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6.3 A2 METERING
6.3 A2 METERING
SS ACTUAL VALUES
SS A2 METERING
The 745 measures all winding currents and their harmonic components as well as system frequency and volt-
age, tap changer position, ambient temperature and an auxiliary analog input channel. From these, derived
values including neutral, sequence components, differential and restraint currents, THD, harmonic derating
factors and current demand are calculated. These processed values are both displayed and used to perform
the required protection and monitoring functions.
For each monitored winding, the fundamental frequency magnitude and phase angle of phase A, B, C and
ground currents are recalculated every half-cycle for use in differential and overcurrent protection. From these
values, neutral, positive, negative and zero-sequence as well as differential, restraint and ground differential
currents are calculated. These are displayed and updated approximately twice a second for readability.
S CURRENT
S [ENTER] for more
a) WINDING 1/2/3 CURRENTS
S W1 CURRENT
S [ENTER] for more
The following Actual Values messages are repeated for Windings 1, 2 and 3.
6
W1 PHASE A CURRENT:
0A at
0°Lag
W1 PHASE B CURRENT:
0A at
0°Lag
W1 PHASE C CURRENT:
0A at
0°Lag
W1 NEUTRAL CURRENT:
0A at
0°Lag
W1 GROUND CURRENT:
0A at
0°Lag
WINDING 1 LOADING:
0% of rated load
W1 AVERAGE PHASE
CURRENT:
0 A
6-4
This is the header of Actual Values page A2 METERING. To view these
actual values press
M E SS AG E
This message indicates the start of the Current actual values. To view these
actual values press
E N TE R
This message indicates the start of the Winding 1 Current actual values
(Windings 2 and 3 are similar). To view these actual values press
press
for the next section.
M E SSA G E
The fundamental frequency current magnitude and phase for Winding 1 (2/
3), phase A is shown. The current angle for Winding 1, phase A is always set
to zero as this angle is used as a reference for all other currents, both
measured and derived.
This message displays the fundamental frequency current magnitude and
phase for Winding 1 (2/3), phase B.
The fundamental frequency current magnitude and phase for Winding 1 (2/
3), phase C is displayed.
This Winding displays the fundamental frequency current magnitude and
phase for winding 1 (2/3), neutral.
This message displays the fundamental frequency current magnitude and
phase for Winding 1 (2/3), ground current input, if used.
This message displays what percentage of its maximum specified load
Winding 1 (2/3) is currently carrying.
The average phase current value in the corresponding winding is displayed.
745 Transformer Management Relay
6 ACTUAL VALUES
or press
to go to the next page header.
A CT U A L
or press
for the next section.
M E SSA G E
6.3.1 DESCRIPTION
6.3.2 CURRENT
or
EN TE R
GE Power Management
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