CHAPTER 5: SETTINGS
Each of the six setting group menus is identical. Setting group 1 (the default active group) is active automatically when no
other group is active.
If the device incorrectly switches to group 1 after power cycling, upgrade the firmware to version 7.31 or later to correct
this issue.
5.7.3 Transformer elements
5.7.3.1 Menu
SETTINGS GROUPED ELEMENTS SETTING GROUP 1(6) TRANSFORMER
TRANSFORMER
This menu contains the settings for the transformer differential elements and the transformer thermal elements.
The thermal elements include hottest-spot temperature, aging factor and loss of life. The computation of these elements
follows IEEE standards C57.91-1995: "IEEE Guide for Loading Mineral-Oil-Immersed Transformers" and C57.96-1989: "IEEE
Guide for Loading Dry-Type Distribution Transformers". The computations are based on transformer loading conditions,
ambient temperature, and the entered transformer data.
5.7.3.2 Percent differential (ANSI 87T)
SETTINGS GROUPED ELEMENTS SETTING GROUP 1(6) TRANSFORMER PERCENT DIFFERENTIAL
PERCENT
DIFFERENTIAL
T35 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
PERCENT
DIFFERENTIAL
INSTANTANEOUS
DIFFERENTIAL
HOTTEST-SPOT
TEMPERATURE
AGING FACTOR
LOSS OF LIFE
PERCENT DIFFERENTIAL
FUNCTION: Disabled
PERCENT DIFFERENTIAL
PICKUP: 0.100 pu
PERCENT DIFFERENTIAL
SLOPE 1: 25%
PERCENT DIFFERENTIAL
BREAK 1: 2.000 pu
PERCENT DIFFERENTIAL
BREAK 2: 8.000 pu
PERCENT DIFFERENTIAL
SLOPE 2: 90%
INRUSH INHIBIT
FUNCTION: Adapt. 2nd
INRUSH INHIBIT
MODE: Per phase
INRUSH INHIBIT
LEVEL: 20.0% fo
OVEREXCITN INHIBIT
FUNCTION: Disabled
GROUPED ELEMENTS
See below
See page 5-205
See page 5-205
See page 5-206
See page 5-207
Range: Disabled, Enabled
Range: 0.050 to 1.000 pu in steps of 0.001
Range: 15 to 100% in steps of 1
Range: 1.000 to 2.000 pu in steps of 0.001
Range: 2.000 to 30.000 pu in steps of 0.001
Range: 50 to 100% in steps of 1
Range: Disabled, Adapt. 2nd, Trad. 2nd
Range: Per phase, 2-out-of-3, Average, 1-out-of-3
Range: 1.0 to 40.0% of f
in steps of 0.1
0
Range: Disabled, 5th
5
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