Vanguard Tri-Phase - Manual (Page 11)

TRI-PHASE OPERATING™ INSTRUCTIONS
11
3.0 Functional Description
The TRI-PHASE™ measures a transformer turns-ratio from its windings by applying a 3-phase test
voltage across the primary (H) winding and sensing the induced voltage on the secondary (X)
winding. The measured voltage ratio between H and X is virtually the same as the turns-ratio of the
windings because of no load on the windings during testing. The TRI-PHASE™ is capable of
testing either single phase or three phase transformers. The need to change test leads to test each
phase on three phase transformers is eliminated using the three-phase cables. The TRI-PHASE™
will automatically test each phase of the transformer. The TRI-PHASE™ also has the following
features:
• Capable of testing with 3 test voltages; 8Vac, 40Vac, and 100Vac.
• Capable of testing three-phase transformers in Delta, Wye, Zig-Zag, and T type
configurations.
• Capable of displaying transformer phase angle relationships between primary and secondary
windings.
• Capable of automatically detecting and testing 130 three-phase transformer types defined by
ANSI, CEI/IEC and Australian standards. Refer to appendix B for the different transformer
configurations.
• Capable of testing phase-shifting transformer turns-ratios and displaying phase shift angles.
• Capable of performing test cable hook-up error checks before each test and automatically
aborting the test when there is an error.
• Capable of calculating the transformer turns-ratio based on the operator data entry of the
transformer nameplate voltages.
• Capable of calculating the percentage error based on the difference between the calculated
and measured turns-ratio values.
• Capable of saving transformer test result(s) in the on-board FLASH EEPROM. The test
result data consists of H and X nameplate voltages, phase A/B/C turns-ratios, excitation
current and phase angle measurements.
• Capable of storing a total of 112 test records in the on-board FLASH EEPROM. A test
record may contain up to 33 tests. Stored test records may be recalled, printed or transferred
to an IBM compatible PC with the built-in RS-232C port or USB interface port.
• Capable of storing up to 128 test plans in the on-board FLASH EEPROM. A test plan
provides the capability to store transformer nameplate voltages.
• Capable of printing “PASS” or “FAIL” test results of each of the transformer tests.
• Capable of storing test records and transformer test plans to an external FLASH memory
drive via the built-in USB FLASH memory thumb drive interface.
• Capable of printing test reports with a built-in 4.5-inch wide thermal printer.
• Capable of alpha-numeric input with the 16-key, alpha-numeric keypad.
• Capable of menu and submenu selection with either the alpha-numeric input or with a rotary
switch knob control.
• Capable of displaying data entry, menus, test results, and status readouts with the Liquid
Crystal Display (LCD) 64 by 128 dot graphic, back-lighted, sunlight readable display.
•
Users can retrieve test records, review test records, and create test plans. Under computer
control operation with the supplied Transformer Turns-Ratio Analyzer (TTRA) software
application, the TTRA software application allows the user to perform a transformer turns
ratio test and saves the test results directl
y to a compatible IBM PC. The test data is stored in
ASCII format for database compatibility.