Date Code 20001006 Setting the Relay 9-37
SEL-351 Instruction Manual
Delta-Connected Voltages
Additional zero-sequence source impedance settings Z0SMAG (magnitude, Ω secondary) and
Z0SANG (angle, degrees) are required so that zero-sequence voltage can be derived for fault
locating.
Enable Settings
Refer to Settings Sheets 1, 2, and 19 of 23.
The enable settings on Settings Sheets 1 and 2 (E50P through EDEM) control the settings that
follow, through Sheet 11. Enable setting EBMON on Settings Sheet 19 controls the settings that
immediately follow it. This helps limit the number of settings that need to be made.
Each setting subgroup on Settings Sheets 2 through 12 has a reference back to the controlling
enable setting. For example, the neutral ground time-overcurrent element settings on Sheet 5
(settings 51NP through 51NRS) are controlled by enable setting E51N.
Other System Parameters
Refer to Settings Sheet 18 of 23.
The global settings NFREQ and PHROT allow you to configure the SEL-351 Relay to your
specific system.
Set NFREQ equal to your nominal power system frequency, either 50 Hz or 60 Hz.
Set PHROT equal to your power system phase rotation, either ABC or ACB.
Set DATE_F to format the date displayed in relay reports and the front-panel display. Set
DATE_F to MDY to display dates in Month/Day/Year format; set DATE_F to YMD to display
dates in Year/Month/Day format.
SETTINGS SHEETS
The settings sheets that follow include the definition and input range for each setting in the relay.
Refer to Relay Element Pickup Ranges and Accuracies in Section 1: Introduction and
Specifications for information on 5 A nominal and 1 A nominal ordering options and how they
influence overcurrent element setting ranges.
Courtesy of NationalSwitchgear.com
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