Three-phase transformer turns ratio tester with true three-phase test voltage
The TRT Standard series verifies the turns ratio, phase shift and excitation current of power, distribution and instrument transformers, with or without a tap changer, under IEC 60076-1.
Advantages
True three-phase test voltage
The TRT33 and TRT63 models apply a genuine three-phase voltage instead of switching a single phase across the three bushings, so special designs - phase-shifting, rectifier or arc-furnace transformers - can be tested without extra modules.
Automatic vector group detection and magnetic balance
Both tests run without altering the cable setup used for the ratio measurement, and results are shown numerically and graphically so core irregularities show up immediately.
One cable setup for six tests
TRT Standard shares its H and X leads with the TWA Winding Analyzer: a single connection to the bushings covers ratio, excitation current, phase angle, winding resistance, tap-changer DVtest and demagnetization.
Remote tap changer control
A built-in control unit drives the on-load tap changer from the instrument itself, so one operator completes a multi-position test without a second person at the OLTC cabinet.
Applications
- Commissioning and periodic testing of power and distribution transformers, with or without a tap changer.
- Ratio and polarity verification of current transformers, from a 1 V AC test voltage.
- Testing of special transformers: phase-shifting, rectifier and arc-furnace units.
- Field maintenance rounds combined with winding resistance testing, sharing the same leads.
About the product
The series covers three voltage levels: TRT03 outputs up to 100 V AC single-phase; TRT33 adds a true three-phase source up to 100 V AC; and TRT63 extends it to 250 V AC. All three share the 0.8 to 50,000 ratio range, with accuracy from ±0.03% and automatic vector group detection.
Results appear on a backlit LCD and are stored in an internal memory of up to 10,000 records, downloadable over USB or optional RS-232. The DV-Win software mirrors the instrument's functions from a PC and exports reports to Excel, Word or PDF. Accessories available: H and X cable sets in several lengths, cable cases, TRTC calibrator, optional Bluetooth module and optional 58 mm thermal printer.
Technical specifications
| Models | TRT03, TRT33 and TRT63 (A/B/C mains variants) |
| Test voltage source | Single-phase (TRT03); single-phase and true three-phase (TRT33, TRT63) |
| Test voltage range | 8-100 V AC (TRT03); 1-100 V AC (TRT33); 1-250 V AC (TRT63) |
| Turns ratio range / accuracy | 0.8 - 50,000; from ±0.03% |
| Excitation current range | 0 - 2 A |
| Internal memory | Up to 10,000 test records |
| Interface | USB (standard); RS-232 (optional) |
| Dimensions and weight | 478 × 194 × 390 mm; 8 kg (TRT03, TRT33) or 9 kg (TRT63) |
Frequently asked questions
What is the practical difference between TRT03, TRT33 and TRT63?
TRT03 only outputs single-phase voltage up to 100 V AC; TRT33 and TRT63 add a true three-phase source, and TRT63 reaches the highest voltage, 250 V AC.
What does “true three-phase test voltage” mean?
The instrument energises all three bushings at once instead of one phase at a time, which measures the real phase shift and tests transformers with irregular vector groups.
Can the same leads be used for winding resistance testing?
Yes: TRT Standard uses the same H and X cable sets as the TWA, so the leads stay connected for both tests.
How are test results documented?
Results are stored in the internal memory and downloaded over USB or RS-232; the DV-Win software presents them numerically and graphically and exports to Excel, Word or PDF.
