Megger TTR100 Hand-held Transformer Tester

Megger TTR100 Handheld Transformer Turns Ratio Tester

The Megger TTR100 is a handheld, single-phase transformer turns ratio (TTR) tester used by electrical engineers, utility teams, and electrical contractors in Ireland to confirm transformer ratio, detect winding faults, and verify tap-changer positions. It is the lightweight, battery-operated instrument that turns "the transformer is fine" into measured, recorded turns ratio data with the accuracy to back it up.

The TTR100-1 is the latest TTR available from Megger in this format, offering the highest turns ratio range and accuracy in a handheld package. For Irish maintenance teams who need a fast, repeatable transformer test on site rather than a benchtop instrument back in the workshop, the TTR100 is the right tool.

What the TTR100 measures and why it matters

• Turns ratio: confirm the actual ratio matches the nameplate, after install, after a tap changer operation, or as part of routine preventive maintenance.
• Excitation current: detect shorted turns, manufacturing or repair errors, and core problems that show up as elevated excitation current.
• Winding resistance on appropriate models, supporting condition assessment of the windings.
• Phase displacement: verify polarity and vector group.
• Tap-by-tap testing: capture turns ratio at each tap position to confirm tap changer integrity.

Turns ratio is one of the simplest, most diagnostic measurements you can take on a transformer. A small change in the measured ratio against the nameplate is often the earliest indication of a problem inside the windings, and the TTR100 is built for the kind of accuracy that lets you trust those small differences.

Key features

• Handheld and lightweight: designed for field testing in tight switchrooms, substations, and pole-mounted transformer environments.
• Battery-operated instrument: no mains supply required on site.
• Fast test cycle: turns ratio results in seconds, with go/no-go indication.
• On-board storage and database program for transferring test files and trending results over time.
• Single-phase test: covers single-phase units directly and three-phase units phase-by-phase.
• Repeatable accuracy across return visits, supporting condition-based maintenance and audit-ready reporting.

Specifications: what to confirm before you order

For full datasheet detail, send us your transformer types and we can confirm the TTR100 covers your worst-case ratio and accuracy requirement before you order.

Target users and applications

• Electrical engineers commissioning new transformers and verifying ratio against the nameplate
• Utilities and DNOs running periodic transformer testing on the distribution network
• Electrical contractors carrying out post-repair verification on rewound or repaired transformers
• Industrial maintenance teams in pharmaceutical, semiconductor, and data centre estates
• Renewable site operators testing wind, solar, and BESS step-up transformers
• Rental and tooling fleets where a hand-held TTR is the right level of capability for fast field work

As authorised Megger distributor in Ireland, Powerpoint Engineering supports the TTR100 with in-house calibration and repair, accessory supply, and training for transformer testing and maintenance.

FAQs

What is a transformer turns ratio test?

A turns ratio test compares the measured ratio of the primary and secondary windings of a transformer against the nameplate ratio. It is the quickest way to confirm a transformer is wired correctly, has not developed shorted turns, and that the tap changer is selecting the right position.

Can the TTR100 test three-phase transformers?

Yes, on a phase-by-phase basis. The TTR100 is a single-phase tester, so for a three-phase transformer the test is performed across each phase pair in turn. For very high test volumes on three-phase units, ask us about the higher-capability Megger TTR fleet.

Does the Megger TTR100 need calibration?

Yes. As a precision measurement instrument, the TTR100 should be recalibrated periodically to remain trusted against acceptance and trending criteria. Powerpoint Engineering's calibration laboratory recalibrates Megger TTR units in-house and supplies a traceable certificate.

To match the right TTR100 configuration to your transformer fleet and accuracy requirement, request a quote or speak to our team for compatibility advice.