Generator Unbalance - GE G60 Instruction Manual

5.5 GROUPED ELEMENTS
PATH: SETTINGS GROUPED ELEMENTS
GENERATOR
UNBALANCE
5
The generator unbalance element protects the machine from rotor damage due to excessive negative-sequence current.
The element has an inverse time stage which is typically used for tripping and a definite time stage typically used for alarm
purposes. The inverse time stage operating characteristic is defined by the following equation:
K
T -------------------------- -
=
2
( ⁄ )
I I
2 nom
• GEN UNBAL INOM: This setting is the rated full load current of the machine.
• GEN UNBAL STG1 PICKUP: This setting defines the pickup of the stage 1 element expressed as a percentage of the
nominal current as specified by
sequence current rating of the machine.
• GEN UNBAL STG1 K-VALUE: This setting is the negative sequence capability constant. This value is normally pro-
vided by the generator manufacturer (refer to ANSI C50.13 for details).
• GEN UNBAL STG1 TMIN: This is the minimum operate time of the stage 1 element. The stage will not operate before
this time expires. This is set to prevent false trips for faults that would be cleared normally by system protections.
• GEN UNBAL STG1 TMAX: This is the maximum operate time of the stage 1 element. This setting can be applied to
limit the maximum tripping time for low level unbalances.
5-128
SETTING GROUP 1(6)
GENERATOR UNBAL
FUNCTION: Disabled
GEN UNBAL SOURCE:
MESSAGE
SRC 1
GEN UNBAL INOM:
MESSAGE
0.800 pu
GEN UNBAL STG1
MESSAGE
PICKUP: 8.00%
GEN UNBAL STG1
MESSAGE
K-VALUE: 1.00
GEN UNBAL STG1 TMIN:
MESSAGE
0.250 s
GEN UNBAL STG1 TMAX:
MESSAGE
600.00 s
GEN UNBAL STG1
MESSAGE
K-RESET: 240.00 s
GEN UNBAL STG2
MESSAGE
PICKUP: 3.0%
GEN UNBAL STG2 PKP
MESSAGE
DELAY: 5.0 s
GEN UNBAL BLOCK:
MESSAGE
Off
GEN UNBAL TARGET:
MESSAGE
Self-Reset
GEN UNBAL EVENTS:
MESSAGE
Disabled
where I is the generator rated current and K is the negative-sequence capability constant nor-
nom
mally provided by the generator manufacturer.
GEN UNBAL INOM
G60 Generator Management Relay

5.5.10 GENERATOR UNBALANCE

GENERATOR UNBALANCE
Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: 0.000 to 1.250 pu in steps of 0.001
Range: 0.00 to 100.00% in steps of 0.01
Range: 0.00 to 100.00 in steps of 0.01
Range: 0.000 to 50.000 s in steps of 0.001
Range: 0.0 to 1000.0 s in steps of 0.1
Range: 0.0 to 1000.0 s in steps of 0.1
Range: 0.00 to 100.00% in steps of 0.01
Range: 0.0 to 1000.0 s in steps of 0.1
Range: FlexLogic™ operand
Range: Self-reset, Latched
Range: Enabled
setting. It is typically set at the maximum continuous negative
5 SETTINGS
,
Disabled
,
Disabled
GE Multilin