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TRM-104 Three-Phase Transformer Ratio Meter

The TRM-104 are three-phase transformer turns ratio meters designed for fast, simultaneous testing of all HV–LV phases of power and distribution transformers.
These advanced instruments measure ratio, phase angle, vector group, polarity, and excitation current, enabling complete transformer characterization with minimal test time.
The TRM-104 offers enhanced accuracy, extended ranges, and stronger noise immunity for substation environments.

Key Features

  • Three-phase simultaneous ratio testing

  • Measures:

    • Turns Ratio

    • Phase Angle

    • Polarity

    • Excitation Current

    • Vector Group

  • Auto phase-by-phase comparison with vector diagrams

  • TRM-104 includes:

    • Extended ratio range

    • Higher accuracy

    • Advanced DSP noise filtering

  • Automatic vector group identification

  • Fast test cycle, ideal for large transformers

  • HV/LV wrong-connection detection and safety interlocks

  • Internal storage + USB export

  • Rugged trolley-style or portable chassis (depending on model)

Technical Specifications

Parameter TRM-104
Ratio Range 0.8–50,000:1
Accuracy ±0.05%
Phase Angle 0–360°
Polarity Automatic
Test Voltage 8–120 V AC
Excitation Current Up to 10 A
Vector Group Support All groups (auto detection enhanced)
Display Large LCD
Storage Internal + USB
Power Supply 220 V AC
Weight ≈ 15–18 kg

Standard Accessories

  • Full three-phase HV test leads

  • Three-phase LV test leads

  • Grounding cable

  • USB cable

  • Power cord

  • Transport case

  • Calibration certificate & user manual

Applications

  • Three-phase transformer ratio testing

  • Vector group and polarity verification

  • Factory QA, commissioning & maintenance

  • Power transformer diagnostics for utilities

  • Substation acceptance tests

Optional Accessories

  • Extended three-phase HV lead set

  • Ruggedized wheeled case

  • Thermal printer kit

  • PC software upgrade for comparison & trending

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