Date Code 20100129
Instruction Manual
SEL-751A Relay
Section 1
Introduction and Specifications
Overview
The SEL-751A Feeder Protection Relay is designed to provide overcurrent
protection to feeders, transformers, etc. The basic relay provides instantaneous
and inverse time-overcurrent protection. Voltage-based, Arc-Flash Detector
(AFD)-based, and RTD-based protection are available as options. All relay
models provide monitoring functions.
This manual contains the information needed to install, set, test, operate, and
maintain any SEL-751A. You need not review the entire manual to perform
specific tasks.
Features
Standard Protection
Features
➤
Phase Instantaneous Overcurrent (50P)
➤
Ground (Residual) Instantaneous Overcurrent (50G)
➤
Neutral Instantaneous Overcurrent (50N)
➤
Negative-Sequence Overcurrent (50Q)
➤
Phase Time Overcurrent (51P)
➤
Ground (Residual) Time Overcurrent (51G)
➤
Neutral Time Overcurrent (51N)
➤
Negative-Sequence Time Overcurrent (51Q)
➤
Frequency (81)
➤
Breaker Failure Protection
➤
Breaker Wear Monitor
Optional Protection
Features
➤
Autoreclosing Control (79)
➤
Voltage-Based Protection
➢
Undervoltage (27)
➢
Overvoltage (59)
➢
Negative-Sequence Overvoltage (59Q)
➢
Residual (Zero-Sequence) Overvoltage (59G)
➢
Power Elements (32)
Summary of Contents for 751A
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