GE t60 Instruction Manual page 287

5 SETTINGS
c) INSTANTANEOUS DIFFERENTIAL
PATH: SETTINGS GROUPED ELEMENTS
INSTANTANEOUS
DIFFERENTIAL
MESSAGE
MESSAGE
MESSAGE
MESSAGE
The instantaneous differential element acts as an instantaneous overcurrent element responding to the measured differen-
tial current magnitude (filtered fundamental frequency component) and applying a user-selectable pickup threshold. The
pickup threshold should be set greater than the maximum spurious differential current that could be encountered under
non-internal fault conditions (typically magnetizing inrush current or an external fault with extremely severe CT saturation).
SETTING
INST DIFFERENTIAL
FUNCTION:
Disabled=0
Enabled=1
SETTING
INST DIFF BLOCK:
Off=0
ACTUAL VALUE
DIFF PHASOR
Iad
Ibd
Icd
Figure 5–82: INSTANTANEOUS DIFFERENTIAL SCHEME LOGIC
d) HOTTEST-SPOT TEMPERATURE
PATH: SETTINGS GROUPED ELEMENTS
HOTTEST-SPOT
TEMPERATURE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
The Hottest-Spot Temperature element provides a mechanism for detecting abnormal winding hottest-spot temperatures
inside the transformer. It can be set to alarm or trip in cases where the computed hottest-spot temperature is above the
pickup threshold for a user-specified time (considered as transformer overheating).
GE Multilin
SETTING GROUP 1(6) TRANSFORMER
INST DIFFERENTIAL
FUNCTION: Disabled
INST DIFFERENTIAL
PICKUP: 8.000 pu
INST DIFF BLOCK:
Off
INST DIFFERENTIAL
TARGET: Self-reset
INST DIFFERENTIAL
EVENTS: Disabled
SETTING
INST DIFFERENTIAL
PICKUP:
RUN
AND
Iad > PICKUP
RUN
Ibd > PICKUP
RUN
Icd > PICKUP
SETTING GROUP 1(6) TRANSFORMER
XFMR HST FUNCTION:
Disabled
XFMR HST PICKUP:
140°C
XFMR HST DELAY:
1 min.
XFMR HST BLOCK:
Off
XFMR HST TARGET:
Self-Reset
T60 Transformer Protection System
5.6 GROUPED ELEMENTS
INSTANTANEOUS DIFFERENTIAL
Range: Disabled, Enabled
Range: 2.000 to 30.000 pu in steps of 0.001
Range: FlexLogic™ operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
FLEXLOGIC OPERANDS
XFMR INST DIFF OP A
XFMR INST DIFF OP B
XFMR INST DIFF OP C
FLEXLOGIC OPERAND
OR XFMR INST DIFF OP
828000A1.CDR
HOTTEST-SPOT TEMPERATURE
Range: Disabled, Enabled
Range: 50 to 300°C in steps of 1
Range: 0 to 30000 min. in steps of 1
Range: FlexLogic™ operand
Range: Self-reset, Latched, Disabled
5
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