Transformer Testing

The Oil Tan Delta (OTD) is a laboratory instrument, which measures the Tan Delta, Resistivity and Relative Permittivity of insulating liquids.  These tests give a wider picture of the overall quality of the insulating oil, and will indicate if there is any contamination. Megger has developed features of the OTD to ensure that productivity levels within laboratories are maximised.

The microprocessor controlled inductive heater means that there is uniformity of temperature throughout the cell, in compliance with IEC 60247, and for cooling a fan effectively speeds up the cell cooling time.  The instrument has a temperature measuring range of 10 to 110 ºC, with an accuracy of ± 1 ºC. It can be set to preheat before testing takes place. The automated oil drain facility negates the need to move the oil vessel.

Over 20 years’ experience has led to the development of the Megger KF875 and KF-LAB MkII Coulometric Karl Fischer Test Sets designed to determine moisture in oil, to provide highly accurate results on-site. The KF875 and KF-LAB MkII are highly portable instruments, complete with integral printer and carrying case, are easy to use and provide highly accurate results.

Optimized for testing insulating oils with a specific gravity of 0.875, the Megger KF875 simply requires the operator to press one button and inject a 1ml sample into the test cell. The simple ‘one touch’ operation makes the KF875 so easy to use that it requires no specialist knowledge or training to use it effectively. Results are presented on the instrument display and on the integral printer in both micrograms of water and in milligrams per kilogram (parts per million, ppm).

The KF-LAB MkII allows the titration of samples with a range of specific gravities from 0.60 to 1.40 and also permits the use of different sample sizes. The KF-LAB MkII also has a default setting optimized for analyzing insulating oils with an SG of 0.875. This means it can be used to measure water content in a variety of different materials but is also easy to set up for transformer insulating oils.

Optimized for testing insulating oils with a specific gravity of 0.875, the Megger KF875 simply requires the operator to press one button and inject a 1ml sample into the test cell. The simple ‘one touch’ operation makes the KF875 so easy to use that it requires no specialist knowledge or training to use it effectively. Results are presented on the instrument display and on the integral printer in both micrograms of water and in milligrams per kilogram (parts per million, ppm).

The KF-LAB MkII allows the titration of samples with a range of specific gravities from 0.60 to 1.40 and also permits the use of different sample sizes. The KF-LAB MkII also has a default setting optimized for analyzing insulating oils with an SG of 0.875. This means it can be used to measure water content in a variety of different materials but is also easy to set up for transformer insulating oils.

The printer may be disabled if not required and results can be calculated in ppm, mg/kg, % and micrograms. For extra flexibility, the results may be calculated based on the weight of the sample or based on the volume and specific gravity of the sample.

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Designed for Laboratory use, these instruments measure the dielectric strength of mineral, ester and silicon insulating oils. With re-thought out ergonomics, the vessels and chambers are particularly easy to drain and clean out. The screw adjusted electrodes have a unique mechanism to lock precisely the electrode gap. The detection circuit offers direct measurement of both voltage and current and the system has an ultra fast HV switch off time of less than 10 μs to reduce oil deterioration. Each instrument has a large, bright, coloured screen to make user interface intuitive. To assist with the labelling of results files and recording of comments there is a phone-like 12 key alphanumeric pad. The products can be configured to meet the testing requirements of the laboratory.

Megger’s automatic laboratory oil test sets perform accurate breakdown voltage tests on mineral, ester and silicon insulating liquids. Moulded test vessels give repeatable results with lock in precision electrode gap setting adjustment wheels. The transparent, shielded lid and large test chamber enable easy access to the test vessel.

All three laboratory models are fitted with a 12 key alphanumeric keypad to facilitate entry of test ID, filenames, notes etc. Alpha characters are entered by repetitive pressing on a key, the same way as text is entered modern cellular telephones.

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Portable Oil Test sets - Weighing in at only 16 kg the OTS60PB is the lightest, most portable oil test set available. Meanwhile the OTS80PB is the most flexible test set because it offers more power in a test set which weighs less than 21 kg. Featuring the same easy-empty vessel and quick-drain chamber design as the laboratory models, the large, bright, colour screens are easy to read in sun light. Features like the electrode precision lock and ultra fast HV switch off time are particularly important for instruments that may not be used in the ideal environment. The OTSPBs can be configured to match the users needs. 60 kV manual oil test set.

Megger’s automatic portable oil test sets perform accurate breakdown voltage tests on mineral, ester and silicon insulating liquids. Moulded test vessels give repeatable results in the field and laboratory with lock in precision electrode gap setting adjustment wheels. The transparent, shielded lid is a key feature enabling users to see what is happening within the test chamber.

Megger portable 60 kV and 80 kV oil test sets are the lightest on the market ranging from 16 kg to 23.5 kg depending on model and configuration. They come complete with optional carry bag and transport case.

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The TTRU1 handheld transformer turns ratiometer will exceed your expectations. It’s the ultimate productivity booster to revolutionise the way you work.

The NEW Megger TTRU3 transformer turns ratiometer uses a revolutionary design to perform a complete series of measurements on a transformer, including 3Ø step up turns ratio testing (patent pending). 3Ø voltage output offers numerous advantages to testing with today’s busy schedules.

The TTRU3 is an important tool for determining the mechanical condition of transformers. All ratio tests are performed in one instrument, with only one 3Ø lead-set connection. The TTRU3 utilizes the latest 7 in. (180 mm) color touch display, as well as an optional printer so results are never lost. This is complimented with remote control which can be operated from a PC, as well as the ability to download results to a USB memory device.

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The MTO106 transformer ohmmeter is an easy-to-use, line-operated instrument specifically designed for safe and accurate field measurement of winding resistance in smaller transmission and distribution transformers. It has dual channels with a measurement range and accuracy suited to provide accurate information about the vast majority of power transformers, reactors and instrument transformers. The test current can be manually set in five different ranges to fit transformers of various sizes.

The instrument is exceedingly simple to use, which minimises the need to train users. It has a single selector switch for test current and a single button to activate the test cycle. The instrument is also supplied with test leads fitted with Kelvin clamps that allow for a single, one-time connection to the unit under test. The test leads are 10 m (33 ft) in length to allow for easy testing of pole mounted transformers.

The compact and lightweight instrument is housed in a rugged plastic case for true portability. When closed, the case is rated IP67, which means your instrument will always arrive safely to the testing location even in the harshest conditions.

Users are protected by an automatic discharge function that de-energises the transformer winding at the end of every test. The discharge function is passive and thus also functions if there is an inadvertent loss of power or if the test or mains leads are accidentally pulled.

IDAX 300 is a very compact instrument and is used together with an external computer. The IDAX 350 has a built-in computer but can also be used with an external computer.

IDAX 300 provides an accurate and reliable condition assessment of insulation in transformers, bushings, generators and cables. The IDAX 300 system maximizes the outcome of maintenance activities allowing for load and service life optimization.

IDAX 300 provides reliable data using true DFR (Dielectric Frequency Response), also known as FDS (Frequency Domain Spectroscopy), without compromises. The state-of-the-art software makes testing both easier and faster, allowing transformer moisture assessment in less than 18 minutes.

IDAX 300 measures the capacitance and tan delta/power factor of the insulation between power transformer windings at multiple frequencies. Plotting the results as a curve makes it possible to assess the condition of the oil and solid insulation, assess the moisture level in the solid insulation and other potential insulation

The DELTA4000 Series is a fully automatic 12 kV insulation power factor/dissipation factor (tan∂) test set designed for condition assessment of electrical insulation in high voltage apparatus such as transformers, bushings, circuit breakers, cables, lightning arresters and rotating machinery. In addition to performing insulation power factor tests, the DELTA4000 Series can be used to measure the excitation current of transformer windings as well as to perform automatic tip-up tests and HV turns-ratio testing (an optional TTR capacitor is available).

The test set is designed to provide a comprehensive AC insulation diagnostic test. The high power variable frequency design generates its own test signal independent of line frequency quality and the hardware design uses the latest technology available for digital filtering of the response signal. As a result, the DELTA4000 Series produces reliable results and stable readings in the shortest time with the highest accuracy, even in high interference substations.

The DELTA4000 Series operates with PowerDB software for automatic testing and reporting or with Delta Control software for real-time manual testing.

Measurements include voltage, current, power (loss), tan delta, inductance, power factor and capacitance. The test results are automatically stored in the computer and can also be downloaded directly to USB storage or a printer.

DELTA4110 test set is to be used with an external computer (not included) while the DELTA4310A test set comes with an on-board computer.

The FRAX series of sweep frequency response analyzers (SFRA) detects potential mechanical and electrical problems that other methods are unable to detect. Major utilities and service companies have used the FRA method for more than a decade. The measurement is easy to perform and will capture a unique fingerprint of the transformer. The measurement is compared to a reference fingerprint and gives a direct answer if the mechanical parts of the transformer are unchanged or not. Deviations indicate geometrical and/or electrical changes within the transformer.

Major utilities and service companies have used the FRA method for more than a decade. The measurement is easy to perform and will capture a unique fingerprint of the transformer. The measurement is compared to a reference fingerprint and gives a direct answer if the mechanical parts of the transformer are unchanged or not. Deviations indicate geometrical and/or electrical changes within the transformer.

The FRAX 101 Sweep Frequency Response Analyzer (SFRA) detects potential mechanical and electrical problems that other methods are unable to detect. Major utilities and service companies have used the FRA method for more than a decade. The measurement is easy to perform and will capture a unique fingerprint of the transformer. The measurement is compared to a reference fingerprint and gives a direct answer if the mechanical parts of the transformer are unchanged or not. Deviations indicate geometrical and/or electrical changes within the transformer.

The Megger MVCT test set is a lightweight, robust, portable unit capable of testing both current and voltage transformers. At less than 20 lb (10Kg) the MVCT is a highly portable unit that also offers accuracy in testing. Capable of performing saturation, ratio, polarity, winding resistance, and insulation tests on current transformers, the MVCT can also be used for testing metering and protection class voltage/potential transformers. The MVCT provides a microprocessor controlled variable voltage and current output along with precision instrumentation for automatically testing single and multi-ratio CTs and VT’s. The MVCT makes testing CTs easy. It will directly connect to multi ratio CT’s and perform all tests – saturation, ratio and polarity, winding resistance, and insulation – on all taps with the push of a button and without changing leads. This greatly reduces testing time. The MVCT can be controlled via its large, full color, high resolution, sunlight readable TFT LCD touch screen display. This interface allows the user to perform manual and automatic testing quickly and easily using the manual test screen, or by using pre-constructed test routines. The large color display also permits the user to easily read all pertinent data while the test is being performed and provides the ability to view the results when the test is complete. The unit can also be configured to come without a display and thus be controlled via a laptop utilizing PowerDB or with Megger’s existing Smart Touch View Interface™(STVI).

The Megger MRCT is a light weight, robust, portable unit used to perform demagnetization, ratio, saturation, winding resistance, polarity, phase deviation, and insulation tests on current transformers. The MRCT automatically calculates ratio errors, saturation curves, and knee points. The MRCT provides a microprocessor-controlled variable voltage and current output and precision instrumentation for automatically testing single and multi ratio CTs, reducing testing time and increasing productivity. The MRCT will directly connect to multi ratio CT’s and perform all tests – saturation, ratio and polarity, winding resistance and insulation – on all taps with the push of a button and without changing leads.

The MRCT can be controlled via Megger’s Smart Touch View Interface (STVI) controller, a full color, high resolution, LCD touch screen which allows the user to perform manual and automatic testing quickly and easily using the manual test screen, as well as using pre-constructed test routines. The large display permits the user to easily read all pertinent data while the test is being performed and provides the ability to view the current transformer’s saturation curve. The unit can also be configured to come without a Megger STVI and can be controlled via a laptop with Megger’s PowerDB software.

Current transformers can be tested in their equipment configuration, such as being mounted in transformers, oil circuit breakers or switchgear. It is necessary for the equipment to be completely isolated from the electrical system prior to testing.

The innovative Sverker 900 test set, which has been conceived as an engineer’s “multi-function testbox” for protection testing. It features an intuitive user interface so that a PC is not required to operate the instrument.

It centres around a touchscreen that provides access to a wide range of pre-configured virtual test instruments, allowing the required test function to be selected quickly and easily. Full manual control and configuration are also supported and, in addition to the touchscreen, the instrument is provided with a large rotary knob that can be configured as required to control the current and voltage generators.

To make the Sverker 900 into a truly versatile “testbox”, additional tools are provided. These include an analogue ammeter and an analogue voltmeter, together with facilities for measuring a wide range of parameters such as phase angle; active, reactive and apparent power; power factor; resistance; reactance and frequency.

Other virtual instruments include a prefault-fault instrument, a ramping instrument and a sequence instrument. An impedance instrument is also provided, which allows relays to be tested directly from the impedance plane with conversion from impedance to voltages and currents carried out automatically by the test set. There is also a CT magnetisation instrument available. Test configurations and test results are stored in internal non-volatile memory and can be readily transferred to and from a PC via the instrument’s USB port.

In developing this innovative solution, key factors the designers took into account were the need for modern distribution relay protection schemes to be tested by three-phase secondary injection and also the requirement for test sets to provide high-power, high-amplitude outputs for use on high burden relays or when carrying out single-phase tests on current and voltage transformers.

The requirement for high-power single-phase test capabilities is addressed by making provision for connecting the three-phase current and voltage generators in series or parallel, as appropriate. This is by no means an unusual arrangement, but it is can involve a tangle of flexible connecting leads with plenty of scope for making wrong connections.

The Sverker 900 uses rigid links to make the necessary connections and the sockets for the links are positioned in such a way that it is physically impossible to make the wrong connections. These simple yet novel ideas allow convenience to be combined with safety and speed.

These high-current supply units have two main fields of application. The first is to conduct primary tests on protective relays. A primary test shows whether all parts of the protection system are functioning together properly within the specified time limits under operating conditions. The second field of application involves conducting current tests on low-voltage circuit breakers and over current devices.

The SPI225 is a high current primary injection test system for all forms of high current testing required in a substation, including testing overcurrent relays, circuit breakers, motor overloads and current transformers.

The SPI system is the FIRST high current test systems to permit a user to type in a predetermined current and the SPI system will generate and regulate the requested high current without preheating the test sample by pulsing the output current at high currents. The SPI system also has the unique ability to turn on at the current zero crossing every time for any load by automatically adjust the output firing angle. This eliminates DC offset for every circuit breaker type and the need for the user to determine and adjust the firing angle for different loads and circuit breakers.

All SPI systems are both fully automated and/or manually controlled. The Smart Touch View Interface “STVI” permits users to manually control the unit and also perform automated testing. The SPI unit can also be controlled by a PC for fully automatic testing and report generation.

This powerful test system is designed for primary injection testing of protective relay equipment and circuit breakers. It is also used to test the turns ratio of current transformers and for other applications that require high variable currents.

This powerful test system is designed for primary injection testing of protective relay equipment and circuit breakers. It is also used to test the turns ratio of current transformers and for other applications that require high variable currents.

The system consists of a control unit and a current unit. The two parts are portable, and INGVAR can be quickly assembled and connected.

The control unit has many advanced features – a powerful measurement section for example, that can display turns ratio as well as time, voltage and current. A second measurement channel can be used to test an additional current or voltage. Current transformer turns ratio, impedance, power, power factor (cos φ) and phase angle are calculated and shown in the display. Current and voltage can be presented as percentages of nominal value. The fast-acting hold function freezes short-duration readings on the digital display when the voltage or contact signal arrives at the stop input, the object under test interrupts the current or injection is stopped.

The MTO106 transformer ohmmeter is an easy-to-use, line-operated instrument specifically designed for safe and accurate field measurement of winding resistance in smaller transmission and distribution transformers. It has dual channels with a measurement range and accuracy suited to provide accurate information about the vast majority of power transformers, reactors and instrument transformers. The test current can be manually set in five different ranges to fit transformers of various sizes.

The instrument is exceedingly simple to use, which minimises the need to train users. It has a single selector switch for test current and a single button to activate the test cycle. The instrument is also supplied with test leads fitted with Kelvin clamps that allow for a single, one-time connection to the unit under test. The test leads are 10 m (33 ft) in length to allow for easy testing of pole mounted transformers.

The compact and lightweight instrument is housed in a rugged plastic case for true portability. When closed, the case is rated IP67, which means your instrument will always arrive safely to the testing location even in the harshest conditions.

Users are protected by an automatic discharge function that de-energises the transformer winding at the end of every test. The discharge function is passive and thus also functions if there is an inadvertent loss of power or if the test or mains leads are accidentally pulled.

The multifunction TAU3 streamlines transformer testing with a one-time connection for all tests, reducing reliance on multiple instruments and minimising testing time, helping you maximise productivity for fast and accurate maintenance decisions. In addition to routine polarity validation, turns ratio, winding resistance, and demagnetization tests, the TAU3 offers short-circuit impedance and efficiency tests with the same one-time lead connection. Guided by colour-coded leads and clamps with on-screen vectors that match the transformer nameplate, the easy-to-follow setup ensures the right result the first time…just click ‘start’ and let the patent-pending internal shorting and lead compensation do the work! 

Included in the substation software package are functions to make a quick functional check of a high voltage circuit breaker. Main timing test for three phases with one break per phase and also pre-insertion resistor timing. Contact resistance at or above standard recommendation current.

• Replaces need for multiple test sets
• Saves time by eliminating need for multiple instruments learning
• User-friendly interface reduces training and testing time
• Portable and compact system components for easy shipping
• State of the art measurement methods for advanced diagnostic testing

TRAX is not just another multi-functional test instrument, but rather many intelligent instruments built into one box. The software includes a number of apps, making it fast and easy to perform a large range of different tests. The hardware offers unmatched flexibility and the range of cables and accessories adds even more flexibility, making the TRAX an efficient and time saving system for any user in the world.

TRAX is a multi-functional solution for transformer testing. It also adds several common substation testing functionalities, and ultimately replaces numerous individual testing devices. Compared to conventional single-functionality instruments, TRAX saves time and is more cost effective.

TRAX applications range from power transformers, where it offers several unique and outstanding features, to instrument transformers, circuit breakers, relays and many other substation components.