Description
Vanguard Instruments TRM-20 Resistance Meter Repair
The Vanguard Instruments TRM-20 Resistance Meter is a transformer turns ratio tester – it energises a transformer winding and measures the ratio, excitation current and phase to confirm the windings and the tap changer are intact. The measurement is a ratio, so small errors in either winding measurement compound.
Certified technicians at June Company service the Vanguard Instruments TRM-20 Resistance Meter for utility transformer crews, substation technicians, and transformer manufacturers. Every instrument is repaired at component level and verified against reference standards before it ships back, with the measured results documented.
Common Vanguard Instruments TRM-20 Resistance Meter problems we fix
- Display, keypad or front-panel faults.
- GPIB, LAN, USB or remote-control faults – which breaks automated test sequences while the instrument still works from the front panel.
- Ratio readings inaccurate – verified across the full range rather than at a single tap, since ratio errors that appear only on certain taps are the ones most often missed.
- Excitation current measurement errors.
- Phase deviation readings incorrect.
- Test lead or clamp faults.
- Output drive stage failure.
- Automatic tap changer sequencing faults.
FAQs
How long does a repair take? Most are completed in 5-10 business days, with a firm quote after evaluation and before any work begins.
Are the measurements verified after repair? Yes, against reference standards, with the measured results documented and returned with the instrument.
Every repair carries a 90-day parts-and-labor warranty, with a firm quote before any work begins. Email us or submit a service request.






