Sel 751A - Section 4: Protection and Logic Functions Overview

4.2
SEL-751A Relay Instruction Manual Date Code 20100129
Protection and Logic Functions
Overview
Synchrophasor Measurement. Describes Phasor Measurement Unit
(PMU) settings for C37.118 Protocol.
Breaker Failure Setting. Lists settings and describes the logic for the
flexible breaker failure function.
Arc-Flash Protection. Lists settings for the arc-flash elements including
arc-flash overcurrent and time-overlight
™
elements.
Analog Inputs. Describes analog input functionality, lists settings and
gives an example.
Analog Outputs. Describes analog output functionality, lists settings and
gives an example.
Station DC Battery Monitor. Describes station dc battery monitor function
and lists settings.
Breaker Monitor. Lists settings and describes the breaker monitor function
which can be used for scheduling circuit breaker maintenance.
Digital Input Debounce. Provides settings for digital input dc debounce or
ac debounce mode of operation.
Data Reset. Lists data reset SELOGIC settings for resetting targets, energy
metering, max/min metering, demand metering and peak demand
metering.
Access Control. Describes SELOGIC setting used for disabling settings
changes from the relay front panel.
Time Synchronization Source. Describes setting used for choosing
IRIG1 or IRIG2 as the time synchronization source.
Port Settings (SET P Command). Lists settings that configure the relay front-
and rear-panel serial ports.
Front-Panel Settings (SET F Command). Lists settings for the front-panel
display, pushbuttons, and LED control.
Report Settings (SET R Command). Lists settings for the sequential event
reports, event, and load profile reports.
DNP Map Settings (Set DNP n command, n = 1, 2, or 3). Shows DNP user map
register settings.
Modbus Map Settings (SET M Command). Shows Modbus
®
user map
register settings.
When you calculate the protection element settings, proceed through the
subsections listed earlier. Skip the RTD- and voltage-based protection
subsections if they do not apply to your specific relay model or installation.
See Section 6: Settings for the list of all settings (SEL-751A Settings Sheets)
and various methods of accessing them. All current and voltage settings in the
SEL-751A are in secondary.
NOTE: The DeviceNet port
parameters can only be set at the rear
of the relay on the DeviceNet card
(see Figure G.1).
You can enter the settings by using the front-panel SET RELAY function (see
Section 8: Front-Panel Operations), the serial port (see Section 7:
Communications), the EIA-485 port (see Appendix E: Modbus RTU
Communications), the DeviceNet port (see Appendix G: DeviceNet
Communications), or the Ethernet port (see Section 7: Communications).