Sel 551 - SEL-551 Model Changes; SEL-551 Applications; Figure 1.1 SEL-551 Relays Applied Throughout the Power System

1.2
SEL-551 Relay Instruction Manual Date Code 20110408
Introduction and Specifications
SEL-551 Model Changes
➤ Relay Word bit differences because of I/O mix and addition of
programmable alarm conditions SALARM and HALARM.
➤ Latch Control Switches to Replace Traditional Latching
Relays.
➤ Optional front-panel EIA-232 serial communications port.
➤ Available with conventional terminal blocks and level-sensitive
optoisolated inputs (see Specifications, General on page 1.4 for
optoisolated inputs ratings).
SEL-551 Model Changes
Old model 05510J has been superseded by model 05510W. This is because of
improvements in the Connectorized
®
SEL-551 Relay (plug-in connectors)—
see Section 2: Installation for more details (following Figure 2.8). Unless
otherwise noted, references to model 05510W also apply to old model 05510J.
SEL-551 Applications
q See Figure 2.14; w see Figure 2.11; e see Figure 2.13; r see Figure 2.9; t see Figure 2.10.
Figure 1.1 SEL-551 Relays Applied Throughout the Power System
52
SEL-551
BF
Initiate
BF
Trip
Transmission Bus
ABC
Retrip
52
SEL-551
ABC
Trip
BF
Trip
N
Trip
ABC
SEL-551
52
BF
Trip
Breaker
Failure
Protection q
Distribution
Bus
Protection e
Transformer
Bank
Protection w
Fast Bus Trip Scheme
Distribution Bus
Trip
BF
SEL-551
ABC
52
Utility Distribution
Feeder Protection
and Reclosing r
52a
or
52b
Trip and
Close
ABC
Trip
BF
SEL-551
Trip
52
N
Core-Balance
Current Transformer
Industrial Distribution
Feeder Protection t