The 2293 is an automatic winding resistance analyzer, optimized for three phase power and distribution transformer measurements. It uniquely combines winding resistance measurement, turns ratio measurement, core demagnetization, transformer type detection, magnetic balance and heat run test (temperature rise and cooling curve) in the fastest single instrument solution on the market.
A simple “one-time-connection” system drastically reduces measuring time: once connected all tests can be performed in a row without any reconnection. The built-in simultaneous winding magnetization method guarantees fast and reliable resistance measurements. Stable measurements are reached even on large power transformers with delta windings on the low voltage side. A progressive method for measuring transformer turns ratio guarantees results closer to the nominal ratio even in large power transformers with tertiary windings.
The demagnetization function eliminates the magnetic remanence, which can cause faulty measurements, high inrush currents and incorrect operation of protective relays.
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WA 2293 Winding Resistance Analyzer Features
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WA 2293 Winding Analyzer Measurement Applications
Winding Resistance (Standard)
The simultaneous winding magnetization method (patented) together with the integrated 100 VDC power-supply guarantees fast and reliable winding resistance measurements. Independent currents can be selected for each winding, which guarantees reliable results even in transformers with large differences between windings.
Demagnetization Function (Standard)
The 2293 includes a fully automatic demagnetization feature which eliminates the magnetic remnant. Select the winding where demagnetization needs to be performed and press start. The unit visualizes the whole demagnetization cycle and performs the correct core demagnetization in seconds.
Transformer Turns Ratio (Optional Upgrade)
The 67 VAC power supply integrated in the 2293 allows fully automatic measurement of turns and voltage ratio, ratio deviation, phase displacement and excitation current of transformers. The specially developed algorithm included in compensated mode reduces the influence of leakage flux while using low voltage, giving results much closer to the nominal ratio.
Vector Group Detection (Optional Upgrade)
The included type detection feature works as a nameplate guesser. It helps the user to determine the correct transformer configuration by showing the possible types and eliminating the wrong vector groups during the automatic detection process.
Arbitrary Phase Shift (Optional Upgrade)
Arbitrary phase shifts or those that do not follow the 30° phase steps between the primary and secondary winding are common in special transformers like phase shifting, rectifier / furnace and traction transformers. With the optional arbitrary phase shift software key (2293/SKAP), the 2293 can measure turns and voltage ratio, phase displacement and excitation current of these special type transformers.
Dynamic Resistance (Optional Upgrade)
The main function of the on-load tap changer is to switch between transformer taps without interrupting the current. The 2293 registers the current while tap changer is operated and records the values at a defined sample rate. Discontinuities or deviations between different taps are a sign of tap changer fault. The tap changer test with the 2293 is done automatically and without reconnection. In addition, the tap changer control accessory allows a complete automatic sequence without human intervention. Calculation of the main curve parameters like time to rise, time to fall or delta, for failure detection, is automatically done.
Magnetic Balance (Optional Upgrade)
Magnetic balance test is performed to detect faults in the magnetic core. The test looks for changes in the reluctance of the magnetic circuit caused by defects in the magnetic core structure, shifting or shape changes in the windings or inter turn insulation fault. The test is performed on three phase transformers by applying a voltage on one of the phases and measures the voltage on the other two.
Short Circuit Impedance (Optional Upgrade)
The 2293 automatically performs a short circuit impedance test at reduced voltage on power and distribution transformers and calculates the three-phase equivalent short circuit impedance for comparison with previous test or with nameplate values.
Heat Run Test
Heat run test on transformers consist of two steps:
- Cooling Curve (Standard): The transformer is disconnected and winding resistance is measured.
- Heat Rise (Optional Upgrade): The transformer runs at nominal losses and transformer temperature rises.
The 2293 performs the measurements on both steps. It monitors the transformer temperature during the heat rise and measures HV and LV side resistances simultaneously during the cooling curve. pre-configured tests according to ANSI and IEC standards are included, calculating the transformer temperature in real time and informing when stabilization is reached.
Frequently Asked Questions
What makes the WA 2293 different from other transformer test systems?
The WA 2293 is an all‑in‑one transformer diagnostic platform, combining winding resistance, turns ratio, dynamic resistance, demagnetization, magnetic balance, short‑circuit impedance, and heat‑run testing in a single compact unit. It eliminates the need for multiple instruments and dramatically reduces testing time.
How does the “one‑time‑connection” system improve testing efficiency?
Once the test leads are connected, the WA 2293 can run nearly all transformer tests sequentially without any reconnection, saving hours in the field or factory. This reduces setup time, minimizes handling errors, and speeds up the entire test workflow.
Why is the WA 2293 ideal for large power transformers?
Its simultaneous winding magnetization method ensures fast, stable resistance measurements—even on large units with delta windings. The advanced turns‑ratio algorithm also delivers highly accurate results on transformers with tertiary windings or non‑standard phase shifts.
Can the WA 2293 help diagnose tap changer issues?
Absolutely. The analyzer includes dynamic resistance measurement and supports fully automated tap changer testing, providing clear insight into contact wear, transition problems, and mechanical irregularities.
Does the WA 2293 include demagnetization capability?
Yes. The built‑in core demagnetization function restores the transformer to a neutral magnetic state after testing. This helps prevent false readings, reduces inrush currents during energization, and supports safer commissioning.
How does the WA 2293 detect mechanical or magnetic core problems?
The instrument performs short‑circuit impedance testing at reduced current to identify mechanical deformation, and its automatic magnetic balance test can reveal core faults or asymmetries that may otherwise go unnoticed.
Is the WA 2293 easy to operate in the field?
Very much so. It features a 7-inch graphical touchscreen, intuitive menus, built‑in printer, USB/LAN data export, and automated test sequences. Even complex multi‑step tests can be run with minimal operator input.
What safety features are built into the system?
Operator safety is supported by an emergency stop button, an active discharge circuit, and a caution indicator that remains active even without line power. An optional interlock connector adds an extra layer of protection.
What comes standard with the WA 2293?
Each unit includes the analyzer, eight 10‑meter Kelvin probe cables, a cable bag, test certificate, and operating manual—everything needed to begin testing immediately.
What measurement principle does the WA 2293 use for winding resistance?
The analyzer uses a simultaneous winding magnetization method, which stabilizes current flow and reduces measurement time, especially on large power transformers or units with delta‑connected LV windings. This approach minimizes inductive time constants and improves repeatability.
What is the maximum DC test current and voltage for resistance measurements?
The WA 2293 provides up to 32 A DC (user‑selectable) with a maximum charging voltage of 100 V DC. This allows accurate measurement across a wide resistance range from 0.1 μΩ to 300 kΩ.
How accurate are the turns ratio and phase displacement measurements?
Turns ratio accuracy depends on the ratio range:
➡️ 0.05% for ratios 1.0–100
➡️ 0.1% for ratios 100–2,000
➡️ 1% for ratios 2,000–20,000
➡️ 5% for ratios 20,000–100,000
Phase accuracy is:
➡️ ±0.25° for ratios 1–500
➡️ ±1.00° for ratios 500–10,000
Can the WA 2293 measure transformers with non‑standard vector groups or phase shifts?
Yes. The instrument supports arbitrary phase‑shifted transformers, enabling ratio and phase measurements even when the transformer does not follow standard clock‑number configurations.
How does the WA 2293 perform dynamic resistance measurement (DRM) on tap changers?
The analyzer injects a controlled DC current and records resistance changes during tap transitions to help visualize contact timing, transition irregularities, and mechanical issues. The system also supports tap changer control signals (optional) for automated sequencing.
What demagnetization method does the instrument use?
The WA 2293 applies a controlled, decreasing DC current waveform to remove residual magnetism from the transformer core. This prevents false ratio readings, reduces energization inrush, and ensures accurate follow‑up measurements.
How does the WA 2293 detect mechanical deformation or core faults?
Two diagnostic methods are included:
➡️ Short‑circuit impedance testing at reduced current to identify mechanical displacement or winding deformation.
➡️ Magnetic balance testing to detect asymmetries or core‑related issues.
How many measurement channels are available?
The WA 2293 includes 8 measurement channels and 6 built‑in temperature channels (PT100 Class A). This supports multi‑winding transformers and heat‑run testing.