DV Power TRT33B - Page 11

TRT3x Getting Started
M-T03XNN-205-EN 11
Available options in the AUTOTRANSFORMER menu are listed in the Table 4.
Table 4: Available options in the autotransformer menu
Config
PH Displacement
Comment
Test mode
Da
displayed
Delta winding
Phase by phase test using
single-phase voltage in turns
or true 3-phase test using 3-
phase voltage, depending on
a particular vector group.
Ya
displayed
Star winding
YNa
displayed
Star winding with neutral point
Za
displayed
Zigzag
ZNa
displayed
Zigzag with neutral point
AVGD
hidden
Automatic vector group
detection
TRUE 3~ TEST
hidden
Only true three-phase test
True 3-phase test using 3-
phase voltage
SINGLE
hidden
Single-phase autotransformer
Single-phase test using
single-phase voltage
Table 5: Available autotransformer vector groups
Configuration
PH displacement
Ya, YNa
0-4-8
Da, Za, ZNa
0-1-2,…11
If a ratio deviation calculation is enabled, the following menu is displayed to enter the name plate voltages
and the tap changer positions:
If the name plate voltages are not entered, TRT3x will perform the test and display the results, but it will not
calculate or display the turns ratio deviation. After the name plate voltages and tap changer position(s) are
entered, press ENTER to confirm a selection. The next display allows a selection of the test voltage.
TRT3x generates both single-phase and true three-phase test voltages. When generating a single-phase
excitation voltage, TRT3x supplies a single-phase excitation test voltage to each of the three transformer
primary windings in turn. The induced voltages across each of the corresponding unloaded transformer
windings are then measured. The ratio of these voltages is calculated and presented on the display. It is
repeated for all three phases.
Figure 3-1:
Input name plate
voltages values
High Voltage Tap Changer
position
Low Voltage Tap Changer
position
Figure 3-2:
The test voltage
selection