YOKOGAWA WT1803 User manual

IM WT1801-01EN
3rd Edition
Precision Power Analyzer
WT1800
Features Guide

i
IM WT1801-01EN
Thank you for purchasing the WT1800 Precision Power Analyzer. This manual contains useful
information about the features of the WT1800. To ensure correct use, please read this manual
thoroughly before beginning operation.
After reading the manual, keep it in a convenient location for quick reference whenever a question
arises during operation. The following manuals, including this one, are provided as manuals for the
WT1800. Please read all the manuals.
Manual Title Manual No. Description
WT1800 Precision Power Analyzer
Features Guide
IM WT1801-01EN This manual. The supplied CD contains the PDF
file of this manual. This manual explains all the
WT1800 features other than the communication
interface features.
WT1800 Precision Power Analyzer
User’s Manual
IM WT1801-02EN The supplied CD contains the PDF file of this
manual. The manual explains how to operate the
WT1800.
WT1800 Precision Power Analyzer
Getting Started Guide
IM WT1801-03EN The manual explains the handling precautions and
basic operations of the WT1800 and provides an
overview of its features.
WT1800 Precision Power Analyzer
Communication Interface
User’s Manual
IM WT1801-17EN The supplied CD contains the PDF file of this
manual. The manual explains the WT1800 series
communication interface features and instructions
on how to use them.
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 figures given in this manual
may differ from those that actually appear on your screen.
•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.
Trademarks
• Microsoft, Internet Explorer, MS-DOS, Windows, Windows NT, and Windows XP are either
registered trademarks or trademarks of Microsoft Corporation in the United States and/or other
countries.
•Adobe and Acrobat are either registered trademarks or trademarks of Adobe Systems
Incorporated.
• In this manual, the ® and TM symbols do not accompany their respective registered trademark
or trademark names.
• Other company and product names are trademarks or registered trademarks of their respective
holders.
Revisions
• 1st Edition: February 2011
• 2nd Edition: August 2011
• 3rd Edition: October 2017
3rd Edition: October 2017 (YMI)
All Rights Reserved, Copyright © 2011 Yokogawa Test & Measurement Corporation

ii IM WT1801-01EN
Contents
1 Items That This Instrument Can Measure
Measurement Functions Used in Normal Measurement............................................................... 1-1
Harmonic Measurement Functions (Option)................................................................................. 1-3
Delta Computation Functions (Option).......................................................................................... 1-5
Motor Evaluation Functions (Option) ............................................................................................ 1-5
Auxiliary Input Measurement Functions (Option).......................................................................... 1-5
High Speed Data Capturing Measurement Functios (Option) ...................................................... 1-5
What Is a Measurement Function?............................................................................................... 1-6
Measurement Period..................................................................................................................... 1-6
2 Fundamental Measurement Conditions
Wiring System Settings (WIRING)................................................................................................ 2-1
Wiring System (Wiring) ................................................................................................................. 2-1
Efciency Equation (η Formula).................................................................................................... 2-4
Independent Input Element Conguration (Element Independent)............................................... 2-5
Delta Computation (Δ Measure; option)........................................................................................ 2-6
Selecting an Element Whose Measurement Range You Want to Specify (ELEMENT)................ 2-8
Selecting All Input Elements (ALL)................................................................................................ 2-9
Voltage Range (RANGE UP/DOWN (V)) ...................................................................................... 2-9
Auto Voltage Range (AUTO (V))................................................................................................. 2-10
Current Range (RANGE UP/DOWN (A)).....................................................................................2-11
Auto Current Range (AUTO (A))..................................................................................................2-11
Power Range .............................................................................................................................. 2-12
External Current Sensor Range (EXT SENSOR; option) ........................................................... 2-12
External Current Sensor Conversion Ratio (SENSOR RATIO; option)....................................... 2-13
External Current Sensor Range Display Format (DIRECT/MEASURE; option) ......................... 2-14
Scaling (SCALING) ..................................................................................................................... 2-14
Valid Measurement Range (CONFIG(V)/CONFIG(A))................................................................ 2-16
Crest Factor (Crest Factor)......................................................................................................... 2-17
Measurement Period (SYNC SOURCE)..................................................................................... 2-18
Line Filter (LINE FILTER)............................................................................................................ 2-19
Frequency Filter (FREQ FILTER) ............................................................................................... 2-19
Data Update Interval (UPDATE RATE)....................................................................................... 2-20
Averaging (AVG) ......................................................................................................................... 2-20
Displaying the Setup Parameter List (INPUT INFO)................................................................... 2-22
3 Harmonic Measurement Conditions (Option)
Harmonic Measurement Conditions (HRM SET).......................................................................... 3-1
PLL Source (PLL Source) ............................................................................................................. 3-1
Measured Harmonic Orders (Min Order/Max Order) .................................................................... 3-2
Distortion Factor Equation (Thd Formula)..................................................................................... 3-3
Input Element Group (Element Settings) ...................................................................................... 3-3
Anti-Aliasing Filter ......................................................................................................................... 3-4

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IM WT1801-01EN
Contents
4 Motor Evaluation Conditions (Option)
Motor Evaluation Conditions and Auxiliary Input Conditions (MOTOR/AUX SET) ....................... 4-1
Scaling Factor (Scaling)................................................................................................................ 4-1
Unit (Unit)...................................................................................................................................... 4-2
Input Signal Type (Sense Type).................................................................................................... 4-2
Analog Input Range ...................................................................................................................... 4-3
Linear Scaling of Analog Input ...................................................................................................... 4-3
Line Filter (Line Filter)................................................................................................................... 4-4
Synchronization Source (Sync Source) ........................................................................................ 4-5
Pulse Input Range ........................................................................................................................ 4-5
Torque Signal Pulse Rating........................................................................................................... 4-5
Revolution signal pulses per revolution (Pulse N) ........................................................................ 4-7
Synchronous Speed (Sync Speed)............................................................................................... 4-7
Electrical Angle Measurement (Electrical Angle Measurement) ................................................... 4-8
Motor Efciency and Total Efciency Computation....................................................................... 4-9
5 Auxiliary Input Conditions (Option)
Auxiliary Input Conditions (MOTOR/AUX SET) ............................................................................ 5-1
Input Signal Name (Aux Name) .................................................................................................... 5-1
Scaling Factor (Scaling)................................................................................................................ 5-1
Unit (Unit)...................................................................................................................................... 5-1
Analog Input Range ...................................................................................................................... 5-1
Linear Scaling of Analog Input ...................................................................................................... 5-2
Line Filter (Line Filter)................................................................................................................... 5-3
6 Holding Measured Values and Performing Single Measurements
Holding Measured Values (HOLD)................................................................................................ 6-1
Single Measurement (SINGLE) .................................................................................................... 6-1
7 Numeric Data Display
Numeric Data Display (NUMERIC)............................................................................................... 7-1
Display Format (FORM)................................................................................................................ 7-1
Numeric Data Display Format....................................................................................................... 7-1
Switching the Displayed Page (PAGE UP/PAGE DOWN) ............................................................ 7-3
Jumping to the First or Last Page (PAGE TOP/PAGE END) ........................................................ 7-3
Number of Displayed Digits (Display Resolution) ......................................................................... 7-4
Display Item (ITEM) ...................................................................................................................... 7-4
4-, 8-, and 16-Value Displays (4 Items/8 Items/16Items) .............................................................. 7-5
Matrix display (Matrix)................................................................................................................... 7-7
All Items Display (All Items) .......................................................................................................... 7-8
Single Harmonics and Dual Harmonics Lists (Hrm List Single/Dual; option)................................ 7-9
Custom Display (Custom)........................................................................................................... 7-10

iv IM WT1801-01EN
Contents
8 Computation
Computation (MEASURE) ............................................................................................................ 8-1
User-Dened Functions (User Dened Function)......................................................................... 8-1
Measuring the Average Active Power ........................................................................................... 8-5
MAX Hold (Max Hold) ................................................................................................................... 8-5
User-Dened Events (User Dened Event) .................................................................................. 8-6
Apparent Power, Reactive Power, and Corrected Power Equations (Formula)............................ 8-8
Sampling Frequency (Sampling Frequency)................................................................................. 8-9
Phase Difference Display Format (Phase).................................................................................. 8-10
Master/Slave Synchronization Measurement (Sync Measure)................................................... 8-10
Voltages or Currents Whose Frequencies Will Be Measured (FREQ MEASURE)......................8-11
9 Integrated Power (Watt hours)
Integration-Related Display Indications ........................................................................................ 9-1
Number of Displayed Digits (Display Resolution) ......................................................................... 9-2
Enabling or Disabling Independent Integration (Independent Control)......................................... 9-4
Independently Integrated Elements (Element Object) .................................................................. 9-4
Starting, Stopping, and Resetting Integration (Start/Stop/Reset) ................................................. 9-5
Integration Conditions (Integ Set) ................................................................................................. 9-7
Integration Mode (Mode)............................................................................................................... 9-7
Integration Timer (Integ Timer).................................................................................................... 9-10
Scheduled Times for Real-Time Integration (Real-time Control) ................................................ 9-10
Integration Auto Calibration On/Off (Auto Cal).............................................................................9-11
Watt Hour Integration Method for Each Polarity (WP ± Type)......................................................9-11
Current Mode for Current Integration (q Mode) ...........................................................................9-11
Rated Time of Integrated D/A Output (D/A Output Rated Time; Option)..................................... 9-12
10 Waveform Display
Waveform Display (WAVE) ......................................................................................................... 10-1
Display Format (FORM).............................................................................................................. 10-2
Number of Windows (Format)..................................................................................................... 10-2
Time Axis (Time/div).................................................................................................................... 10-2
Vertical Axis (Amplitude) ............................................................................................................. 10-4
Trigger (Trigger Settings)............................................................................................................ 10-5
Advanced Waveform Display Settings (Display Settings)........................................................... 10-7
Waveform Mapping (Wave Mapping).......................................................................................... 10-8
Display Item (ITEM) .................................................................................................................... 10-8
11 Trend Display
Other Displays (OTHERS)...........................................................................................................11-1
Trend Display (Trend) ..................................................................................................................11-1
Display Format (FORM)...............................................................................................................11-2
Display Item (ITEM) .....................................................................................................................11-3
12 Bar Graph Display (Option)
Bar Graph Display (OTHERS (Bar)) ........................................................................................... 12-1
Display Format (FORM).............................................................................................................. 12-1
Display Item (ITEM) .................................................................................................................... 12-2

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Contents
13 Vector Display (Option)
Vector Display (OTHERS (Vector))............................................................................................. 13-1
Display Format (FORM).............................................................................................................. 13-2
Display Item (ITEM) .................................................................................................................... 13-2
14 Split Display
Split Display (OTHERS).............................................................................................................. 14-1
Split Displays with the Numeric Display (Numeric+***)............................................................... 14-1
Split Displays with the Waveform Display (Wave+***) ................................................................ 14-1
Split Displays with the Trend Display (Trend+***)....................................................................... 14-1
Split Display Settings .................................................................................................................. 14-1
15 Cursor Measurement
Cursor Measurement (CURSOR) ............................................................................................... 15-1
Turning Cursor Measurement On and Off (Cursor) .................................................................... 15-1
Waveform Measured by Cursor 1 (+; C1+ Trace)....................................................................... 15-1
Waveform Measured by Cursor 2 (x; C2x Trace) ....................................................................... 15-1
Cursor Path (Cursor Path) .......................................................................................................... 15-2
Position of Cursor 1 (+; C1+ Position) ........................................................................................ 15-2
Position of Cursor 2 (x; C2x Position)......................................................................................... 15-2
Linking Cursor Movement (Linkage)........................................................................................... 15-2
Measured Items .......................................................................................................................... 15-2
Cursor Movement ....................................................................................................................... 15-4
16 High Speed Data Capturing
High Speed Data Capturing (OTHERS(High Speed Data Capturing)) ....................................... 16-1
High Speed Data Capturing (HS) Settings (FORM).................................................................... 16-4
Number of Data Captures (Capture Count) ................................................................................ 16-4
Viewing and Optimizing the Maximum Capturing Count (Optimize Count) ................................ 16-4
Capture Control Settings (Control Settings)................................................................................ 16-5
Recording to a File (Record to File)............................................................................................ 16-7
Save Conditions (File Settings)................................................................................................... 16-8
Starting and Stopping High Speed Data Capturing (Start/Stop)................................................. 16-9
Display Items (ITEM) .................................................................................................................16-11
17 Data Storage
Storage-Related Display Indications........................................................................................... 17-1
Storage Conditions (STORE SET).............................................................................................. 17-1
Storage Control (Control Settings).............................................................................................. 17-2
Stored Items (Item Settings) ....................................................................................................... 17-4
Save Conditions (File Settings)................................................................................................... 17-5
Starting, Stopping, and Resetting Storage (STORE START, STORE STOP,
and STORE RESET) .................................................................................................................. 17-6
Storage Operations in Each Storage Mode ................................................................................ 17-8

vi IM WT1801-01EN
18 Saving and Loading Data
Storage Media............................................................................................................................. 18-1
Saving Setup Data (Save Setup)................................................................................................ 18-2
Saving Waveform Display Data (Save Wave)............................................................................. 18-2
Saving Numeric Data (Save Numeric)........................................................................................ 18-2
File Save Conditions................................................................................................................... 18-3
Loading Setup Data (Load Setup) .............................................................................................. 18-5
File Operations (Utility) ............................................................................................................... 18-6
19 Saving Screen Images
Conditions for Saving Screen Image Data (IMAGE SAVE MENU)............................................. 19-1
Saving a Screen Image (IMAGE SAVE) ..................................................................................... 19-1
20 Printing Screen Images and Numeric Data (Option)
Printing Conditions (PRINT MENU)............................................................................................ 20-1
Output Format (Format).............................................................................................................. 20-1
Automatic Printing Execution (Auto Print ON) ............................................................................ 20-2
Automatic Printing (Auto Print Settings)...................................................................................... 20-2
Comment (Comment) ................................................................................................................. 20-3
Paper Feed (Paper Feed)........................................................................................................... 20-3
Print Timing for Different Print Modes ......................................................................................... 20-4
Printing (PRINT).......................................................................................................................... 20-6
21 Ethernet Communication (Network)
TCP/IP (TCP/IP) ......................................................................................................................... 21-2
FTP Server (FTP Server)............................................................................................................ 21-3
Network Drive (Net Drive)........................................................................................................... 21-4
SNTP (SNTP) ............................................................................................................................. 21-5
22 Utility
Utility (UTILITY) .......................................................................................................................... 22-1
Overview (System Overview)...................................................................................................... 22-2
Initializing the Settings (Initialize Settings).................................................................................. 22-2
Remote Control (Remote Control) .............................................................................................. 22-3
System Conguration (System Cong)....................................................................................... 22-5
D/A Output (D/A Output Items; option)........................................................................................ 22-8
Self-Test (Selftest)......................................................................................................................22-11
23 Other Features
Zero-Level Compensation (CAL) ................................................................................................ 23-1
NULL Feature (NULL SET) ......................................................................................................... 23-1
Enabling and Disabling the NULL Feature (NULL) ..................................................................... 23-3
Clearing Remote Mode (LOCAL)................................................................................................ 23-3
Key Lock (KEY LOCK)................................................................................................................ 23-3
Index
Contents

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IM WT1801-01EN
1 Items That This Instrument Can Measure
The items that you can measure with this instrument are listed below. For details about how the values of the
measurement functions are determined, see appendix 1 in the getting started guide, IM WT1801-03EN. For
explanations of the terms measurement function, input element, and wiring unit, see “What Is a Measurement
Function?”
Click here.
The input elements and wiring units referred to in each measurement function table are listed below. However,
the input elements and wiring units that you can measure vary depending on how many input elements are
installed in the WT1800.
•Input elements: Element1, Element2, Element3, Element4, Element5, Element6
• Wiring units: ΣA, ΣB, ΣC
Measurement Functions Used in Normal Measurement
Voltage
Function Description Input Element Wiring Unit
Urms True rms voltage Yes Yes
Umn Rectified mean voltage calibrated to
the rms value
Yes Yes
Udc Simple voltage average Yes Yes
Urmn Rectified mean voltage Yes Yes
Uac AC voltage component Yes Yes
U+pk Maximum voltage Yes No
U−pk Minimum voltage Yes No
CfU Voltage crest factor Yes No
Current
Function Description Input Element Wiring Unit
Irms True rms current Yes Yes
Imn Rectified mean current calibrated to the
rms value
Yes Yes
Idc Simple current average Yes Yes
Irmn Rectified mean current Yes Yes
Iac AC current component Yes Yes
I+pk Maximum current Yes No
I−pk Minimum current Yes No
CfI Current crest factor Yes No
Power
Function Description Input Element Wiring Unit
P Active power Yes Yes
S Apparent power Yes Yes
Q Reactive power Yes Yes
λPower factor Yes Yes
ΦPhase difference Yes Yes
Pc Corrected Power Yes Yes
P+pk Maximum power Yes No
P−pk Minimum power Yes No
Frequency
Function Description Input Element Wiring Unit
fU Voltage frequency Yes No
fI Current frequency Yes No
fPLL1 Frequency of PLL11No No
fPLL2 Frequency of PLL22No No
1 On models with the harmonic measurement option or the simultaneous dual harmonic measurement
option.
2 Only on models with the simultaneous dual harmonic measurement option.

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Integrated Power (Watt hours)
Function Description Input Element Wiring Unit
Time Integration time Yes No
WP Sum of positive and negative watt
hours
Yes Yes
WP+ Sum of positive P values Yes Yes
WP− Sum of negative P values Yes Yes
q Sum of positive and negative ampere
hours
Yes Yes
q+ Sum of positive I values Yes Yes
q− Sum of negative I values Yes Yes
WS Volt-ampere hours Yes Yes
WQ Var hours Yes Yes
Efficiency
Function Description
η1 to η4 Efficiency
User-Defined Functions
Function Description
F1 to F20 User-defined functions
User-defined events
Function Description
Ev1 to Ev8 User-defined events
1 Items That This Instrument Can Measure

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IM WT1801-01EN
Harmonic Measurement Functions (Option)
Function Description Input Element Wiring Unit
U(k) Rms voltage of harmonic order k Yes Yes
I(k) Rms current of harmonic order k Yes Yes
P(k) Active power of harmonic order k Yes Yes
S(k) Apparent power of harmonic order k Yes Yes
Q(k) Reactive power of harmonic order k Yes Yes
λ(k) Power factor of harmonic order k Yes Yes
Φ(k) Phase difference between the voltage
and current of harmonic order k.
Yes No
ΦU(k) Phase difference between the
fundamental signal, U(1), and
harmonic voltage U(k)
Yes No
ΦI(k) Phase difference between the
fundamental signal, I(1), and harmonic
current I(k)
Yes No
Z(k) Impedance of the load circuit Yes No
Rs(k) Series resistance of the load circuit Yes No
Xs(k) Series reactance of the load circuit Yes No
Rp(k) Parallel resistance of the load circuit Yes No
Xp(k) Parallel reactance of the load circuit Yes No
Uhdf(k) Harmonic voltage distortion factor Yes No
Ihdf(k) Harmonic current distortion factor Yes No
Phdf(k) Harmonic active power distortion factor Yes No
Uthd Total harmonic voltage distortion Yes No
Ithd Total harmonic current distortion Yes No
Pthd Total harmonic active power distortion Yes No
Uthf Telephone harmonic factor of the
voltage
Yes No
Ithf Telephone harmonic factor of the
current
Yes No
Utif Telephone influence factor of the
voltage
Yes No
Itif Telephone influence factor of the
current
Yes No
hvf Harmonic voltage factor Yes No
hcf Harmonic current factor Yes No
K−factor K factor Yes No
ΦUi−Uj1Phase difference between the
fundamental voltage of element i,
Ui(1), and the fundamental voltage of
element j, Uj(1).
No Yes
ΦUi−Uk1Phase difference between Ui(1) and
the fundamental voltage of element k,
Uk(1)
No Yes
ΦUi−Ii1Phase difference between Ui(1) and
the fundamental current of element i,
Ii(1)
Yes2Yes
ΦUj−Ij1Phase difference between Uj(1) and
the fundamental current of element j,
Ij(1)
No Yes
ΦUk−Ik1Phase difference between Uk(1) and
the fundamental current of element k,
Ik(1)
No Yes
1 i, j, and k are input element numbers. For example, when the number of input elements in wiring unit ΣA is
six and the wiring system of elements 1, 2, and 3 is three phase, four wire, i is 1, j is 2, and k is 3. ΦUi – Uj
represents ΦU1 – U2, the difference between the fundamental voltage signal of element 1, U1(1), and the
fundamental voltage signal of element 2, U2(1). In the same way ΦUi – Uk, ΦUi – Ii, ΦUj – Ij, and ΦUk−Ik
represent to ΦU1 – U3, ΦU1 – I1, ΦU2 – I2, and ΦU3 – I3, respectively.
2 Setting i to an input element, is the same as setting k to 1 in Φ(k).
1 Items That This Instrument Can Measure

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Harmonic Measurement Function Orders
The harmonic orders that you can specify are indicated below.
Input Element Harmonic Measurement Functions
Measurement
Function
Characters or Numbers in Parentheses
Total 0 (DC) 1 k
U( ) Yes Yes Yes 2 to 500
I( ) Yes Yes Yes 2 to 500
P( ) Yes Yes Yes 2 to 500
S( ) Yes Yes Yes 2 to 500
Q( ) Yes Fixed at 0 Yes 2 to 500
λ( ) Yes Yes Yes 2 to 500
Φ( ) Yes No Yes 2 to 500
ΦU( ) No No No 2 to 500
ΦI( ) No No No 2 to 500
Z( ) No Yes Yes 2 to 100
Rs( ) No Yes Yes 2 to 100
Xs( ) No Yes Yes 2 to 100
Rp( ) No Yes Yes 2 to 100
Xp( ) No Yes Yes 2 to 100
Uhdf( ) No Yes Yes 2 to 500
Ihdf( ) No Yes Yes 2 to 500
Phdf( ) No Yes Yes 2 to 500
Uthd Yes No No No
Ithd Yes No No No
Pthd Yes No No No
Uthf Yes No No No
Ithf Yes No No No
Utif Yes No No No
Itif Yes No No No
hvf Yes No No No
hcf Yes No No No
K-factor Yes No No No
Functions with parentheses will produce different values depending on which of the following is contained in their
parentheses.
• Total: Total value (The total value of all harmonic components from the minimum order to N.*For information
about how the value is determined, see appendix 1 in the getting started guide, IM WT1801-03EN.)
• 0(DC): DC value
• 1: Fundamental harmonic value
• k: The value of any order from 2 to N.*
* N is the maximum measurable order. The maximum measurable harmonic order is the smallest of the three
orders listed below.
• The specified maximum measurable harmonic order
•The value determined automatically according to the PLL source frequency (see section 6.4 in the getting
started guide, IM WT1801-03EN)
• When the data update interval is 50 ms, the maximum measurable harmonic order is 100.
1 Items That This Instrument Can Measure

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IM WT1801-01EN
Wiring Unit Harmonic Measurement Functions (Σ functions)
Measurement
Function
Characters or Numbers
in Parentheses
Total 1
UΣ( ) Yes Yes
IΣ( ) Yes Yes
PΣ( ) Yes Yes
SΣ( ) Yes Yes
QΣ( ) Yes Yes
λΣ( ) Yes Yes
Functions with parentheses will produce different values depending on which of the following is contained in their
parentheses.
• Total: Total value
• 1: Fundamental harmonic value
Delta Computation Functions (Option)
Function Description
ΔU1 The values returned by the delta computation
functions vary depending on the specified delta
computation type.
ΔU2
ΔU3
ΔUΣ
ΔI
ΔP1
ΔP2
ΔP3
ΔPΣ
For details about delta computation functions, see “Delta Computation (Δ Measure; optional).”
Click here.
Motor Evaluation Functions (Option)
Function Description
Speed Motor rotating speed
Torque Motor torque
SyncSp Synchronous speed
Slip Slip (%)
Pm Mechanical output of the motor (mechanical power)
EaU1 to 6*Electrical angle: Phase angles of U1 to I6 with the
falling edge of the signal received through the Z
terminal of the motor evaluation function as the
reference.
EaI1 to 6*
* On models with the harmonic measurement option or the simultaneous dual harmonic measurement
option.
Auxiliary Input Measurement Functions (Option)
Function Description
Aux1 Auxiliary input 1
Aux2 Auxiliary input 2
High Speed Data Capturing Measurement Functios (Option)
• For the U and I of each input element and wiring unit: Select rms, mean, dc, or r-mean.
• The P of each input element and wiring unit
• Motor evaluation function (option) speed, torque, and Pm
• Auxiliary inputs (option) Aux1 and Aux2
• The maximum and minimum values of the above measurement functions
1 Items That This Instrument Can Measure

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What Is a Measurement Function?
Measurement Function
The physical values (such as rms voltage, average current, power, and phase difference) that the WT1800
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.
Element
Element refers to a set of input terminals that can receive a single phase of voltage and current to be measured.
The WT1800 can contain up to six elements, numbered from 1 to 6. An element number is appended to the
measurement function symbol for the measured data that the WT1800 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 System
You can specify five wiring systems on the WT1800 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 three-phase, three-wire with three-voltage, three-current method.
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. There can be up to three wiring units: ΣA, ΣB, and ΣC.
Click here.
Σ Functions
The measurement function of a wiring unit is called a Σ function.
For example, “UrmsΣA” corresponds to the average of the voltages of the input elements that are assigned to
the wiring unit ΣA. The average value represents the true rms value.
Click here.
Three-phase,
three-wire
Σ A
Element
1
Element
2
Element
3
Element
4
Three-phase,
three-wire
Σ B
Wiring system
Wiring unit
Voltage input
Current input
Element
5
Element
6
Three-phase,
three-wire
Σ C
Measurement Period
For information about the measurement period for computing measurement functions, see “Measurement Period
(SYNC SOURCE).”
Click here.
1 Items That This Instrument Can Measure

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IM WT1801-01EN
2 Fundamental Measurement Conditions
Wiring System Settings (WIRING)
The wiring system settings are listed below.
• Wiring system (Wiring)
• Efficiency equation (η Formula)
• Independent input element configuration (Element Independent)
• Delta computation (Δ Measure; option)
Wiring System (Wiring)
There are five wiring systems available on the WT1800. The selectable wiring systems vary depending on the
number of installed input elements.
• 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
Wiring Unit
Wiring units are sets of two or three input elements of the same wiring system that are grouped together. You
can define up to three wiring units: ΣA, ΣB, and ΣC.
• When there is one wiring unit, that unit is ΣA. You cannot make ΣB or ΣC the first wiring unit.
• When there are two wiring units, those units are ΣA and ΣB. You cannot make ΣC one of the first two wiring
units.
• When there are three wiring units, those units are ΣA, ΣB, and ΣC.
• When there are multiple wiring units, element numbers are assigned to them in ascending order. The element
numbers are assigned to ΣA, ΣB, and then ΣC.
• Wiring units are composed of input elements that are next to each other. Wiring units cannot consist of input
elements that are not next to each other.
• A wiring unit must either be composed of only 50 A input elements or only 5 A input elements. Wiring units
cannot consist of different types of input elements.
Σ Functions
The measurement function of a wiring unit is called a Σ function.
For example, “UrmsΣA” corresponds to the average of the voltages of the input elements that are assigned to
the wiring unit ΣA. The average value represents the true rms value.
Wiring System Combinations
The following tables provide examples of the wiring system combinations that you can use and the input
elements that you can assign to wiring system ΣA, ΣB, or ΣC depending on the number of installed input
elements. In addition to the combinations indicated in the tables below, you can also configure any pattern that
meets the conditions for wiring units described above.
For details about the relationship between wiring systems and how the values of the measurement functions are
determined, see appendix 1 in the getting started guide, IM WT1801-03EN.

2-2 IM WT1801-01EN
Input Element 1
Wiring system
combination
1P2W
Input Element 1 2
Wiring system
combination
1P2W 1P2W
1P3W or 3P3W:ΣA
Input Element 1 2 3
Wiring system
combination
1P2W 1P2W 1P2W
1P3W or 3P3W:ΣA 1P2W
1P2W 1P3W or 3P3W:ΣA
3P4W or 3P3W:ΣA
Input Element 1 2 3 4
Wiring system
combination
1P2W 1P2W 1P2W 1P2W
1P3W or 3P3W:ΣA 1P3W or 3P3W:ΣB
3P4W or 3P3W:ΣA 1P2W
1P2W 3P4W or 3P3W:ΣA
Input Element 1 2 3 4 5
Wiring system
combination
1P2W 1P2W 1P2W 1P2W 1P2W
1P3W or 3P3W:ΣA 1P3W or 3P3W:ΣB 1P2W
1P3W or 3P3W:ΣA 3P4W or 3P3W(3V3A):ΣB
3P4W or 3P3W:ΣA 1P3W or 3P3W:ΣB
Input Element 1 2 3 4 5 6
Wiring system
combination
1P2W 1P2W 1P2W 1P2W 1P2W 1P2W
1P3W or 3P3W:ΣA 1P3W or 3P3W:ΣB 1P3W or 3P3W:ΣC
1P3W or 3P3W:ΣA 3P4W or 3P3W(3V3A):ΣB 1P2W
3P4W or 3P3W:ΣA 1P3W or 3P3W:ΣB 1P2W
3P4W or 3P3W:ΣA 3P4W or 3P3W(3V3A):ΣB
Select the wiring system to match the actual wiring of the circuit under measurement. The method in which
the Σ functions (wiring unit measurement 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.
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 six input elements installed.
When the wiring systems
of elements 1 to 6 are set
to single-phase, two-wire
When the wiring system of elements 1, 2,
and 3 is set to three-phase, four-wire and the
wiring system of elements 4 and 5 is set to
three-phase, three-wire
Wiring unit and system
The elements that compose
the wiring unit are shown
in the frame.
Wiring unit and system
The elements that compose
the wiring unit are shown
in the frame.
2 Fundamental Measurement Conditions

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IM WT1801-01EN
Settings of Elements Grouped in a Wiring Unit
If independent input element configuration is off and a wiring system other than 1P2W is selected when the
measurement range, valid measurement range, or valid synchronization source settings of each input element
are different, these settings are changed in the manner described below:
•The measurement range is set to the greatest of the measurement ranges of the input elements assigned to
the same wiring unit. The external current sensor input range has precedence over the direct input current
range.
• The auto range on/off 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 setting of
the input element with the smallest input element number takes precedence.
• In the valid measurement range settings, all measurement ranges are enabled (selected).
• The synchronization source for a wiring unit is set to the input element whose number is the smallest of the
elements in the unit.
At the same time that you press ELEMENT to select the element that you want to set the voltage or current
range of, the indicators for the input elements that have been assigned to the same wiring unit illuminate.
Wiring System during High Speed Data Capturing
Click here.
2 Fundamental Measurement Conditions

2-4 IM WT1801-01EN
Efficiency Equation (η Formula)
You can create an efficiency equation by combining measurement function symbols. The WT1800 can determine
the energy conversion efficiency of the device using the numeric values of the measurement functions.
η1 to η4
You can create four efficiency equations (η1 to η4), using the following measurement functions as operands.
• The active powers of each element (P1 to P6)
• The active powers of the Σ functions (PΣA to PΣC)
• The motor output (Pm; on models with the motor evaluation option)
• Udef1 and Udef2
Udef1 and Udef2
To add active powers and motor output and use them in η1 to η4, use Udef1 and Udef2. You can add up to four
operands consisting of the measurement functions listed above.
Equation Examples
•Efficiency of a Single-Phase, Two-Wire Input/Single-Phase, Two-Wire Output Device
Input: Power of element 1 (P1)
Output: Power of element 2 (P2)
Efficiency equation: P2/P1 × 100 (%)
Converter
(inverter, etc.)
Input power: P1 Output power: P2
• Efficiency of a Single-Phase, Two-Wire Input/Three-Phase, Three-Wire Output Device
Input: Power of element 1 (P1)
Output: Σ power of elements 2 and 3 (PΣA)
Efficiency equation: PΣA/P1 × 100 (%)
• Efficiency of a Three-Phase, Three-Wire Input/Three-Phase, Three-Wire Output Device
Input: Σ power of elements 1 and 2 (PΣA)
Output: Σ power of elements 3 and 4 (PΣB)
Efficiency equation: PΣB/PΣA × 100 (%)
• Efficiency of a Motor with a Single-Phase, Two-Wire Input
Input: Power of element 1 (P1)
Output: Motor output (Pm)
Efficiency equation: Pm/P1 × 100 (%)
• Efficiency of a Motor with a Three-Phase, Three-Wire Input
Input: Σ power of elements 1 and 2 (PΣA)
Output: Motor output (Pm)
Efficiency equation: Pm/PΣA × 100 (%)
To correctly compute the efficiency, set the power coefficients of all elements so that all power units used in
the computation are the same. For example, the efficiency cannot be computed correctly if elements or wiring
units used in the computation have different power units, such as W (watt) and J (joule).
2 Fundamental Measurement Conditions

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Independent Input Element Configuration (Element Independent)
In the wiring system settings, you can select whether to set the measurement range or sync source of input
elements in the same wiring unit collectively or independently.
Turning Independent Input Element Configuration On or Off
For example, assume that the wiring system on a model with three input elements is set as follows:
Input elements 1 to 3: Three-phase, four-wire system (3P4W). Input elements 1 to 3 are assigned to a single
wiring unit ΣA.
•ON
The measurement range and sync source can be set independently for each input element included in a
wiring unit.
• OFF
The measurement range and sync source of input elements 1 to 3 are set to the same setting. This is
convenient because when you are measuring a three-phase device, you can set the range and sync source
settings of all input elements included in a wiring unit simultaneously.
Settings That Are Shared between Input Elements When Independent Input Element Configuration Is
Turned Off
• Measurement range (including auto range on or off)
• Direct current input or external current sensor input
• Valid measurement range
• Synchronization source
• Input element group for harmonic measurement (applies to models with the simultaneous dual harmonic
measurement option).
Settings That Can Be Configured Independently Even When Independent Input Element Configuration Is
Turned Off
• External current sensor conversion ratio (option)
•Scaling values (VT ratio, CT ratio, and power coefficient)
• Input filters (line filter and frequency filter)
These settings can be configured independently for each input element regardless of whether independent input
element configuration is turned on or off.
How Settings Are Aligned When You Turn Independent Input Element Configuration from On to Off
When independent input element configuration is switched from on to off, the measurement range, valid
measurement range, and sync source settings of each input element in a wiring unit (ΣA, ΣB, or ΣC) are
changed as follows:
•The measurement range is set to the greatest of the measurement ranges of the input elements assigned to
the same wiring unit. The external current sensor input range has precedence over the direct input current
range.
• The auto range on/off 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 setting of
the input element with the smallest input element number takes precedence.
• In the valid measurement range settings, all measurement ranges are enabled (selected).
• The synchronization source for a wiring unit is set to the input element whose number is the smallest of the
elements in the unit.
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Delta Computation (Δ Measure; option)
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.
Types of Delta Computation (ΔMeasure Type)
The following types of delta computation are available:
•Differential voltage and differential current (Difference)
• Line voltage and phase current (3P3W > 3V3A)
• Star-delta transformation (Star>Delta)
• Delta-star transformation (Delta>Star)
The delta computation types that you can select vary as indicated below according to the wiring system.
Wiring System Delta Computation Type
1P3W Difference, 3P3W>3V3A
3P3W Difference, 3P3W>3V3A
3P4W Star>Delta
3P3W(3V3A) Delta>Star
• Differential Voltage and Differential Current (Difference)
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 you perform delta computation on wiring unit ΣA, the available measurement functions are as follows.
ΔU1rms[UdiffA], ΔU1mn[UdiffA], ΔU1dc[UdiffA], ΔU1rmn[UdiffA], ΔU1ac[UdiffA]
ΔIrms[IdiffA], ΔImn[IdiffA], ΔIdc[IdiffA], ΔIrmn[IdiffA], ΔIac[IdiffA]
* In the measurement functions, rms, mn(mean), dc, rmn(r-mean), and ac are the delta computation modes.
Aindicates the wiring unit.
Click here.
• Line Voltage and Phase Current (3P3W > 3V3A)
You can compute unmeasured line voltages and phase currents by converting the data of a three-phase,
three-wire system to the data of the three-voltage, three-current method (3V3A).
T
R
ST
R
S
When you perform delta computation on wiring unit ΣA, the available measurement functions are as follows.
ΔU1rms[UrsA], ΔU1mn[UrsA], ΔU1dc[UrsA], ΔU1rmn[UrsA], ΔU1ac[UrsA]
ΔIrms[ItA], ΔImn[ItA], ΔIdc[ItA], ΔIrmn[ItA], ΔIac[ItA]
±
±
±
±
I
R
S
T
U
U
I
N
I1
I2
U2
U1
Urs
It
* In the measurement functions, rms, mn(mean), dc, rmn(r-mean), and ac are the delta computation modes.
Aindicates the wiring unit.
Click here.
2 Fundamental Measurement Conditions

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IM WT1801-01EN
• Star-delta transformation (Star>Delta)
You can use the data from a three-phase, four-wire system to compute the data of a delta connection from the
data of a star connection.
R
ST
R
ST
When you perform delta computation on wiring unit ΣA, the available measurement functions are as follows.
ΔU1rms[UrsA], ΔU1mn[UrsA], ΔU1dc[UrsA], ΔU1rmn[UrsA], ΔU1ac[UrsA]
ΔU2rms[UstA], ΔU2mn[UstA], ΔU2dc[UstA], ΔU2rmn[UstA], ΔU2ac[UstA]
ΔU3rms[UtrA], ΔU3mn[UtrA], ΔU3dc[UtrA], ΔU3rmn[UtrA], ΔU3ac[UtrA]
ΔUΣrms[UΣA], ΔUΣmn[UΣA], ΔUΣdc[UΣA], ΔUΣrmn[UΣA], ΔUΣac[UΣA]
ΔIrms[InA], ΔImn[InA], ΔIdc[InA], ΔIrmn[InA], ΔIac[InA]
I
I
R
S
T
U
UU
I
N
I1
I2
I3
U1
U2U3
Urs
Utr
Ust
In
±
±
±±
±
±
* In the measurement functions, rms, mn(mean), dc, rmn(r-mean), and ac are the delta computation modes.
Aindicates the wiring unit.
Click here.
• Delta-star transformation (Delta>Star)
Using the data from a three-phase, three-wire system that uses a three-voltage, three-current method, you
can compute the data of a star connection from the data of a delta connection. This function is useful when
you wish to observe the phase voltage of an object that has no neutral line, such as a motor. The center
N of the star connection is computed as the center of the delta connection. If the actual center of the star
connection does not match the center of the delta connection, an error results.
R
ST
R
ST
When you perform delta computation on wiring unit ΣA, the available measurement functions are as follows.
ΔU1rms[UrA], ΔU1mn[UrA], ΔU1dc[UrA], ΔU1rmn[UrA], ΔU1ac[UrA]
ΔU2rms[UsA], ΔU2mn[UsA], ΔU2dc[UsA], ΔU2rmn[UsA], ΔU2ac[UsA]
ΔU3rms[UtA], ΔU3mn[UtA], ΔU3dc[UtA], ΔU3rmn[UtA], ΔU3ac[UtA]
ΔUΣrms[UΣA], ΔUΣmn[UΣA], ΔUΣdc[UΣA], ΔUΣrmn[UΣA], ΔUΣac[UΣA]
ΔIrms[InA], ΔImn[InA], ΔIdc[InA], ΔIrmn[InA], ΔIac[InA]
ΔP1[PrA]
ΔP2[PsA]
ΔP3[PtA]
ΔPΣ[PΣA]
2 Fundamental Measurement Conditions