Transformer Turns Ratio Tester

Automated Turns Ratio & Vector Group Verification

Transformer Turns Ratio Tester

The transformer turns ratio (TTR) test verifies that a transformer's winding ratio matches its nameplate specification and that all tap positions are correct. Green Watt's TTR tester provides fast, accurate automated ratio measurement for transformers from distribution level to EHV.

Key Features

  • Automatic ratio measurement — calculates ratio and deviation from nominal
  • Wide ratio range: 0.8 to 10,000+ covering distribution to EHV transformers
  • Tests all OLTC and OCTC tap positions sequentially
  • Phase angle measurement to verify winding polarity and vector group
  • Vector group verification (Dyn11, YNyn0, etc.)
  • Ratio error measurement to ±0.1% or better
  • Automatic three-phase testing in a single connection setup
  • Safety protection — HV detection circuit prevents incorrect connection damage

Applications

  • Commissioning of new power and distribution transformers
  • Periodic maintenance testing to detect tap changer problems and shorted turns
  • Post-repair verification after transformer rewinding or bushing replacement
  • Factory acceptance testing at transformer manufacturing works
  • Post-lightning or fault event assessment

Technical Specifications

Ratio Range0.8 to 10,000 (or higher)
Ratio Accuracy±0.1% or better
Phase Angle Accuracy±1 minute
StandardsIEC 60076-1, IS 2026, IEEE C57.12.90

Enquire About This Product

Request a quote, arrange a product demonstration, or speak to our technical team.

Take EnquiryContact Us

Category

Transformer Diagnostics

Explore All Products

View Full Product Range →