GE T35 UR Series Instruction Manual page 211

5 SETTINGS
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The T35 Transformer Protection System has been designed to provide primary protection for medium to high voltage power
transformers. It performs this function on a variety of power transformer configurations with up to six sets of three phase
inputs available.
b) GENERAL TRANSFORMER SETTINGS
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PATH: SETTINGS SYSTEM SETUP
 GENERAL

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The general transformer settings apply to all windings. Settings specific to each winding are shown in the following section.
• NUMBER OF WINDINGS: Selects the number of windings for transformer setup.
• REFERENCE WINDING: When set to Automatic Selection, a CT ratio mismatch can occur in firmware versions up to
7.1x that can cause signal clamping and misoperation on the differential element. To avoid this, manually select the
winding as outlined in the T35/T60 Reference Winding Selection and CT Ratio Mismatch Application Note (document
GET-8548). For releases subsequent to 7.1x, contact GE Digital Energy to inquire if this applies.
• PHASE COMPENSATION: Selects the type of phase compensation to be performed by the relay. If set to "Internal
(software)", the transformer phase shift is compensated internally by the relay algorithm. If set to "External (with CTs)",
the transformer phase shift is externally compensated by the CT connections.
• LOAD LOSS AT RATED LOAD: This setting should be taken from the transformer nameplate. If not available from the
nameplate, the setting value can be computed as
the three-phase series resistance. The setting is used as an input for the calculation of the hottest-spot winding tem-
perature.
• RATED WINDING TEMP RISE: This setting defines the winding temperature rise over 30°C ambient temperature. The
setting is automatically selected for the transformer type as shown in the table below.
GE Multilin
 WINDING 4

 WINDING 5

 WINDING 6
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TRANSFORMER GENERAL
NUMBER OF WINDINGS:
2
REFERENCE WINDING:
Automatic Selection
PHASE COMPENSATION:
Internal (software)
LOAD LOSS AT RATED
LOAD: 100 kW
RATED WINDING TEMP
RISE: 65°C (oil)
NO LOAD LOSS:
10 kW
TYPE OF COOLING:
OA
TOP-OIL RISE OVER
AMBIENT: 35°C
THERMAL CAPACITY:
100.00 kWh/°C
WINDING THERMAL TIME
CONSTANT: 2.00 min
2
P I
=
R n W (
T35 Transformer Protection System
See page 5–91.
See page 5–91.
See page 5–91.
Range: 2 to 6 in steps of 1
Range: Automatic Selection, Winding 1, Winding 2,...,
Winding 6
Range: Internal (software), External (with CTs)
Range: 1 to 20000 kW in steps of 1
Range: 55°C (oil), 65°C (oil), 80°C (dry), 115°C (dry),
150°C (dry)
Range: 1 to 20000 kW in steps of 1
Range: OA, FA, Non-directed FOA/FOW, Directed FOA/
FOW
Range: 1 to 200°C in steps of 1
Range: 0.00 to 200.00 kWh/°C in steps of 0.01
Range: 0.25 to 15.00 min. in steps of 0.01
×
R , where I is the winding rated current and R is
) n W ( )
5.4 SYSTEM SETUP
5
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