S2 System Setup; Current Sensing; Voltage Sensing - GE Multilin 489 Instruction Manual

5.3

S2 System Setup

5.3.1

Current Sensing

CURRENT
5.3.2

Voltage Sensing

VOLTAGE
5–18
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PATH: SETPOINTS S2 SYSTEM SETUP
PHASE CT PRIMARY:
[ ] -------------
GROUND CT:
MESSAGE
50:0.025
GROUND CT RATIO:
MESSAGE
100: 1
GROUND CT RATIO:
MESSAGE
100: 5
As a safeguard, the
PHASE CT PRIMARY
defaulted to "--------" when shipped, indicating that the 489 was never programmed. Once
these values are entered, the 489 will be in service. Select the Phase CT so that the
maximum fault current does not exceed 20 times the primary rating. When relaying class
CTs are purchased, this precaution helps prevent CT saturation under fault conditions. The
secondary value of 1 or 5 A must be specified when ordering so the proper hardware will
be installed. The
PHASE CT PRIMARY
the output CTs.
For high resistance grounded systems, sensitive ground current detection is possible if the
50:0.025 Ground CT is used. To use the 50:0.025 CT input, set
additional ground CT messages will appear. On solid or low resistance grounded systems,
where fault currents may be quite large, the 489 1 A/5 A secondary Ground CT input should
be used. Select the Ground CT primary so that potential fault current does not exceed 20
times the primary rating. When relaying class CTs are purchased, this precaution will
ensure that the Ground CT does not saturate under fault conditions.
The 489 uses a nominal CT primary rating of 5 A for calculation of pickup levels.
PATH: SETPOINTS S2 SYSTEM SETUP
VT CONNECTION TYPE:
[ ] None
VOLTAGE TRANSFORMER
MESSAGE
RATIO: 5.00:1
NEUTRAL VOLTAGE
MESSAGE
TRANSFORMER: No
NEUTRAL VT
MESSAGE
RATIO: 5.00:1
CURRENT SENSING
Range: 1 to 5000 in steps of 1, Not
Programmed
Range: None, 1A Secondary, 5A
Secondary, 50:0.025
Range: 10 to 10000 in steps of 1. Seen
only if Ground CT Type is 1 A
Range: 10 to 10000 in steps of 1. Seen
only if Ground CT Type is 5 A
and
GENERATOR PARAMETERS
setpoint applies to both the neutral end CTs as well as
GROUND CT
VOLTAGE SENSING
Range: Open Delta, Wye, None
Range: 1.00:1 to 300.00:1 in steps of
0.01
Range: No, Yes
Range: 1.00:1 to 240.00:1 in steps of
0.01.
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
setpoints are
to "50:0.025". No