GE T60 Instruction Manual page 343

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).
Figure 5–101: 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 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

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
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