S2 System Setup; Description; Transformer - GE TRANSFORMER MANAGEMENT RELAY 745 Instruction Manual

5 SETPOINTS

5.4S2 SYSTEM SETUP

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

TRANSFORMER

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To provide accurate and effective transformer protection, the parameters of both the transformer and the system configura-
tion 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.
• FREQUENCY TRACKING: In situations where the AC signals contain significant amount of sub-harmonic compo-
nents, it may be necessary to disable frequency tracking.
• PHASE SEQUENCE: Enter the phase sequence of the power system. Systems with an ACB phase sequence require
special considerations. See Section 5.2.3: Phase Shifts on Three-Phase Transformers on page 5–7 for details.
GE Multilin
Courtesy of NationalSwitchgear.com
TRANSFORMER
ð
NOMINAL FREQUENCY:
ENTER
60 Hz
ESCAPE
FREQUENCY TRACKING:
ESCAPE
Enabled
MESSAGE
PHASE SEQUENCE:
ESCAPE
ABC
MESSAGE
TRANSFORMER TYPE:
ESCAPE
Y/d30°
MESSAGE
LOAD LOSS AT RATED
ESCAPE
LOAD: 1250 kW
MESSAGE
LOW VOLTAGE WINDING
ESCAPE
RATING: Above 5 kV
MESSAGE
RATED WINDING TEMP
ESCAPE
RISE: 65°C (oil)
MESSAGE
NO LOAD LOSS:
ESCAPE
125.0 kW
MESSAGE
TYPE OF COOLING:
ESCAPE
OA
MESSAGE
RATED TOP OIL RISE
ESCAPE
OVER AMBIENT: 10°C
MESSAGE
XFMR THRML CAPACITY:
ESCAPE
1.00 kWh/°C
MESSAGE
WINDING TIME CONST:
ESCAPE
2.00 min.
MESSAGE
SET ACCUMULATED LOSS
ESCAPE
OF LIFE: 0 x 10h
MESSAGE
745 Transformer Management Relay
5.4 S2 SYSTEM SETUP

5.4.1 DESCRIPTION

5.4.2 TRANSFORMER
Range: 50 Hz, 60 Hz
Range: Enabled, Disabled
Range: ABC, ACB
Range: Refer to Table 5–1: Transformer Types on
page 5–10
Range: 0 to 20000 kW in steps of 1 (Auto-ranging; see
the table in description below)
Range: Above 5 kV, 1 kV to 5 kV, Below 1 kV
Range: 65°C (oil), 55°C (oil), 80°C (dry), 115°C (dry),
150°C (dry)
Range: 0.1 to 2000.0 kW in steps of 0.1 (see the table in
description below)
Range: FA, OA, Directed FOA, FOW,
Non-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
Range: 0 to 20000 x 10h in steps of 1
5
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