Winding Resistance
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Product
Transformer Winding Resistance Meters
RMO TW Series
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The RMO-TW instrument can perform a simple, fast and reliable verification of a transformer on-load tap changer. This instrument allows measurements of a winding resistance at each tapping position of an on-load tap changer without discharging between tests. Problems with OLTC switching, such as interruption, can be detected with these measurements. The results are displayed on a backlit LCD screen.
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Product
Transformer Winding Resistance Meters
TWA Standard Series
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The TWA standard series instruments are designed to measure the resistance of six coils and simultaneously analyze the three-phase tap changer on load of the primary and secondary transformer coils (provided by model TWA40). This is done in a single cable configuration, with test currents up to 40A. Each transformer configuration has a special measurement algorithm that is optimized for rapid stabilization of test results. The TWA instruments generate a true DC current without ripple. Both current injection and magnetic circuit energy discharge are automatically regulated.
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Product
Transformer Winding Resistance Meters
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Vanguard Instruments Company, Inc.
The TRM-40 is Vanguard Instruments’ third generation transformer winding resistance meter. The TRM-40 is designed specifically to measure DC resistance values of transformer windings, rotating machine windings, or any dc resistance of an inductive device.
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Product
Three-Phase Transformer Winding Resistance Meters
TWA Standard Series
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When it comes to winding resistance measurement on three-phase power transformers and autotransformers, TWA Standard series offers some of the most technically advanced instruments with LCD display in the market. Both models are capable of testing six transformer windings with a one-time cable connection, as well as three-phase automatic transformer demagnetization. The stored magnetic energy is safely automatically discharged at the end of the test. The built-in tap changer control unit enables automated test mode, where the instrument operates the tap changer without operator input and records winding resistance results based on pre-selected stabilization criteria. This option makes the operator’s job significantly easier.Both models can output test currents from 5 mA to 25 A DC for the purpose of winding resistance measurement. TWA40D has a special test mode for checking the synchronization of on-load tap changers with three phases simultaneously tested in parallel, in which the total test current can rise to up to 40 A DC.TWA40D has additional advantages when it comes to non-intrusive tap changer analysis. The unique DVtest method enables checking the moving contacts of on-load tap changers during the transition, measuring the transition time, detecting open circuits, and many other types of faults. It is performed with 0.1 ms sampling rate, simultaneously with the measurement of tap changer motor current which helps with the detection of motor and mechanical issues. A special proprietary algorithm is used for testing tap changers connected through a built-in series (booster) transformer. The DVtest can be performed either on one phase or on three phases simultaneously. It can also be performed as an additional test simultaneously with the winding resistance test in all tap positions.An additional unique advantage of TWA40D is the capability of simultaneously testing the winding resistance of all three phases of a three-phase transformer (connected in a YN configuration). This can significantly shorten the total testing time – for example, it enables the operator to perform 33 measurements instead of 99 on a tap changer with 33 tap positions.The test leads for TWA three-phase transformer winding ohmmeters are interchangeable with the TRT turns ratio testers, which means that both sets of tests can be performed with a single test lead connection to the power transformer terminals.
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Product
Single-Phase Transformer Winding Resistance Meters
RMO-TD Series
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Using the most advanced switch-mode technology available today, the RMO-TD series is ideal for winding resistance measurements of inductive objects. Transformer resistance meters and tap changer analyzers are perfect for testing:transformer windings (power transformers, distribution, autotransformers),all types of tap changers,generators,electrical motors,high-current busbar joints,cable splices,and welding joints.In addition, transformer demagnetization can also be done with all RMO-TD instruments.The RMO-TD series contains 3 models, with maximal test currents from 25 A (RMO25TD) to 60 A (RMO60TD).The three independent voltage sense channels enable testing of three windings in series. This enables measurements of winding resistance in every tap position of an on-load tap changer without discharging between the tests.All RMO-TD transformer resistance meters have a built-in tap changer control unit. It enables remote control of on-load tap changer (OLTC) directly from the device. In order to make the most out of this feature, DV-Win software is included which can be programmed to do everything automatically – running winding resistance tests and changing OLTC tap positions.The DV-Win software also enables control and observation of the test process, as well as saving and analyzing the results on a PC. It provides a test report, arranged in a selectable form as an Excel spreadsheet, PDF, Word, or ASCII format. Additionally, DV-Win measures and calculates the OLTC transition time, the ripple and the winding resistance for each tap changing operation. The software can also perform the calculations necessary for the “Heat Run” test.All results can be exported in the report format.
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Product
Winding Resistance Meter 15Amps, 2 Channels Rack
WR14R
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Raytech Digital Winding Resistance meter WR14 R is the rack mount version of the WR14. They are designed for high degree of accuracy for the measurement of very low resistance of any inductive loads.
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Product
Transformer Winding Resistance Meter
10A
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*10A DC continuous current in 4 ranges of 0.01A, 0.1A, 1A and 10A.*4 ½ digit display for higher resolution.*Dual channel measurement.*Suitable for operation in energized switchyard conditions.*Specialized protection circuits for suppression of inductive voltage kickback.*SMPS based - lightweight and portable.
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Product
Single-Phase Transformer Winding Resistance Meters
RMO-TW Series
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RMO-TW series is perfect for winding resistance measurements of inductive objects. It is ideal for testing transformer windings (power transformers, distribution, autotransformers) and for on-load tap changer verification. In addition, any RMO-TW transformer ohmmeter & tap changer analyzer can also perform transformer demagnetization.The series contains 4 models, with maximal test currents from 10 A (RMO10TW) to 50 A (RMO50TW). They are fitted in a portable and lightweight metal housing.All transformer ohmmeters from RMO-TW series generate a true DC ripple-free current with automatically regulated measurement and discharging circuit. The injection of current and discharge of energy from the test object are automatically regulated.Three independent channels enable testing of three windings in series. Consequently, this enables measurements of winding resistance in every tap position of an on-load tap changer without discharging between the tests.DV-Win software enables control and observation of the test process, as well as saving and analyzing the results on a PC. It provides a test report, arranged in a selectable form as an Excel spreadsheet, PDF, Word, or ASCII format. Additionally, DV-Win measures and calculates the OLTC transition time, the ripple and the winding resistance for each tap changing operation. The software can also perform the calculations necessary for the “Heat Run” test. Finally, a user can export all results in the form of a report.
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Product
Three-Phase Transformer Winding Resistance Meters
TWA Advanced Series
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TWA Advanced series is the latest DV Power solution for three-phase transformer winding resistance measurement and tap changer analysis. They are capable of testing six transformer windings with a single cable connection, as well as three-phase automatic transformer demagnetization. It has the option of the automated test mode, where the instrument operates the tap changer without operator input (minimizing the risk of human error) and records winding resistance results based on pre-selected stabilization criteria.The unique DVtest method of tap changer analysis enables checking the moving contacts of on-load tap changers during the transition, measuring the transition time, detecting open circuits, and many other types of faults. It is performed with 0.1 ms sampling rate, together with the measurement of tap changer motor current which detects motor and mechanical issues. A special proprietary algorithm is used for testing tap changers connected through a built-in series (booster) transformer. The DVtest can be performed either on one phase or simultaneously on three phases. It can also be performed together with the winding resistance test in all tap positions.A unique advantage of TWA Advanced instruments is the capability of simultaneously testing the winding resistance of all three phases of a three-phase transformer connected in a YN configuration. This can significantly speed up the testing– for example, it enables the operator to perform 33 measurements instead of 99 on a tap changer with 33 tap positions.TWA500 is equipped with a large 10.1” graphical touch-screen display, while TWA400 has a 7” graphical touch-screen display. Besides making the interface much more user-friendly compared to older winding ohmmeters, it also enables certain test options that were previously available only with DV-Win software. The most important among them are DVtest, tap changer motor current measurement, “Heat Run” test, test templates, and automatic test mode.
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Product
Winding Resistance Tester
JYR-50C/40C/20C
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1. With demagnetization function.2. Testing range reach to 20k3. Also apply to testing tranformer with high winding resistance.
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Product
Single-Phase Transformer Winding Resistance Meters
RMO-TT Series
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RMO-TT series is perfect for measuring winding resistance of inductive objects such as power and distribution transformers or autotransformers. Additionally, every transformer resistance meter from RMO-TT series can analyze:tap changers,generators,electrical motors,high-current busbar joints,cable splices,and welding joints.Transformer demagnetization can also be performed with all RMO-TT instruments.The series is consisted of 3 models, with maximal test current from 40 A (RMO40TT) to 100 A (RMO100TT). RMO100TT is the only portable transformer resistance meter in the market with 100 A DC output current.The three independent channels enable testing of three windings in series. Consequently, a user can measure winding resistance in every tap position of an on-load tap changer without discharging between the tests.In addition to winding resistance measurement, a user can perform a detailed on-load tap changer analysis by analyzing recorded graphs (10 kHz sampling rate) and by measuring vibrations on an external tap changer tank.All RMO-TT instruments have a built-in tap changer control unit. Because of this, it is possible to remotely control on-load tap changer (OLTC) directly from the device. Also, a user can program DV-Win software to do everything automatically – running winding resistance tests and changing OLTC tap positions.The DV-Win software also enables control and observation of the test process, as well as saving and analyzing the results on a PC. It provides a test report, arranged in a selectable form as an Excel spreadsheet, PDF, Word, or ASCII format. Additionally, DV-Win measures and calculates the OLTC transition time, the ripple and the winding resistance for each tap changing operation. The software can also perform the calculations necessary for the “Heat Run” test.All results can be exported in the report format.
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Product
Transformer Winding Resistance Meters
RMO TD Series
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The RMO-TD Series On-Load Tap & Winding Resistance Analyzer is designed for the measurement of winding resistance of inductive elements, and for tap changer analysis. The RMO-TD series is based on the latest technology, using the most advanced switching technology available today. The RMO-TD series is accurate (0.1%), powerful (up to 60 A) and lightweight. It generates true, ripple-free DC current with automatic metering control and a discharge circuit.
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Product
Portable Winding Resistance Tester
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1. Handheld winding resistance meter2. Conversion function for standard temperature resistance.3. 500 test data can be saved and download by flash disk.4. Temperature testing function.
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Product
Winding Resistance Meter 50Amps, 3 Channels Rack
WR50-13R
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Raytech Digital Winding Resistance meter WR50-13R is the enhanced version winding resistance system with a most advanced demagnetizing circuit as a rack version. It is designed for high degree of accuracy for the measurement of very low resistance of any inductive loads.
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Product
Automatic Transformer Winding Resistance Meter 25A
ATWRM-25
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The Eltel ATWRM-25 with its latest " State of the art" design is an unmatched high performance of winding resistance measurement providing fast measurements, wide continuous test current ranges, high accuracy and is ideally suited for low resistance measurements both in the laboratory and in HV switchyards.
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Product
Winding Resistance Meter
TRM 25
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SCOPE introduces 25 A state of the art precision winding resistance meter, specially designed for field testing as well as factory testing of large transformers up to 500 MVA. Winding resistance value of transformer and rotating machine are directly displayed on 5.7” TFT display. TRM 25 is designed to work in live EHV switchyard conditions, ensuring operator’s safety and repeatability of results. Maintenance time saving is ensured by one time connection to transformer with simultaneous resistance measurement of three / six windings, measurement of resistances of all taps with automated tap change and demagnetization facility. The meter is protected against the back-EMF offered by large inductive windings.
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Product
Winding Resistance Test
20A DC booster
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The 20A DC STCS booster allows to perform resistance tests on a PT with a current up to 20 A DC. The option is used together with STS 5000 and STS 4000 and must be connected to STCS module.
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Product
Handheld Turns Ratio & Winding Resistance Tester
TWR-H Series
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Handheld TWR-H device is DV Power single-phase instrument designed for measuring transformer winding resistance and turns ratio.The instrument has two output DC sources for measuring transformer winding resistance. The first DC source can output up to 2 A DC and is used for injecting current to the transformer’s high voltage winding. The second DC source can output up to 10 A DC and is used for testing the transformer’s low voltage winding. This is especially useful when measuring winding resistance of distribution transformers. These transformers have large turns ratio and therefore a big difference between resistances of high voltage and low voltage windings. Upon the winding resistance test, it is also possible to demagnetize the transformer core. The demagnetization process is completely automatic and safe.Together with the turns ratio, the instrument also measures excitation current and phase shift. This enables detecting transformer core or winding turns failures which cannot be spotted by measuring turns ratio only. The instrument can output test voltage up to 40 V AC for this test, but it can also output a very low test voltage of 1 V AC which is necessary for turns ratio verification of the majority of current transformers.TWR-H is powered by an internal Li-Ion battery. Up to 100 tests can be performed with a fully charged battery.
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Product
Current Transformer Tester
HTCT-300
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Full-featured, can not only satisfy various CT (eg: protection, measurement and TP category) but also PT type electromagnetic unit for its excitation characteristics (ie voltage current characteristics), ratio, polarity, secondary winding resistance, secondary load, ratio deviation, angle deviation and other test requirements.
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Product
Electrical Measurement Equipment
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Portable equipment designed for maintenance and commissioning of substations and power plants. Low resistance micro ohmmeters, digital timers, windings resistance, contact resistance, circuit breaker timing and motion, phase angle and frequency measurements.
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Product
STDETransformer Demagnetizer
STDE
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This option allows neutralizing the residual magnetization of the power transformer core after the winding resistance test. The principle of the option is to apply a constant current of alternate polarities to the transformer winding, as per the IEEE 0062 1995 standard.
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Product
Switch Module
STCS
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The external module STCS allows performing automatically the following PT tests: ratio per tap; winding resistance; OLTC dynamic test. The connection to the transformer under test, to STS and to the measurement taps is performed just once; then, all transformer tests are performed without interruptions.
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Product
Winding Resistance Tester with Demagnetisation Circuit
WRT-10D
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The WRT-10D is a high performance winding resistance tester designed for power transformer and large motor applications. It is equipped with a bright LCD display, a rugged high quality cable set, a built-in printer, a full QWERTY keypad and a demagnetisation circuit.
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Product
Winding Resistance Meter 100Amps, 3 Channels
WR100-13R
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Raytech Digital Winding Resistance meter WR100-13R is the enhanced version winding resistance system with a most advanced demagnetizing circuit as a rack version. It is designed for high degree of accuracy for the measurement of very low resistance of any inductive loads.
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Product
Winding Resistance Tester
JYR20S/10S
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DC winding resistance testing is regarded as another essential routine screening tool. It indicates problems such as loose, defective or incorrect connections, which cause enough transformer failures each year to be regarded as a failure category of its own.
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Product
Primary Current Injection Test Set
T 2000
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T 2000 is a portable current transformer test set which allows to perform many different measurements such as saturation, ratio and polarity tests and CT winding resistance test. Substation maintenance and commissioning test equipment, T 2000 is extremely appreciated by electrical engineers for its high accuracy and portability.
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Product
DIGITAL TURNS TESTER AND DIGITAL LCRTZ METER
TURNS-LCRTZ
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Digital TURNS TESTER with LCR for Counting / Measuring Number of Turns for Toroidal Coils , Current Sensor , Current Transformer , Round Core Coils. Can measure, Turns along with Winding Polarity , DC Resistance , Inductance (L), Capacitance (C), DC Resistance, Rac, Q, D, ESR and Tan.Toroidal Turns Platforms :TTPT100 : 5 T - 1000 T , TTPT1000 : 500T-10000 T The Platform has 2 connections for the coil and 2 for the probe wire. Measurement principle is based on dynamic comparison of the voltage across one turn and the coil. You will be able to get the polarity or winding indication with respect to the one turn reference.Accuracy : + 0.2% + 0.5T for high and medium permeability cores at suitable test frequency. Internal Diameter must be able to pass a wire as thin as 0.2 mm. External Diameter as high as 200 mm.Test Frequency Selectable in Step : 50 Hz, 100 Hz , 500 Hz, 1 KHz, 5 KHz, 10 KHz. Test Voltage adjustable : 100mV to 1V in steps of 50mV.
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Product
Automatic Transformer Observation System
ATOS
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Raytech – The World leader in design and manufacturing of high-quality precision measuring instruments and systems, offering flexibility and versatility. Our modular Automatic Transformer Observation System (ATOS) allow you to create a unique and custom solution for any application. ATOS is designed to drastically reduce measuring time and increase test performance, without losing accuracy compared to individual test instruments. With the choice of up to three Multiplexers (primary, secondary, and tertiary), three Winding Resistance Meters, each with three maximum current range options (up to 15A, 50A, or 100A), Turns Ratio, and Integrated power security and safety panel (ISU R), Raytech can create a system with your needs and budget in mind.
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Product
Microohmmeter
MMR-6700
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The MMR-6700 digital meter is designed for measuring low resistances with a stabilised current of up to 200 A. The use of test clamps enables the safe measurement of breakers (high-, medium- and lowvoltage), isolators and other components earthed on both sides. The MMR-6700 series meters are equipped with a unique module in their class that measures inductive components which have a current of up to 10 A, enabling the winding resistance of motors, transformers and other inductive components to be measured. Another useful function is the temperature measurement and the automatic compensation of results with relation to the measured temperature or temperature set by the user. The system is completed with a recorder function. Special measuring algorithms and additional functions allow an appropriate measuring method to be chosen depending on the measured component and measurement conditions, thus, widening the application areas of the meter. The state-of-the-art user interface, various communication interfaces, wireless communication and communication with the computer, printer, 2D code reader are integrals features which enable full, comfortable and intuitive management of not only measurements and their results but also ID data of measured components.
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Product
Automatic Three Phase Transformer Ratio Meter
ATRM PLUS
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*Fully Automatic measurement.*Wide selection of Excitation Voltages of 10V, 40V, 100V, 230V & 250V from front panel.*4V Excitation voltage provided for CT measurements*Ratio range of up to 5000; direct display of measured ratio.*No conversions required.*Automatic Jumper selecting as per the vector*Diagram of Transformer.*Automatic testing of all 3 phases in 3 phase transformers*Without manual intervention.*Displays % deviation from a nominal ratio.*External storage facility using pen drive.*Internal storage up to 10000 readings.*Touch screen 7” Color TFT display with backlighting with*Resolution of 800 X 480.*Tap changer facility.*Computer interface using RS-232 or USB.*Windows Interface software provided for data transfer.*USB printer interface.*Four terminal measurements to reduce errors due to*Winding and lead resistance.*Auto print and storage facility.Fast measurements.





























