Megger MRCT Relay and Current Transformer Test Set

The Megger MRCT Relay and Current Transformer Test Set is a lightweight, robust, and highly portable test set designed to deliver fast, accurate testing of current transformers. Combining multiple functions into one compact unit, the MRCT performs demagnetisation, ratio, saturation, winding resistance, polarity, phase deviation, and insulation tests with ease. Its advanced microprocessor-controlled outputs and precision instrumentation allows automatic testing of single and multi-ratio CTs, calculating ratio errors, knee points, and saturation cureves at the push of a button, without the need to change leads. This not only simplifies operation, but also saves valuable time in the field.

The MRCT can be operated via Megger’s Smart Touch View Interface (STVI), which offers maximum flexibility, and is an optional, full-colour, high-resolution touchscreen controller that supports both manual and automated test routines whilst clearly displaying all test data and saturation curves. Alternatively, the unit can be controlled through a laptop using Megger’s PowerDB software, providing seamless integration into asset management and reporting workflows. The MRCT is designed for real-world applications, allowing CTs to be tested in their installed positions, whether mounted in transformers, circuit breakers, or switchgear, ensuring accurate results without compromising convenience. This powerful yet portable solution makes CT testing faster, simpler, and more reliable than ever.

Applications of the MVCT

With a single push of a button, the MRCT performs a CT saturation test and calculates the rated knee point. The saturation test can be carried out at 50 or 60Hz up to 2,000V to meet IEC requirements, and the MRCT can also be configured to test kneepoints up to 40kV using an alternative DC technique. This allows most CTs to be tested at line frequency while still enabling larger generation-class CTs to be tested with a portable instrument. The MRCT calculates the rated knee point in compliance with IEEE C57.13.1, IEC 60044-1, IEC 60044-6, or IEC 61869 standards, including specialised CT types such as PX, TPS, TPX, and TPY. While testing, it plots the CT saturation curve on the STVI display and can display up to 10 curves simultaneously for multi-ratio CTs. Ratio testing is performed by comparing the voltage applied to the secondary winding with the resulting voltage on the primary, while polarity is automatically verified. Winding resistance is measured by injecting a test voltage, monitoring the DC current, and calculating temperature-compensated resistance to ensure accurate results. The MRCT also provides automatic demagnetisation of CTs, a crucial step to guarantee correct saturation test results in accordance with ANSI and IEC recommendations.

The MRCT measures connected CT burden by injecting secondary current into a disconnected load, reporting the burden in VA and power factor along with voltage magnitude and phase angle. Insulation testing is performed with 500V or 1000V to confirm proper insulation of CT secondary windings and wiring, with automated switching for all required H-L, H-G, and L-G tests. The MRCT is designed for upgradeability, with modular configurations and optional accessories that allow testing capabilities to expand as new CT testing requirements arise.

Megger part number: MRCT

Ordering Options

The MRCT can be customised entirely to suit the specific needs required, with the graphic below showing how to build a model and the options that are available to you.

Key Features

• Performs demagnetisation, ratio, saturation, winding resistance, polarity, phase deviation, insulation, and burden tests in a single portable unit
• Micro-processor controlled outputs calculate ratio errors, knee points, and saturation curves automatically, handling single and multi-ratio CTs without changing leads
• Operated via the optional STVI touchscreen or a laptop with PowerDB software, supporting manual, automated, and fully computer-controlled testing
• Enables CTs to be tested in their installed positions (transformers, circuit breakers, switchgear) while meeting IEC and IEEE standards
• Conducts 50/60Hz saturation tests up to 2000V, DC kneepoint tests up to 40kV, plots up to 10 curves simultaneously, and includes automatic demagnetisation
• Offers insulation resistance testing (500V/1000V) with automated switching for H-L, H-G, and L-G, ensuring compliance with ANSI/EC standards
• Modular design with upgrade options to expand testing capabilities as requirements evolve