Yokogawa WT500 User Manual

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IM 760201-01E

1st Edition

Power Analyzer

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PIM 103-02E

IM 760201-01E

Thank you for purchasing the WT500 Power Analyzer. The WT500 is an instrument capable of measuring parameters such as voltage, current, and power with high precision. This user’s manual explains the features, operating procedures, and handling precautions of the WT500. To ensure correct use, please read this manual thoroughly before beginning operation. Keep this manual in a safe place for quick reference in the event that a question arises. This manual is one of two WT500 manuals. Please read both manuals.

Manual Title Manual No. Description

WT500 Power Analyzer User’s Manual

IM760201-01E This manual. Explains all WT500 features,

except for the communication features, and

the operating procedures that relate to them. WT500 Power Analyzer Communication Interface User’s Manual (CD-ROM)

IM760201-17E Explains the features related to using

communication commands to control the

WT500.

Notes

• The contents of this manual are subject to change without prior notice as a result of continuing improvements to the instrument’s performance and functionality. The appearance of the figures given in this manual may differ from the appearance of your actual display.

•

Every effort has been made in the preparation of this manual to ensure the accuracy

of its contents. However, should you have any questions or find any errors, please contact your nearest YOKOGAWA dealer.

•

Copying or reproducing all or any part of the contents of this manual without the

permission of YOKOGAWA is strictly prohibited.

•

The TCP/IP software of this product and the documents concerning it have been

developed/created by YOKOGAWA based on the BSD Networking Software, Release 1 that has been licensed from the Regents of the University of California.

Trademark Acknowledgements

• Microsoft, Internet Explorer, MS-DOS, Windows, Windows NT, and Windows Vista are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries.

•

Adobe, Acrobat, and PostScript are trademarks of Adobe Systems Incorporated.

• In this manual, the TM and ® symbols do not accompany their respective registered trademark or trademark names.

•

Other company and product names are registered trademarks or trademarks of their

respective holders.

Revisions

• 1st Edition: June 2008

IM 760201-01E

Checking the Package Contents

After receiving the product and opening the package, check the items described below. If the wrong items have been delivered, if items are missing, or if there is a problem with the appearance of the items, contact your nearest YOKOGAWA dealer.

WT500

Check that the model name and suffix code given on the name plate on the side panel are the same as those on your order.

MODEL SUFFIX

NO.

Made in Japan

MODEL SUFFIX

NO.

Made in J apan

MODEL and SUFFIX Codes

Model/Item Suffix Code Description

760201 760202 760203

Number of installed input elements: 1 Number of installed input elements: 2 Number of installed input elements: 3

Power cord -D UL, CSA standard power cord

-F VDE standard power cord

-Q BS standard power cord

-R AS standard power cord

-H GB standard power cord (CCC-compatible)

Options /C1 GP-IB interface

/C7 Ethernet interface /EX1 External sensor input (only selectable with the 760201) /EX2 External sensor input (only selectable with the 760202) /EX3 External sensor input (only selectable with the 760203) /G5 Harmonic measurement /DT Delta computation /FQ Frequency measurement add-on (enables simultaneous

measurement of all input elements)

/V1 VGA output

Suffix Code Example

On a model with three input elements installed that comes with the GP

-IB interface, external input sensor, and harmonic measurement options and a UL, CSA standard power cord, the suffix code is 760203-D/C1/EX3/G5.

NO. (Instrument number)

When contacting the dealer from which you purchased the instrument, please give them the instrument number.

iii

IM 760201-01E

Standard Accessories

The WT500 is shipped with the following accessories.

Item Model/Part No. Quantity Note

Power cord One of the following power cords is included according to the suffix code on the previous

page. A1006WD 1 UL, CSA standard power cord

Maximum rated voltage: 125 V, Maximum rated current: 7 A

A1009WD 1 VDE standard power cord

Maximum rated voltage: 250 V, Maximum rated current: 10 A

A1054WD 1 BS standard power cord

Maximum rated voltage: 250 V, Maximum rated current: 10 A

A1024WD 1 AS standard power cord

Maximum rated voltage: 250 V, Maximum rated current: 10 A

A1064WD 1 GB standard power cord (CCC-compatible)

Maximum rated voltage: 250 V, Maximum rated current: 10 A

Rubber feet A9088ZM 1 There are two feet in a pair

. Current input protective cover

B9319BX 1 Comes with two screws.

Safety terminal adapter set 758931 See the

note on the right.

Same number of sets as the number of installed input elements 760201:

One set with one hexagonal socket wrench 760202: Two sets with one hexagonal socket wrench 760203: Three sets with 1 hexagonal socket wrench

User’s Manual IM760201-01E 1 This manual Communication Interface User’s Manual

IM760201-17E 1 CD-ROM

(CD-ROM part number: B9319ZZ)

(Printed manuals can be purchased separately. Contact your nearest YOKOGAWA dealer.)

Rubber feet A9088ZM

Current input protective cover B9318BX

Safety terminal adapter set 758931

User’s Manual (this manual) IM760201-01E

Communication Interface User’s Manual IM760201-17 (CD-ROM)

A1006WD

(-D)

A1009WD

(-F)

A1024WD

(-R)

Power cord (One of the following power cords is included according to the suffix code)

A1054WD

(-Q)

A1064WD

(-H)

Checking the Package Contents

IM 760201-01E

Optional Accessories (Sold separately)

The following optional accessories are available for purchase separately.

Item Model/Part

No.

Quantity Sold

Note

Measurement lead 758917 1 Two leads in one set. Used with the

separately sold 758922 or 758929 adapter. Length: 0.75 m. Rated voltage: 1000 V.

Safety terminal adapter set 758923 1 Two pieces in one set. Rated voltage 600 V.

758931 1 Two pieces in one set. Rated voltage

1000V.

Alligator clip adapter set 758922 1 Two pieces in one set. For the 758917

measurement lead. Rated voltage: 300 V.

758929 1 Two pieces in one set. For the 758917

measurement lead. Rated voltage: 1000V.

Fork terminal adapter set 758921 1 Two pieces in one set. For the 758917

measurement lead.

Rated voltage: 1000 V. Rated current: 25 A. BNC-BNC 366924 1 42 V or less. Length: 1 m. Measurement lead 366925 1 42 V or less. Length: 2 m. External sensor cable B9284LK 1 For connecting the current sensor input

connector of the WT500.

Length: 0.5 m. Conversion adapter 758924 1 BNC-4 mm socket adapter. Rated voltage:

500 V.

Measurement lead 758917

Alligator clip adapter set 758922

Alligator clip adapter set 758929

Fork terminal adapter set 758921

Safety terminal adapter set 758923

External sensor cable B9284LK

Safety terminal adapter set 758931

BNC cable 366924 (1 m) 366925 (2 m)

Conversion adapter 758924

Checking the Package Contents

IM 760201-01E

Safety Precautions

This instrument is an IEC safety class 01 instrument (provided with a terminal for protective earth grounding). The general safety precautions described herein must be observed during all phases of operation. If the instrument is used in a manner not specified in this manual, the protection provided by the instrument may be impaired. Yokogawa Electric Corporation assumes no liability for the customer’s failure to comply with these requirements.

The following symbols are used on this instrument.

Handle with care. To protect the instrument and its users, refer to the explanation

in the User’s Manual or Service Manual.

Electric shock, danger

Alternating current

Both direct and alternating current

Power on

Power off

Power-on state

Power-off state

Grounding

IM 760201-01E

Failure to comply with the precautions below could lead to injury or death.

WARNING

Use the Correct Power Supply

Make sure that the power supply voltage matches the WT500 rated supply voltage and that it does not exceed the maximum voltage range specified for the power cord.

Use the Correct Power Cord and Plug

To prevent fire and electric shock, use the power cord supplied by YOKOGAWA. The main power plug must be plugged into an outlet with a protective earth terminal. The earth protection will be nullified if you use an ungrounded extension cord.

Connect to a Protective Earth Terminal

To prevent electric shock, be sure to connect to a protective earth terminal before turning on the power. The power cord that comes with the instrument is a threeprong cord. Connect the power cord to a properly grounded three-prong outlet.

Do Not Impair the Protective Grounding

Never cut off the internal or external protective earth wire or disconnect the wiring to the protective earth terminal. Doing so may result in electric shock or damage to the instrument.

Do Not Operate with Defective Protective Grounding or Fuses

Do not operate the instrument if its protective grounding or one of its fuses might be defective. Check the grounding and the fuses before operating the instrument.

Do Not Operate in an Explosive Atmosphere

Do not operate the instrument in the presence of flammable gasses or vapors. Doing so is extremely dangerous.

Do Not Remove Covers

Only qualified YOKOGAWA personnel should remove the instrument’s covers. The inside of the instrument is dangerous because parts of it have high voltages.

Ground the Instrument before Making External Connections

Securely connect the protective grounding before connecting to the item under measurement or to an external control unit. Before touching a circuit, turn off its power and check that it has no voltage.

Operating Environment Limitations

CAUTION

This is a class A instrument designed for an industrial environment. Operation of this equipment in a residential area can cause radio interference, in which case users will be required to correct the interference.

Safety Precautions

vii

IM 760201-01E

Waste Electrical and Electronic Equipment

Waste Electrical and Electronic Equipment (WEEE), Directive 2002/96/EC

(This directive is only valid in the EU.)

This product complies with the WEEE Directive (2002/96/EC) marking

requirement. This marking indicates that you must not discard this electrical/

electronic product in domestic household waste.

Product Category

With reference to the equipment types in the WEEE direct

ive Annex 1, this

product is classified as a “Monitoring and Control instrumentation” product.

Do not

dispose in domestic household waste. When disposing products in the EU,

contact your local Yokogawa Europe B. V. office.

viii

IM 760201-01E

Conventions Used in This Manual

Notes and Cautions

The notes and cautions in this manual are categorized using the following symbols.

Improper handling or use can lead to injury to the user or damage

to the instrument. This symbol appears on the instrument to indicate that the user must refer to the user’s manual for special instructions. The same symbol appears in the corresponding place in the user’ s manual to identify those instructions. In the manual, the symbol is used in conjunction with the word “WARNING” or “CAUTION.”

WARNING

Calls attention to actions or conditions that could cause serious or

fatal injury to the user, and precautions that can be taken to prevent such occurrences.

CAUTION

Calls attention to actions or conditions that could cause light injury

to the user, or cause damage to the instrument or user’s data, and precautions that can be taken to prevent such occurrences.

Note

Calls attention to information that is important for proper operation of

the instrument.

Symbols Used in Procedural Explanations

The procedural explanations in chapters 3 to 13 use the following symbols, characters, and words to identify their contents.

Procedure

Follow the order of the step numbers when carrying out procedures.

Procedural explanations assume that the procedures are being performed for the first time. You may not need to perform every step in a procedure when you are altering settings that have already been made before.

Explanation

Limitations and settings related to the procedure are explained here.

The feature itself is not usually explained here. For information about the features themselves, see chapter 2.

Characters and Terminology Used in Procedural Explanations

Panel Keys and Soft Keys

Bold characters in procedural explanations are used to indicate panel keys that are used in the procedure and menu items that appear on the screen.

SHIFT+Panel Key

When SHIFT+panel key appears in a procedural explanation, it means to press the shift key so that it lights, and then to press the indicated panel key. The setup menu marked in purple below the panel key that you pressed appears on the screen.

Units

k Denotes 1000. Example: 12 kg, 100 kHz

K Denotes 1024. Example: 459 KB (file size)

IM 760201-01E

Workflow

The figure below is provided to familiarize the first-time user with the workflow of WT500 operation. For a description of an item, see the relevant section or chapter. In addition to the sections and chapters that are referenced in the figure below, this manual also contains safety precautions for handling the instrument and performing wiring work. Be sure to observe the precautions.

Section 3.2

Sections 3.3 and 3.4

Section 3.8

Sections 3.9 to 3.11

Chapter 4

Sections 5.1 to 5.5 and

5.13 to 5.16 Sections 5.6 to 5.12 Section 5.17 Chapter 6

Chapter 7 Chapter 8

Install the instrument

Connect the power supply and turn the power switch on

Select the measurement method

Wire the circuit that you will measure

Set the measurement conditions

Read the precautions in sections 3.5 and 3.7 thoroughly before connecting the wires. Also, if necessary, assemble the input terminal adapter that connects to the voltage input terminal (see section 3.6) before connecting the wires.

RGB video signal (VGA) output (optional)

Send data through USB or the optional GP-IB or Ethernet interface.

Prepare for Measurement

Display Measured/Calculated Results

Measured power values

Integrated values Delta computation (optional) Harmonic measurements (optional), bar graphs, vectors Voltage/current waveforms Trends

Chapter 11

Acquire Data

Store data to internal memory Save data to USB memory Send data through the optional Ethernet interface

Communication Interface User’s Manual IM760201-17E (CD-ROM)

Section 12.1

Chapter 9

Chapter 10

IM 760201-01E

Checking the Package Contents.......................................................................................................ii

Safety Precautions ............................................................................................................................v

Waste Electrical and Electronic Equipment .................................................................................... vii

Conventions Used in This Manual ................................................................................................. viii

Workow .......................................................................................................................................... ix

Chapter 1 Component Names and Functions

1.1 Front Panel, Rear Panel, and Top Panel .......................................................................... 1-1

1.2 Setup Menu Display and Operation Keys ........................................................................ 1-3

1.3

Screen Display ................................................................................................................. 1-8

Chapter 2 Features

2.1 SystemCongurationandBlockDiagram ........................................................................ 2-1

2.2 Measurement Functions and Periods ............................................................................... 2-3

2.3

Measurement Conditions ............................................................................................... 2-10

2.4

Power Measurement ...................................................................................................... 2-16

2.5

Computation ................................................................................................................... 2-19

2.6

Integration ...................................................................................................................... 2-22

2.7

Waveform Display .......................................................................................................... 2-26

2.8

Trend, Bar Graph, and Vector Displays .......................................................................... 2-33

2.9

Saving and Loading Data, and Other Miscellaneous Functions ..................................... 2-36

Chapter 3 Before You Start Measuring

3.1 Handling Precautions ....................................................................................................... 3-1

3.2 Installing the Instrument ................................................................................................... 3-3

3.3 Connecting the Power Supply .......................................................................................... 3-5

3.4 Turning the Power Switch On and Off .............................................................................. 3-6

3.5 Precautions for Wiring the Circuit That You Will Measure ................................................ 3-8

3.6 Assembling the Adapter for the Voltage Input Terminal .................................................. 3-10

3.7

Wiring for Accurate Measurements ................................................................................ 3-12

3.8

Guide for Selecting the Method Used to Measure the Power ........................................ 3-13

3.9

Wiring the Circuit That You Will Measure for Direct Input............................................... 3-14

3.10

Wiring the Circuit That You Will Measure with a Current Sensor ................................... 3-17

3.1

1 Wiring the Circuit That You Will Measure with a VT or CT ............................................. 3-21

3.12

Setting the Date and Time .............................................................................................. 3-24

3.13

Initializing the Settings .................................................................................................... 3-26

3.14

Entering Values and Character Strings .......................................................................... 3-27

3.15

Entering Character Strings on a USB Keyboard ............................................................ 3-29

3.16

Switching the Display ..................................................................................................... 3-31

3.17

Displaying a List of Setup Parameters ........................................................................... 3-33

3.18

Selecting the Message Language .................................................................................. 3-34

3.19

Setting the USB Keyboard Language ............................................................................ 3-35

Chapter 4 Measurement Conditions

4.1 Panel Keys and Setup Menus Used in This Chapter ....................................................... 4-1

4.2 Selecting a Wiring System ............................................................................................... 4-2

4.3

SelectingIndependentInputElementConguration ........................................................ 4-5

4.4

Setting the Measurement Ranges for Direct Input ........................................................... 4-7

App

Index

IM 760201-01E

4.5 Setting the Measurement Ranges for an External Current Sensor (Optional) ............... 4-13

4.6 Setting the Scaling Feature When Using a VT or CT ..................................................... 4-16

4.7 Setting the Measurement Period .................................................................................... 4-19

4.8 Selecting an Input Filter .................................................................................................. 4-22

4.9

Selecting the Data Update Rate ..................................................................................... 4-24

4.10

Selecting an Averaging Method ...................................................................................... 4-26

4.1

1 Selecting a Crest Factor ................................................................................................. 4-29

4.12

Holding the Display and Performing Single Measurements ........................................... 4-30

Chapter 5 Power Measurement

5.1 Panel Keys and Setup Menus Used in This Chapter ....................................................... 5-1

5.2 Displaying Numeric Data and Changing Displayed Items ................................................ 5-2

5.3

Setting the EquationforEfciency ................................................................................... 5-9

5.4

Setting the Equations for Apparent and Reactive Power ................................................5-11

5.5

Selecting a Phase Difference Display Format ................................................................ 5-13

5.6

Integration ......................................................................................................

................ 5-15

5.7 Setting Manual Integration ............................................................................................. 5-20

5.8

Setting Normal or Continuous Integration ...................................................................... 5-23

5.9

Setting Real-Time Integration or Real-Time Continuous Integration .............................. 5-26

5.10

Turning Integration Auto Calibration On or Off ............................................................... 5-30

5.1

1 Selecting a Watt Hour Integration Method for Each Polarity .......................................... 5-31

5.12

Selecting a Current Integration Mode ............................................................................. 5-32

5.13

Setting User-DenedFunctions ..................................................................................... 5-33

5.14

Setting the MAX Hold Feature ........................................................................................ 5-38

5.15

Measuring the Average Active Power ............................................................................. 5-40

5.16

Selecting What Frequency to Measure .......................................................................... 5-41

5.17

Setting Delta Computation (Optional) ............................................................................. 5-42

Chapter 6 Harmonic Measurement (Optional)

6.1 Panel Keys and Setup Menus Used in This Chapter ....................................................... 6-1

6.2 Changing Numeric Data Display Items ............................................................................ 6-2

6.3 Selecting the PLL Source ................................................................................................. 6-8

6.4 Setting the Measured Harmonic Orders ......................................................................... 6-10

6.5

Selecting a Distortion Factor Equation ........................................................................... 6-12

6.6

Setting the Anti-Aliasing Filter ........................................................................................ 6-13

6.7

Displaying Bar Graphs and Making Cursor Measurements ........................................... 6-15

6.8

Displaying Vectors .......................................................................................................

... 6-20

Chapter 7 Waveform Display

7.1 Panel Keys and Setup Menus Used in This Chapter ....................................................... 7-1

7.2 Displaying Waveforms ...................................................................................................... 7-2

7.3

Selecting Which Waveforms to Display ............................................................................ 7-3

7.4

Setting the Time Axis .......................................................................................................

. 7-4

7.5 Setting the Trigger ............................................................................................................ 7-5

7.6 Vertically Zooming and Shifting Waveforms ..................................................................... 7-9

7.7

Displaying Waveforms in Split Screens ...........................................................................7-11

7.8

Selecting a Graticule and Turning Interpolation, Scale Value Display, and

Wave Labels On or Off ................................................................................................... 7-13

7.9

Measuring with Cursors .................................................................................................. 7-17

Contents

xii

IM 760201-01E

xii

IM 760201-01E

Contents

Chapter 8 Trend Display

8.1 Panel Keys and Setup Menus Used in This Chapter ....................................................... 8-1

8.2 Displaying Trends .......................................................................................................

...... 8-2

8.3 Selecting What Trend Data to Display .............................................................................. 8-3

8.4

Setting Which Measurement Functions to Display Using Trends ..................................... 8-4

8.5

Setting Trend Scaling ......................................................................................................

. 8-7

8.6 Setting the Time Axis .......................................................................................................

. 8-9

8.7 Displaying Trends in Split Screens ................................................................................. 8-10

8.8

Selecting a Graticule and Turning Interpolation, Scale Value Display, and

Wave Labels On or Off .

....................................................................................................... 8-11

8.9 Restarting Trends ......................................................................................................

..... 8-12

8.10 Measuring with Cursors ..................................................................................................... 8-13

Chapter 9 Storing Numeric Data and Saving Stored Numeric Data

9.1 Panel Keys and Setup Menus Used in This Chapter ....................................................... 9-1

9.2 Setting the Storage Mode ................................................................................................. 9-2

9.3

Setting What Numeric Data to Store ................................................................................ 9-3

9.4

Setting the Store Count, Store Interval, and the Scheduled Storage Start and

End Times ......................................................................................................

.................. 9-5

9.5 Choosing Where to Store Numeric Data .......................................................................... 9-8

9.6

Storing Numeric Data ..................................................................................................... 9-13

9.7

Converting a Stored Binary Format File to CSV Format ................................................ 9-15

Chapter 10 Saving and Loading Data

10.1 Panel Keys and Setup Menus Used in This Chapter ..................................................... 10-1

10.2 About USB Memory .......................................................................................................

. 10-2

10.3 Saving Setup Parameters, Waveform Display Data, and Numeric Data ........................ 10-4

10.4

Saving Screen Image Data .......................................................................................... 10-12

10.5

Loading Setup Parameters and Displaying File Properties .......................................... 10-16

10.6

Deleting Files .......................................................................................................

......... 10-19

10.7 Copying Files .......................................................................................................

......... 10-22

Chapter 11 Ethernet Interface (Optional)

11.1 Panel Keys and Setup Menus Used in This Chapter ......................................................11-1

11.2 Connecting to a Network .................................................................................................11-2

1.3 ConguringTCP/IP Settings ............................................................................................11-3

1.4 Accessing the WT500 from a PC or Workstation (FTP server feature) .........................11-12

1.5 Checking the MAC Address and Whether the WT500 Is Equipped with the

Ethernet Interface Option ..............................................................................................11-15

Chapter 12 RGB Video Signal (VGA) Output (Optional) and Other Features

12.1 Panel Keys and Setup Menus Used in This Chapter ..................................................... 12-1

12.2 RGB Video Signal (VGA) Output (Optional) ................................................................... 12-2

12.3

Zero-Level Compensation .............................................................................................. 12-3

12.4

NULL Feature ......................................................................................................

........... 12-4

12.5 Setting the Key and Shift Locks ..................................................................................... 12-5

12.6 Master and Slave Synchronized Measurement .............................................................. 12-6

Chapter 13 Troubleshooting, Maintenance, and Inspection

13.1 Troubleshooting .............................................................................................................. 13-1

13.2 Error Messages and Troubleshooting Methods .............................................................. 13-2

13.3

Self-Test ......................................................................................................

................... 13-6

App

Index

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Contents

13.4 Displaying the System Overview .................................................................................... 13-9

13.5

Recommended Part Replacement ............................................................................... 13-10

Chapter 14 Specications

14.1 Input ............................................................................................................................... 14-1

14.2 Display ............................................................................................................................ 14-2

14.3

Normal Measurement Functions (Measured Items) ....................................................... 14-3

14.4

Harmonic Measurement Functions (Measured Items) ................................................... 14-5

14.5

Accuracy ......................................................................................................................... 14-6

14.6

Functions ...................................................................................................................... 14-10

14.7

External Input and Output (Master and slave synchronization signals and

clock input) ......................................................................................................

............. 14-15

14.8 RGB Video Signal (VGA) Output (Optional) ................................................................. 14-15

14.9

USB PC Interface ......................................................................................................... 14-16

14.10

USB PERIPHERAL Interface ....................................................................................... 14-16

14.1

1 GP-IB Interface Option ................................................................................................. 14-16

14.12

Ethernet Interface Option ............................................................................................. 14-17

14.13

Safety Terminal Adapter ............................................................................................... 14-17

14.14

GeneralSpecications ................................................................................................. 14-18

14.15

External Dimensions .................................................................................................... 14-19

Appendix

Appendix 1 Symbols and Determination of Measurement Functions ...................................App-1

Appendix 2 List of Initial Settings and Numeric Data Display Order ..................................... App-7

Appendix 3

Power Basics (Power, harmonics, and AC RLC circuits) .................................App-13

Appendix 6

USB Keyboard Character Assignments ........................................................... App-29

Index

1-1

IM 760201-01E

Component Names and Functions

Chapter 1 Component Names and Functions

1.1 Front Panel, Rear Panel, and Top Panel

Front Panel

Power switch (see section 3.4)

LCD

Handle

Use this handle to move the WT500. (see section 3.1)

Setup menu display and operation keys

These are the first keys that you press when you make settings or perform operations. Pressing a setup menu display key will display its corresponding setup menu. Pressing an operation key will execute its corresponding operation. (see section 1.2)

SHIFT key When you press the SHIFT key, the key illuminates, and pressing a panel keys produces the effect indicated by the purple letters below it.

USB ports Use to connect USB memory or a USB keyboard.

ESC

RESET

SET

CAL

PAGE

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUMERIC WAVE OT HERS

FORM ITE M

CURSOR

INTEGRATOR

SETUP

INPUT INF O

START/

STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

FILE IMAGE

STORE

STORE SET

POWER

Cursor keys

Set values (and select digits), move the cursor, and select items in setup operations.

SET key

Enters or confirms the item or value selected using the cursor keys.

SHIFT + SET (CAL) key combination

Executes zero-level compensation.

ESC key

Closes setup menus and dialog boxes.

SHIFT + ESC (RESET) key combination

Returns the item or value selected with the cursor to its default value.

PAGE key Because not all measured items can be displayed on the screen at the same time, the WT500 uses pages to display measured values. You can switch between pages using PAGE and PAGE . (see section 5.1)

Rear Panel

Input element 1 (see section 2.3)

Input element 2

Input element 3

Ethernet port (optional) (see section 11.2)

Power connector (see section 3.3)

USB port (PC) See the Communication Interface User’s Manual IM760201-17E (CD-ROM).

External clock input/External start signal output connector

• Receives the synchronization source (signal), which defines the measurement period. (see section 4.7)

• Receives the external PLL source (signal) for harmonic measurement. (see section 6.3)

• Used when performing master/slave synchronized measurement.(see section 12.6)

• Receives the external trigger, which determines when a waveform is displayed. (see section 7.5)

GP-IB Connector (optional; see the Communication Interface User's Manual IM760201-17E on the

CD-ROM)

RGB video signal (VGA) output connector (optional)

Transmits image signals. (see section 12.2)

Current input terminal

For connecting current measurement cables.

(see sections 3.8, 3.9, and 3.11)

External current sensor input connector (optional)

For connecting the external current sensor cable.

(see section 3.10)

Voltage input terminal

For connecting voltage measurement cables.

(see sections

3.8 to 3.11)

ELEME NT

VOLTAGE

1000V

MAX

EXT

CURREN T

ALL TE RMINA LS

1000V MAX

CAT

EXT. CLK

GP-IB (

IEEE 488

)

LINK/ ACT

VIDEO-OU T

(

VGA

)

100LINK

ETHERN ET 1 00BA SE-T X

USB

100- 240 V AC

50 VA MAX 50/60 Hz

10V

MAX

1000VMA X

40A

MAX

ELEME NT

VOLTAGE

1000V

MAX

EXT

CURREN T

ALL TE RMINA LS

1000V MAX

CAT

10V

MAX

1000VMA X

40A

MAX

ELEME NT

VOLTAGE

1000V

MAX

EXT

CURREN T

ALL TE RMINA LS

1000V MAX

CAT

10V

MAX

1000VMA X

40A

MAX

1-2

IM 760201-01E

Top Panel

Handle

Vent holes (see section 3.2 for details)

There are inlet holes on the bottom panel.

1.1 Front Panel, Rear Panel, and Top Panel

1-3

IM 760201-01E

Component Names and Functions

1.2 Setup Menu Display and Operation Keys

This section describes the WT500 panel keys and their functions.

Keys for data storage and saving

Display (see section 1.3)

Keys for setting measurement conditions

Keys for setting the measurement range

Keys for displaying measured/calculated results

Other keys

Integration key

Keys for changing the display

ESC

RESET

SET

CAL

PAGE

ELEMENT

ELEM ENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUME RIC WAVE OTH ERS

FORM ITE M

CUR SOR

INTEGR ATOR

SETU P

INPU T INFO

START/

STOP

RESE T

HOLD

SING LE

SHIF T

MISC

NULL

LOC AL

KEY L OCK

FILE IMAGE

STOR E

STORE SET

POWE R

Keys for Changing the Display

ESC

RESET

SET

CAL

PAGE

Cursor Keys ( )

Use these keys to move the cursor in setup menus and dialog boxes, to set values, to select digits when setting numbers, and to select menu items.

SET

Use this key to display menus that you select with the cursor keys, confirm items and values, and open a menu for changing displayed items when the menu display is turned off in a numeric data display.

ESC

Use this key to close setup menus and dialog boxes, and to move up a level in a menu.

SHIFT+ESC (RESET) Key Combination

Use this key combination to return the item or value selected with the cursor to its default value.

PAGE and PAGE

Use these keys in numeric value displays and other displays, when all of the measured items do not fit into a single page, to change the displayed page. You can go to the first page by pressing SHIFT+PAGE

and to the last page by pressing SHIFT+PAGE .

SHIFT+SET (CAL) Key Combination

Use this key combination to execute zero-level compensation. When zero level compensation is executed, the WT500 creates a zero input condition in its internal circuitry and sets the level at that point to the zero level.

1-4

IM 760201-01E

1.2 Setup Menu Display and Operation Keys

Keys for Setting the Measurement Range

ELEMENT

ELE MENT

ALL

RANGE

VOLTAGE CURRENT

AUTO A UTO

ELEMENT

• Use this key to select the input element that you want to set the measurement range for. The selected input element will change each time you press ELEMENT.

•

When selecting a wiring system, the input elements that are part of the same wiring

system will be selected together.

SHIFT+ELEMENT (ALL) Key Combination

Use this key combination to set the voltage and current ranges of all elements at the same time. Press ELEMENT again to make settings for individual elements.

and (See sections 4.3 and 4.4)

Use these keys to select the voltage, current, and current sensor ranges. The ranges selected with these keys are valid when the AUTO indicators described below are not lighted (when the manual range feature is being used).

SHIFT+ (AUTO) Key Combination

Use this key combination to activate the auto range feature (the AUTO indicator will light when this feature is activated). This feature automatically sets the voltage, current, or current sensor range depending on the amplitude of the received electrical signal. Press SHIFT+

(AUTO) again to activate the manual range feature (the AUTO indicator light

will turn off).

Keys for Setting Measurement Conditions

SETU P

INPU T INFO

DISPLAY

NUM ERIC WAVE OTH ERS

FOR M ITEM

CUR SOR

INTEG RATOR

START /

STOP

RESE T

HOLD

SING LE

SHIF T

MIS C

NULL

LOC AL

KEY LOCK

SETUP

Use this key to display the Setup menu for setting measurement conditions. The following items appear in the Setup menu:

• Wiring (See sections 4.1, 4.2, 5.7, and 5.8)

Select this item to display a menu for selecting the wiring system, configuring

individual input element settings, setting the efficiency equation, etc.

• Ranges (See sections 4.3 and 4.4)

You can select this item to set the voltage, current, or current sensor range, just as

you can with the panel RANGE keys. If you select AUTO, the auto feature will be activated and the AUTO indicators underneath the RANGE keys will light.

• Scaling (See section 4.5)

Select this item to display a menu for setting the VT and CT ratios and the power

factor for each input element. The power coefficients are used to convert the VT/CT output or the power derived from measuring the VT and CT outputs to the voltage, current, and power of the object being measured.

• Sync Source (See section 4.7)

Select this item to display a menu for setting the synchronization source for each

wiring unit. The synchronization source defines the period (measurement period) over which sampled data, which is used to produce numeric data (i.e., measured values such as voltage, current, and power), is acquired.

• Filters (See section 4.8)

Select this item to display a menu for setting the line filter (which is inserted into the

measurement circuit) and the frequency filter (which is inserted into the frequency measurement circuit) for each element.

• Update Rate (See section 4.9)

Select this item to display a menu for selecting the period (data update rate) at which

sampled data, which is used to produce numeric data (i.e., measured values such as voltage, current, and power), is acquired.

• Averaging (See section 4.10)

Select this item to display a menu for setting the measured value averaging feature.

1-5

IM 760201-01E

Component Names and Functions

• Integration (See sections 5.6 to 5.12)

Select this item to display a menu for setting the integration mode, integration auto

calibration, the integration timer, the reservation time, the watt hour integration method for each polarity, and the ampere hour integration mode.

• Details.../Hide Details

Select this item to switch between displaying all menu items and only displaying a

portion of the menu items.

• Measure (See sections 5.3 to 5.5 and 12.6)

Select this item to display a menu for setting master/slave synchronized measurement

and for selecting the equation for apparent/reactive power and the format for phase difference display.

• User Function (See sections 5.13 and 5.14)

Select this item to display a menu for setting user-defined functions and the MAX hold

feature.

• Freq Items (See section 5.16)

This item only appears on models without the frequency measurement option. Select

this item to display a menu for selecting which frequencies to measure. Because models with the frequency measurement option measure all voltages and currents, this menu will not appear.

• Harmonics (See sections 6.3 to 6.5)

This item only appears on models with the harmonic measurement option. Select this

item to display a menu for setting the PLL source, the measured harmonic orders, and the equation for the harmonic distortion factor, in harmonic measurement.

• Delta Measure (See section 5.17)

This item only appears on models with the delta computation option. Select this item

to display a menu for selecting the delta computation type and the voltage or current mode that will be the object of delta computation.

Note

While displaying any submenu in the Setup menu, you can press PAGE or PAGE to display

the previous or next menu. This feature is useful when you want to check the measurement

conditions set in each menu.

SHIFT+SETUP (INPUT INFO) Key Combination

Use this key combination to display a list of the conditions for acquiring the data from a measured voltage or current signal, such as the wiring system for each element, the wiring unit, the measurement range, the scaling, the synchronization source, and the input filter.

1.2 Setup Menu Display and Operation Keys

1-6

IM 760201-01E

Keys for Displaying Measured/Computed Results

SETU P

INPU T INFO

DISPLAY

NUM ERIC WAVE OTH ERS

FOR M ITEM

CUR SOR

INTEG RATOR

START /

STOP

RESE T

HOLD

SING LE

SHIF T

MIS C

NULL

LOC AL

KEY LOCK

NUMERIC (See sections 3.16, 5.1, and 6.2)

Use this key to display numeric data.

• Each time you press NUMERIC, the number of displayed items switches in this order: 4 Items > 8 Items > 16 Items > Matrix > All Items > Single List

> Dual List* > 4 Items >

and so on.

* Only appears on models with the harmonic measurement option.

• When you are displaying numeric data, you can press FORM, which is described later in this section, to display a menu for changing the number of displayed items.

•

When you are displaying numeric data, you can press ITEM, which is described later

in this section, to display a menu for changing the displayed items.

WAVE (See sections 3.16, 6.7, and 7.2)

Use this key to display waveforms.

• Each time you press WAVE, the waveform display split screen setting switches in this order: Single > Dual > Triad > Quad > Single > and so on.

•

When you are displaying waveforms, you can press FORM, which is described later

in this section, to display a menu for setting the time-axis of the displayed waveforms, the trigger for waveform display, the number of waveform display split screens, and the assignment of waveforms to split screens.

•

When you are displaying waveforms, you can press ITEM, which is described later

in this section, to display a menu for selecting and zooming in on the displayed waveforms.

OTHERS (See sections 3.16, 6.7, 6.8, 7.2, and 8.2)

Use this key to switch between the Trend, Bar Graph*, and Vector* displays. Each time you press OTHERS, the display switches in this order: Trend > Bar* > Vector* > Trend > and so on.

* Only appears on models with the harmonic measurement option.

FORM (See sections 5.2, 6.2, 6.7, 6.8, 7.4, 7.5, 7.7, 7.8, and 8.6 to 8.9)

Use this key to display a menu for setting the format of the display that has been selected using NUMERIC, WAVE, or OTHERS.

SHIFT+FORM (CURSOR) Key Combination (See sections 7.9 and 8.10)

Use this key when you are displaying waveforms, trends, or bar graphs* to display a menu for using cursors to measure waveform and graph values.

* Only appears on models with the harmonic measurement option.

ITEM Key (See sections 5.2, 6.2, 6.7, 6.8, 7.3, 7.6, and 8.3 to 8.5)

Use this key to display a menu for setting the displayed items in the display that has been selected using NUMERIC, WAVE, or OTHERS.

Keys for Data Storage/Saving

FILE IMA GE

STOR E

STOR E SET

FILE

Use this key to display a menu for saving and loading setup parameters, saving measured data, deleting files, copying files, and so on.

IMAGE

Use this key to save the screen image data.

SHIFT+IMAGE (MENU) Key Combination

Use this key combination to display a menu for setting screen image data save options such as the file name, data format, color mode, data compression, and comments.

STORE

Use this key to execute, stop, or reset a storage operation.

SHIFT+STORE (STORE SET) Key Combination

Use this key to display a setup menu for the storage feature.

1.2 Setup Menu Display and Operation Keys

1-7

IM 760201-01E

Component Names and Functions

Other Keys

SETU P

INPU T INFO

DISPLAY

NUM ERIC WAVE OTH ERS

FOR M ITEM

CUR SOR

INTEG RATOR

START /

STOP

RESE T

HOLD

SING LE

SHIF T

MIS C

NULL

LOC AL

KEY LOCK

START/STOP Key

Use this key to start or end integration. You can view the integration condition in the integration setup/condition display (see section 1.3).

SHIFT+START/STOP (RESET) Key Combination

Use this key combination to reset the integrated value.

HOLD (See section 4.12)

Press HOLD to stop data measurement and display operations and to hold the numeric display (the HOLD key illuminates when the numeric display is held). During integration, the numeric display is held but measurement is not stopped. Press HOLD again to allow the numeric data display to be updated (the HOLD key will no longer be illuminated).

SHIFT+HOLD (SINGLE) Key Combination (See section 4.12)

Use this key combination while the display is held to measure the signal once at the set data update rate, and then to re-hold the display.

LOCAL

Use this key to switch from remote mode (the REMOTE indicator will appear at the upper right of the screen) to local mode (in which front panel key operations are valid). This key is invalid when the WT500 is in local lockout mode.

SHIFT+LOCAL (KEY LOCK) Key Combination

Use this key combination to turn the key lock on or off. When the key lock is on, no keys or key combinations other than SHIFT+LOCAL are valid, and LOCK appears in the upper right of the screen.

MISC

Use this key to display a menu for viewing the system status, initializing setup parameters, configuring or viewing the settings of remote control through communication commands (using the USB, GP-IB, or Ethernet interface option), setting the date/time, selecting the message and menu languages, selecting the crest factor, setting the USB peripheral interface, setting the optional Ethernet interface, setting the self test, etc.

SHIFT+MISC (NULL) Key Combination

Use this key combination to activate the NULL feature, which removes the DC component from the sampled data (the NULL indicator appears on the screen when the NULL feature is activated). Press SHIFT+MISC (NULL) again to deactivate the NULL feature (the NULL indicator will no longer appear).

SHIFT

When you press the SHIFT key, the key illuminates, and pressing a panel key produces the effect indicated by the purple letters below it. Holding down SHIFT for 2 seconds or more will lock the WT500 into the shifted state. Pressing SHIFT again will release the shifted state (and the SHIFT key will no longer be illuminated).

1.2 Setup Menu Display and Operation Keys

1-8

IM 760201-01E

1.3 Screen Display

Display Example When Measuring Power (Numeric display) in Normal Measurement Mode

For a description of the screens in other display modes, see the chapters that cover those modes.

Date/time (see section 3.11)

Input peak over-range indicator (see section 5.2)

Measurement mode (see section 7.2)

Display items that can be changed directly (see section 5.2)

Indication of on/off status of various features

• Scaling (see section 4.6)

• Averaging (see section 4.10)

• Line filter (see section 4.8)

• Frequency filter (see section 4.8)

• NULL feature (see section 12.4)

Page bar (see section 5.2)

Input element setup parameters

• Measurement range (see sections 4.4 to 4.5)

• Wiring system (see section 4.2)

Integration setting/status (see section 5.11)

Data update count (see section 5.2)

Data update rate (see section 4.9)

Non-Numeric Displays

Overload

Displayed if the measured value exceeds 140% of the measurement range.

Overflow

Displayed if the measured or computed result cannot be displayed using the specified decimal place or unit.

No data

Displayed if a measurement function is not selected or if there is no numeric data.

Error

Displayed in cases such as when a measured value is outside of its determined range.

2-1

IM 760201-01E

Features

2.1 System Configuration and Block Diagram

System Configuration

ESC

RESET

SET

CAL

PAGE

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUMERIC WAVE O THERS

FORM ITEM

CURSOR

INTEGRATOR

SETUP

INPUT INFO

START/

STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

FILE IMAGE

STORE

STORE SET

POWER

ELEMENT

VOLTAGE

CURRENT

EXT

Object Being Measured

Voltage

(Apply one or the other)

Current

(Apply one of them)

Current sensor (optional)

Input element

External clock input

Master/slave sync signal

USB keyboard

Internal memory Stores numeric data

USB memory

CRT

Numeric data Waveform display data Screen image data Stored data

Setup parameters

Numeric data Waveform display data Screen image data

Setup parameters

Measurement start/ Measurement stop

GP-IB interface (optional)/ Ethernet interface (optional)/ USB interface

RGB video signal (VGA) output (optional) Image signal

(Apply one or the other)

Chapter 2 Features

2-2

IM 760201-01E

Block Diagram

L.P.F.

5.5 kHz

L.P.F.

500 Hz

L.P.F.

5.5 kHz

L.P.F.

500 Hz

A/D

Isolator Isolator

Zero-crossing detector

Peak detector

Current sensor

(EXT; optional)

Voltage input circuit

Current input circuit

Input element 1

Input elements 2 and 3

DSP

CPU

LCD

USB port

(for peripherals)

USB port

(PC)

GP-IB

(optional)

Ethernet

(optional)

VGA output (optional)

KEY

Voltage Input

Current input

A/D

Zero-crossing detector

Peak detector

Input Signal Flow and Process

Input elements 1 through 3 consist of a voltage input circuit and a current input circuit. The input circuits are mutually isolated. They are also isolated from the case.

The voltage signal that is applied to the voltage input terminal (U, ±) is normalized using the voltage divider and the operational amplifier (op-amp) of the voltage input circuit . It is then sent to a voltage A/D converter. The current input circuit is equipped with two types of input terminals, a current input terminal (I, ±) and an optional current sensor input connector (EXT). Only one can be used at any given time. The voltage signal from the current sensor that is received at the current sensor input connector is normalized using the voltage divider and the operational amplifier (op-amp). It is then sent to a current A/D converter. The current signal that is applied to the current input terminal is converted to a voltage signal by a shunt. Then, it is sent to the current A/D converter in the same fashion as the voltage signal from the current sensor.

The voltage signal that is applied to the voltage A/D converter and current A/D converter is converted to digital values at an interval of approximately 10 µs. These digital values are isolated by the isolator and passed to the DSP. In the DSP, the measured values are derived based on the digital values. The measured values are then transmitted to the CPU. The measured values and computed values are displayed and transmitted as measurement functions of normal measurement.

The harmonic measurement functions are derived in the following manner (harmonic measurement is an option). The voltage signal sent to the A/D converter is converted to digital values at a sampling frequency that is determined by the PLL source signal. The DSP derives the measured value of each harmonic measurement item by performing an FFT on the converted digital values.

2.1 System Configuration and Block Diagram

2-3

IM 760201-01E

Features

2.2 Measurement Functions and Periods

Measurement Functions

The physical values (such as rms voltage, average current, power, and phase difference) that the WT500 measures and displays are called measurement functions. Each measurement function is displayed using symbols that correspond to its physical value. For example, “Urms” corresponds to the true rms voltage.

Types of Measurement Functions Used in Normal Measurement

The data of measurement functions (numeric data) is measured or computed from the sampled data that is described in “Measurement Period” on page 2-9.

1 The WT500 samples the instantaneous values of the voltage and current signals at the

specified sample rate. The sampled data is processed as numeric data or data used to display waveforms on the screen (waveform display data).

The sample rate is the number of data points that are sampled within 1 s. For example, at a

sample rate of 100 kS/s, 100000 data points are sampled every second.

Types of Measurement Functions

• Input Element Measurement Functions

The following 23 measurement functions are available. For details about the

determination of measurement function data, see appendix 1.

U (voltage Urms, Umn, Udc, Urmn, Uac), I (current Irms, Imn,

Idc, Irmn, Iac), P (active power), S (apparent power), Q (reactive power), λ (power factor), f (phase difference), fU/fI (also expressed as FreqU/FreqI; measures the frequencies of up to two voltage/ current signals),

U+pk/U-pk (maximum/minimum voltage values), I+pk/I-pk (maximum/ minimum current values), and CfU/CfI (crest factor of voltage/current; peak-to-rms ratio)

2 The voltage and current frequencies of all input elements can be measured on models with

the frequency measurement add-on option.

• Wiring UnitΣ Measurement Functions (Σ Functions)

The following 15 measurement functions are available. For details about the

determination of measurement function data, see appendix 1.

UΣ (voltage average UrmsΣ, UmnΣ, UdcΣ, UrmnΣ, UacΣ), IΣ (current average IrmsΣ,

ImnΣ, IdcΣ, IrmnΣ, IacΣ), PΣ (sum of active powers), SΣ (sum of apparent powers), QΣ (sum of reactive powers), λΣ (power factor average), and fΣ (phase difference average)

•Efficiency (Σ functions) and User-Defined Functions

There are two ef

ficiency functions, η1 and η2. The available user-defined functions

are F1 to F8. For details, see section 2.5.

•

Integration Functions

See section 2.6.

• Delta Computation (Optional)

There are four delta functions, ΔF1 to Δ F4. For details, see section 5.17.

2-4

IM 760201-01E

Determining Voltage and Current

The following five types of voltage (U) and current (I) measurement functions are available.

•

Urms and Irms (True rms value)

These values are the true rms values of the voltage and current. The instantaneous

values over one period are squared and averaged. Then, the square root of the average is determined. f(t) is the input signal as a function of time. T is the period of the input signal.

Urms or Irms =

1 T

f(t)2 dt

• Umn and Imn (Rectified mean value calibrated to the rms value)

This function rectifies one period of the voltage or current signal, determines the

average, and multiplies the result by a coefficient. The coefficient is a value that when applied to a sinusoidal input signal, gives the true rms value. When the input signal is a distorted or DC waveform, these values will differ from the true rms values. f(t) is the input signal as a function of time. T is the period of the input signal.

Umn or Imn =

•

f(t) dt

• Udc and Idc (Simple average, DC)

These are the average values of the voltage and current signal over one period. This

function is useful when determining the average value of a DC input signal or the DC component that is superimposed on an AC input signal.

Udc or Idc =

1 T

f(t) dt

• Uac and Iac (AC component)

This function determines the AC component of the voltage or current. The function

calculates the square root of the square of the true rms value minus the square of the DC component.

Uac=

Urms

–Udc

Iac=

Irms

–Idc

, or

• Urmn and Irmn (Rectified mean value)

This function rectifies one period of the voltage or current signal and determines the

average.

Urmn or Irmn =

1 T

f(t) dt

Elements

Element refers to a set of input terminals that can receive a single phase of voltage and current to be measured. The WT500 can contain up to three elements, numbered from 1 to 3. An element number is appended to the measurement function symbol for the measured data that the WT500 displays, so that you can tell which data belongs to which element. For example, “Urms1” corresponds to the true rms voltage of element 1.

Wiring Systems

You can specify five wiring systems on the WT500 to measure the power of various single-phase and three-phase power transmission systems: single-phase, two-wire; single-phase, three-wire; three-phase, three-wire; three-phase, four-wire; and threephase, three-wire with three-voltage, three-current method. For details, see section 2.3.

2.2 Measurement Functions and Periods

2-5

IM 760201-01E

Features

Wiring Unit

The wiring unit is a set of two or three input elements of the same wiring system that are grouped to measure three-phase power. The wiring unit is represented by Σ. The measurement function of a wiring unit is called a Σ function. For example, “UrmsΣ” corresponds to the average of the voltages of the input elements that are assigned to the wiring unit. The average represents the true rms value.

•

Wiring System and Wiring Unit Configuration Example

Voltage input

Current input

Three-phase, three-wire

Element 1

Element 2 Element 3

Single-phase, two-wire

Wiring system

Wiring unit

2.2 Measurement Functions and Periods

2-6

IM 760201-01E

Types of Measurement Functions Used in Harmonic Measurement (Optional)

The data of harmonic measurement functions (numeric data) is measured or computed from the sampled data that is described later in “Measurement Period.”

* For information about sampled data, see the explanation under “Types of Measurement

Functions Used in Normal Measurement,” earlier in this section.

Types of Harmonic Measurement Functions

• Input Element Harmonic Measurement Functions

The following 15 harmonic measurement functions are available. For details about the

determination of measurement function data, see appendix 1.

Yes

Always 0

Yes

Total

Yes

All

parentheses

Yes

U( ) I( ) P( ) S( ) Q( )

λ( ) φ( ) φU( ) φI( )

Uhdf( ) Ihdf( ) Phdf( ) Uthd Ithd Pthd

Characters or Numbers in Parentheses

Measurement Function

Yes: Numeric data available

No: No numeric data available

• Functions with parentheses will produce different values depending on which of the following is contained in their parentheses.

•

total: The total value is displayed.

•

dc: The dc component numeric data is displayed.

• 1: The numeric data of the fundamental signal is displayed.

• k: The numeric data from harmonic orders 2 to N is displayed. N is the upper

limit of harmonic order analysis (see section 17.6 for details). The upper limit of harmonic analysis is either set to an automatically determined value or to the value that you set, whichever is smaller. It can go up to the 50th harmonic order.

•

All: Functions without parentheses display numeric data.

• Functions Uhdf to Pthd are measurement functions that express values that are unique to harmonics. For details about how the values are determined, see appendix 1.

2.2 Measurement Functions and Periods

2-7

IM 760201-01E

Features

• Harmonic Measurement Functions That Express the Voltage and Current Phase Differences (f) between and within Input Elements

There are five kinds of harmonic measurement functions that e

xpress phase

differences:

fUi-Uj, fUi-Uk, fUi-Ii, fUi-Ij, fUi-Ik (i, j, and k are input element numbers) The following explanation of the five kinds of harmonic measu

rement functions is for the case when the number of input elements in wiring unit Σ is three and their common wiring system is three phase, four wire. Also, i = 1, j = 2, and k = 3.

In this case, the following numeric data for the phase dif

ferences between elements 1,

2, and 3 is calculated.

•

fU1-U2

The phase dif

ference between the fundamental voltage of element 1, U1(1), and

the fundamental voltage of element 2, U2(1).

•

fU1-U3

The phase dif

ference between the fundamental voltage of element 1, U1(1), and

the fundamental voltage of element 3, U3(1).

•

fU1-I1

The phase dif

ference between the fundamental voltage of element 1, U1(1), and

the fundamental current of element 1, I1(1).

• fU1-I2 The phase dif

ference between the fundamental voltage of element 1, U1(1), and

the fundamental current of element 2, I2(1).

•

fU1-I3

The phase dif

ference between the fundamental voltage of element 1, U1(1), and

the fundamental current of element 3, I3(1).

•

Functions for Averaging and Summing Input Elements (Σ functions)

The following six harmonic measurement functions are available. For details about

how the measurement function values are determined, see appendix 1.

Yes

Total

Yes

U3( ) I3( ) P3( ) S3( ) Q3( ) L3( )

Characters or number in parentheses

Measurement Function

Yes: Numeric data available

Functions with parentheses will produce different values depending on which of the

following is contained in their parentheses.

•

total: The total value is displayed.

• 1: The numeric data of the fundamental signal is displayed.

2.2 Measurement Functions and Periods

2-8

IM 760201-01E

Elements

Element refers to a set of input terminals that can receive a single phase of voltage and current to be measured. The WT500 can contain up to three elements, numbered from 1 to 3. The element number follows the function symbols discussed in “Input Element Harmonic Measurement Functions” earlier in this section. For example, “U1(2)” corresponds to the voltage of the second harmonic of element 1.

Wiring Systems

The selectable wiring system patterns vary depending on the number of input elements that are installed in the WT500.

Wiring Unit

The wiring unit is a set of two or three input elements of the same wiring system that are grouped to measure three-phase power. The wiring unit is represented by Σ. The measurement function of a wiring unit is called a Σ function. For example, “UΣ(1)” corresponds to the average of the fundamental voltages of the input elements that are assigned to the wiring unit.

PLL Source (See section 6.3 for operating instructions)

To measure harmonics, the fundamental period (the period of the fundamental signal) that will be used to analyze the harmonics must be determined. The signal for determining the fundamental period is the PLL (phase locked loop) source. For stable harmonic measurement, choose an input signal for the PLL source that has as little distortion and fluctuation as possible. The ideal signal when the crest factor is set to 3 (see section 5.11 for details) is a rectangular wave with an amplitude that is 50% or more of the measurement range (see section 1.3 for details). When the crest factor is set to 6, the ideal signal is a rectangular wave with an amplitude that is 100% or more of the measurement range. Also, applying a clock signal (Ext Clk) with the same period as the waveform whose harmonics are being measured makes stable harmonic measurement possible.

2.2 Measurement Functions and Periods

2-9

IM 760201-01E

Features

Measurement Period (See section 4.7 for operating instructions)

Measurement Functions Used in Normal Measurement

• The measurement period is set within the data update interval between the first point where the reference input signal (synchronization source) crosses the level zero point (center of the amplitude) on the rising trigger slope (or falling trigger slope) and the last point where the synchronization source crosses the level zero point (center of the amplitude) on the rising slope (or falling slope).

1, 2

However, the measurement period for determining the numeric data of the peak voltage or peak current is the entire span of the data update interval. Therefore, the measurement period for the measurement functions that are determined using the maximum voltage or current value (U+pk, U-pk, I+pk, I-pk, CfU, and CfI) is also the entire span of the data update interval.

•

The WT500 determines whether to define the measurement period using the rising

or falling edge automatically by choosing the method that will result in the longest measurement period.

•

If there is not more than one rising or falling slope within the data update interval, the

entire data update interval is set as the measurement period.

•

You can select which input signal will be the synchronization source (synchronized

to the zero-crossing point of the input signal) for each element. You can set the synchronization source signal to the voltage, current, or external clock input signal.

•

For details, see appendix 6.

1 Trigger slope refers to the movement of the signal from a low level to a high level (rising edge)

or from a high level to a low level (falling edge).

2 The data update interval is the interval at which the data that is used in measurement

functions is sampled. For details on how to set the interval, see section 2.3, “Data Update Rate.”

Data update interval

Measurement period

Sync source

zero crossing zero crossing

Data update interval

Measurement period

Measurement Functions Used in Harmonic Measurement

The measurement period is the first 1024 points from the beginning of the data update interval at the harmonic sampling frequency. The WT500 determines the harmonic sampling frequency automatically based on the period of the signal that is set as the PLL source. The sampled data and the measurement period used for computation may differ from the sampled data and the measurement period used for measurement functions.

2.2 Measurement Functions and Periods

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2.3 Measurement Conditions

Number of Installed Input Elements and Wiring Systems (See sections 4.2 and 4.3 for operating instructions)

Wiring Systems

• There are five wiring systems available on the WT500. 1P2W: Single-phase, two-wire system 1P3W: Single-phase, three-wire system 3P3W: Three-phase, three-wire system 3P4W: Three-phase, four-wire system 3P3W

(3V3A): Three-voltage, three-current method

* In this manual, “3P3W” is used to indicate a three-phase, three-wire system and a three-

phase, three-wire system with a three-voltage, three-current method. Since the two types of

wiring systems cannot be distinguished if only 3P3W is written, “3P3W (3V3A)” is used to

indicate the three-voltage, three-current method.

• The selectable wiring systems vary depending on the number of installed elements.

Wiring Unit

The wiring unit is a set of two or three input elements of the same wiring system that are grouped together. The wiring unit is represented by Σ. For example, “UrmsΣ” corresponds to the average of the voltages of the input elements that are assigned to the wiring unit. The average value represents the true rms value.

Wiring System Patterns

• The following table shows the relationship between the number of installed input elements, the selectable wiring system patterns, and the assignment of input elements to wiring unit Σ.

For example, there are four wiring system patterns on a WT50

0 that has three input

elements installed.

•

The input element assignment to wiring unit Σ and how Σ functions (such as voltage,

current, active power, apparent power, reactive power, power factor, and phase difference) are determined are based on the wiring system pattern. For details about the relationship between the wiring system and how Σ functions data is determined, see Appendix 1.

Number of installed input elements

Wiring system Pattern 1

1P2W

Number of installed input elements

Wiring system Pattern 1

Wiring system Pattern 2

1P2W

1P3W:3 or 3P3W:3

Number of installed input elements

Wiring system Pattern 1

Wiring system Pattern 2

Wiring system Pattern 3

Wiring system Pattern 4

1P2W

1P3W:3 or 3P3W:3

3P4W:3 or 3P3W (3V3A):3

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Features

Measurement Range (See section 4.4 for operating instructions)

Set the measurement range using an rms value. When directly applying voltage or current signals to an input element, two types of measurement ranges are available: fixed range and auto range. When waveforms are displayed and the crest factor (see section 4.6 for details) is set to 3, the vertical display range corresponds to 3 times the measurement range. When the crest factor is set to 6, the vertical display range corresponds to 6 times the measurement range. For details about waveform display, see section 2.7, “Waveform Display.”

Fixed Range

Select each range from the given choices. The selected range does not change even if the amplitude of the input signal changes. For voltage, the maximum and minimum selectable ranges when the crest factor is set to 3 are 1000 V and 15 V. When the crest factor is set to 6, the maximum and minimum selectable ranges are 500 V and 7.5 V.

Auto Range

The measurement range is switched automatically depending on the amplitude of the input signal. The different ranges used in the auto range are the same as those available for the fixed range.

•

Range Increase

• The measurement range is increased when the data of measurement function Urms or Irms exceeds 110% of the currently set measurement range.

•

The measurement range is increased when the crest factor is set to 3 and the peak

value of the input signal exceeds 330% of the currently set measurement range, or when the crest factor is set to 6 and the peak value of the input signal exceeds 660% of the currently set measurement range.

•

Range Decrease

The measurement range is decreased when the data of the measurement function

Urms or Irms is less than or equal to 30% of the measurement range and Upk

and

Ipk

are less than or equal to 300% of the next lower range when the crest factor is set

to 3, or 600% of the next lower range when the crest factor is set to 6.

* Even if the NULL feature is on, the values are determined as if though it were off.

Power Range

The measurement ranges (power ranges) of active power, apparent power, and reactive power are determined by the wiring system, voltage range, and current range as shown below. For the actual power range values, see section 4.3, “Setting the Measurement Range during Direct Input.”

Wiring System Power Range

1P2W (single-phase, two-wire system) Voltage range × current range 1P3W (single-phase, three-wire system) 3P3W (three-phase, three-wire system) 3V3A (three voltage, three current method)

Voltage range × current range × 2 (when the voltage and current ranges on the elements in the wiring unit are set to the same range)

3P4W (three-phase, four-wire system) Voltage range × current range × 3

(when the voltage and current ranges on the elements in the wiring unit are set to the same range)

2.3 Measurement Conditions

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Scaling (See sections 4.5 and 4.6 for operating instructions)

When applying current signals through an external current sensor or applying voltage or current signals through an external VT (voltage transformer) or CT (current transformer), the conversion ratio or coefficient can be specified.

When Applying Current Signals through an External Current Sensor

The output of current sensors that output voltage, such as shunts and clamps, can be applied to the current sensor connector (EXT) and measured. Set how many millivolts the current sensor transmits when 1 A of current is applied (conversion ratio). Then, the input signal can be made to correspond to the numeric data or waveform display data that is obtained when the current is directly applied to the input terminals.

Measurement Function Conversion

Ratio

Data before Transformation

Transformation Result

Current I E I

(current sensor output) IS/E

Active power P E P

PS/E

Apparent power S E S

SS/E

Reactive power Q E Q

QS/E

Max./Min. current value Ipk E Ipk

(current sensor output) IpkS/E

When Applying Voltage or Current Signals through an External VT or CT

• VT ratio and CT ratio

You can convert the input signal into the numeric data or waveform display data of the

voltage or current before transformation by setting the VT ratio, CT ratio, and power factor (coefficient multiplied to the power determined from the voltage and current).

•

Power factor

By setting the power factor (SF), you can display the measured active power, apparent

power, and reactive power after they have been multiplied by a coefficient.

Measurement Function Data before

Transformation

Transformation Result

Voltage U U

(secondary output

voltage of the VT)

U2×V V: VT ratio

Current I I

(secondary output of

the CT)

I2×C C: CT ratio

Active power P P

P2×V×C×SF SF: Power factor

Apparent power S S

S2×V×C×SF

Reactive power Q Q

Q2×V×C×SF

Max./Min. voltage value Upk Upk

(secondary output

of the VT)

Upk2×V

Max./Min. current value Ipk Ipk

(secondary output of

the CT)

Ipk2×C

2.3 Measurement Conditions

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Features

Input Filter (See section 4.8 for operating instructions)

There are two types of input filters. The WT500 makes measurements by synchronizing to the input signal. Therefore, the frequency of the input signal must be measured accurately.

Line Filter

The line filter is inserted into the voltage, current, and power measurement input circuits and directly affects the voltage, current, and power measurements (see the block diagram in section 2.1). When the line filter is turned on, the measured value does not contain high frequency components. The voltage, current, and power of inverter waveforms, strain waveforms, etc., can be measured with their high frequency components eliminated. You can select the cutoff frequency.

Frequency Filter

The frequency filter is inserted into the frequency measurement input circuit and affects frequency measurements. It affects the detection of the measurement period for voltage, current, and power measurements (see section 4.7 and appendix 5). The frequency filter is also used to accurately detect the zero crossing (see section 2.2 and appendix 5). The frequency filter is not inserted into the voltage, current, and power measurement input circuit. Therefore, the measured values include high frequency components even when the frequency filter is turned on.

Note

The frequency filter is turned on when the line filter is set to 500 Hz.

Data Update Rate (See section 4.9 for operating instructions)

You can select an update interval from 100 ms, 200 ms, 500 ms, 1 s, 2 s, and 5 s. The numeric data is updated at the selected interval. To capture relatively fast load fluctuations in the power system, select a fast data update rate. To capture relatively low frequency signals, select a slow data update rate.

2.3 Measurement Conditions

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Averaging (See section 4.10 for operating instructions)

The averaging function is effective when reading of the numeric display is difficult due to fluctuations. This occurs when the fluctuation of the power supply or the load is large or when the input signal frequency is low.

During Normal Measurement

Two types of averages are available: exponential averages and moving averages.

• Exponential Average

Numeric data can be exponentially averaged using a specified attenuation constant.

Averaging is performed according to the following equation.

Dn =

(Mn – Dn – 1)

Dn – 1 +

Dn: Displayed value that has been exponentially averaged n times. (The first

displayed value D

is equal to M1.)

n–1

: Displayed value that has been exponentially averaged n–1 times.

: Measured data at the nth time.

K: Attenuation constant (can be selected from 2, 4, 8, 16, 32, and 64)

•

Moving Average

Numeric data can be linearly averaged using a specified average count. Averaging is

performed according to the following equation.

Dn =

Mn – (m – 1) + •••Mn – 2 + Mn – 1 + Mn

Dn: Displayed value obtained by linearly averaging m points of numeric data

from the n–(m–1)

to the nth time

n−(m–1)

: Measured data at the n–(m–1)th time.

••••••••••••••••••••••••••••••

•••••••••••••••••••••••••••••• M

n–2

: Measured data at the n–2th time.

n-1

: Measured data at the n-1st time.

: Measured data at the nth time.

m: Average count (can be selected from 8, 16, 32, 64, 128, and 256)

During Harmonic Measurement

When exponential averaging is specified, the harmonic measurement functions are averaged. When averaging is set to moving average, averaging is only performed on normal measurement functions, not on harmonic measurement functions.

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Features

Crest Factor (See section 4.11 for operating instructions)

The crest factor is defined as the ratio of the peak value of the waveform to the rms value.

Peak value

Rms value

Crest factor (CF) =

Peak value

Rms value

Input signal waveform

The crest factor on the WT500 is determined by the ratio of the maximum peak value that can be applied for rated input to the measurement range.

Peak value that can be input

Measurement range

Crest factor (CF) =

The crest factor can be set to 3 or 6. The measurable crest factor is as follows:

{measurement range × CF setting (3 or 6)}

Measured value (rms value)

Crest factor (CF) =

* However, the peak value of the input signal must be less than or equal to the maximum

allowable input.

If the crest factor of the measured signal is greater than the specifications of the measurement instrument (the crest factor defined at the rated input), the signal can be measured by setting a greater measurement range. For example, even if CF is set to 3, measurement is possible for signals with a crest factor greater than or equal to 5 when the measured value (rms value) is less than 60% of the measurement range. If the minimum effective input (1% of the measurement range) is being applied at CF = 3, measurement for CF = 300 is possible. The voltage range, current range, effective input range, and measurement accuracy vary depending on the crest factor setting. For details, see chapter 14, “Specifications.”

Hold (See section 4.12 for operating instructions)

The data display of each measurement function can be held. The communication output data while the display is held is the same as the held numeric data.

Single Measurement (See section 4.12 for operating instructions)

While the display is held, the signal is measured once at the set data update rate, and then the display is re-held.

2.3 Measurement Conditions

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2.4 Power Measurement

When the screen is set to numeric display, measured data such as voltage, current, and power can be displayed.

Display Resolution

The display resolution for voltage, current, active power, apparent power, reactive power, and so on is 60000. When the range rating (rated value of the specified measurement range) is specified, the Σ functions of the voltage, current, active power, apparent power, reactive power, and so on are set to the decimal place and unit of the element with the lowest display resolution of the target elements. For information about the display resolution for integration, see section 5.8.

Numeric Display during Normal Power Measurement (See section 5.1 for operating instructions)

Selecting the Number of Displayed Items

The number of items can be selected from 4, 8, 16, Matrix, and All Items. Not all of the data will fit onto a single screen. You can scroll through the displayed items to view data that is not on the screen.

•

Eight-Item Display Example

Data

Measurement function

• Matrix Display Example

Data

Measurement function

Element and wiring system

• All-Item Display Example

Data

Measurement function

Element and wiring system

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Features

Changing the Displayed Items

You can select a displayed item to change the numeric data that is displayed at that item’ s position.

Change the measurement function of the third item

Change the element of the third item

Scrolling through Pages

The numeric display consists of up to nine pages. The number of pages varies depending on the installed options and the number of displayed items. You can set the displayed items on each page. The page can be scrolled to switch the page, and the displayed items can be changed collectively.

Page 1

Page 2

Page 3

Page 4

Display example Displays the voltage, current, power, and power factor of elements 1 to 3 on pages 1 to 3. Displays the voltage, current, power, and power factor of wiring unit Σ on pages 4.

Page bar The current page is highlighted.

Resetting the Numeric Display

If the number of displayed items is set 4, 8, 16, or matrix, the display order of measurement functions can be reset to the factory default configuration.

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Numeric Display during Harmonic Measurement (See section 6.1 for operating instructions)

In addition to the 4, 8, 16, matrix, and All displays, list displays (the single list and double list displays) are also available.

Selecting the Number of Displayed Items

Just as in ordinary measurement, the number of items can be selected from 4, 8, 16, Matrix, and All Items.

List Display

For each measurement function, the numeric data for each harmonic can be displayed in two columns.

•

Single List

The data of a single measurement function can be divided into even and odd harmonics

and displayed. The selectable measurement functions are U, I, P, S, Q, λ, f, fU, and fI.

Measurement function 1

Data of each harmonic order

Relative harmonic content of each harmonic (Uhdf, Ihdf, and Phdf are displayed when the selected measurement function are U, I, and P, respectively.)

Numeric data of each harmonic order

Measurement function display

Data related to all harmonics

• Dual List

The data from two different measurement functions can be displayed in two separate

columns. The selectable measurement functions are U, I, P, S, Q, λ, f, fU, and fI.

Measurement function 1

Measurement function 2

Data of each harmonic order

Relative harmonic content of each harmonic (Uhdf, Ihdf, and Phdf are displayed when the selected measurement function are U, I, and P, respectively.)

Numeric data of each harmonic order

Measurement function display

Data related to all harmonics

Scrolling through Pages

Just as in ordinary measurement, you can scroll through pages one page at a time.

Resetting the Numeric Display

If the number of displayed items is set 4, 8, 16, or matrix, the display order of measurement functions can be reset to the factory default configuration.

2.4 Power Measurement

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Features

2.5 Computation

The following computations can be performed with the data of measurement functions. In addition, there is a function that allows you to select the equation used to determine the measurement function data.

Setting the Equation for Computing Efficiency (See section 5.3 for operating instructions)

To measure the input/output efficiency of a device, set the equations for η1 and η2. For example, if the input power to a device is P1 and the output power is PΣ, you can compute the power conversion efficiency of the device by setting the equation to η = (PΣ)/(P1) × 100.

Setting the Equation for Computing Apparent Power (See section 5.4 for operating instructions)

Apparent power is the product of voltage times current. The voltage and current used to determine the apparent power can be selected from (1) the true rms values explained under “Determining Voltage and Current” in section 2.2, “Measurement Functions and Periods”; (2) the rectified mean values calibrated to the rms values; (3) the linear averages; (4) the rectified mean value calibrated to the rms value of the voltage and the rms value of the current; and (5) the rms values.

Selecting the Computing Equation for Apparent Power and Reactive Power (See section 5.4 for operating instructions)

There are three types of power: active power, reactive power, and apparent power. In general, they are defined by the following equations.

Active power P = UIcosf .............................................................. (1)

Reactive power Q = UIsinf ..........................................................(2)

Apparent power S = UI .................................................................(3)

U = rms voltage; I = rms current; f = Phase difference between voltage and current The power values are related as follows: (Apparent power S)

= (Active power P)2 + (Reactive power)2 ....(4)

The three-phase power is the sum of the power of each phase.

These definitions only apply for sine waves. The measured values for apparent power and reactive power vary for distorted waveform measurement depending on which of the above definitions are combined for the computation. Because the equations for deriving the power for distorted waveforms are not defined, none of the equations can be said to be more correct than the other. Therefore, the WT500 provides three equations for determining the apparent power and reactive power. Unlike apparent power and reactive power, active power is derived directly from the sampled data, so errors resulting from different definitions do not occur.

Type 1 (The method used in the normal mode of conventional WT series power meters)

The apparent power of each phase is calculated using equation 3, and the reactive power of each phase is calculated using equation 2. The results are summed to derive the power. Active power for a three-phase, four-wire system

PΣ = P1 + P2 + P3

Apparent power for a three-phase, four-wire system SΣ = S1 + S2 + S3( = U1×I1 +

U2 × I2 + U3 × I3)

Reactive power for a three-phase, four-wire system

QΣ = Q1 + Q2 + Q3

(= s1×

(U1 × I1)

– P12 + s2 × (U2 × I2)2 – P22 + s3 × (U3 × I3)2 – P32)

The sign for s1, s2, and s3 is positive when the current leads the voltage and negative

when the current lags the voltage.

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Type 2

The apparent power of each phase is determined from equation 3, and the results are added to derive the three-phase apparent power. The three-phase reactive power is calculated from the three-phase apparent power and the three-phase active power using equation 4. Active power for a three-phase, four-wire system

PΣ = P1 + P2 + P3

Apparent power for a three-phase, four-wire system

SΣ = S1 + S2 + S3( = U1×I1 +

U2 × I2 + U3 × I3)

Reactive power for a three-phase, f

our-wire system

Q3=

– P3

Type 3 (The method used in the harmonic measurement mode of the WT1600, the PZ4000, and the WT3000)

The reactive power of each phase is calculated directly using equation 2. The threephase apparent power is calculated using equation 4. This equation can be selected on models with the harmonic measurement option. Active power for a three-phase, four-wire system

PΣ = P1 + P2 + P3

Apparent power for a three-phase, four-wire system

S3=

+ Q3

Reactive power for three-phase, four-wire system QΣ = Q1 + Q2 + Q3

Phase Difference (See section 5.5 for operating instructions)

You can select the format for displaying the voltage and current phase differences between and within each element. With the voltage of each element as a reference, one format displays the phase difference using 360° in the clockwise direction, and the other format displays lead up to 180° in the counterclockwise direction (D) and lag up to 180° in the clockwise direction (G). In harmonic measurement (optional), the phase differences between harmonics 1 to 50 of the voltage and current signals are displayed using a 360° format or a 180° format with no sign for lead and a negative sign for lag.

User-Defined Functions (See section 5.13 for operating instructions)

Equations can be created (defined) by combining the measurement function symbols and operators. The numeric data that corresponds to the equation can then be determined. The combination of a measurement function and an element number, “Urms1:URMS(E1)” for example, constitutes an operand. Eight equations (F1 through F8) can be defined.

Operators

There are 11 operators: +, –, *, /, ABS (absolute value), SQR (square), SQRT (square root), LOG (logarithm), LOG10 (common logarithm), EXP (exponent), and NEG (negation).

Number of Operands

There can be up to 16 operands in one equation.

MAX Hold (See section 5.14 for operating instructions)

The maximum value of a type of numeric data can be held. The measurement functions that the MAX hold is applied to are selected from the user-defined functions.

Setting the Average Active Power (See section 5.15 for operating instructions)

The average active power can be computed for devices, such as intermittent control devices, whose power fluctuates. The equation for computing the average active power is specified using a user-defined function.

2.5 Computation

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Features

Delta Computation (Optional; See section 5.17 for operating instructions)

The sum or difference of the instantaneous voltage or current values (sampled data) between the elements in a wiring unit can be used to determine various types of data such as the differential voltage and phase voltage. This operation is called delta computation. Delta computation can be applied in the following ways:

•

The differential voltage and differential current between two elements can be

computed on a single-phase, three-wire system or on a three-phase, three-wire system (when using two elements).

•

The line voltage and phase current that are not measured can be computed on

a single-phase, three-wire system or on a three-phase, three-wire system (when using 2 elements).

• Using the data from a three-phase, four-wire system, the data of a delta connection can be computed from the data of a star connection (star-delta transformation).

• Using the data from a three-phase, three-wire system (three-voltage, threecurrent method), the data of a star connection can be computed from the data of a delta connection (delta-star transformation). This function is useful when you wish to observe the phase voltage of an object that has no neutral line.

Equations for Computing the Distortion Factor (See section 6.5 for operating instructions)

Models with the harmonic measurement option can compute distortion factors. There are two equations for computing the distortion factor, each with different denominators. For information about these equations, see appendix 1.

2.5 Computation

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2.6 Integration

The WT500 can integrate the active power (watt hour), the current (ampere hour), the apparent power (volt-ampere hour), and the reactive power (var hour) values. During integration, the measured and computed values of normal measurements can be displayed in addition to the watt hour, ampere hour, volt-ampere hour, var hour, and integration time values.

Integration Functions

Input Element Measurement Functions

The following nine types of numeric data can be determined. For details about the determination of measurement function data, see appendix 1. (1) WP: watt hours, i.e., the sum of positive and negative watt hours, (2) WP+: positive watt hours consumed, (3) WP-: negative watt hours returned to the power supply, (4) q: ampere hours, i.e., the sum of positive and negative ampere hours, (5) q+: positive ampere hours consumed, (6) q-: negative ampere hours returned to the power supply, (7) WS: volt-ampere hours, (8) WQ: var hours, and (9) Time: integration time.

•

Watt Hour Integration Method for Each Polarity (See section 5.11 for operating

instructions)

For positive and negative watt hours, WP+ and WP-, you can

set the integration equation to determine the DC or AC watt hours. (DC watt hours are computed by integrating each sampled data item. AC watt hours are computed by integrating the values at each data update interval.)

•

Current Integration Modes (See section 5.12 for operating instructions)

You can select the type of current whose values will be integrated.

Wiring UnitΣ Measurement Functions (Σ Functions)

The following eight types of numeric data can be determined. For details about the determination of measurement function data, see appendix 1. (1) WPΣ: sum of WP values, (2) WP+Σ: sum of WP+ values, (3) WP-Σ: sum of WPvalues, (4) qΣ: sum of q values, (5) q+Σ: sum of q+ values, (6) q-Σ: sum of q- values, (7) WSΣ: sum of SΣ values, and (8) WQΣ: sum of QΣ values.

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Features

Integration Mode (See sections 5.6 and 5.7 for operating instructions)

The integration feature has five modes: manual integration mode, normal integration mode, continuous integration mode, real-time integration mode, and real-time continuous integration mode.

Manual Integration Mode

Integration continues from when you start it until you stop it. However, when the integration time reaches its maximum (10000 hours) or the integrated value reaches its maximum or minimum displayable value (see section 5.6 for details), integration is stopped, and the integration time and integrated value at that point are held.

Integration time

ResetStart

Integrated value

Stop Start Reset

Hold

When STOP is pressed or the maximum integration time is reached

When the integrated value upper limit is reached

Normal Integration Mode

Integration continues for a specified amount of time (which is determined by the timer setting), and then stops. However, if the integrated value reaches its maximum or minimum displayable value before the specified amount of time has elapsed, integration is stopped, and the integration time and integrated value at that point are held.

Integration time

ResetStart

Integrated value

Hold

Timer value

2.6 Integration

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Continuous Integration Mode

Integration continues for a specified amount of time, and then resets and starts again. Integration repeats until you press STOP. If the integrated value reaches its maximum or minimum displayable value before the specified amount of time has elapsed, integration is stopped, and the integration time and integrated value at that point are held.

Start

Reset

Integration time

Integrated value

Hold

Timer value

Press STOP

Real-Time Normal Integration Mode

You specify the dates and times when integration will start and end. When the specified stop time is reached, or when the integrated value reaches its maximum or minimum displayable value, integration is stopped, and the integration time and integrated value at that point are held.

Integration time

Integrated value

Hold

Start date/time

End date/time

Reset

2.6 Integration

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Features

Real-Time Continuous Integration Mode (Continuous integration)

You specify the dates and times when integration will start and end, and integration repeats within the start and end times at the interval specified by the timer. When the amount of time specified by the timer elapses, integration resets and starts again. When the specified stop time is reached, or when the integrated value reaches its maximum or minimum displayable value, integration is stopped, and the integration time and integrated value at that point are held.

Integration time

Integrated value

Hold

Timer value

Start date/time

End date/time

Reset

2.6 Integration

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2.7 Waveform Display

The WT500 displays waveforms based on the data sampled within the data update rate.

Selecting the Waveform to Display (See section 3.7 for operating instructions)

You can select whether to show or hide the voltage and current waveforms of each input element. This makes waveforms easier to see by allowing you to only show the waveforms that you want to examine.

Vertical (Amplitude) Axis

The range of the vertical display is based on the specified measurement range. For example, if the crest factor is set to 3 and the voltage measurement range is set to 100 Vrms, the display range is set so that the top of the screen is 300 Vpk (100 Vrms × 3) and so that the bottom is –300 Vpk (–100 Vrms × 3), with the zero input line at the center. If the crest factor is set to 6 and the voltage measurement range is set to 50 Vrms, the display range is set so that the top of the screen is 300 Vpk (50 Vrms × 6) and so that the bottom is –300 Vpk (–50 Vrms × 6), with the zero input line at the center. The waveform is clipped if this range is exceeded.

1 grid division = 300 V

1 grid division = 100 V

When measured with a measurement range of 100 Vrms

When the same signal is measured with a measurement range of 300 Vrms

Input zero line

300 Vpk

–300 Vpk

900 Vpk

–900 Vpk

Horizontal (Time) Axis (See section 7.4 for operating instructions)

Set the length of the horizontal axis by specifying the time per grid division. The time axis can be set up to the point in which the time corresponding to one screen is equal to the data update rate, in 1, 2, 5 steps. For example, if the data update rate is 500 ms, the time per division can be changed in this order: 1 ms > 2 ms > 5 ms > 10 ms > 20 ms > 50 ms. In this case, the time corresponding to one screen changes in this order: 10 ms > 20 ms > 50 ms > 100 ms > 200 ms > 500 ms.

1 grid division = 10 ms

1 grid division = 20 ms

100 ms

(Observation time)

200 ms

(Observation time)

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IM 760201-01E

Features

Note

• Waveform sampling data and waveform display data (the number of displayed points on the screen)

Waveform sampling data and waveform display data are both measured waveform data, but

they differ as described below.

Waveform sampling data: Data derived through A/D conversion of the input signal

The WT500 A/D conversion rate is approximately 100 kS/s. Therefore, if the data update

rate is set to 1 s, the number of data points sampled from a single input signal in a single

measurement is approximately 100000 (see the figure below). Waveform sampling data is

also called acquisition data or raw wave data.

Waveform display data: Waveform data displayed on the WT500 screen (1002 points)

When displaying waveforms on the WT500, data points are displayed in horizontal rasters

(along the time axis). The number of rasters is 501. Each raster contains two points of

waveform display data. The two data points are the maximum and minimum values of the

waveform data in each raster. Therefore, the number of waveform display data points (the

number of points displayed on the screen) for a single input signal is 1002.

Extraction of waveform display data from waveform sampling data (p-p compression)

This example assumes that a 2-Hz sine wave is measured at a data update rate of 1 s.

To display this waveform on the WT500 screen, the number of data points is converted

from approximately 100000 to 1002 (501 pairs of maximum and minimum values). Thus,

two points (a pair) of waveform display data are derived from approximately 200 points

of waveform sampling data. This conversion is called p-p (peak-peak) compression. The

compression rate of p-p compression varies depending on the data update rate and the

horizontal scale (time axis) of the WT500 waveform display.

501 rasters

Number of data points:

1002 (501 pairs)

0 500

Time axis

Waveform sampling data

Waveform display data (WT500 screen)

p-p compression Compresses approximately 200 points of waveform sampling data to 2 points (Extracts the maximum and minimum values and draws them in each raster)

A/D-converted data

1 s

Number of data points:

Approx. 100000

With display interpolation on

Vertical axis

2.7 Waveform Display

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IM 760201-01E

• Aliasing

When the sample rate is low compared to the frequency of the input signal, the high

frequency components of the signal are lost. In accordance with the Nyquist sampling

theorem, the high frequency components in the signal are misread as low frequency

components. This is called aliasing.

Aliased signal Input signal Sampled points

• Sampling of waveform display data

The WT500 samples waveform display data and stores it to memory at a rate of

approximately 100 kS/s. The WT500 can accurately display the waveforms of signals with

frequencies up to approximately 5 kHz.

2.7 Waveform Display

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Features

Trigger (See section 7.5 for operating instructions)

A trigger is said to have “occurred” when the specified trigger condition is met and a waveform is displayed on the screen.

Trigger Mode

The trigger mode specifies the conditions for updating the display.

• Auto Mode

If a trigger occurs within a set amount of time (about 100 ms), which is referred to as

the timeout period, the waveform display is updated. If the timeout period elapses without a trigger occurring, the display will be updated automatically.

•

Normal Mode

The display is only updated when the trigger occurs. If the trigger does not occur, the

display will not be updated.

Trigger Source

The trigger source is the signal that is used to check for the trigger condition.

Trigger Slope

Slope refers to the movement of the signal from a low level to a high level (rising edge) or from a high level to a low level (falling edge). When the slope is used as one of the trigger conditions, it is called a trigger slope.

Trigger Level

The trigger level is the level at which the trigger slope is determined.

When the trigger source passes through the specified trigger level on a rising or falling edge, a trigger occurs. You can select the input signal from any element or from the external clock signal as the trigger source.

Trigger level

When set to rising ( ), the trigger occurs here (trigger point)

Trigger source

Trigger Point

The trigger point is the point at which a trigger occurs. The trigger point is always displayed at the left end of the screen. After the trigger is activated, the waveform display continues from the left of the screen to the right of the screen with the passage of time.

Trigger point

Time

2.7 Waveform Display

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IM 760201-01E

Vertical Waveform Zoom (See section 7.6 for operating instructions)

Each displayed waveform can be scaled vertically by a zoom factor of 0.1 to 100. The waveform is scaled around the zero-input line.

150 Vpk

300 Vpk

–150 Vpk

–300 Vpk

300 Vpk

–300 Vpk

Input zero line

When the zoom factor is doubled

Range displayed on the screen

Vertical Waveform Position (See section 7.6 for operating instructions)

You can vertically shift the displayed position of a waveform. This is useful when you want to view the relationship between voltage and current waveforms, or when the section of the waveform that you want to view does not fit into the display frame.

100%

–100%

Position moved by 50%

Position moved by –50%

2.7 Waveform Display

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Features

Split Waveform Display and Assignment (See section 7.7 for operating instructions)

The screen can be divided into windows, and waveforms can be assigned to those windows. The screen can be divided into up to four windows. This function is useful when there are many waveforms and it is difficult to view them all in a single display. Waveforms can be assigned to windows in one of the following three ways.

•

Auto

The waveforms whose displays are turned on are assigned in order according to

their element numbers, with an element’s voltage waveform coming before its current waveform.

•

Fixed

Regardless of whether their displays are on or off, waveforms are assigned in order

according to their element numbers, with an element’s voltage waveform coming before its current waveform.

•

User

Waveforms can be assigned to windows by the user, regardless of whether their

displays are on or off.

Waveform Display Interpolation (See section 7.8 for operating instructions)

The waveform display data can be connected linearly to display the waveform smoothly.

Linear Interpolation

Fills in the space between two data points with a straight line.

Interpolation OFF

No interpolation is performed. Only the data points are displayed.

Graticule (See section 7.8 for operating instructions)

A grid or cross-hair can be displayed on the screen. You can also choose to not display a grid or cross-hair.

Scale Value Display (See section 7.8 for operating instructions)

You can turn on or off the display of the upper and lower limits of the vertical axis and the values at the left and right ends of the horizontal axis (time axis) of each waveform.

2.7 Waveform Display

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Waveform Label Display (See section 7.8 for operating instructions)

You can turn the display of waveform labels on or off.

Time at the right end of the screen

Time at the left end of the screen

Minimum values

Maximum values

Waveform labels

Cursor Measurement (See sections 7.9 and 8.10 for operating instructions)

The value at the crossing point of the waveform and cursor can be measured and displayed. The voltage or current at specific sections of the waveform and the data on the horizontal axis (X-axis) can be measured. Cursor measurements are performed on the data that is displayed on the screen.

Two cursors, marked by a plus sign and an x, appear on the screen. For each cursor, the vertical value can be measured, and the X-axis value relative to the left end of the screen can be measured. The differences between the cursor’s vertical values and X-axis values can also be measured.

Measured values

+ cursor

x cursor

2.7 Waveform Display

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Features

2.8 Trend, Bar Graph, and Vector Displays

Trends of each measurement function, bar graphs of each harmonic, and vectors of the fundamental signals of each element (when using the harmonic measurement option) can be displayed.

Trend Display

The trends of all measurement functions that are measured during normal measurement and harmonic measurement are displayed.

Voltage (Urms1) trend

Voltage (U1) frequency trend

Trend Display Data

When the sampling of waveform display data is off during normal measurement, the numeric data of measurement functions that are determined at each data update interval is P-P compressed for each display segment (raster) and made into trend display data.* When the sampling of waveform display data is on during normal measurement, the numeric data of measurement functions that are determined whenever a trigger occurs is P-P compressed for each display segment (raster) and made into trend display data.*

* In some cases, P-P compression is not performed.

Scale Settings (See section 8.5 for operating instructions)

The WT500 can automatically set the values at the top and bottom of the screen based on the maximum and minimum values of the trend display data (this is referred to as auto scaling). The values at the top and bottom of the screen can also be set manually (manual scaling).

Horizontal (Time) Axis (See section 8.6 for operating instructions)

The time per division can be set in the range of 3 s to 1 day.

Split Display and Window Assignment (See section 8.7 for operating instructions)

Up to eight trends, T1 to T8, can be displayed. You can set trends T1 to T8 to any measurement function for any element. In harmonic measurement, you can also set the trends to harmonic orders. You can also divide the screen into as many as four windows, and each trend whose display is turned on will be assigned in numeric order to one of these windows.

Display Interpolation, Graticule, Scale Value Display, and Label Display (See section 8.8 for operating instructions)

The settings specified for waveform display are used.

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IM 760201-01E

Bar Graph Display of Harmonic Data (See section 6.7 for operating instructions)

On models with the harmonic measurement option, you can display harmonics using bar graphs. The harmonic orders are lined up on the horizontal axis, and the vertical axis represents the amplitude of each harmonic. You can choose which harmonic function, element, and orders to display. The selectable harmonic measurement functions are U, I, P, S, Q, λ, f, fU, and fI.

Bar graph of voltage U1

Bar graph of current I1

Vector Display of Harmonic Data (See section 6.8 for operating instructions)

On models with the harmonic measurement option, you can select a wiring unit to display vectors of the phase differences and amplitudes (rms values) of the fundamental signals, U(1) and I(1), in each element in the unit. The positive vertical axis is set to zero (angle zero), and the vector of each input signal is displayed. You can also zoom in on vectors or display amplitude values and the phase difference values between signals simultaneously.

The vector display is shown on the next page.

The elements whose vectors are displayed vary depending on the number of installed input elements and the selected wiring pattern. The following explanation is of the vector assignments when the number of input elements is three and when the wiring system of wiring unit Σ is set to three-phase, fourwire.

The vectors of elements 1, 2, and 3 are displayed. Vectors 1, 2, and 3 correspond to elements 1, 2, and 3, respectively. The relationships between the phase differences and amplitudes of U1(1), U2(1), U3(1), I1(1), I2(1), and I3(1) are displayed as vectors.

2.8 Trend, Bar Graph, and Vector Displays

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Features

I1(1)

I3(1)

I2(1)

F2(1)

F1(1), FU1-I1

F3(1)

FU1-U3

U1(1)

I1(1)

I3(1)

U3(1)

I2(1)

U2(1)

FU1-U2

FU1-I3

FU1-I2

• Vector Display When the Wiring System Is 3P3W (3V3A; Three-voltage, three-current)

U1(1), U2(1), and U3(1) are line voltages. I1(1), I2(1), and I3(1) are line currents.

By moving the vectors U1(1), U2(1), and U3(1) so that the starting points of all vectors are at the origin O, the phase relationship can be observed in the same fashion as the 3P4W system. (The WT500 does not provide a function for moving the vectors.)

U1(1)

I1(1)

I3(1)

U3(1)

I2(1)

U2(1)

• Vector Display When the Wiring System Is 3P3W (Three-phase, three-wire)

U1(1), U2(1), and U3(1) are line voltages. I1(1), I2(1), and I3(1) are line currents. However, U3(1) and I3(1) are not actually measured for the 3P3W system. The vectors are displayed through computation.

F2(1)

F1(1), FU1-I1

F3(1)

FU1-U3

FU1-I2

U1(1)

I1(1)

I3(1)

U3(1)

I2(1)

U2(1)

FU1-U2

FU1-I3

• Vector Display When the Wiring System Is 3P4W (Three-phase, four-wire)

U1(1), U2(1), and U3(1) are phase voltages. I1(1), I2(1), and I3(1) are line currents.

U1(1)

U3(1)

U2(1)

FU1-U2

FU2-U3

FU3-U1

The phase difference between the line voltages can be determined from the phase difference measurement functions

FU1-U2 and FU1-U3.

FU1-U2 = Measurement function FU1-U2 FU2-U3=(FU1-U3) – (FU1-U2) – 180 FU3-U1=–(FU1-U3)

2.8 Trend, Bar Graph, and Vector Displays

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IM 760201-01E

2.9 Saving and Loading Data, and Other Miscellaneous Functions

Storage (See chapter 9 for operating instructions)

Numeric data can be stored to the WT500 internal memory or USB memory. The data is stored at the data update rate or at a specified time interval.

Saving and Loading from the Storage Medium (See chapter 10 for operating instructions)

The WT500 has USB ports (for peripheral devices). You can save numeric data, waveform display data, screen image data, and setup parameters to USB memory. You can load saved setup parameters as necessary. Also, you can insert image data into documents in a word-processing application.

USB memory

ESC

RESET

SET

CAL

PAGE

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUMERIC WAVE OTHERS

FORM ITEM

CURSOR

INTEGRATOR

SETUP

INPUT INFO

START/

STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

FILE IMAGE

STORE

STORE SET

POWER

WT500

How WT500 Numeric Data and Waveform Display Data Can Be Transferred to a Personal Computer

WT500

Save

Load

1 Data acquisition using USB, Ethernet (optional), or GP-IB (optional) 2 Data acquisition using USB memory

Online

Offline

WT Viewer

Binary format

(*.wta)

Microsoft Excel

CSV format

(*.csv)

ASCII format (*.CSV)

Data stored in binary format (*.WTS and *.HDS)

Internal RAM disk

Save

USB storage

Numeric display data

Waveform display data

Store

2-37

IM 760201-01E

Features

Ethernet Interface (Optional) (See chapter 11 for operating instructions)

Using the FTP server function, you can access the WT500 from an FTP client* on the network and retrieve files from the WT500 internal memory or USB storage.

* PC or workstation with FTP client features.

File

ESC

RESET

SET

CAL

PAGE

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUMERIC WAVE OTHERS

FORM ITEM

CURSOR

INTEGRATOR

SETUP

INPUT INFO

START/ STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

FILE IMAGE

STORE

STORE SET

POWER

WT500

USB, GP-IB (Optional), and Ethernet (Optional) Communication (See the

Communication Interface User’s Manual IM760201-17E)

You can transfer measured data to a PC through a standard-equipped USB port, the optional GP-IB interface, or the optional Ethernet interface and analyze it on the PC. You can also make measurements by using an external controller to control the WT500.

PC Communication interface

ESC

RESET

SET

CAL

PAGE

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUMERIC WAVE OTHERS

FORM ITEM

CURSOR

INTEGRATOR

SETUP

INPUT INFO

START/

STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

FILE IMAGE

STORE

STORE SET

POWER

WT500

Entering Values and Strings on a USB Keyboard (See section 3.15 for operating instructions)

You can connect a USB keyboard to a USB port and enter file names, comments, and so on.

USB keyboard

ESC

RESET

SET

CAL

PAGE

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUMERIC WAVE OTHERS

FORM ITEM

CURSOR

INTEGRATOR

SETUP

INPUT INFO

START/

STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

FILE IMAGE

STORE

STORE SET

POWER

WT500

Initialization (See section 3.13 for operating instructions)

All setting made using panel keys and soft keys can be restored to their factory default settings. For information about the initial settings, see appendix 2, “List of Initial Settings and Numeric Data Display Order.”

2.9 Saving and Loading Data, and Other Miscellaneous Functions

2-38

IM 760201-01E

Selecting the Message Language (See section 3.18 for operating instructions)

You can set the language of the error messages displayed on the screen during operation to English or Japanese.

Selecting the Menu Language (See section 3.18 for operating instructions)

You can set the language of the menus displayed on the screen to English or Japanese.

RGB Video Signal (VGA) Output (Optional) (See section 12.2 for operating instructions)

The RGB video signal (VGA, Video Graphics Array) can be output to an external monitor. This allows values and waveforms to be displayed on a large screen.

Zero-Level Compensation (See section 12.3 for operating instructions)

Zero-level compensation is when the WT500 creates a zero input condition in its internal circuitry and sets the level at that point to the zero level. Zero-level compensation must be performed to satisfy the specifications of this instrument (see chapter 14). Zero level compensation is automatically performed when the measurement range or input filter is changed. However, when the measurement range and input filter are not changed over an extended time, the zero level may change due to the changes in the environment surrounding the instrument. In such cases, you can manually perform zero-level compensation. There is also a function that automatically performs zero-level compensation during integration.

NULL Feature (See section 12.4 for operating instructions)

When the NULL feature is turned on, the Udc and Idc values (numeric data of the simple average of the voltage and current) are set as NULL values. The NULL values are subtracted from the sampled voltage and current values. All measurement functions are affected by the NULL values.

Setting the Key Lock or Shift Lock (See section 12.5 for operating instructions)

The key lock can be used to prevent inadvertent operation errors. The shift lock can be used to reduce the number of times you press SHIFT.

Master/Slave Synchronized Measurement (See section 12.6 for operating instructions)

The measurement of two WT500s can be synchronized by making one WT500 the master and the other WT500 the slave. The master outputs a measurement start signal, and the slave receives the signal.

System Condition Check (See section 13.4 for operating instructions)

You can view information about the WT500, such as the model, firmware version (ROM version), input element configuration, and installed options.

Self-Test Feature (See section 13.3 for operating instructions)

The WT500 can evaluate its internal memory (RAM) and panel keys to determine if they are working properly.

2.9 Saving and Loading Data, and Other Miscellaneous Functions

3-1

IM 760201-01E

Before You Start Measuring

3.1 Handling Precautions

Safety Precautions

If you are using this instrument for the first time, make sure to thoroughly read “Safety Precautions,” on pages vi and vii.

Do Not Remove the Case

Do not remove the case from the instrument. Some parts of the instrument use high voltages and are extremely dangerous. For internal inspection and adjustment, contact your nearest YOKOGAWA dealer.

Unplug If Abnormal Behavior Occurs

If you notice smoke or unusual odors coming from the instrument, immediately turn off the power and unplug the power cord. Also, turn off the power to any circuits under measurement that are connected to the input terminals. Then, contact your nearest YOKOGAWA dealer.

Do Not Damage the Power Cord

Nothing should be placed on top of the power cord, and it should be kept away from any heat sources. When removing the plug from the power outlet, do not pull on the cord. Pull from the plug. If the power cord is damaged, purchase a replacement with the same part number as the one indicated on page iv.

Chapter 3

Before You Start Measuring

3-2

IM 760201-01E

General Handling Precautions

Do Not Place Objects on Top of the Instrument

Never stack the instrument or place other instruments or any objects containing water on top of it. Doing so may damage the instrument.

Keep Electrically Charged Objects Away from the Instrument

Keep electrically charged objects away from the input terminals. They may damage the internal circuitry.

Do Not Damage the LCD

Because the LCD is very vulnerable and can be easily scratched, do not allow any sharp objects near it. Also, do not apply vibration or shock to it.

Unplug during Extended Non-Use

Turn off the power to the circuit under measurement and the instrument and remove the power cord from the outlet.

Carry the Instrument Properly

First, turn off the circuit under measurement and remove the measurement cables. Then, turn off the instrument and remove the power cord and any attached cables. When moving the instrument, hold the handles on each side as shown below.

POWER

FILE

IMAGE

STORE

STORE SET

DISPLAY

NUMERIC

WAVE

OTHERS

FORM ITEM

CURSOR

INTEGRATOR

SETUP

INPUT INFO

START/

STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

ESC

RESET

SET

CAL

PAGE

When Cleaning the Instrument

When cleaning the case or the operation panel, turn off the circuit under measurement and the instrument and remove the instrument’s power cord from the outlet. Then, wipe the instrument lightly with a clean dry cloth. Do not use volatile chemicals such as benzene or thinner, because they might cause discoloring and deformation.

3.1 Handling Precautions

3-3

IM 760201-01E

Before You Start Measuring

3.2 Installing the Instrument

Installation Conditions

Install the instrument in an indoors environment that meets the following conditions.

Flat, Even Surface

Install the instrument on a surface that is flat and even in all directions. If you install the instrument on an uneven or tilted surface, the accuracy of its measurements may be impeded.

Well-Ventilated

Inlet holes are located on the top and vent holes are located on the bottom of the instrument. To prevent internal overheating, allow at least 20 mm of space around the inlet and vent holes.

When connecting measurement wires and other various cables allow extra space for operation.

Appropriate Ambient Temperature and Humidity

Ambient temperature: 5 to 40°C Ambient humidity: 20 to 80% RH

No matter what the circumstances, there must be no condensation.

Do not install the instrument in the following kinds of places.

• In direct sunlight, or near sources of heat

• In an environment with excessive amounts of soot, steam, dust, or corrosive gases

• Near strong magnetic fields

• Near high voltage equipment or power lines

• In a place that is subject to large levels of mechanical vibration

• On an u

nstable surface

Note

• For the most accurate measurements, use the instrument in the following kind of

environment.

Ambient temperature: 23 ± 5°C Ambient humidity: 30 to 75%RH (no condensation)

When using the instrument in a place where the ambient temperature is 5 to 18°C or 28 to

40°C, add the temperature coefficient to the accuracy as specified in chapter 14.

• When installing the instrument in a place where the ambient humidity is 30% or below, take

measures to prevent static electricity such as using an anti-static mat.

• Condensation may form when the instrument is moved from a low temperature/humidity

environment to a high temperature/humidity environment, or when there is a sudden change

in temperature. In these kinds of circumstances, wait for at least an hour before using the

instrument, to acclimate it to the surrounding temperature.

Storing the Instrument

When storing the instrument, avoid the following kinds of places.

• Where the relative humidity is 80% or higher

• Where the level of mechanical vibration is high

• In direct sunlight

• Where there are corrosive or explosive gasses

• Where the temperature is 60°C or higher

• Where an excessive amount of soot, dust, salt, or iron is present

• Near a strong source of heat or moisture

• Where water, oil, or chemicals may splash We recommend that the instrument be stored in an environment where the temperature is between 5 and 40°C and the relative humidity is between 20 and 80% RH.

3-4

IM 760201-01E

Installation Position

Desktop

Place the instrument on a flat, even surface as shown in the figure below. If the instrument is installed in a horizontal position, rubber stoppers can be attached to the feet to prevent the instrument from sliding. One set of rubber feet (two feet) are included in the package. Do not install the instrument in positions other than the left two positions indicated below.

Mounting in a Rack

To mount the instrument in a rack, use the separately sold rack mount kit.

Part Name Model Note

Rack mount kit (for single mount) 751533-E4 for EIA Rack mount kit (for multiple mount) 751534-E4 for EIA Rack mount kit (for single mount) 751533-J4 For JIS Rack mount kit (for multiple mount) 751534-J4 For JIS

An outline of the attachment procedures is given below. For detailed procedures, see the instructions that are included with the rack mount kit.

Remove the handles from the left side of the instrument.

Remove the four feet from the bottom of the instrument.

Remove the two plastic rivets and the four seals covering the rack mount

attachment holes on each side of the instrument near the front.

Place seals over the feet and handle attachment holes.

Attach the rack mount kit.

Mount the instrument on the rack.

LINK/ ACT

100 LINK

ETHERNET 100BASE -TX ON

USB

VIDEO-OUT

( VGA )

100-240 V A C

50 VA MAX

50/60 Hz

EXT

MAX

TO CAT

MINALS

CLK

88 )

Note

• When mounting the instrument to a rack, allow at least 20 mm of space around the inlet and

vent holes to prevent internal heating.

• Make sure to provide adequate support from the bottom of the instrument while avoiding

blocking the inlet and vent holes.

3.2 Installing the Instrument

3-5

IM 760201-01E

Before You Start Measuring

3.3 Connecting the Power Supply

Before Connecting the Power Supply

To avoid electric shock and damage to the instrument, follow the precautions below.

WARNING

• Confirm that the power source voltage matches the instrument’s rated power source voltage before connecting the power cord.

•

Confirm that the power switch is off before connecting the power cord.

•

To prevent fire and electric shock, use the power cord supplied by YOKOGAWA.

• To prevent electric shock, make sure to

ground the instrument. Insert the

instrument’s power cord into a grounded three-prong outlet.

•

Do not use an ungrounded extension cord. If you do, the device will not be

grounded.

•

Use an AC outlet that matches the power cord provided, and make sure that the

instrument is properly grounded. If an appropriate AC outlet is unavailable and protective grounding cannot be furnished, do not use the instrument.

Connecting the Power Cord

Check that the power switch is off.

Connect the instrument’s power cord to the power inlet on the rear panel.

Connect the plug on the other end of the power cord to an outlet that meets the

conditions below. The AC outlet must be a three-prong outlet with a protective earth ground terminal.

Item Specification

Rated supply voltage 100 to 240 VAC Permitted supply voltage range 90 to 264 VAC Rated supply frequency 50/60 Hz Permitted supply voltage frequency range 48 to 63 Hz Maximum power consumption 80 VA

The instrument can use a 100-V or a 200-V power supply. Check that the voltage supplied to

the instrument is less than or equal to the maximum rated voltage of the power cord provided with the instrument before using it (see page iii for the maximum rated voltage).

3-prong outlet

Power cord (included in the package)

ALL TER MINAL S

1000V M AX

EXT. CLK GP-IB (

IEEE 488

)

LINK/ ACT

100 LINK

ETHERNE T 10 0BAS E-TX ONLY

USB

VIDEO-OUT

( VGA

)

100-2 40 V A C

50 VA MAX 5 0/60 Hz

ELEMEN T

EXT

MAX

CAT

3-6

IM 760201-01E

3.4 Turning the Power Switch On and Off

Before Turning On the Power, Check That:

• The instrument is installed properly (see section 3.2, “Installing the Instrument”).

• The power cord is connected properly (see section 3.3, “Connecting the Power Supply”).

Power Switch Location

The power switch is located in the lower left of the front panel.

Turning the power switch on and off

The power switch is a push button. Press the button once to turn the instrument on and press it again to turn the instrument off.

OFF ON

FILE

POWER

Operations Performed When the Power Is Turned On

When the power switch is turned on, a self-test starts automatically. When the self-test completes successfully, the display shows the screen that was displayed immediately before the power switch was turned off.

Note

If the instrument does not operate as described above when the power switch is turned on, turn

the power switch off and check that:

• The power cord is securely connected.

• The power outlet is receiving the correct voltage (see section 3.3, “Connecting the Power

Supply”).

• After checking the above, try turning on the power switch while holding down ESC to reset

the settings to their initial values (the factory default). For information about the initial

settings, see section 3.13, “Initialization.”

If the instrument still does not work properly, contact your nearest YOKOGAWA dealer for

repairs.

3-7

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Before You Start Measuring

To Make Accurate Measurements

• Allow the instrument to warm up for at least 30 minutes after turning on the power switch.

•

Perform zero-level compensation after you have allowed the instrument to warm up (see

section 12.3, “Performing Zero- Level Compensation”).

Operations Performed When the Power Is Turned Off

After the power switch is turned off, the instrument stores the setup parameters in its memory before shutting down. The same operation is performed when the power cord is removed. The next time the power switch is turned on, the instrument powers up using the stored setup parameters.

Note

A lithium battery is used to retain the setup parameters. When the lithium battery voltage falls

below a certain level and you turn the power switch on, the instrument displays a message

on the screen (see section 13.2 for details). If this message appears frequently, the battery

should be replaced quickly. Do not try to replace the battery yourself. Contact your nearest

YOKOGAWA dealer to have the battery replaced. For information about the battery life, see

section 13.5.

3.4 Turning the Power Switch On and Off

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3.5 Precautions for Wiring the Circuit That You Will Measure

To avoid electric shock and damage to the instrument, follow the precautions below.

WARNING

• Ground the instrument before connecting measurement cables. The power cord that comes with the instrument is a three-prong cord. Insert the power cord into a grounded three-prong outlet.

• T

urn off the power to the circuit under measurement when wiring or disconnecting it. Connecting or removing measurement cables while the power is on is dangerous.

•

Do not wire a current circuit to the voltage input terminal or a voltage circuit to

the current input terminal.

•

Strip the insulation covers of measurement cables so that when they are wired

to the input terminals, the conductive parts (bare wires) do not protrude from the terminals. Also, make sure to fasten the input terminal screws securely so that cables do not come loose.

•

Only connect cables that have safety terminals that cover the conductive parts

to the voltage input terminals. Using a terminal with bare conductive parts (such as a banana plug) can be dangerous if the terminal comes loose.

•

Only connect cables that have safety terminals that cover the conductive parts

to the current sensor input terminals. Using a terminal with bare conductive parts (such as a banana plug) is dangerous if the terminal comes loose.

•

When the voltage from the circuit under measurement is being applied to the

current input terminals, do not touch the current sensor input terminals. Doing so is dangerous because the terminals are electrically connected inside the instrument.

•

When connecting a measurement cable from an external current sensor to a

current sensor input connector, remove the cables connected to the current input terminals. In addition, when the voltage of the circuit under measurement is being applied to a current sensor input terminal, do not touch the current input terminals. Doing so is dangerous because the terminals are electrically connected inside the instrument.

•

When using an external voltage transformer (VT) or current transformer (CT),

make sure that it has enough dielectric strength for the voltage (U) being measured (2U + 1000 V recommended). Also, make sure that the secondary side of the CT does not become an open circuit while the power is being applied. If this happens, high voltage will appear at the secondary side of the CT, making it extremely dangerous.

•

When using an external current sensor, make sure to use a sensor that comes in

a case. The conductive parts and the case should be insulated, and the sensor should have enough dielectric strength for the voltage being measured. Using a bare sensor is dangerous, because you might accidentally touch it.

•

When using a shunt-type current sensor as an external current sensor, turn off

the circuit under measurement. Connecting or removing the sensor while the power is on is dangerous.

•

When using a clamp-type current sensor as an external current sensor, confirm

that there are no shock hazards, after making sure that you understand the voltage of the circuit under measurement and the specifications and handling of the clamp-type sensor.

•

For safety reasons, when using the instrument on a rack mount, set up a switch

for turning off the circuit under measurement from the front side of the rack.

•

After connecting measurement cables, attach the current input protection cover

using the screws provided. Make sure that the conductive parts do not protrude from the protection cover.

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Before You Start Measuring

• To make the protective measures effective, before applying the voltage or current from the circuit under measurement, check that:

•

The power cord provided with the instrument is being used to connect to the

power supply and that the instrument is grounded.

•

The instrument’s power switch is turned on.

• The current input protective cover provided with the instrument is being used.

• When the instrument’s power switch is turned on, do not apply a signal that exceeds the following values to the voltage or current input terminals. When the instrument is turned off, turn off the circuit under measurement. For information about other input terminals, see chapter 14.

Instantaneous Maximum Allowable Input (1 s or less)

Voltage Input

Peak value of 2000 V or rms value of 1500 V, whichever is less.

Current input

Direct input

Peak value of 150 A or rms value of 45 A, whichever is less.

External Sensor Input

Peak value less than or equal to 10 times the range.

Continuous Maximum Allowable Input

Voltage Input

Peak value of 1500 V or rms value of 1000 V, whichever is less.

Current input

Direct input

Peak value of 100 A or rms value of 45 A, whichever is less.

External Sensor Input

Peak value less than or equal to 5 times the range.

CAUTION

• Use measurement cables with dielectric strengths and current capacities that are appropriate for the voltage or current being measured.

Example:

When making measurements on a current of 20 A, use copper wires that have a conductive cross-sectional area of 4 mm

. or greater.

• Connecting cables may cause radio interference, in which case users will be required to correct the interference.

Note

• After you finish wiring, you must select the wiring system. For details, see section 4.2, “Selecting the Wiring System.”

•

If you are measuring large currents, voltages or currents that contain high frequency

components, take special care in dealing with mutual interference and noise when wiring.

• Keep measurement cables as short as possible to minimize the loss between the circuit under measurement and the instrument.

• The thick lines on the wiring diagrams shown in sections 3.9 to 3.11 are the sections where the current flows. Use wires that are suitable for the current levels.

• To make accurate measurements of the voltage of the circuit under measurement, connect the cable to the circuit as closely as possible.

• To make correct measurements, separate the measurement cables as far away from the ground wires and the instrument’s case as possible to minimize static capacitance to the ground.

•

To measure the apparent power and power factor more accurately on an unbalanced three-

phase circuit, we recommend that you use a three-voltage, three-current method with a three-phase, three-wire system (3P3W; 3V3A).

3.5 Precautions for Wiring the Circuit That You Will Measure

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3.6 Assembling the Adapter for the Voltage Input Terminal

Assembling the 758931 Safety Terminal Adapter

When connecting a measurement cable to a WT500 voltage input terminal, use the 758931 Safety Terminal Adapter that comes with the package or the 758923 Safety Terminal Adapter that is sold separately. When using the 758931 Safety Terminal Adapter, assemble it according to the following procedure.

Assembling the Safety Terminal Adapter

Remove approximately 10 mm of the covering from the end of the cable and pass

it through the internal insulator.

Cable

Internal insulator

Attachable cable Covering: Max. diameter 3.9 mm Core wire: Max. diameter 1.8 mm

Insert the tip of the cable into the plug. Fasten the cable in place using the

hexagonal wrench.

Insert the hexagonal wrench into the plug and tighten.

Plug

Hexagonal wrench

Insert the plug into the internal insulator.

Attach the external cover. Make sure that the cover does not come off.

Cover

Note

Once the cover is attached, disassembly is difficult. Use care when attaching the cover.

Below is an illustration of the adapter after it has been assembled.

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Before You Start Measuring

Explanation

Wire the adapters that come with the WT500 or the adapters and various sensors that are sold separately as shown below:

Wiring to the Voltage Input Terminal

Voltage under measurement

758921

758922

758917

758923

758931

758929

WT500 voltage input terminal

ELEMENT

VOLTAGE

1000V

MAX

EXT

CURRENT

ALL TERMI NALS

1000V MAX

CAT

10V

MAX

1000VMAX

40A

MAX

ELEMENT

VOLTAGE

1000V

MAX

EXT

CURRENT

ALL TERMI NAL

1000V MAX TO CAT

10V MAX

1000VMAX

40A

MAX

Use the separately sold clamp-on probes as follows:

Wiring to the Current Input Terminal

751550 (voltage output type)

* The current input terminal and EXT input terminal cannot be wired (used) simultaneously.

751552 (current output type)

758917 758921

758924

Current under measurement

WT500 current input terminal

Connecting a clamp-on probe

WT500 EXT input terminal

ELEMENT

VOLTAGE

1000V

MAX

EXT

CURRENT

ALL TERMI NALS

1000V MAX

CAT

10V

MAX

1000VMAX

40A

MAX

ELEMENT

VOLTAGE

1000V

MAX

EXT

CURRENT

ALL TERMI NAL

1000V MAX TO CAT

10V MAX

1000VMAX

40A

MAX

3.6 Assembling the Adapter for the Voltage Input Terminal

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3.7 Wiring for Accurate Measurements

To make accurate measurements, refer to the items below when wiring the voltage input and current input terminals.

Effects of Stray Capacitance

When measuring a single-phase device, the effects of stray capacitance on measurement accuracy can be minimized by connecting the instrument’s current input terminal to the side that is closest to the earth potential of the power source (SOURCE).

SOURCE

LOAD

SOURCE

• Easily affected • Not easily affected

Effects of the Measured Voltage and Current Amplitudes

SOURCE

LOAD

SOURCE

• When the measured current is relatively large Connect the voltage input terminal to the load end.

• When the measured current is relatively small Connect the current input terminal to the load end.

± ±

Explanation

For details on the effects of stray capacitance and the effects of the measured voltage and current amplitudes, see appendix 4, “How to Make Accurate Measurements.”

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Before You Start Measuring

3.8 Guide for Selecting the Method Used to Measure the Power

Select the measurement method according to the amplitude of the measured voltage or current from the table below. For details about a wiring system or method, see its corresponding section indicated in the table.

Voltage Measurement Methods

When the voltage is less than or equal to 1000 V

When the voltage exceeds 1000 V

See section 3.9

Voltage wiring

Direct input is not possible

See section 3.11

Direct input

VT (voltage transformer)

Current Measurement Methods

When the voltage is less than or equal to 1000 V

When the current is less than or equal to 40 A

When the current exceeds 40 A

When the voltage exceeds 1000 V

See section 3.9

Current wiring

Direct input is not possible

Shunt resistors cannot be used

See section 3.10

See section 3.11

Direct input

Shunt resistor

Clamp-type current sensor (voltage output type)

Clamp-type current sensor (current output type)

CT (current transformer)

Notes when Replacing Other Power Meters with the WT500

In three-phase, three-wire systems (3P3W) and three-phase, three-wire systems that use a three-voltage, three-current method (3P3W; 3V3A), the wiring system of the WT500 may be different from that of another product (another digital power meter) depending on whether the reference voltage used to measure the line voltage (see appendix 4 for details) is based on single-phase or three-phase power. To make correct measurements, see the referenced sections in the selection guide above and check the wiring method of the three-phase, three-wire system.

The three-phase, three-wire systems are different

WT500 WT3000 WT1600 PZ4000

WT2000 WT1000 WT230 WT130 2533 2532 etc.

For example, if you replace the WT2000 (used in a three-phase, three-wire system) with the WT500 and leave the wiring unchanged, the measured power of each element will be different between the WT2000 and the WT500. Refer to this manual and re-wire the system correctly.

Note

In the wiring examples that follow, models are referred to by number. For information about the

different WT500 models and their specifications, see page iii.

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3.9 Wiring the Circuit That You Will Measure for Direct Input

This section explains how to wire the measurement cable directly from the circuit that you will measure to the voltage or current input terminal. To avoid electric shock and damage to the instrument, follow the precautions given in section 3.5, “Precautions for Wiring the Circuit That You Will Measure.”

Connecting to the Input Terminal

Voltage Input Terminal

The terminal is a f4-mm safety banana jack (female). Insert the safety terminal (whose conductive parts are not exposed) into the voltage input terminal. If you are using the 758931 Safety Terminal Adapter that comes with the package, see section 3.6.

Current Input Terminal

• When the voltage of the circuit under measurement is being applied to the current input terminals, do not touch the current sensor input terminals. Doing so is dangerous because the terminals are electrically connected inside the instrument.

•

When connecting measurement cables from external current sensors to current

sensor input connectors, remove the cables connected to the current input terminals. In addition, when the voltage of the circuit under measurement is being applied to current sensor input terminals, do not touch the current input terminals. Doing so is dangerous because the terminals are electrically connected inside the instrument.

•

The terminal is a binding post, and the screws are M6. Either wind the wire around the

screw or pass the crimp-on lugs through the screw axis, then tighten firmly with the terminal knob.

3.1

2.1

Unit: mm

Number of Installed Input Elements and Wiring Systems

The selectable wiring systems vary depending on the number of installed elements. For example, the three-phase, four-wire (3P4W) system cannot be selected on models with two input elements. For details, see “Number of Installed Input Elements and Wiring Systems” in section 2.3, “Measurement Conditions.”

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Before You Start Measuring

The assignment of elements to the input terminals in the wiring example figures below varies depending on the number of installed input elements. For details, see “Number of Installed Input Elements and Wiring Systems” in section 2.3, “Measurement Conditions.”

Note

• After you have finished wiring, you must select the wiring system. For details, see section 4.2,

“Selecting the Wiring System.”

• The thick lines on the wiring diagrams are the sections where the current flows. Use wires

that are suitable for the current levels.

Single-Phase, Two-Wire System Wiring Example (Applicable for models 760201, 760202, and 760203)

If three input elements are available, three single-phase, two-wire systems can be set up. See section 3.7 for information about which of the wiring systems shown below should be selected.

SOURCE

LOAD

SOURCE

LOAD

Input terminal

SOURCE

LOAD

Input terminal

!pm!

Single-Phase, Three-Wire System Wiring Example (Applicable for models 760202 and 760203)

If three input elements are available, two single-phase, three-wire systems can be set up (elements 1 and 2, or elements 2 and 3).

SOURCE

LOAD

SOURCE

Input terminal 1

LOAD

Input terminal 2

3.9 Wiring the Circuit That You Will Measure for Direct Input

3-16

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Three-Phase, Three-Wire System Wiring Example (Applicable for models 760202 and 760203)

If three input elements are available, two three-phase, three-wire systems can be set up (elements 1 and 2, or elements 2 and 3).

SOURCE

LOAD

SOURCE

Input terminal 1

LOAD

Input terminal 2

R S T

Wiring Example of a Three-Phase, Three-Wire System with a Three-Voltage, Three-Current Method (3P3W; 3V3A) (Applicable for model 760203)

If three input elements are available, one three-phase, three-wire system with a threevoltage, three-current method can be set up (elements 1, 2, and 3).

SOURCE

LOAD

SOURCE

Input terminal 1

LOAD

Input terminal 2

R S T

U3 U1

Input terminal 3

±±

Three-Phase, Four-Wire System Wiring Example (Applicable for model 760203)

If three input elements are available, one three-phase, four-wire system can be set up (elements 1, 2, and 3).

SOURCE

LOAD

SOURCE

Input terminal 1

LOAD

Input terminal

R S T N

U2U3

Input terminal 3

± ±±

Note

For details about the relationship between the wiring system and how measured and

computed values are determined, see appendix 1, “Symbols and Determination of

Measurement Functions.”

3.9 Wiring the Circuit That You Will Measure for Direct Input

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Before You Start Measuring

3.10 Wiring the Circuit That You Will Measure with a Current Sensor

To avoid electric shock and damage to the instrument, follow the precautions given in section 3.5, “Precautions for Wiring the Circuit That You Will Measure.”

If the maximum current value of the circuit under measurement exceeds the maximum range of the current input terminal, 40 Arms, you can measure the current by connecting an external sensor to the current sensor input connector.

Current sensor output type

• In the wiring example in this section, you can use a shunt resistor or a clamp-type current sensor as the external current sensor.

•

When using a clamp-type current sensor that outputs current, see section 3.11.

Connecting to the Input Terminal

Voltage Input Terminal

The terminal is a f4-mm safety banana jack (female). Insert the safety terminal (the conductive parts are not exposed) into the voltage input terminal. If you are using the 758931 Safety Terminal Adapter that comes with the package, see section 3.6.

External Current Sensor Input Terminal

Connect an external sensor cable with a BNC connector (B9284LK, sold separately) to an external current sensor input connector. Remove the measurement cable connected to the current input terminal. Because the current sensor input terminal and the current input terminal are connected internally, connecting both terminals simultaneously not only results in measurement errors but may also cause damage to the instrument. In addition, when the voltage of the circuit under measurement is being applied to the current sensor input terminal, do not touch the current input terminals. Doing so is dangerous because the terminals are electrically connected inside the instrument.

Number of Installed Input Elements and Wiring Systems

The selectable wiring systems vary depending on the number of input elements that are installed in the WT500. For details, see “Number of Installed Input Elements and Wiring Systems” in section 2.3, “Measurement Conditions.”

3-18

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Note

• After wiring has been completed, the wiring system must be selected. See section 4.2,

“Selecting the Wiring System.”

• The thick lines on the wiring diagrams are the sections where the current flows. Use wires

that are suitable for the current levels.

• To measure the apparent power and power factor more accurately on an unbalanced three-

phase circuit, we recommend that you use a three-voltage, three-current method with a

three-phase, three-wire system (3P3W; 3V3A).

• The current sensor input conversion feature can be used to convert the input signal data to

the corresponding data that would be acquired from direct measurements. For information

about how to set up this feature, see section 4.5, “Setting the Measurement Range for an

External Current Sensor (Optional).”

• Note that the frequency and phase characteristics of the current sensor affect the measured

data.

• Make sure that you have the polarities correct when you make connections. Otherwise,

the polarity of the measurement current will be reversed, and you will not be able to make

correct measurements. Be especially careful when connecting the clamp type current

sensor, because it is easy to reverse the connection.

• To minimize error when using a shunt resistor, follow the guidelines below when connecting

the external sensor cable.

• Connect the shielded wire of the external sensor cable to the L side of the shunt output

terminal (OUT).

• Minimize the area of the space between the wires connecting the shunt resistor to the

external sensor cable. This reduces the effects of the lines of magnetic force (which are

caused by the measurement current) and the external noise that enter the space.

Shunt resistor

OUT H

OUT L

Shielded wire

External sensor cable (B9284LK, sold separately)

WT500

Space between the connection wires

• Connect a shunt resistor to the power earth ground as shown in the figure below. If you have

to connect the sensor to the non-earth side, use a wire that is thicker than AWG18 (conductive

cross-sectional area of approx. 1 mm2) between the sensor and the instrument to reduce the

effects of common mode voltage. Take safety and error reduction into consideration when

constructing an external sensor cable.

LOAD

Shunt resistor

External current sensor input connector

Voltage input terminal

Power meter

• When the circuit under measurement is not grounded and the signal is high in frequency or

large in power, the effects of the inductance of the shunt resistor cable become large. In this

case, use an isolation sensor (CT, DC-CT, or clamp).

Clamp-type current sensor

External current sensor input connector

Voltage input terminal

Power meter

LOAD

3.10 Wiring the Circuit That You Will Measure with a Current Sensor

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Before You Start Measuring

The following wiring examples are for connecting shunt resistors. When connecting a clamp-type current sensor that outputs voltage, substitute the shunt-type current sensor with the clamp-type.

Shunt resistor

±±

OUT LOUT H

External current sensor input connector (EXT)

Input terminal

External current sensor input connector (EXT)

Input terminal

Clamp-type current sensor that outputs voltage

The assignment of elements to the input terminals in the figures below varies depending on the number of installed input elements. For details, see “Number of Installed Input Elements and Wiring Systems” in section 2.3, “Measurement Conditions.”

Wiring Example of a Single-Phase, Two-Wire System (1P2W) with a Shunt Resistor

SOURCE

LOAD

Earth side

Shunt resistor

OUT L OUT H

External current sensor input connector (EXT)

Input terminal

Wiring Example of a Single-Phase, Three-Wire System (1P3W) with a Shunt Resistor

SOURCE LOAD

±I

OUT L

OUT H

± ±

OUT L

OUT H

External current sensor input connector (EXT)

Input terminal 1

External current sensor input connector (EXT)

Input terminal 2

3.10 Wiring the Circuit That You Will Measure with a Current Sensor

3-20

IM 760201-01E

Wiring Example of a Three-Phase, Three-Wire System (3P3W) with a Shunt Resistor

SOURCE LOAD

±I

OUT L

OUT H

OUT L

OUT H

External current sensor input connector (EXT)

Input terminal 1

External current sensor input connector (EXT)

Input terminal 2

Wiring Example of a Three-Phase, Three-Wire System with a Three-Voltage, Three-Current Method (3P3W; 3V3A) and a Shunt Resistor

SOURCE

LOAD

±I

OUT L

OUT H

± ±

OUT L

OUT H

OUT L

OUT H

External current sensor input connector (EXT)

Input terminal 1

External current sensor input connector (EXT)

Input terminal 2

External current sensor input connector (EXT)

Input terminal 3

Wiring Example of a Three-Phase, Four-Wire System (3P3W) with a Shunt Resistor

SOURCE LOAD

±I

OUT LOUT H

± ± ±

OUT LOUT H

External current sensor input connector (EXT)

Input terminal 1

External current sensor input connector (EXT)

Input terminal 2

External current sensor input connector (EXT)

Input terminal 3

Note

For details about the relationship between the wiring system and how measured and computed

values are determined, see appendix 1, “Symbols and Determination of Measurement

Functions.”

3.10 Wiring the Circuit That You Will Measure with a Current Sensor

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Before You Start Measuring

3.11 Wiring the Circuit That You Will Measure with a VT or CT

This section explains how to wire a measurement cable from an external VT or CT to a voltage or current input terminal. Also refer to this section when wiring a clamp-type current sensor that outputs current. To avoid electric shock and damage to the instrument, follow the precautions given in section 3.5, “Precautions for Wiring the Circuit That You Will Measure.” When the maximum voltage of the circuit under measurement exceeds 1000 Vrms, you can make measurements by connecting an external VT to the voltage input terminal. If the maximum current value of the circuit under measurement exceeds the maximum range of the input elements, 40 Arms, you can measure the current by connecting an external CT, or a clamp-type sensor that outputs current, to a current input terminal.

Connecting to the Input Terminal

Voltage Input Terminal

The terminals are f4-mm safety banana jacks (female). Only insert a safety terminal whose conductive parts are not exposed into a voltage input terminal. If you are using the 758931 Safety Terminal Adapter that comes with the package, see section 3.6.

Current Input Terminal

•

When connecting a measurement cable from an external current sensor to a current

sensor input connector, remove the cables connected to the current input terminals. In addition, when the voltage of the circuit under measurement is being applied to a current sensor input terminal, do not touch the current input terminal. Doing so is dangerous because the terminals are electrically connected inside the instrument.

•

The screws used on the terminal (binding post) are M6 screws. Wind the wire around

the screw, use the separately sold Fork Terminal Adapter (758921), or pass the crimpon lugs through the screw axis, then tighten firmly with the terminal knob.

•

For the dimensions of the terminal parts, see section 3.9.

Number of Installed Input Elements and Wiring Systems

General VT and CT Handling Precautions

• Do not short the secondary side of a VT. Doing so may damage it.

• Do not short the secondary side of a CT. Doing so may damage it.

Also, follow the VT or CT handling precautions in the manual that comes with the VT

or CT that you are using.

3-22

IM 760201-01E

Note

• After you have finished wiring, you must select the wiring system. For details, see section 4.2,

“Selecting the Wiring System.”

• The thick lines on the wiring diagrams are the sections where the current flows. Use wires

that are suitable for the current levels.

• Make sure that you have the polarities correct when you make connections. If the polarity

is reversed, the polarity of the measurement current will be reversed, and you will not be

able to make correct measurements. Be especially careful when connecting the clamp type

current sensor, because it is easy to reverse the connection.

• The scaling feature can be used to transform the input signal to data that corresponds to

direct measurements. For information about how to set up this feature, see section 4.6,

“Setting the Scaling Feature When Using a VT or CT.”

• Note that the frequency and phase characteristics of the VT or CT affect the measured data.

• For safety reasons, the common terminals (+/–) of the secondary side of the VT and CT are

grounded in the wiring diagrams in this section. However, the necessity of grounding and

the grounding location (ground near the VT or CT or ground near the power meter) vary

depending on the object being measured.

• To measure the apparent power and power factor more accurately on an unbalanced three-

phase circuit, we recommend that you use a three-voltage, three-current method with a

three-phase, three-wire system (3P3W; 3V3A).

The following wiring examples are for connecting a CT. When connecting a clamp-type current sensor that outputs current, substitute the CT with the clamp-type current sensor. The assignment of elements to the input terminals in the figures below varies depending on the number of installed input elements. For details, see “Number of Installed Input Elements and Wiring Systems” in section 2.3, “Measurement Conditions.”

Wiring Example of a Single-Phase, Two-Wire System (1P2W) with a VT and CT

SOURCE

LOAD

SOURCE

LOAD

Input terminal

Wiring Example of a Single-Phase, Three-Wire System (1P3W) with a VT and CT

SOURCE

LOAD

Input terminal 1

Input terminal 2

3.11 Wiring the Circuit That You Will Measure with a VT or CT

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Before You Start Measuring

Wiring Example of a Three-Phase, Three-Wire System (3P3W) with a VT and CT

SOURCE

LOAD

R S T

Input terminal 1

Input terminal 2

Wiring Example of a Three-Phase, Three-Wire System with a Three-Voltage, Three-Current Method (3P3W; 3V3A), a VT, and a CT

SOURCE

LOAD

R S T

Input terminal 1

Input terminal 2

Input terminal 3

Wiring Example of a Three-Phase, Four-Wire System (3P4W) with a VT and CT

SOURCE

LOAD

R S T N

Input terminal 1

Input terminal 2

Input terminal 3

Note

For details about the relationship between the wiring system and how measured and computed

values are determined, see appendix 1, “Symbols and Determination of Measurement

Functions.”

3.11 Wiring the Circuit That You Will Measure with a VT or CT

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IM 760201-01E

3.12 Setting the Date and Time

Procedure

Press MISC to display the Misc Menu.

Turning the Date and Time Display On or Off

Use the cursor keys to select Date/Time.

Press SET to display the Date/Time dialog box.

Use the cursor keys to select Display.

Press SET to select ON or OFF.

Setting the Date or Time Manually

Use the cursor keys to select one of the Date (year, month, and day) or Time (hour,

minute, and second) boxes.

Press SET to display an entry box.

Use the cursor keys to set the year, month, date, hour, minute, or second that

you selected in step 6.

Press SET or ESC to close the entry box.

10.

Repeat steps 6 to 8 to set the year, month, date, hour, minute, and second.

11.

Use the cursor keys to select Set.

12.

Press SET. If you selected ON in step 5, the new date and time are displayed in

the lower right corner of the screen. If you cancel the procedure without pressing SET, the new settings are not reflected on the display.

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Before You Start Measuring

Explanation

Turning the Date and Time Display On or Off

You can select whether or not to display the date and time in the lower right of the screen.

•

OFF: Do not display the date and time.

• ON: Display the date and time.

Setting the Date and Time

• Setting the Date

The format for setting the date is YY/MM/DD (year/month/day).

• Setting the Date/Time

The format for setting the time is HH:MM:SS (hour:minute:second). The hour can be

set to a value from 0 to 23.

Note

• The date and time information is backed up with an internal lithium battery when the power

is turned off.

• The WT500 contains leap year information. The instrument determines the leap year

calendar when new settings are confirmed. If you enter 2/29 for the date on a non-leap year,

an error message will be displayed.

3.12 Setting the Date/Time

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3.13 Initializing the Settings

Procedure

Note

Only initialize the WT500 if you are sure that it is okay for all of the settings to return to their

initial values. You cannot undo an initialization. We recommend that you save the setup

parameters before initializing the WT500 (see section 10.3 for details).

Press MISC to display the Misc Menu.

Use the cursor keys to select Initialize Settings.

Press SET. An alert message appears.

Use the cursor keys to select OK.

Press SET to execute initialization.

To cancel the initialization, select Cancel in step 3 and press SET.

Explanation

The values specified by using the panel keys can be reset to their factory default values. This is useful when you wish to clear previous settings or start the settings from scratch. For information about the initial settings, see appendix 2, “List of Initial Settings and Numeric Data Display Order.”

Settings That Cannot Be Initialized

• Date and time settings

• Menu and message language settings

• The designation of the files display (Filter)

• File utility operation (Function)

• USB interface, GP-IB interface (optional), and Ethernet interface (optional) settings

Initializing at Power Up

To make the WT500 start up with the initial settings, turn on the power. Then, when the message “Boot OK” appears, press and hold ESC until the NUMERIC key blinks. All of the settings listed under “Settings That Cannot be Initialized,” except for the date and time, are initialized. A message indicating that the settings have been initialized appears on the screen.

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Before You Start Measuring

3.14 Entering Values and Character Strings

Entering Values

When you select a setup parameter with SET, an entry box appears. Then, you can change the value by using the cursor keys. Use the left and right cursor keys to select digits, and use the up and down cursor keys to set the value of a digit.

Note

Some of the parameters that can be changed using the cursor keys are reset to their initial

values when SHIFT+ESC (RESET) is pressed.

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Entering Character Strings

Units, file names, the equations for user-defined functions, and the user name and password for the Ethernet Interface (optional) can be entered using the keyboard that is displayed on the screen. Use the cursor keys and SET to navigate the keyboard and enter a character string.

Use the cursor keys to select a character.

Press SET to enter that character into the entry box.

If there are characters already in the entry box, use the Page and Page cursor keys to

select the entry position.

Repeat steps 1 and 2 to enter all of the characters in the string.

After entering all of the characters, select on the keyboard, and press SET.

If you enter an incorrect user-defined function, an error message appears.

Moves the cursor to the left.

Moves the cursor to the right.

Deletes the previous character.

Enters a character string.

Keys Other Than the Character Keys

• CAPS: Switches between uppercase and lowercase.

• SPACE: Enters a space.

•

: Enters the displayed characters.

Usable Characters and Maximum String Lengths

Setting Max. Length Usable Characters

Equation 1 to 50 characters Spaces and all characters that are displayed on the

keyboard

Unit 1 to 8 characters Spaces and all characters that are displayed on the

keyboard File name 1 to 8 characters 0-9, A-Z, %, _, parentheses, and minus signs Comment 0 to 25 characters Spaces and all characters that are displayed on the

keyboard Server name 0 to 40 characters Spaces and all characters that are displayed on the

keyboard User name 0 to 15 characters Spaces and all characters that are displayed on the

keyboard Password 0 to 15 characters Spaces and all characters that are displayed on the

keyboard

Note

File names are not case-sensitive. Comments are case-sensitive. The following file names

cannot be used due to MS-DOS limitations.

AUX, CON, PRN, NUL, CLOCK, COM1 to COM9, and LPT1 to LPT9

3.14 Entering Values and Character Strings

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Before You Start Measuring

3.15 Entering Character Strings on a USB Keyboard

You can connect a USB keyboard to a USB port and enter file names, comments, and so on.

USB PERIPHERAL Connector

Use a USB cable to connect a USB keyboard to a USB PERIPHERAL connector on the left side of the front panel. There are two USB PERIPHERAL ports.

2 3 4

Ports

Pin No. Signal Name

1 VBUS : +5 V 2 D- : -Data 3 D+ : +Data 4 GND : Ground

Usable Keyboards

The following keyboards conforming to USB Human Interface Devices (HID) Class Ver1.1 can be used.

•

When the USB keyboard language is English: 104 keyboard

• When the USB keyboard language is Japanese: 109 keyboard Section 3.19 explains how to select one of these two keyboards.

Note

• For USB keyboards that have been tested for compatibility, contact your nearest

YOKOGAWA dealer.

• Do not connect USB devices other than USB keyboards or USB memory to the USB

PERIPHERAL ports.

• The WT500 has two USB PERIPHERAL ports. However, USB devices whose maximum

current consumption exceeds 100 mA cannot be connected simultaneously to the two ports.

Connection Procedure

Connect the USB keyboard to the WT500 directly using a USB cable as shown below. You can connect/disconnect a USB cable at any time regardless of whether the WT500 is on or off (supports hot-plugging). Connect the type A connector of the USB cable to the WT500, and connect the type B connector to the keyboard. When the power switch is on, the keyboard is detected and enabled approximately six seconds after it is connected.

USB connection

USB keyboard

ESC

RESET

SET

CAL

PAGE

ELEMENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUMERIC WAVE OTHERS

FORM ITEM

CURSOR

INTEGRATOR

SETUP

INPUT INFO

START/

STOP

RESET

HOLD

SINGLE

SHIFT

MISC

NULL

LOCAL

KEY LOCK

FILE IMAGE

STORE

STORE SET

POWER

WT500

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Note

• Connect the keyboard directly, not through a USB hub.

• Do not connect USB devices other than USB keyboards or USB memory to the USB

PERIPHERAL ports.

• Do not connect multiple keyboards.

• Holding down a key on the keyboard does not enter the character or value repetitively.

• Do not connect and disconnect multiple USB devices repetitively. Leave a 10-second

interval between removal and connection.

• Do not connect or disconnect the USB cable after the power is turned on until key operation

is possible (approximately 20 to 30 s).

Confirming What Keyboard Is Connected

To confirm what keyboard is connected to the WT500, carry out the procedure below.

Press MISC.

Use the cursor keys to select USB.

Press SET to display the USB dialog box.

Use the cursor keys to select Device List.

Press SET to select USB Device List. Information about the connected USB

keyboard appears.

Entering File Names, Comments, Etc.

When a keyboard is displayed on the screen, you can enter file names, comments, and other items using the USB keyboard. The characters that are entered by each key on the USB keyboard vary depending on the keyboard type.

Executing Functions Corresponding to the Keys on the Front Panel of the WT500

The keys on a USB keyboard can be used to perform the same operations that can be performed using the front panel keys. The assignment of front panel key functions to USB keyboard keys varies depending on the keyboard type. For details, see appendix 6.

3.15 Entering Character Strings on a USB Keyboard

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Before You Start Measuring

3.16 Switching the Display

Procedure

Switching to the Numeric Display

Press NUMERIC to display numeric values.

Switching to the Waveform Display

Press WAVE to display waveforms.

Switching to the Trend, Bar Graph, or Vector Display

Press OTHERS to display the Others menu.

Using the Cursor Keys

Use the cursor keys to set the display to Trend, Bar, or Vector.

Press SET. The selected display appears.

Using OTHER

Press OTHER to switch between display modes in this order: Trend > Bar >

Vector > Trend > and so on.

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Explanation

On the WT500, you can choose from the following kinds of displays.

Display Mode

Without the harmonic measurement option

Power measurement (numeric display) (Numeric)

Waveform display (Wave)

Trend display (Trend)

Bar graph display (Bar)

Vector display (Vector)

With the Harmonic Measurement Option

For operating instructions, see chapter 5. For an explanation of the features, see section 2.4.

For operating instructions, see chapter 6. For an explanation of the features, see section 2.4.

For operating instructions, see chapter 6. For an explanation of the features, see section 2.8.

For operating instructions, see chapter 7. For an explanation of the features, see section 2.7.

For operating instructions, see chapter 8. For an explanation of the features, see section 2.8.

Bar graph display is not possible.

Vector display is not possible.

Note

When waveforms are displayed, the measurement mode indicated on the screen is Normal

Mode (Trg). For details, see section 7.1.

3.16 Switching the Display

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Before You Start Measuring

3.17 Displaying a List of Setup Parameters

Procedure

Displaying the Setup Parameter List

Press SHIFT+SETUP (INPUT INFO). A list of input conditions (such as the wiring

units for each element, the measurement range, the scaling coefficient, the synchronization source, and the input filter) appears.

Closing the Setup Parameter List

Press SHIFT+SETUP (INPUT INFO) or ESC (when no menus are displayed). The

list of setup parameters closes.

Explanation

Setup Parameter List

The figure below is an example of a setup parameter list when the crest factor is set to 3.

Note

The list of input conditions shows the settings when measurement took place. If the

measurement range or some other setting is changed while the hold feature is on, the changes

will not be reflected in the list.

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3.18 Selecting the Message Language

Procedure

Press MISC to display the Misc Menu.

Use the cursor keys to select System Config.

Press SET to display the System Config menu.

Selecting the Message Language

Use the cursor keys to select Message Language.

Press SET to select JPN or ENG.

Selecting the Menu Language

Use the cursor keys to select Menu Language.

Press SET to select JPN or ENG.

Explanation

Selecting the Message Language

Error messages appear when errors occur. You can choose to display these messages using one of the following languages. The error codes that accompany error messages are the same for both English and Japanese messages. For more information about error messages, see section 13.2.

JPN:

Japanese

ENG: Englis

Selecting the Menu Language

You can choose to display menus using one of the following languages.

JPN: Japanese ENG: English

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Before You Start Measuring

3.19 Setting the USB Keyboard Language

Procedure

Press MISC to display the Misc Menu.

Use the cursor keys to select USB.

Press SET to display the USB menu.

Use the cursor keys to select Keyboard.

Press SET to select JPN or ENG.

Explanation

Set the language to use when entering file names, comments, and other items (see section 3.15 for details) from the USB keyboard. The following keyboards conforming to USB Human Interface Devices (HID) Class Ver1.1 can be used.

•

ENG: 104 keyboard

• JPN: 109 keyboard

The characters that are entered by each key on the USB keyboard vary depending on the keyboard type. For details, see appendix 6.

Note

For USB keyboards that have been tested for compatibility, contact your nearest YOKOGAWA

dealer.

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Measurement Conditions

4.1 Panel Keys and Setup Menus Used in This Chapter

Panel Keys Used in This Chapter

ESC

RESET

SET

CAL

PAGE

ELEMENT

ELEM ENT

ALL

RANGE

VOLTAGE CURRENT

AUTO AUTO

DISPLAY

NUME RIC WAVE OTH ERS

FORM ITE M

CUR SOR

INTEGR ATOR

SETU P

INPU T INFO

START/

STOP

RESE T

HOLD

SING LE

SHIF T

MISC

NULL

LOC AL

KEY L OCK

FILE IMAGE

STOR E

STORE SET

POWE R

Cursor keys

4.4 Setting the Measurement Range for Direct Input

4.5 Setting the Measurement Ranges for an External Current Sensor (Optional)

4.4 Setting the Measurement Range for Direct Input

4.12 Holding and Performing Single Measurements

Displays the SETUP menu (see below for the contents of the menu)

Displays the MISC menu (see below for the contents of the menu)

Select and confirm menu items

Setup Menus Used in This Chapter

To set a parameter, access its menu by pressing the appropriate panel key. The setup menus and menu items used in this chapter are shown below, along with the sections that correspond to their operating instructions.

SETU P

MISC

SETUP key

MISC key

4.11 Selecting a Crest Factor

4.10 Selecting an Averaging Method

4.6 Setting the Scaling Feature When Using a VT or CT

4.7 Setting the Measurement Period

4.8 Selecting an Input Filter

4.9 Selecting the Data Update Rate

4.4 Setting the Measurement Range for Direct Input

4.5 Setting the Measurement Ranges for an External Current Sensor (Optional)

4.2 Selecting a Wiring System

4.3 Selecting Independent Input Element Configuration

Chapter 4 Measurement Conditions

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4.2 Selecting a Wiring System

Procedure

Press SETUP to display the Setup menu.

Use the cursor keys to select Wiring.

Press SET to display the Wiring Settings dialog box.

Selecting a Wiring System

Use the cursor keys to select Wiring.

Press SET. The pattern selection dialog box appears.

Use the cursor keys to select a pattern.

Press SET to confirm the pattern.

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Measurement Conditions

Explanation

Wiring System

• There are five wiring systems available on the WT500. The selectable wiring systems vary depending on the number of elements installed in the WT500.

(1) 1P2W

, single-phase, two-wire; (2) 1P3W, single-phase, three-wire; (3) 3P3W, three-phase, three-wire; (4) 3P4W, three-phase, four-wire; and (5) 3V3A, threevoltage, three-current.

•

The wiring system determines how input elements are assignment to wiring unit Σ

and how Σ functions (such as voltage, current, active power, apparent power, reactive power, power factor, and phase difference) are determined. For details about the relationship between the wiring system and how Σ functions are determined, see Appendix 1.

•

The following table shows the relationship between the number of installed input

elements, the selectable wiring systems, and the assignment of input elements to wiring unit Σ.

Number of installed input elements

Wiring system Pattern 1

1P2W

Number of installed input elements

Wiring system Pattern 1

Wiring system Pattern 2

1P2W

1P3W:Σ or 3P3W:Σ

Number of installed input elements

Wiring system Pattern 1

Wiring system Pattern 2

Wiring system Pattern 3

Wiring system Pattern 4

1P2W

1P3W:Σ or 3P3W:Σ

3P4W:Σ or 3P3W (3V3A):Σ

Note

• Select the wiring system to match the actual wiring of the circuit under measurement. The

method in which the

functions are determined varies depending on the wiring system. If

the selected wiring system does not match the wiring of the actual circuit, measurements

and computation will not be correct.

•

For details about the relationship between the wiring system and how

functions are

determined, see Appendix 1.

Wiring System Display

The wiring system configuration is displayed on the right side of the screen. Because it is displayed behind the menu, to view it, you need to press the ESC key to hide the menu. The figure below shows wiring system display examples for a model with three input elements installed.

When elements 1 to 3 are set to single-phase, two-wire system

When element 1 and 2 are set to single-phase, three-wire system, and element 3 is set to single-phase, two-wire system

Wiring unit and system

The elements that make up the wiring unit are contained in the frame.

4.2 Selecting a Wiring System

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Settings of Elements Grouped in a Wiring Unit

If the independent configuration of input elements (described in section 4.3) is off and a wiring system other than 1P2W is selected when the measurement range or synchronization source settings of each input element are different, the following settings are changed in the manner described below:

•

The measurement range of all input elements included in the wiring unit is set to the

highest range among all input elements. The external current sensor input range has precedence over the direct input current range.

•

The auto range settings are changed to match the setting of the input element whose

measurement range is highest. If multiple input elements are set to a common highest measurement range, the settings of the input element with the smallest input element number take precedence.

•

The synchronization source setting is changed to match the setting of the input

element with the smallest input element number among the input elements included in

the wiring unit. When you press ELEMENT to select the element to be configured, the LEDs of input elements in the wiring unit light simultaneously.

4.2 Selecting a Wiring System

Yokogawa WT500 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Checking the Package Contents

Safety Precautions

Waste Electrical and Electronic Equipment

Conventions Used in This Manual

Workflow

Contents

Chapter 1 Component Names and Functions

1.1 Front Panel, Rear Panel, and Top Panel

1.2 Setup Menu Display and Operation Keys

1.3 Screen Display

2.1 System Configuration and Block Diagram

Chapter 2 Features

2.2 Measurement Functions and Periods

2.3 Measurement Conditions

2.4 Power Measurement

2.5 Computation

2.6 Integration

2.7 Waveform Display

2.8 Trend, Bar Graph, and Vector Displays

2.9 Saving and Loading Data, and Other Miscellaneous Functions

3.1 Handling Precautions

3.2 Installing the Instrument

3.3 Connecting the Power Supply

3.4 Turning the Power Switch On and Off

3.5 Precautions for Wiring the Circuit That You Will Measure

3.6 Assembling the Adapter for the Voltage Input Terminal

3.7 Wiring for Accurate Measurements

3.8 Guide for Selecting the Method Used to Measure the Power

3.9 Wiring the Circuit That You Will Measure for Direct Input

3.10 Wiring the Circuit That You Will Measure with a Current Sensor

3.11 Wiring the Circuit That You Will Measure with a VT or CT

3.12 Setting the Date and Time

3.13 Initializing the Settings

3.14 Entering Values and Character Strings

3.15 Entering Character Strings on a USB Keyboard

3.16 Switching the Display

3.17 Displaying a List of Setup Parameters

3.18 Selecting the Message Language

3.19 Setting the USB Keyboard Language

4.1 Panel Keys and Setup Menus Used in This Chapter

Chapter 4 Measurement Conditions

4.2 Selecting a Wiring System