top of page

TRM-50 / TRM-50+ Transformer Ratio Meter

The TRM-50 Series is a high-accuracy transformer turns ratio meter designed for testing power and distribution transformers of all vector groups.
It measures turns ratio, phase angle, polarity, and excitation current with exceptional speed and precision.
The TRM-50+ adds extended ratio ranges, enhanced accuracy, and stronger interference suppression for substation environments.

Model Options

Key Features

  • Fast, accurate turns ratio testing for all transformer types

  • Measures ratio, phase angle, polarity, and excitation current

  • Auto vector group identification

  • TRM-50+: extended ratio range and improved accuracy

  • Automatic demagnetization (model-dependent)

  • Clear LCD with vector diagrams

  • Internal storage + USB export

  • Fast test cycle ideal for field work

  • Lightweight and rugged for substation testing

Technical Specifications

Parameter TRM-50 TRM-50+
Ratio Range 0.8–10,000:1 0.8–50,000:1
Accuracy ±0.1% ±0.05%
Phase Angle Range 0–360° 0–360°
Polarity Check Automatic Automatic
Test Voltage 8–120 V AC 8–120 V AC
Excitation Current Up to 5 A Up to 10 A
Vector Group Support All All + auto recognition
Display Backlit LCD Backlit LCD
Memory Internal + USB Internal + USB
Power Supply 220 V AC 220 V AC
Weight ≈ 7 kg ≈ 8 kg

Standard Accessories

  • HV & LV test leads

  • Ground cable

  • USB cable

  • Power cable

  • Carry case

  • Calibration certificate & user manual

Applications

Applications

  • Power transformer TTR (Turns Ratio) testing

  • Distribution transformer commissioning

  • Routine maintenance and vector group verification

  • Polarity, phase displacement & excitation testing

  • Substation acceptance and QA testing

Optional Add-Ons

  • Extended 10–30 m leads

  • HV shielded cable set

  • Ruggedised hard transport case

  • On-site thermal printer module

bottom of page