
14
SEL Application Guide 2020-04
Date Code 20200326
52AA1
Circuit Breaker Status Equation
IN201
Assign to the circuit breaker 52a status.
ORDER
b
Ground Directional Priority
Set to match the remote relay.
a
In the DCB logic, use Z2PGS instead of M2P OR Z2G to provide individual carrier coordination delay timers for the Level 2
directional elements, and use 67QG2S instead of 67Q2 OR 67G2 to provide carrier coordination delay timers to the Level 2
directional elements.
b
Match the ORDER setting value in the SEL-421-5 to the ORDER setting value in the SEL-311C-1.
Table 15
SEL-311C-1 DCB Logic Settings
Setting
Setting Description
Setting Value
Comment
TRCOMM
Communications-Assisted Trip Conditions
Z2PGS +
67QG2S
a
a
In the DCB logic, use Z2PGS instead of M2P + Z2G to provide individual carrier coordination delay timers for the Level 2
directional elements, and use 67QG2S instead of 67Q2 + 67G2 to provide carrier coordination delay timers to the Level 2
directional elements.
Elements that allow high-speed
communications-assisted tripping.
TMB1A
Transmit Channel A Mirrored Bit 1
DSTRT
Send a block signal to the remote end.
BT
Block Trip Equation
RMB1A
Receive a block signal from the remote
end.
OUT101
Output Contact 101 Equation
TRIP
Trip the output to the circuit breaker.
52A
Circuit Breaker Status Equation
IN101
Assign to the circuit breaker 52a status.
ORDER
b
b
Match the ORDER setting value in the SEL-421-5 to the ORDER setting value in the SEL-311C-1.
Ground Directional Priority
Set to match the remote relay.
Table 16
SEL-321-1 DCB Logic Settings
Setting
Setting Description
Setting Value
Comment
MTCS
Mask for Communications-Assisted Tripping
M2P + Z2G +
67N2 + 67Q2
(default)
Elements that allow high-speed
communications-assisted tripping.
TMB1
Transmit Mirrored Bit 1
START + M3P
+ Z3G + 67N3
+ 67Q3
Send a block signal to the remote end.
RMB1
a
a
When PROTOCOL = MB, set RMB1 in Global settings.
Receive Mirrored Bit 1
BT
Receive a block signal from the remote
end.
OUT1
Output Contact Logic OUT1
3PT
Trip the output to the circuit breaker.
IN1
Input Contact 1 Assignment
52A1
Assign to the circuit breaker 52a status.
Table 14
SEL-421-5 DCB Logic Settings (Sheet 2 of 2)
Setting
Setting Description
Setting Value
Comment
Figure 12
Simplified DCB Logic Between the SEL-421-5 and SEL-311C-1 Relays
Zone 3
TRIP
SEL-421-5
TRCOMM
RMB1A (BT)
DSTRT (TMB1A)
Zone 3
TRIP
SEL-311C-1
TRCOMM
BT (RMB1A)
DSTART (TMB1A)