GE 745 Instruction Manual page 130

S2 SYSTEM SETUP
5.4 S2 System Setup
5.4.1 Description
5.4.2 Transformer
 TRANSFORMER
5–34
This group of setpoints is critical for the protection features to operate correctly. When the
relay is ordered, the phase and ground CT inputs must be specified as either 5 A or 1 A. The
characteristics of the equipment installed on the system are entered on this page. This
includes information on the transformer type, CTs, VT, ambient temperature sensor, onload
tap changer, demand metering, analog outputs and analog input.
PATH: SETPOINTS S2 SYSTEM SETUP
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[ ] NOMINAL FREQUENCY:
60 Hz
FREQUENCY TRACKING:
MESSAGE
Enabled
PHASE SEQUENCE:
MESSAGE
ABC
TRANSFORMER TYPE:
MESSAGE
Y/d30°
LOAD LOSS AT RATED
MESSAGE
LOAD: 1250 kW
LOW VOLTAGE WINDING
MESSAGE
RATING: Above 5 kV
RATED WINDING TEMP
MESSAGE
RISE: 65°C (oil)
NO-LOAD LOSS:
MESSAGE
125.0 kW
TYPE OF COOLING:
MESSAGE
OA
RATED TOP OIL RISE
MESSAGE
OVER AMBIENT: 10°C
XFMR THRML CAPACITY:
MESSAGE
1.00 kWh/°C
WINDING TIME CONST:
MESSAGE
2.00 min.
SET ACCUMULATED LOSS
MESSAGE
OF LIFE:
To provide accurate and effective transformer protection, the parameters of both the
transformer and the system configuration must be supplied to the 745 relay.
• NOMINAL FREQUENCY: Enter the nominal frequency of the power system. This
setpoint is used to determine the sampling rate in the absence of a measurable
frequency. Frequency is measured from the VT input when available. If the VT input is
not available, current from Winding 1 Phase A is used.
TRANSFORMER

Range:
Range:
Range:
Range:
Range:
Range:
Range:
Range:
Range:
Range:
Range:
Range:
Range:
0 x 10h
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
50 Hz, 60 Hz
Enabled, Disabled
ABC, ACB
Refer to Transformer types on
page 5–13
0 to 20000 kW in steps of 1
(Auto-ranging; see table below)
Above 5 kV, 1 kV to 5 kV, Below
1 kV
65°C (oil), 55°C (oil), 80°C (dry),
115°C (dry), 150°C (dry)
0.1 to 2000.0 kW in steps of 0.1
(see description below)
FA, OA, Directed FOA/FOW,
Non-Directed FOA/FOW
1 to 200°C in steps of 1
0.00 to 200.00 kWh/°C in steps
of 0.01
0.25 to 15.00 min. in steps of
0.01
0 to 20000 x 10h in steps of 1