Transformer turns ratio (TTR) is a test to help determine that the transformer has the correct primary turns to secondary turns ratio. This test can help to detect faulty transformer windings, such as open windings, improper winding connections, and shorted turns, as well as defective tap changer positions. The excitation current and phase angle between the primary and secondary windings also provides additional information regarding the winding condition.
The rugged and portable 2796 Fully Automated 3 Phase 250 V Transformer Turns Ratio Meter from HAEFELY is ideal for acceptance testing and on-site maintenance testing of transformers according to IEEE, IEC, and ANSI standards. The instrument combines mobility and user friendly handling with unmatched accuracy of up to 0.03%. The higher test voltage of 250 V, together with the high precision, assures authentic results especially on large power transformers. Advanced analysis features like trending allow the user to detect problems at an early stage.
The automatic winding connection identification feature aids to find the correct transformer configuration. With the optional arbitrary phase shift software special transformers with irregular vector groups can also be measured. During production and also in the field the TTR 2796 turns ratio tester is a highly valued diagnostic instrument. Within half a minute after connecting the measurement cables to the terminals of the transformer, the voltage ratio, turns ratio, ratio deviation, excitation current and phase deviation are displayed.
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TTR 2796 Transformer Turns Ratio Tester Features
Fully automated measurement of turns ratio, voltage ratio, phase displacement and excitation current.
Highest measurement accuracy in the industry of up to 0.03% for ratios 0.8 – 100
Better transformer excitation due to higher test voltage of 250 V
Ratios of up to 50,000 can be measured
Measurement of phase displacement of transformers with irregular vector groups, such as phase shifting, arc-furnace, and traction transformers
Simplistic user interface for quick test setup
Color coded and labeled test leads for easy setup
Safety connection control feature that proofs test setup before applying regular test voltage to guarantee safety of the test personnel and instrument
Automatic winding connection identification (AWCI) and automatic vector group detection supports the quick and easy operation
Remote control via laptop and application software, including automatic report generation
Built-in printer for quick test report generation
Lightweight, compact and rugged design for use in harsh environments
TTR 2796 Transformer Turns Ratio Tester Applications
Power transformers
Distribution transformers
Instrument transformers
Easy to Use
The measurement procedure is automated; select the basic transformer configuration (single phase, delta, star, etc.), and the auto-detection will determine the transformer phase shift and perform the turns ratio measurement in seconds. The rotary switch allows test configuration in just a few clicks. The function soft keys, together with the display, show the operator the right options at each screen. The included Windows-based software enables remote control and measurement from a Windows-based computer, allowing test reports to be quickly prepared.
Increased Test Voltage up to 250V
Working closely with major transformer manufacturers has revealed that an increased test voltage yields better results when measuring the turns and voltage ratio of large power transformers. Comparison measurements on a 350MVA transformer with tertiary winding show significantly improved accuracy with higher test voltage.
The TTR2796 Transformer Turns Ratio Tester with 250V measuring voltage reduced measured error on these large power transformers, which is sometimes critical to keep results within specified in the IEC 60076-1 and IEEE C57.12.00-2006-1.
Remote Software
The included TTR APSW software offers remote setup and control of the TTR 2796 Transformer Turns Ratio Tester from a computer through a USB connection. Additionally advanced analysis is available trough customized graphs, trending and report generation capabilities. Data can be analyzed in real time or stored and recalled for analysis.
The comprehensive user interface guides the operator through the setup steps by entering nameplate info, transformer vector group, environmental conditions and user comments.
Setting parameters of multi-tapped transformers is greatly simplified by an intuitive setup wizard that enables the user to easily program the taps for primary, secondary or tertiary windings.
Measurements are performed via the MEASURE window. Values of the actual measurement are shown in the top while the history of all measurements taken is recorded in the bottom of the screen. Automated or manual test of taps are controlled and performed by the software.
The software offers additional tools for in depth analysis of the measured transformer data. Flexible graphs allow quick comparison of several measurement series from live or pre-captured data. Additional limit lines show a colourful graphical interpretation of preset margins.