6-10
745 Transformer Management Relay
GE Multilin
6.3 A2 METERING
6 ACTUAL VALUES
6
6.3.3 FREQUENCY
PATH: ACTUAL VALUES
ÖØ
A2 METERING
ÖØ
FREQUENCY
The
SYSTEM FREQUENCY
is calculated from the voltage input provided that voltage sensing is enabled and the injected volt-
age is above 50% of VT. If these criteria are not satisfied, then it is determined from Winding 1 Phase A current provided
that it is above 0.05
×
CT. If frequency still cannot be calculated, "0.00 Hz" is displayed, though the sampling rate is then set
for the
S2 SYSTEM SETUP
Ö
TRANSFORMER
Ö
NOMINAL FREQUENCY
setpoint. The
FREQUENCY DECAY RATE
can only be cal-
culated if system frequency can be calculated.
6.3.4 TAP CHANGER
PATH: ACTUAL VALUES
ÖØ
A2 METERING
ÖØ
TAP CHANGER
This message displays the actual tap position. If tap position sensing is disabled, "n/a" will be displayed.
6.3.5 VOLTAGE
PATH: ACTUAL VALUES
ÖØ
A2 METERING
ÖØ
VOLTAGE
For phase-to-neutral input voltages, the
SYSTEM LINE-TO-LINE VOLTAGE
displays its line-to-line equivalent.
6.3.6 DEMAND
a) MAIN MENU
PATH: ACTUAL VALUES
ÖØ
A2 METERING
ÖØ
DEMAND
Current demand is measured on each phase of each monitored winding. These parameters can be monitored to reduce
supplier demand penalties or for statistical metering purposes. The calculated demand is based on the
S2 SYSTEM SETUP
ÖØ
DEMAND METERING
Ö
CURRENT DEMAND METER TYPE
setpoint value. For each quantity, the 745 displays the demand
over the most recent demand time interval, the maximum demand since the last date that the demand data was reset, and
the time and date stamp of this maximum value.
FREQUENCY
[ENTER] for more
SYSTEM FREQUENCY:
0.00 Hz
FREQUENCY DECAY
RATE: 0.00 Hz/s
TAP CHANGER
[ENTER] for more
TAP CHANGER
POSITION: n/a
VOLTAGE
[ENTER] for more
SYSTEM LINE-TO-LINE
VOLTAGE: 0.00 kV
VOLTS-PER-HERTZ:
0.00 V/Hz
LINE-NTRL VOLTAGE:
0.00 kV at
0° Lag
DEMAND
[ENTER] for more
DEMAND DATA CLEAR
[ENTER] for more
See page 6–11.
W1 CURRENT DEMAND
[ENTER] for more
See page 6–11.
W2 CURRENT DEMAND
[ENTER] for more
W3 CURRENT DEMAND
[ENTER] for more
ENTER
ESCAPE
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MESSAGE
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ENTER
ESCAPE
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ENTER
ESCAPE
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ð
MESSAGE
ESCAPE
MESSAGE
ESCAPE
ENTER
ESCAPE
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MESSAGE
ESCAPE
MESSAGE
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MESSAGE
ESCAPE