• Dutco Tennant LLC, PO Box 233, Dubai, U.A.E.
Transformer Winding Resistance Meter (HV&MV) Transmission

SCOPE introduces 50 A state of the art precision winding resistance meter, specially designed for field testing as well as factory testing of large transformers up to 500 MVA. Winding resistance value of transformer and rotating machine are directly displayed on 5.7” TFT display. TRM 50 is designed to work in live EHV switchyard conditions, ensuring operator’s safety and repeatability of results. Maintenance time saving is ensured by one time connection to transformer with simultaneous resistance measurement of three / six windings, measurement of resistances of all taps with automated tap change and demagnetization facility. The meter is protected against the back-EMF offered by large inductive windings.


  • Can measure DC winding resistance of large rotating machines, highly inductive test objects like Transformer, Generators and Motors etc.
  • 50 A DC current makes it possible to measure low resistances with high accuracy.
  • One time connection to either all windings of primary and / or secondary. Simultaneous measurement reduces connection and measurement time.
  • Change in winding resistance, short or open windings can be detected from measured values.
  • Automatic temperature measurement and temperature corrected value calculation.
  • Measurements of winding resistance of all taps of phases in one go. Recoding, printing and storage of results.

OLTC contact opening and compete OLTC performance test facility. Testing of either single or three phases in one test. Single report generation.

To know condition of OLTC contacts, OLTC mechanism, transition resistor. Discharges and demagnetizes the object after test.


  • No of Channels: 3/6 Current Channels, 3/6 Volatge Channels , 1 tempreture Channel
  • Connections: One time connection to primary or secondary winding of transformer
  • Current Ranges : 50A, 40A, 25A, 10A, 5A, 1A, 100mA, 10mA
  • Resistance Ranges: Up to 2000 Ω (Auto ranging)
  • Resolution : 4 ½ digit
  • Accuracy: Value ± 0.5% ± 5 counts

Current and Resistance ranges

  • Open Circuit Voltage: 50 V
  • Demagnetization Facility: Yes
  • Display: 5.7” TFT display with touch screen
  • Printer: 58 mm, Inbuilt thermal printer
  • Communication Port: Ethernet for PC communication
  • Data Port: USB for extrernal memory stick connection
  • External Control: Possible via Notebook PC through Ethernet port and software
  • Temperature measurement: Range 0 to 100 deg, Accuracy ± 1 deg, Resolution 0.1deg
  • Temperature correction: For Aluminium & Copper
  • Temperature Input Channel: Compatible to accept RTD input
  • User Interface: Resistive touch screen
  • Back EMF Protection: Yes. Automatic protection after measurement and during accidental disconnection of current path. Protection operates even if Mains supply fails.
  • Discharge Facility & Indication: Automatic Discharge of DUT & messages on screen
  • Tap Changer Test: Detects discontinuity during tap changer test
  • OLTC Test Facility(Optional): OLTC test facility with current v/s time graph, Single or Three Phases simultaneously.

Available in control through PC option only.

  • OLTC current Ranges: 50A, 40A, 25A, 10A, 5A
  • Protection: Shut down of power source on Over voltage, Over current,Over temperature
  • Indications: Polarity reversal, Test connection continuity and discharge
  • Diagnostics: Check At power On instrument does self-check of channels and shows the message
  • Test Leads: Measuring leads, AC supply, earth leads and temperature sensor lead
  • Operating Environment: -10°C to 50°C, 95% RH (non condensing)
  • Storage Temperature: -20°C to 60 °C
  • Heat Run test: Yes
  • Delta connection Measurement: values of each arm of delta winding is calculated and displayed
  • One side earthing: Instrument is able to do the measurement with one side earthing (with Neutral earthing)
  • Input Supply: 110V AC ±15% 50/60 Hz ±10% Or 220V AC ±15% 50/60 Hz ±10%.
  • Dimensions: 630 x 500 x 302mm
  • Weight: 22 Kg. Approx