Megger TTR20 Handheld transformer turns ratio tester (TTR)

Description

Compact Handheld Solution for Transformer Ratio Testing

The Megger TTR20 Handheld Transformer Turns Ratio Tester is a compact, battery-operated instrument designed for precision measurement of the turns ratio, excitation current, and polarity of transformer windings. This includes single-phase and phase-by-phase testing of three-phase distribution and power transformers, as well as current transformers (CTs), potential transformers (PTs), and tapped transformers. Measuring turns ratio is a critical step in transformer maintenance and fault diagnosis, as deviations can indicate problems in winding integrity or in the magnetic core circuit. Thanks to its rugged yet lightweight design, the TTR20 delivers high accuracy (up to 10,000:1) even at the lowest excitation voltage. This robust device is ideal for technicians who demand efficiency, repeatability, and portability—all in one solution. The TTR20 is now a discontinued model, making it a sought-after product for maintenance engineers and transformer manufacturers. However, it is still available from specialized suppliers such as tpt24, the world’s premier online store for this product, offering an authenticity guarantee and worldwide delivery.

Unique Ergonomics for Efficient Field Operation

A major advantage of the TTR20 lies in its one-handed operation capability, which allows users to hold, position, and operate the unit without requiring additional support surfaces. This design significantly speeds up testing by eliminating the need for technicians to kneel or bend awkwardly during measurements. The instrument weighs only about 870 g (1.9 lbs), making it one of the lightest professional-grade transformer testers on the market. Special attention has been given to its ruggedness—its high-impact, shock-resistant case is built to endure harsh substation conditions, transformer manufacturing facilities, and challenging outdoor environments. A high-contrast, backlit LCD ensures excellent visibility in both bright sunlight and low-light conditions, so testing can proceed without interruption. Whether in high-voltage yards, meter shops, or field installations, the TTR20 maximizes productivity without compromising safety or accuracy.

Comprehensive Applications Across Power Infrastructure

The TTR20’s range of applications extends far beyond conventional power transformer checks. In substations, it is used to validate transformer installation integrity and assess winding condition before energization. In transformer manufacturing plants, it accelerates quality control processes by ensuring production units meet specified turns ratio tolerances. In meter shops, it verifies the no-load accuracy of CTs and PTs and can quickly determine whether suspected faulty units require further laboratory testing. This versatility makes it an indispensable tool for utility companies, maintenance contractors, and equipment manufacturers. Particularly well suited for transformers up to 1 MVA, it applies voltage to the transformer’s high-voltage winding and measures the resulting voltage from the low-voltage winding, accurately calculating the turns ratio. It also evaluates excitation current and polarity without the need for additional software. This all-in-one capability streamlines workflows, reduces testing complexity, and speeds up maintenance cycles.

High Precision Measurement with Advanced Accuracy

One of the TTR20’s strongest attributes is its measurement accuracy. It delivers repeatable results with a turns ratio accuracy of ±0.20% (0.8 to 4,000) and ±0.25% (4,001 to 10,000) at excitation current levels below preset thresholds. It also features a wide turns ratio range from 0.8 to 10,000 and supports excitation currents up to 100 mA with a 4-digit resolution. Importantly, the internally generated 55 Hz test frequency allows it to operate universally in both 50 Hz and 60 Hz environments. Safety and compliance are addressed through adherence to IEC-1010-1, CE, and ASTM D999.75 standards, ensuring reliability and operator protection. The precise application of low excitation voltage minimizes potential stress on transformer windings during testing, preserving equipment integrity while still delivering comprehensive diagnostic data.

Simplified Operations for Faster Transformer Diagnostics

Ease-of-use has been prioritized in the TTR20’s design. With its single-button operation, even complex transformer tests can be initiated and completed in under five seconds. Results are displayed instantly on the easy-to-read LCD screen, allowing quick interpretation and decision-making in the field. For users who require printed results for documentation or regulatory compliance, an optional printer package is available. This includes a serial thermal printer, interface cable, paper rolls, and a charger, enabling field report generation without returning to an office. Because the unit is powered by six standard AA (IEC LR-6) batteries, it eliminates dependency on mains power or proprietary rechargeable packs, offering up to 12 hours of operation per set of batteries. This makes the TTR20 particularly suited to remote or outage-prone locations.

Rugged Power for Harsh Testing Environments

The TTR20 has been engineered to thrive in demanding environments. It operates flawlessly across a temperature range of -20°C to +55°C (-5°F to +130°F) and can be stored in conditions from -50°C to +60°C (-55°F to +140°F). Its humidity tolerance extends to 90% non-condensing in operation and 95% in storage. Protective devices include a high-voltage side shorting relay, transient voltage suppressors, and gas surge voltage protectors, safeguarding both the instrument and the transformer under test. Such hardware robustness makes the TTR20 a dependable asset for professionals working in desert substations, humid coastal installations, and high-altitude grid points alike. Combined with its shock-resistant housing, the tester stands as a field-ready workhorse that can endure repeated handling and transportation.

Discontinued Yet In-Demand Industry Workhorse

Although the TTR20 has been officially discontinued, it remains in considerable demand among industry professionals familiar with its efficiency, precision, and portability. Many consider it a benchmark device against which newer models are compared. The scarcity of new units has increased its desirability, especially among maintenance teams looking to match existing fleet equipment. The prominent online store tpt24 continues to offer this model, ensuring authenticity and full-quality assurance. Tpt24 also provides rapid global delivery, meaning that no matter where a technician is stationed—from urban substations to remote grid outposts—they can receive the TTR20 without logistical delays. This availability, paired with a proven operational record, keeps the TTR20 relevant and valuable within the transformer testing sector.

Summary of Benefits for Professional Technicians

The Megger TTR20 condenses high-performance transformer testing into a handheld, user-friendly package. By combining wide application versatility, precise measurement capability, rugged portability, and ergonomic ease, it empowers power engineers and service technicians to diagnose equipment quickly and efficiently. It is perfectly suited for substations, transformer production lines, utility maintenance crews, and calibration labs. Though discontinued, its reputation for reliability and quality continues to drive strong demand, particularly through trusted suppliers such as tpt24. When measured against its operational simplicity, accuracy, and durability, the TTR20 stands as one of the most respected transformer ratio testers of its generation—an indispensable companion for any technician committed to maintaining power system integrity.