WT3000 Precision Power Analyzer

OBSOLETE – Replaced by WT5000
High-end Power Meter (up to 4 elements, Range: 2A or 30A)
Basic Power Accuracy: 0.02% of reading, DC and 0.1 Hz–1 MHz bandwidths
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WT3000 Digital Power Analyzer— Watch the WT3000 Video —


  • Basic Accuracy 0.01% of reading
  • Basic Power Accuracy 0.02% of reading
  • Motor Efficiency and Total Efficiency Measurement
  • Voltage Range: 15-1000V
  • Current Range: 0.5-30A ; 5mA – 2A
  • Frequency power range: DC, 0.1 Hz to 1 MHz – 2 ch up to 8 ch.
  • Continuous Maximum Common Mode Voltage (50/60 Hz)
  • Simultaneous Measurement with 2 Units (8 Power Input Elements)
  • 50 ms Data Storing Interval
  • Low Power Factor Error [Power factor influence when cosø=0 0.03% of S (apparent power)]
  • Sampling Seed of 200 kS/s
  • 2A or 30A current input element
  • 30MB internal storage
IIII [+] Options and Applications


  • Advanced Computation: (IEC standard testing, harmonic, FFT, FET, Waveform computation)
    • IEC61000-3-2 Harmonic Measurement,
    • IEC61000-3-3 Voltage Fluctuation/ Flicker Measurement
    • Delta Calculation, Cycle by Cycle
  • 20ch D/A output
  • Add-on Frequency Measurement
  • Motor Efficiency and Total Efficiency Measurement


  • Simultaneous measurement of voltage, current, and THD (distortion factor)
  • Measuring efficiency with high precision: simultaneous measurement of input and output
  • Measurement of Power Consumption in Mobile Phones
  • Measuring Conversion Efficiency of Power Conditioner
  • High Accuracy Measurements of Transformers


Yokogawa’s WT3000 is a precision power analyzer with a basic accuracy of ±0.02% reading, DC and 0.1 Hz-1 MHz bandwidth, and up to four input elements for single or three phase power analysis.
The WT3000 can obtain highly precise and simultaneous measurements of the power conversion efficiency of a piece of equipment and unparalleled equipment evaluation efficiency by making simultaneous power evaluations and tests easy and fast.

IIII [+] Read More

The WT3000 is the first model in the WT Series which is standard- equipped with a PC card slot (ATA flash card slot). The WT3000 is also standard-equipped with a GP-IB port. In addition, a serial (RS-232) port, Ethernet port, USB port for peripheral, and USB port for PC connections are available as options. The variety of interface choices allows customers to use the best interfaces for a wide variety of equipment, media, and network environments.

The WT3000 is the ideal measurement solution for applications such as product efficiency testing, engineering, R&D inverter work, motor drives, lighting systems and electronic ballasts, UPS systems, aircraft power systems, transformer testing and other power conversion devices.

  • Literature
  • Specifications
  • Functions
  • Optional Functions
  • Software
  • Acc.
Model: Yokogawa WT3000 Power Analyzer
  760301 760302 760303 760304
Number of elements 1 input 2 input 3 input 4 input
  Available with 2A or 30A input elements
Basic power accuracy: 0.02% of reading +0.04% of range
DC power accuracy 0.05% of reading +0.1% of range
Power frequency range: DC, 0.1 Hz to 1 MHz
V / A frequency range: 1 MHz
Sapmpling Speed: approximately 200 kS/s
Accuracy range – V / A: 1% to 130%
Plug-in inputs Crest Factor: Maximim 300
Input type Floating input
Resistive voltage divider Direct input: Shunt input External
input: Resistive voltage divider
(for crest factor 3) 15 V, 30 V, 60 V, 100 V, 150 V, 300 V, 600 V, 1000 V
(for crest factor 6) 7.5 V, 15 V, 30 V, 50 V, 75 V, 150 V, 300 V, 500 V
Direct Input: Current
2 A input element  
(for crest factor 3) 5mA, 10mA, 20mA, 50mA, 100mA, 200mA, 500mA, 1A, 2A
(for crest factor 6) 2.5mA, 5mA, 10mA, 25mA, 50mA, 100mA, 250mA, 500mA
30 A input element  
(for crest factor 3) 500 mA, 1 A, 2 A, 5 A, 10 A, 20 A, and 30 A
(for crest factor 6) 250 mA, 500 mA,1 A, 2.5 A, 5 A, 10 A, and 15 A
External Input: Current Sensor
(for crest factor 3) 50 mV, 100 mV, 200 mV, 500 mV, 1 V, 2 V, 5 V, and 10 V
(for crest factor 6) 25 mV, 50 mV, 100 mV, 250 mV, 500 mV, 1 V, 2.5 V, and 5 V
A/D converter Simultaneous voltage and current conversion and 16-bit resolution. Conversion speed (sampling rate): Approximately 5 μs
Data Update  
Rate: 50 m, 100 m, 200 m, 500 m, 1, 2, 5, 10, 20 [sec]
Measurement Parameters
Main: Voltage, current, active power, reactive power, apparent power, power factor, phase angle, frequency, peak voltage, peak current,crest factor, integration (Wh, Ah, varh, Vah)
  MAX hold
Voltage RMS/MEAN simultaneous measurement
Average active power (user defined function)
Active power integration (WP) (Wh)
Apparent power integration (WS) (VAh)
Reactive power integration (WQ) (varh)
Motor evaluation Torque, A / B / Z phase signal inputs (/MTR),4 inputs, & motor evaluation (opt
Delta Calculation Voltage (V) difference, 3P3W ⇒ 3V3A, DELTA ⇒ STAR, STAR ⇒ DELTA
Current (A) difference, 3P3W ⇒ 3V3A, DELTA ⇒ STAR, STAR ⇒ DELTA
Power (W) DELTA ⇒ STAR
FFT Number of points 20,000 points or 200,000 points
Window functions Rectangular, Hanning, or Flattop
Measured parameters Voltage, current, active power, and reactive power of each input element.
Active power and reactive power of an Σ wiring unit.
Torque and speed signals (analog input) of motor input
Type PS (power spectrum)
Harmonic Measurement in Normal Measurement Format PLL synchronization method
Frequency range Range in which the fundamental frequency of the PLL source is 10 Hz to 2600 Hz
Measured parameters Voltage, current, active power, and reactive power of each input element.
Active power and reactive power of an Σ wiring unit.
Torque and speed signals (analog input) of motor input
Type PS (power spectrum
Window functions Rectangular
FFT data length 9000 with 32 bits processing word length
Cycle-by-cycle measurement Synch source Select an external source of U1, I1, U2, I2, U3, I3, U4, or I4
parameters are measured continuously for each cycle of the one sync source signal
No. of meas. 10-3000
Synch source frequency range 1 Hz to 1000 Hz (for U and I)
0.1 Hz to 1000Hz (for external sync source)
Accuracy U, I, P: Add [(0.3+2*f) % of rdg + ((0.05+0.05*f) % of range] Add [(0.3+2*f)% of reading to accuracy
Voltage Fluctuation/Flicker Measurement Type: Normal Flicker Measurement Mode
Measurement of dmax Caused by Manual Switching Mode
Items Common to Measurement Modes
Number of measurements dc Relative steady-state voltage change
dmax Maximum relative voltage change
d(t) The time during which the relative voltage change during a voltage fluctuation period exceeds the threshold level
Pst Short-term flicker value
Plt Long-term flicker value
Synch source frequency range

1 Hz to 1000 Hz (for U and I) 0.1 Hz to 1000Hz

Accuracy U, I, P: Add [(0.3+2*f) % of rdg + ((0.05+0.05*f) % of range] Add [(0.3+2*f)% of reading to accuracy
Display: 6.4-inch color TFT liquid crystal display (640 x 480 px)
Waveform Display
Numerical: Select 4, 8, 16, all, single list, or dual list, display res: 600000
Bar: Displays the size of each harmonic in a bar graph
Vector: phase difference in the fundamental waves of voltage and current.
Simultaneous display: Two windows can be selected (from numerical display, waveform display, bar graph display, or trend display) and displayed in the upper and lower parts of the screen
Trend display: Number of measurement channels Up to 16 parameters
Displays trends (transitions) in numerical data of the measurement functions in a sequential line graph.
Built-in Printer (/B5 Option)
Print type: Thermal line/dot matrix - 8dot/mm, 112 mm [Effective print width: 104 mm]
Power supply: 100 to 120VAC/220 to 240VAC (automatic switching) — 50/60Hz
Power consumption: Max 150 VA (when using printer)
Operating Temperature: 5 to 40°C, 20 to 85% RH
Dimensions: Approximately 426 (W) x 177 (H) x 450 (D) mm (including 253710 printer cover; does not include knobs and projections)
Weight: Approx. 15 kg (main unit with four power modules installed)

Simple and easy to use, Exceptional crisp display

The WT3000 was designed with user-friendly functions and controls in response to user requests for a simpler range setting operation and more user-friendly parameter setting display process

  • Range settings using direct key input The range indicator on the WT3000 is a seven-segment green LED, so the set range can be monitored at all times. The range can easily be switched using the up and down arrows.
  • WT3000 item pages used to set display preferences The WT3000 has nine numeric item pages for displaying measurement values. Once you set the measurement parameters you want displayed on a particular item page, you can easily switch between entire groups of displayed parameters.

Wide range of standard functions

— The WT3000 is equipped with an array of sophisticated functions for precise and simultaneous measurements of the power conversion efficiency of instrument, as well as, equipment evaluation efficiency by making simultaneous power evaluations and tests easier and faster.

  • Display formats The WT3000 lets you display input signal waveforms in addition to numerical value data. You don’t need to connect a special waveform analyzer to check signal waveforms. The optional advanced computation function lets you display vectors and bar graphs for enhanced visual presentation
  • 50ms data updating intervals Fast updating allows you to precisely capture rapidly changing transient states. The WT3000 switches between two different calculation systems depending on the data updating interval
  • Compensation functions This function compensates for the loss caused by the wiring of each element. The WT3000 has the following three types of correction functions to measure the power and efficiency
  • Wiring Compensation This function compensates for the loss caused by the wiring of each element
  • Efficiency Compensation The power measurement on the secondary side of a power transformer such as an inverter includes loss caused by the measurement instrument. This loss appears as error in the efficiency computation. This function compensates for this loss.
  • Compensation for the Two-Wattmeter Method* In the two-power wattmeter method, an error results when current flows through the neutral line. This function computes the currents that flows through the neutral line for measurements using the two-wattmeter method with a three phase, three wire (3V3A) system and adds the compensation value to the measured power. *Requires the delta computation option (/DT).
  • Store Function Voltage, current, power, and other measured data can be stored to the unit’s approximately thirty megabytes of internal memory. These data can be saved in binary or ASCII format on a PC card or USB memory
  • User-defined function As many as twenty user-defined formulas can be set in the WT3000. These equations can be used to calculate various parameters, such as mean active power
  • A Variety of integration functions
    • Active power, current, apparent power, reactive power In addition to the active power integration function (WP) and current integrationfunction (q) included in earlier models, the WT3000 also has a new apparent power integration function (WS) and reactive power integration function (WQ).
    • A wide effective input range for high-precision integration The WT3000 has a wide effective input range, from 1% to 130% of the measurement range.
    • Average active power (using user-defined settings) Average active power can be calculated over an integration interval. This feature is useful for evaluating the power consumed by intermittent-control instruments in which the power value fluctuates

Motor Version (-MV option)

— Motor evaluation: Rotating speed, Torque, SyncSp, Slip[%] and Motor output Pm

  • Calculation of motor and total efficiency In addition to the functions of the standard version, the new models offer powerful motor/inverter evaluation functions
  • Voltage, current, and power measurement with torque and speed input Measures torque meter and speed sensor output (analog or pulse output), and allows calculation of torque, revolution speed, mechanical power, synchronous speed, slip, motor efficiency, and total efficiency in a single unit.

Advanced Computation (/G6)

The advanced calculation function (/G6 option) meets these measuring needs with advanced, powerful features for making power analysis measurements more efficient

  • Harmonic Measurement in Normal Measurement Mode
    Same as Harmonic Measurement Function /G5 You can measure harmonic data while in normal measurement mode. This is effective for observing values from normal measurements and harmonic data at the same time.
  • Wide Bandwidth Harmonic Measurement This dedicated harmonic measurement function is distinct from the harmonic measurements that can be taken in normal measurement mode. The function is useful for ascertaining the distortion factor and harmonic components in strain measurements of fundamental frequencies from 0.1 Hz to 2.6 kHz. It allows wide bandwidth measurements of signals that include high frequency waves, such as from power supplies and acceleration of motor revolution
  • Waveform Computation You can perform computations on measured waveforms, and display power (instantaneous voltage × instantaneous current) and other waveforms on screen
  • FFT You can analyze and display a waveform’s individual frequency components. You can also check signal components other than the integer multiples of the fundamental wave
  • Waveform Sampling Data Saving You can save sampling data of input waveforms, waveform computations, and FFT computations. The data is available for any kind of computation by PC software.
  • IEC harmonic measurement mode (/G6)
    Performing IEC harmonic standards tests Harmonic measurement software can be used in this dedicated mode for harmonic measurement that supports international standards. This allows confirmation of whether or not home electronics, office automation equipment, or other devices conform with harmonic standards.
  • Voltage Fluctuation and Flicker Measurement (/FL) Enables voltage fluctuation/flicker measurement conforming to IEC61000-3-3. The following values related to voltage fluctuation that are stipulated by the IEC61000- 3-3 standard can be calculated from the measured data: dc (relative steady-state voltage change), dmax (maximum relative voltage change), dt (relative voltage change time), short-term flicker value Pst, long-term flicker value Plt, instantaneous flicker sensation, and others. In this mode, you can judge whether voltage fluctuations in the item under test relative to a specified minimum value are within the standard.
  • Delta Calculation (/DT)
    Checking phase voltage when you measure line voltage This function allows you to calculate individual phase voltages from the line voltage measured in a three-phase, three-wire (3V3A) system. R-S line voltage can be calculated in systems measured from a three-phase, three-wire method (using two elements). This is useful when you want to determine the phase voltage in motors and other items under test with no neutral lines.
  • Cycle by Cycle Measurement (/CC)
    Capturing cycle-by-cycle fluctuations The function takes measurements of parameters such as voltage, current, and active power for each cycle, then lists the data on screen in a time series. Input frequencies from 0.1 Hz to 1000 Hz can be measured. Up to 3000 data can be saved in CSV format. Also, with the WTViewer software (model 760122, sold separately), data can be displayed in graphs by cycle.
  • Added Frequency Measurement (/FQ)
    Checking the frequencies of all inputs In addition to the standard two channels of frequency measurement, a six-channel frequency measurement option is also available. This option provides frequency measurement of voltage and current on all eight channels (with input elements 1 through 4 installed). This is necessary when you want to measure voltage and current frequency from the instrument’s I/O as well as voltage and current frequencies of multiple items under test at the same time
  • D/A Output (/DA)
    • 20 Channels Measured values and calculated value by user-defined function can be output as ± 5V FS DC voltages from the D/A output connector on the rear panel.
    • D/A zoom This function allows the any input signal range to be scaled to between -5V and 5V* in the D/A output as Upper and Lower ranges. This makes it possible to enlarge input signal fluctuations for observation using a recorder or loggers

WTViewer for WT3000 Series

The measurement procedures and settings for harmonic/flicker standards testing have been precisely defined. Engineers must also stay current with the specialized knowledge and up-to-date information required to periodically review the contents of the standards and perform the standards conformance tests. The model 761922 Harmonic/Flicker Measurement Software enables engineers without specialized knowledge to perform a range of operations using the WT3000 Precision Power Analyzer including judging standards compliance and outputting test reports.

  • Harmonics EN61000-3-2 / IEC61000-3-2
    Limits for harmonic current emissions of the latest Edition
    (Equipment i rated current of 16 A per phase or less)
    EN61000-3-12 / IEC61000-3-12
    Limits for harmonic current emissions
    (Equipment rated current is of 75 A per phase or less, and more than 16 A per phase)
  • Voltage fluctuation/flicker EN61000-3-3 / IEC61000-3-3
    Limitation of voltage fluctuations and flicker
    (Equipment rated current of 16 A per phase or less, and not subject to conditional)
    EN61000-3-11 / IEC61000-3-11
    Limitation of voltage fluctuations and flicker supply systems
    (Equipment rated current of 75 A or less, and subject to conditional)
  • IEC61000-4-7 1991(window widths of 16 cycles), IEC61000-4-7 2002(Harmonic and interharmonic measurement supporting window widths of 50 Hz/60 Hz, 10/12 cycles)
  • Viewing Trends You can capture various types of data measured into your PC at 200ms fixed intervals. Thus, you can view trends graphically. This feature lets you monitor power supply voltage fluctuations, changes in current consumption and other time-based variations.
  • Harmonic Current Measurement Value List Displays harmonic measurement data as a single list.
  • Harmonic Current Bar Graph Evaluates whether harmonic data is within the standard limit value, and displays the result as a bar graph. The display of evaluation results is color-coded, in colors such as red and blue.
  • Measurement Value Judgement Graph Measures the harmonic current over the set observation time, and evaluates it in conformance with the standard. Evaluation results are displayed as PASS or FAIL
  • Waveform Observation Lets you display voltage or current signal waveforms, and measure frequencies and peak values. Moving the cursor lets you display values for the displayed waveform.
  • Automatic Report Generation You can print harmonic measurement results as value lists and graphs, and save image data. Titles and comments can be entered in reports, letting you enter information such as measurement dates/times, device names or control numbers.

Voltage Fluctuation and Flicker Measurement

  • Measured Value and Judgment for Each Observation Period
    (Normal Voltage Fluctuation and Flicker Measurement)
    • The final values of dc, dmax, and d(t) are compared with the respective limits, and the judgment (pass or fail) is displayed to the right of the final value. If a steady-state condition does not occur during the measurement period, it is considered to be a fluctuating condition. The measurement result of dc is displayed as Undef (undefined), and the judgment of dc is displayed as Error
    • The short-term flicker value, Pst, is calculated, compared to the limit, and the judgment (pass or fail) is displayed.
  • Displaying the Trend Graph You can show Trend Graph View. You can select from the following measurement functions.
  • Displaying the CPF Graph You can select the element and color to be displayed on the CPF graph.
    Up to four elements can be displayed simultaneously. You can set a separate color for each element.
  • Printing You can create reports using the data measured with the software.

System Configuration for 1Ø and 3Ø

Plug-in modules
arrow 751521 — Power Measurement Module — With Safety Terminals DC to 100 kHz (-3 dB). -600 A to 0 A to +600 A (DC,) ±(0.05% of rdg* + 40 mA)
— Single-phase
arrow 751523 — Power Measurement Module — With Safety Terminals DC to 100 kHz (-3 dB). -600 A to 0 A to +600 A (DC,) ±(0.05% of rdg* + 40 mA)
— Three-phase U, V, Three-phase U, W, Three-phase U, V,Three-phase U, V
BNC Cables
366924 — BNC cable BNC–BNC, 1 m — Qty 1 BNC cable BNC–BNC, 1 meter
366925 —BNC cable BNC–BNC, 2 m — Qty 1 BNC cable BNC–BNC, 2 meters
Adapter Sets
758917 —Measurement lead — Qty 1 75 cm, two leads (red and black) in a set
758921 —(Fork terminal adapter set) — Qty 1 4 mm fork terminal, banana terminal conversion, red and black (one each)
758922 — Alligator clip adapter (rated for 300 V) — Qty 1 Banana–alligator conversion, two in a set
758923 — Safety terminal adapter — Qty 1 (spring-hold type) Two adapters to a set.
758924— Conversion adapter — Qty 1 BNC-banana-jack(female) adapter
758931 — Safety terminal adapter — Qty 1 (screw-fastened type) Two adapters to a set. 1.5 mm hex Wrench is attached
701959 — Safety mini-clip — Qty 1 Hook type. Two in a set
Clamp on Probe / Current transducer
751552 — Clamp-on probe — Qty 1 30 Hz to 5 kHz, 1400Apk (1000Arms)
751574 —Current transducer — Qty 1 DC to 100 kHz (-3dB), 600Apk
arrow 760122 —WTViewer— For WT3000 Software
arrow 7601922 —Harmonic/Voltage fluctuation/Flicker Measurement Software— For WT3000 Standard-compliant measurement - (IEC 6000-3-2)(IEC 6000-3-12)(IEC 6000-3-3)
B9316FX — Printer roll pager — Qty 1 Thermal paper, 10 meters (1 roll)
B9284LK —External sensor cable — Qty 1 Current sensor input connector. Length 0.5m
arrow 701960 — Compact Instrument Cart — Qty 1 Compact Cart
arrow 701961 — Deluxe Instrument Cart — Qty 1 Deluxe Cart
arrow 701962 — General-purpose Instrument Cart — Qty 1 General-purpose Cart