Category: Transformer Test Equipment

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Transformer Test Equipment

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Winding Resistance and Turns Ratio Meter | MRC7300A

Winding Resistance & Turns Ratio Meter - Overview

This instrument can precisely and safely determine winding resistances, transformation ratios, and phase angles of distribution transformers up to 100MVA and more. Further, it is possible to automatically move the tap charger of the H.V. winding to the next tap and perform cool-down measurements in temperature rise tests to calculate the resistance in the case of a load disconnection. The Winding Resistance & Turns Ratio Meter MRC7300A can be used by transformer manufacturers, electricity supply companies, and repair companies which carry out on-site measurements under unfavourable conditions. Resistance values ranging from 50 µΩ to 500 µΩ can easily be measured and logged with the internal measuring current of a maximum of 15 A up to a power of Approx. 100 MVA and more. To allow a comparison of the measured values to previous measurements, a conversion of the temperature of the test object is provided to compare measurements of a detached transformer carried out in winter and measurements carried out in other seasons. The measuring range is between 0.9:1 and 2500:1 in the case of the transformation ratio; the resolution of the angle measurement is 0.1 degrees. The logging of all measured values is performed by a separate printer, computer, or via the internal memory. The magnetic loading of the transformer is performed quickly to a relatively high rating voltage (50V). The unloading of the core is very safe, as the energy is dissipated in the MRC7300A by a ballast resistor and varistors except for a negligible rest.

Winding Resistance and Turns Ratio Meter- Features
- Automatic measurement without any manual interaction
- Resistance measurement with high accuracy and up to 15 A current
- Ratio measurement including phase angle and magnetizing current
- Dual measuring method for faster measurements
- Automatic vector group detection
- Tap changer control measures all transformers tap automatically
- Heat-up measurement including an algorithm for resistance at t=0
- Temperature measurement and compensation to 20 °C for Cu or AI
- USB port to get full external control over the instrument
- Thermo printer
Datasheet

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Battery Operated Transformer Ratio Meter | PWR1-3B

Battery Operated Transformer Ratio Meter - Overview

The Battery-Operated Transformer Ratio Meter PWR1-3B is a battery-powered instrument that can also be driven by normal line voltage. It is designed to measure transformation ratio, phase error, and magnetizing current of power and distribution transformers for all three-phases simultaneously. Voltage and current transformers are single-phase, power transformers normally are three-phase. Due to the bad quality of industrial lines (phase jitter and shifting, voltage differences between the three phases) all measurements normally are done in single-phase, even on three-phase ratiometers. The design of the PWR1-3B contains an internal sinus power oscillator which delivers the necessary exciting voltage with very low distortion and stable voltage not found in industrial lines. This allows for very stable and precise single and three-phase measurements. The Battery-Operated Transformer Ratio Meter uses a large LCD display with a backlight to present the values of ratio and phase difference of “H.V. Winding” to “L.V. Winding”, and the excitation voltage and the magnetizing current of the high voltage winding. Additionally, the instrument performs self-calibration and has different warning messages before each measurement in case of reversed connections and other failures.

Battery Operated Transformer Ratio Meter - Features
- Ratio range from 8 to 2,500
- Fully automated measurement
- Measuring voltage 10 V / 100 V selectable
- The display shows:
  - Ratio
  - Phase-angle
  - Excitation voltage
  - Magnetizing current
- Easy to read large LC display for all three-phases with backlight
- Built-in printer (optional)
- A robust mobile case for field use
Datasheet

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Winding Resistance Transformer and Motor Meter | MR 8050

Winding Resistance Transformer and Motor Meter - Overview

The MR8050 can measure highly inductive windings of transformers, motors, and reactors with a range of 100µΩ with 0.01µΩ resolution up to 6kΩ. The performance of the measured objects can be up to 800MVA or even more. The magnetic loading of a transformer is performed quickly using a high loading voltage (60V), this is important for time-critical measurements (cooling curves). The unloading of the transformer's core is fast and safe, as the energy is dissipated in the MR8050. The temperature of the measured objects can be pre-set or measured using a PT100 temperature sensor and the resistance is calculated for 20°C using the temperature coefficient for copper or aluminum heat-loss measurements. The resistance at t=0 (disconnection of load) is shown as a result of the internal regression algorithm. Two windings (mostly HV and LV) can be measured simultaneously in the DUAL measuring method. The MR 8050 also features automatic tap-changer control for measuring different taps without interrupting the measuring current.

Winding Resistance Transformer and Motor Meter - Features
- 2 channels for DUAL measurements
- Measuring time short due to very fast uploading
- Discharge time 1/10 of uploading time
- Heat - loss measurements with regression algorithm
- LCD-Display with 240 x 128 pixels with backlight
- USB standard and RS232C 9600 baud
- PT100 connector for PT100 temperature probe
- Tap changer connector for automatic tap control
- Warning system connector for a separate warning light
- Internal test storage for up to 1000 measurements
- Inputs full protected against static and transient voltages
- Wide current ranges from 50mA to 60A
Datasheet

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1
Advanced Three-Phase Winding Resistance Meters | TWA Std Series

Advanced Three-Phase Winding Resistance Meters - Overview

The TWA Standard series has LCD displays. Both models are capable of testing six transformer windings with a one-time cable connection, as well as three-phase automatic transformer demagnetisation. The stored magnetic energy is safely and 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 stabilisation criteria. Both models can output test currents from 5 mA to 30 A DC for the purpose of winding resistance measurement. TWA40D has a special test mode for checking the synchronisation 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. 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 a 0.1 ms sampling rate, simultaneously with the measurement of the tap changer motor current, which helps with the detection of motor and mechanical issues. An 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.

Advanced Three-Phase Winding Resistance Meters - Features
- Resistance measurement of all tap positions in all six windings performed in a single test
- True three-phase on-load tap changer (OLTC) DVtest (dynamic resistance measurement)
- Quick measurement, single-step cable setup
- Rapid automatic demagnetisation
- Fully automated test mode
- Built-in tap changer control unit
- Temperature measurement channel
https://www.youtube.com/watch?v=aUJ0BNudhI4

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1
Three Phase Transformer Measuring Bridge | MLS 7100

Three-Phase Transformer Measuring Bridge - Overview

The MLS 7100 was particularly designed to simplify the determination of transformer core and copper losses, which is an ideal choice when working on site. The measuring bridge features open-circuit as well as short-circuit measuring. Many transformers can be directly connected to the MLS 7100 without needing further transducers. Core losses are an important transformer quantity in electrical efficiency, operating expenses, and the overall transformer value.

Steel losses are typically determined using open-circuit measurement, as a relatively small magnetising current is flowing. Using this technique, the copper losses are minimized due to the square correlation of power and current. Copper losses are determined using short circuit measurement, as the magnetising modulation of the steel core should be minimized. In addition, the short circuit voltage is determined this way, which is also an important quantity.

Three Phase Transformer Measuring Bridge - Features
- Open circuit measurements
- Short circuit measurements
- Free selectable voltage and current dividers
- 1000 kV with transducer
- 1000 kA with transducer
- 550 V (chained) 6 A directly connectable
- Measures and displays:
  - Voltages
  - Currents
  - Power
  - Short Circuit Values
  - Frequency
- Centronics printer port
- RS232C port for external control
Datasheet

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Three-Phase Transformer Turns Ratio Tester | PWR3A

Three-Phase Transformer Turns Ratio Tester - Overview

The great advantage of the Three-Phase Transformer Tester PWR3A is its simple set-up. You simply type in the vector group with the keys to set up, connect the transformer to the device, and release the measurement. All three phases are measured consecutively. All connecting and short-circuited procedures at the primary and secondary voltage sides are performed automatically before each measurement. It is also possible to measure just one phase. An adjustable set value allows an error or deviation of the measured transformation ratio to be displayed. Automatic control of the tap changer is provided. All phases and taps are measured consecutively, and the results are stored inside the instrument and transferred to a PC. The transformer-specific data can be easily programmed via a connected PC but it is also possible via the internal keyboard. The PWR3A is connected to the H.V. and L.V. sides via four connections each. It also powers the test object at a selected voltage, supplied by an internal isolating transformer. An external excitation using different voltages and frequencies is also possible.

Three-Phase Transformer Turns Ratio Tester - Features

• Ratio range from 0.75 to 20,000 (higher ratios with CVT-Ext.)
• Fully automated measurement
• Features market unique Vector Group Detection
• Measuring voltage from 8 V to 230 V
• Measuring voltage up to 5 kV by CVT-Extension: PWR3A-CVT
• Using 3-phase voltage for phase angles other than 0°/180°
• Easy to handle tap changer automatic
• Internal memory stores all dates (Reading with PWR3A-XFER)
• LC display (256 x 128 pixel) with backlight
• Easy input of vector group and measuring conditions
• USB/RS232C port to get full instrument control
• Centronics printer port or built in printer (optional)
• Robust mobile case for field use
• Factory Certificate

Datasheet

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1
Dielectric Oil Breakdown Voltage Flash Point Tester | PORTATEST A-2

Oil Dielectric Breakdown Voltage Tester - Overview

The PORTATEST A-2 Oil tester is a fully automatic tester for the determination of the dielectric breakdown voltage of the insulating liquid. Otherwise known as a flashpoint tester. It has been designed for laboratory use as well as field use for servicing and commissioning. The PORTATEST A-2 is very comfortable and easy to use. The requested testing standard may be selected via the menu. The corresponding electrode type as well as the electrode spacing will be displayed for confirmation before starting the test. After placing the test vessel with the oil sample into the test chamber, the protection lid needs to be closed. For maximum operator security, the protection lid is equipped with a security interlock key switching off the HV when opened during testing. When starting the test, sample temperature as well as a customer-specific sample number may be entered and will then be integrated into the test report printout. The testing sequence according to the selected testing standard is performed fully automatically.

Oil dielectric breakdown voltage tester - Features
- Fully automatic Oil tester for laboratory and field use during service and commissioning
- Testing voltage up to 100 kV
- Pre-Programmed for common national and international testing standards
- Up to ten free programmable user testing sequences
- Short switch-off time <1ms avoiding carbonization of the sample
- Indication of individual breakdown values, average value, and standard deviation
- Graphic-Display with backlight
- Clear operator guiding via four soft keys F1 - F4
- Input dialogue for sample temperature and sample number if required
- Multi-language menu, language selected via the Setup menu
- PC-data storage via serial interface RS232
- Glass test vessel with a lid and magnetic stirrer
- Different electrodes available (mushroom, sphere, or disc)
- Electrode spacing adjustable
- Integrated printer
- Rugged aluminium housing with shielded test chamber
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Handheld Turns Ratio Tester | TRT-H

Handheld Turns Ratio Tester - Overview

The TRT-H is a battery operated, handheld, fully automatic test set designed for turns ratio, excitation current and phase shift measurements of transformers. The transformer turns ratio is determined by applying AC voltage across high-voltage winding, accurately measuring AC voltage across the corresponding unloaded transformer winding, and then displaying the ratio of these voltages. The user can enter a transformer’s nameplate voltages, so that the turns ratio deviation can be calculated. This feature eliminates any error otherwise caused by an operator’s manual calculation. It compares measured turns ratio with the nameplate ratio and prints out the % of error for each test. Applications include: Turns ratio measurement of distribution transformers; Turns ratio verification of instrument transformers; Turns ratio deviation calculation; Excitation current measurement of distribution and instrument transformers; Phase angle measurement of distribution and instrument transformers; and Polarity check of instrument transformers.

Handheld Turns Ratio Tester - Features
- Unique handheld instrument
- Extremely lightweight – only 1.4 kg / 3.1 lbs
- Measures 3 transformer parameters:
  - Turns ratio
  - Excitation current
  - Phase angle
- Single-phase test voltage up to 40 V AC
- Turns ratio accuracy up to ±0.1%
- Battery-powered
- Tests single-phase and three-phase transformers
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Handheld Turns Ratio and Winding Resistance Meter | TWR-H Series

Handheld Turns Ratio and Winding Resistance Meter - Overview

This handheld, battery-operated, fully automatic test set is designed for turns ratio, phase shift, excitation current of transformers, and winding resistance measurement of transformers and other inductive objects. It can also perform demagnetisation of transformers, motors, and generators. The device generates true DC ripple-free currents. Both the injection of the current and the discharge of energy from transformer magnetic circuit are automatically regulated.

Handheld Turns Ratio and Winding Resistance Meter - Features
- Unique handheld instrument on the market
- Performs 3 different tests: Turns ratio, Winding resistance, Demagnetisation
- Single-phase test voltage up to 40 V AC
- Two DC current sources: Test current up to 2 A DC for transformer HV side, Test current up to 10 A DC for transformer LV side
- Extremely lightweight – only 1.4 kg / 3.1 lbs
- Battery-powered
- Tests single-phase and three-phase transformers
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DO7 Plus Micro Ohmmeter

Micro Ohmmeter - DO7 plus - Overview

The DO7Plus is a 10A micro ohmmeter, suitable for applications within aerospace, utilities, cable or machine manufacturers or where a cooling curve is required to plot peak resistance. Sealed in an IP67 case, it is ruggedly constructed to ensure durability. This micro ohmmeter has a display length of 60,000 counts and auto averaging of forward and reverse measurement removes thermal emf differences. The DO7Plus micro ohmmeter has built in rechargeable batteries which will provide up to 1 hour of continuous use at 10A, and up to 20 hours at all other ranges. The data log memory using FRAM technology offers unlimited read/write cycles and over 10 years of data retention, without relying on internal batteries.

DO7 Plus Micro Ohmmeter - Features
- Backlit LCD graphic panel with programmable timer for battery conservation
- Qwerty Keyboard
- Temperature compensation via PT100
- Coefficients for Copper and Aluminum
- Display length of 60,000 counts
- Auto Averaging with a forward reverse measurement (removes thermal emf diff)
- Log Memory can be plotted to calculate peak resistance value at t=0
- Memory 1000 time stamped readings
- Software included to view data via download with USB, RS232
- Ruggedly constructed case IP 67 when lid is closed a d IP53 when lid is open.
- On-screen, real-time graphical plotting cooling curve facilities with peak resistance value calculator
- Reading rate of 2 readings per second
- Measuring ranges from 6mΩ - 6kΩ
- Resolution 100nΩ on 6mΩ range
- Single pulse measurement for fast resistance tests
- Continuous measurement current for inductive tests
- Full test lead continuity testing and diagnostic display
- Multilingual - display available in English, French, German, Spanish or Italian
https://www.youtube.com/watch?v=OqDCdP8Jodo

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