GE T60 Instruction Manual page 366

5.6 GROUPED ELEMENTS
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).
• XFMR HST PICKUP: Enter the hottest-spot temperature required for operation of the element. This setting should be
based on the maximum permissible hottest-spot temperature under emergency transformer loading conditions and
maximum ambient temperature.
• XFMR HST DELAY: Enter an appropriate time delay before operation of the element.
5
e) AGING FACTOR
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PATH: SETTINGS GROUPED ELEMENTS
 AGING FACTOR

The Aging Factor element detects transformer aging in per-unit normal insulation aging. The element can be set for alarm
or trip whenever the computed aging factor is greater than the user-defined pickup setting for the specified time delay.
• AGING FACTOR PICKUP: Enter a value above which the aging factor element will operate. Enter a setting greater
than the maximum permissible aging factor under emergency loading conditions and maximum ambient temperature.
5-220
Figure 5–102: TRANSFORMER HOTTEST-SPOT TEMPERATURE LOGIC
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SETTING GROUP 1(6)
AGING FACTOR
FUNCTION: Disabled
AGING FACTOR PICKUP:
MESSAGE
2.0 pu
AGING FACTOR
MESSAGE
DELAY:
AGING FACTOR BLOCK:
MESSAGE
Off
AGING FACTOR TARGET:
MESSAGE
Self-Reset
T60 Transformer Protection System
 
TRANSFORMER
Range: Disabled, Enabled
Range: 1.1 to 10.0 pu in steps of 0.1
Range: 0 to 30000 min. in steps of 1
10 min.
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
5 SETTINGS
AGING FACTOR
GE Multilin