay can be set as low as 100 milliseconds. If the application requires a reclose time
delay of less than 250 milliseconds, it is recommended that the close logic expression be modified to prevent
mis-coordination between the TRIP and CLOSE outputs.
A hold timer for each output relay is provided to
hold the output closed for approximately 200
milliseconds. This prevents the relay contacts
from opening before the breaker auxiliary
contact interrupts the trip coil current. For high-
speed reclosing, the hold timer must be
disabled so that the output contact follows the
VO1 output expression. To modify the logic,
add the expression “reclose 79C AND NOT trip
VO1 to the close logic. Examples 1 and 2 show
a close expression and hold disable setting for
high-speed reclosing. Figure 8-20 illustrates
this high-speed reclose interlock logic scheme.
Example 1.
Close Expression: SL-VO2=79C*/VO1+101C
Example 2.
Hold Disable Setting: SG-HOLD1=0
Block Load Tap Changer
A block load tap changer output is not provided in any of the preprogrammed logic schemes. However, one
of the output relays can be programmed to operate when the recloser is running (79RNG) and wired to
energize a normally closed auxiliary relay. The 79RNG logic variable is high when any of the timers are
timing and low when the reclosing function is in a lockout or reset state.
Block Neutral and Negative Sequence Protection
The neutral and negative sequence overcurrent elements provide greater sensitivity to unbalanced faults
than the phase overcurrent elements because they can be set to pickup below balanced three-phase load.
This can lead to a mis-operation during periods of load imbalance. The BE1-951 provides a neutral and
