Power analyser accuracy can save thousands of euros

“When every kilowatt lost beyond specified limits can cost thousands of dollars in fines, it is vital to have confidence in the measurement of power losses, particularly under no-load conditions and at power factors as low as 0.01”, says Terry Marrinan, Vice-President, T&M Business Unit, Yokogawa T&M Europe and Asia Pacific: “To address this challenge, the WT3000E Transformer Version is calibrated at power factors of 1, 0.5, 0.05, 0.01 and 0.001 to enable engineers in transformer testing to accurately capture and measure any drift outside the limits described in the IEC60076-8 Standard.”

As a result, the power analyser further exceeds the requirements for accuracy in the standard at a power factor of 0.01 and is now also specified down to a power factor of 0.001.

It maintains high levels of accuracy over a wide range of power factors. The ±0.01% total power accuracy figure applies at a power factor of 1 and a frequency of 44-66Hz. The corresponding value for power factors in the range 0.02 to 0.01 is 0.5%, and for power factors in the range 0.01 to 0.001 it is 7%.

Every instrument is supplied with a calibration certificate from Yokogawa’s ISO 17025 accredited calibration laboratory in the Netherlands.

Like other models in the Yokogawa WT3000E Series, the WT3000E Transformer Version features an intuitive 8.4in. high-resolution TFTdisplay which can be used to compare up to four waveforms in split-screen mode with clear safety & overload indicators.

The analyser features measurement ranges that are optimised to match the potential and current parameter values used in the transformer industry. It also enables users to measure harmonics and distortions while simultaneously measuring power.

It can analyse and display a waveform’s individual frequency components, as well as checking signal components other than the integer multiples of the fundamental wave.

User-defined triggers can be set to capture readings that satisfy or fall outside user-defined conditions. Users can also define and use up to 20 custom computations.

Delta computation, provided as a standard function, allows calculation of individual phase voltages from line voltages measured in a 3-phase/3-wire system.

Another standard feature is cycle-by-cycle trend analysis, which allows users to list voltage, current, active power and other parameters for each cycle. Direction sensitive energy measurements are also enabled, with the facility for the integration of instantaneous values for positive and negative readings.

The instrument is supplied with free application software which is used to read numeric, waveform, and harmonic data through a communications interface such as GP-IB, USB or Ethernet.