GE G30 Instruction Manual page 420

GROUPED ELEMENTS
5.7.3.3 Hottest-spot temperature
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  TRANSFORMER  HOTTEST-SPOT TEMPERATURE
 HOTTEST-SPOT
 TEMPERATURE
The Hottest-Spot Temperature element provides a mechanism to detect 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).
— Enter the hottest-spot temperature required for operation of the element. Base this setting on the
XFMR HST PICKUP
maximum permissible hottest-spot temperature under emergency transformer loading conditions and maximum ambient
temperature.
— Enter an appropriate time delay before operation of the element.
XFMR HST DELAY
5
5.7.3.4 Aging factor
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  TRANSFORMER  AGING FACTOR
 AGING FACTOR

The Aging Factor element detects transformer aging in per-unit normal insulation aging. The element can be set to alarm
or trip whenever the computed aging factor is greater than the user-defined pickup setting for the specified time delay.
5-206
XFMR HST FUNCTION:

Disabled
XFMR HST PICKUP:

140°C
XFMR HST DELAY:

1 min.
XFMR HST BLOCK:

Off
XFMR HST TARGET:

Self-Reset
Figure 5-104: Transformer hottest-spot temperature logic
AGING FACTOR

FUNCTION: Disabled
AGING FACTOR PICKUP:

2.0 pu
AGING FACTOR

DELAY: 10 min.
AGING FACTOR BLOCK:

Off
AGING FACTOR TARGET:

Self-Reset
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
Range: Disabled, Enabled
Range: 1.1 to 10.0 pu in steps of 0.1
Range: 0 to 30000 min. in steps of 1
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
G30 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS