Schweitzer Engineering Laboratories SEL-300G - Relay Word Bits

2-36 Relay Element Settings
Date Code 20020206 SEL-300G Instruction Manual
Level 1 Neg.-Seq. O/C Pickup (OFF, 2–100%) 46Q1P = 8
Level 1 Neg.-Seq. O/C Time Delay (0.02–999.90 s) 46Q1D = 5.00
The Level 1 element is typically applied as an unbalance alarm. The pickup is defined
in percent of machine nominal phase current, INOM. Any desired delay should be
added using the 46Q1D setting. Disable the element by setting 46Q1P = OFF.
The 46Q1 Relay Word bit asserts without time delay when the measured negative-
sequence current exceeds 46Q1P percent of INOM. The 46Q1T Relay Word bit asserts
46Q1D seconds after 46Q1 asserts if the unbalance condition continues.
Level 2 Neg.-Seq. Time-O/C Pickup (OFF, 2–100%) 46Q2P = 8
Level 2 Neg.-Seq. Time-O/C Time-Dial (1–100 s) 46Q2K = 10
The negative-sequence time-overcurrent element operates with an I
2
2
t time
characteristic. Set the pickup value equal to the minimum percent of nominal current
to which the element must respond. Set the 46Q2K setting equal to the generator rated
I
2
2
t short time-current capability rating defined by the generator manufacturer.
The 46Q2 Relay Word bit asserts without time delay when the measured negative-
sequence current is greater than 46Q2P percent of INOM. The 46Q2T Relay Word bit
asserts in a time defined by the time-overcurrent element operating characteristic.
The negative-sequence time-overcurrent element resets using a fixed linear time equal
to 240 seconds. The 46Q2R Relay Word bit asserts when the element is fully reset.
46Q Element Torque Control (SEL
OGIC Control Equation) 46QTC = 1
The negative-sequence overcurrent elements are disabled when the 46QTC SEL
OGIC
Control Equation equals logical 0. The elements are allowed to operate when the
46QTC SEL
OGIC Control Equation equals logical 1. With the example setting, the
elements are always allowed to operate.
Relay Word Bits
Relay Word Bit
Function Description Typical Applications
46Q1
Level 1 Neg.-Seq. O/C Pickup Indication, Testing
46Q1T
Level 1 Neg.-Seq. O/C Pickup With
Definite-Time Delay
Indication, Event Triggering,
SER Triggering
46Q2
Level 2 Neg.-Seq. Time-O/C Pickup Indication, Event Triggering,
SER Triggering, Testing
46Q2T
Level 2 Neg.-Seq. Time-O/C Trip Tripping, SER Triggering
46Q2R
Level 2 Neg.-Seq. Time-O/C Reset Testing