YOKOGAWA CW140 User's Manual

User's

Manual

CW140

CLAMP-ON POWER METER

IM CW140-E

IM CW140-E 3rd Edition July 2001 (YK)

Introduction

Thank you for purchasing our CW140 Clamp-on Power Meter. This User’s manual explains the functions of the CW140, as well as its operating methods and handling precautions. Before using the CW140, read this manual thoroughly to ensure correct use of the instrument.

The Operation Guide manual is available separately, in addition to this manual. The Operation Guide manual briefly describes the basic procedures for performing such tasks as measurement operations and settings. Use the manual together with this in-depth User’s manual.

When you have finished reading this manual, carefully store it in a place that provides ease of access for later reference. This manual will come in handy when you are unsure of how to operate the instrument.

Notices

The contents of this manual are subject to change without prior notice. In addition, figures and illustrations representing display views in this manual may differ from real views.

Every effort has been made to ensure accuracy in the preparation of this manual. Should any doubts arise or errors come to your attention however, please contact one of the Yokogawa M&C sales offices listed on the back cover of this manual or the sales representative from which you purchased the instrument.

The contents of this manual may not be transcribed or reproduced, in part or in whole, without prior permission.

Trademark Acknowledgments

The company and product names referred to in this document are either trademarks or registered trademarks of their respective holders.

Revision Information

February 2000: First edition

July 2001: 3rd edition

Disk No. CW140-E

3rd Edition: July 2001 (YK)

All Rights Reserved. Copyright © 2000, Yokogawa M&C Corporation

IM CW140-E

1

Examining Items Contained in the Package

After opening the package, be sure to examine the product as instructed below before use. Should the delivered product be the wrong model, lack any item, or show any flaw in its appearance, contact the vendor from which you purchased the product.

CW140 Main Unit

Check the model name and the suffix (specifications) code in the MODEL and SUFFIX fields of the nameplate located at the back of the instrument to ensure that the instrument is exactly as specified in your purchase order.

Model Name and Suffix Codes

Model		Suffix Code			Specifications
CW140
AC adapters			D		Power cord: UL/CSA standard
			F		VDE standard
			R		SAA standard
			S		BS standard
Option codes				/DA	D/A output
				/C1	Clamp-on probe for 20/200A (2 pcs/set)
				/C2	Clamp-on probe for 20/200A (4 pcs/set)
				/C3	Clamp-on probe for 50/500A (2 pcs/set)
				/C4	Clamp-on probe for 50/500A (4 pcs/set)
				/C5	Clamp-on probe for 200/1000A (2 pcs/set)
				/C6	Clamp-on probe for 200/1000A (4 pcs/set)
				/PM1	NiMH (nickel-hydrogen) battery pack and carrying case
				/PM2	“PM1” and FDD unit
No. field:		Denotes the instrument number.

Refer to this number when inquiring to the vendor about the instrument.

Accessories

Make sure that the package contains all the accessories listed below and that they are all free from any damage.

	Product Name		Part Number	Qty	Remarks
1.		AC adapter for power supply	788011	1 set	Yokogawa’s AC adapter
2.		AA alkaline dry cells	—	6	(alkaline batteries)
3.		Voltage probes	91007	4	Supplied together with two sets of ring
					markers of three different colors.
4.		Instruction manual	IM CW140-E	1
5.		Operation Guide manual	IM CW140P-E	1
1.			2.		3.

4.

5.

2	IM CW140-E

Examining Items in the Package

Peripherals (Optional)

The products listed below are available as optional peripherals. For technical and ordering inquiries concerning the peripherals, contact the vendor from which you purchased the instrument. If the instrument you purchased includes any one of the optional peripherals, make sure it is free from any damage.

Product Name	Part Number	Minimum Order Qty Remarks
Clamp-on probe for 20/200 A	96030	1	* See the option codes for a choice of
			probe kits.
Clamp-on probe for 50/500 A	96031	1	*
Clamp-on probe for 200/1000 A	96032	1	*
Voltage probe	91007	4
Floppy disk drive unit	97020	1 set	FDD unit
Carrying case	93020	1
AC adapter	788011	1 set	Yokogawa’s AC adapter
NiMH battery pack	94004	1
Printer	97010	1
AC adapter (for printer, Europe)	94006	1
AC adapter (for printer, USA)	94007	1
Thermal paper for printers	97080	10 rolls

TIP

It is advisable that the packing box be stored, as it is useful when you transport the instrument.

● Housing CW140 Main Unit and Accessories

An optional carrying case can accommodate the CW140 main unit with its current-sensing clamp-on probes and voltage probes connected to the unit. The case can also house such accessories as an AC adapter, NiMH battery pack, floppy drive unit, instruction manual, floppy disks, recording paper, and so on. It therefore comes in handy when transporting a complete kit of tools necessary for your measurement.

Example of Housing:

Instruction manual

Clamp-on probes

NiMH battery pack

Floppy drive unit

CW140 main unit

AC adapter

Voltage probes

IM CW140-E

3

Precautions for Safe Use of the Instrument

When operating the instrument, be sure to observe the cautionary notes given below to ensure correct and safe use of the instrument. If you use the instrument in any other way than instructed in this manual, the instrument’s protective measures may be impaired. Yokogawa M&C Corporation is by no means liable for any damage resulting from use of the instrument in contradiction to these cautionary notes.

The following safety symbols are used in the instrument and this manual.

Danger! Handle with Care.

This symbol indicates that the operator must refer to an explanation in the instruction manual in order to avoid risk of injury or death of personnel or damage to the instrument.

Direct Current

This symbol indicates DC voltage/current.

Alternating Current

This symbol indicates AC voltage/current.

ON

This symbol indicates On (power).

OFF

This symbol indicates Off (power).

Double Insulation

This symbol indicates double insulation.

WARNING

Indicates a hazard that may result in the loss of life or serious injury of the user unless the described instruction is abided by.

CAUTION

Indicates a hazard that may result in an injury to the user and/or physical damage to the product or other equipment unless the described instruction is abided by.

NOTE

Indicates information that is essential for handling the instrument or should be noted in order to familiarize yourself with the instrument’s operating procedures and/or functions.

TIP

Indicates information that complements the present topic.

SEE ALSO

Indicates the reference location(s) for further information on the present topic.

4	IM CW140-E

Precautions for Safe Use of the Instrument

Strictly observe the following cautionary notes in order to avoid the risk of injury or death of personnel or damage to the instrument due to such hazards as electrical shock.

WARNING

●Removal of Case from the Instrument

•Do not remove the case from the instrument or disassemble/modify the instrument itself.

•Some parts of the inside of the instrument contain high-voltage and, therefore, access to the internal assembly is extremely hazardous. For inspection and/or adjustment of the internal assembly, contact the vendor from which you purchased the instrument.

●Use of the Instrument in a Gas Atmosphere

Do not operate the instrument in a location where any flammable or explosive gas/vapor is present. It is extremely hazardous to operate the instrument in such an atmosphere.

●Inspection of Power Source

•Before turning on the instrument, always make sure the voltage of the power source to be applied matches the instrument’s supply voltage.

•When using alkaline batteries or an NiMH battery pack, carefully read the cautionary notes on battery handling later in this manual.

●Use of Clamp-on Current Probes

•When using clamp-on current probes, keep the circuit voltage below 600 V AC in order to avoid possible short-circuits or accidents resulting in injury or death.

•Avoid using the instrument if it has been exposed to rain or moisture or if your hands are wet.

•Do not use clamp-on current probes with any non-insulated conductors.

●Measures In Case of Anomalies

If the instrument begins to emit smoke, becomes too hot, or gives off an unusual smell, immediately turn it off and disconnect the power cord from the outlet. Also turn off power to the object under measurement that is connected to the instrument’s input terminals. Never attempt to use the instrument again. If any such anomalies as noted above occurs, contact the vendor from which you purchased the instrument. Do not attempt to repair the instrument yourself, as doing so is extremely dangerous.

●Handling of Power Cords

Do not place any load on the power cord or allow the power cord to come into accidental contact with any heat source. Hold the plug of the power cord, rather than holding and pulling the cord itself, when disconnecting it from the outlet. If the power cord is damaged, contact the vendor from which you purchased the instrument. See page 2 for information on the AC adapter that is necessary when ordering a replacement power cord.

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5

Contents

Introduction	..............................................................................................................	1
Examining Items Contained in the Package ..........................................................		2
Precautions ..........................................................for Safe Use of the Instrument		4
Chapter 1. Product ...............................................................................Overview		1-1
1.1 ........................................................................................	Product Overview	1-1
Chapter 2. Components, .....Their Use and Overrange, and Error Indications		2-1
2.1 ................................................................	Front Panel and Connector Block	2-1
2.2 ....................................................................	Operation and Functions Keys	2-2
2.3 ...	Connecting Input Signals to Be Measured and External Input Terminals	2-3
2.4 ..........................	Overrange and Other Marks Shown during Measurement	2-6
Chapter 3. Precautions ...................................................for Safe Measurement		3-1
3.1 ..................................................................................	Handling Precautions	3-1
3.2 ..................................................................................	Installation Procedure	3-3
3.3 ..............................................	Precautions for Wiring the Circuit under Test	3-4
3.4 ............................................................................	Diagrams of Basic Wiring	3-5
3.5 ....................................	Wiring the Circuit under Test Using External VT/CT	3-8
3.6 ......................................	Connecting a Power Supply and Turning It On/Off	3-9
3.7 .....................................	Performing Measurements with Higher Precision	3-18
Chapter 4. Basic ...................................Operation Flow and Top Menu Screen		4-1
4.1 ..................................................................................	Basic Operation Flow	4-1
4.2 ........................................................................................	Top Menu Screen	4-2
Chapter 5. System ..................................................................................Settings		5-1
5.1 ..........................................................................................	System Settings	5-1
5.2 ..............................................................................................	System Reset	5-4
Chapter 6. File .......................................................................................Handling		6-1
6.1 ...............................................................................................	File Handling	6-1
6.2 ........................................................................	File Name and File Attribute	6-4
6.3 ...................................................................................	Entering a File Name	6-5
Chapter 7. Common .....................................................Functions of All Modes		7-1
7.1 ..........................................................................................................	Wiring	7-1
7.2 ..........................................................................................	Checking Wiring	7-3
7.3 .....................................................................	Ranges and Number of Digits	7-6
7.4 .........................................	Sampling Frequencies and Integration Periods	7-14
7.5 ........................................	Frequency Measurement and Low - pass Filters	7-16
7.6 ....................................................................................	Averaging Function	7-18
7.7 ..........................................................................	Scaling Function (VT/CT)	7-19
Chapter 8. Instant ........................................................................Measure Mode		8-1
8.1 ..................	Detailed View of Data Items on Instant Measure Mode Screen	8-1
8.2 ..................................................................	Working with the Function Keys	8-4
8.3 ...............	Expanded View of Data Items on Instant Measure Mode Screen	8-5
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			Contents
8.4	Logging in Instant Measure Mode ...............................................................		8-7
8.5	Setup Data Items of Instant Measure Mode ..............................................		8-10
8.6	Computational Expressions .......................................................................		8-15
Chapter 9. Electric Energy Measure Mode .........................................................			9-1
9.1	Data Items on Electric Energy Measure Mode Screen ...............................		9-1
9.2	Working with the Function Keys ..................................................................		9-3
9.3	Integration in Electric Energy Measure Mode .............................................		9-4
9.4	Setup Data Items of Electric Energy Measure Mode ..................................		9-7
Chapter 10.	Key .............................................................................................		10-1
10.1	Simple Electric Energy Measurement with	Key ..................................	10-1
Chapter 11 Demand Measure Mode .................................................................			11-1
11.1	About Demand ..........................................................................................		11-1
11.2	Data Items Shown on Demand Measure Mode Screen ............................		11-2
11.3	Working with the Function Keys ................................................................		11-4
11.4	Demand Measurement in Demand Measure Mode ..................................		11-5
11.5	Setup Data Items of Demand Measure Mode ...........................................		11-8
Chapter 12. Harmonics Measure Mode .............................................................			12-1
12.1	Showing Tables in Harmonics Measure Mode ..........................................		12-1
12.2	Showing Graphs in Harmonics Measure Mode	.........................................	12-3
12.3	Working with the Function Keys ................................................................		12-5
12.4	Logging in Harmonics Measure Mode ......................................................		12-6
12.5	Setup Data Items of Harmonics Measure Mode .......................................		12-9
12.6	Computational Expressions .....................................................................		12-15
Chapter 13. File Functions .................................................................................			13-1
13.1	Saving, Loading and Printing with File Functions ......................................		13-1
Chapter 14. External I/O Functions ...................................................................			14-1
14.1	Optional D/A Output ..................................................................................		14-1
14.2	External Control Input ...............................................................................		14-8
14.3	Event Input ................................................................................................		14-9
Chapter 15. RS-232C Communication Function ..............................................			15-1
15.1	RS-232C Interface Specifications .............................................................		15-1
15.2	Connecting CW140 through RS-232C Interface .......................................		15-2
15.3	Handshake Methods .................................................................................		15-4
15.4	Matching the Data Format .........................................................................		15-7
Chapter 16. In the Event of a Power Failure .....................................................			16-1
16.1	In the Event of a Power Failure .................................................................		16-1
Chapter 17. Auxiliary Functions ........................................................................			17-1
17.1	Auxiliary Functions ....................................................................................		17-1
17.2	Floppy Disk Drive (Optional) ......................................................................		17-7
17.3	Printer (Optional) .......................................................................................		17-8
Chapter 18. Troubleshooting .............................................................................			18-1
18.1	Corrective Action in Case of Failure ..........................................................		18-1
18.2	Messages and Corrective Measures .........................................................		18-2

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

App

Index

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7

Contents

Chapter 19. Specifications .................................................................................		19-1
19.1 Specifications ............................................................................................		19-1
19.2 Specifications of Current Clamps ............................................................		19-15
Appendix .........................................................................................................		App1-1
Appendix 1	Block Diagram of CW140 Main Unit .............................................	App1-1
Appendix 2. Communication Commands ..........................................................		App2-1
Appendix 3.	Explanation of Data Item to be Saved/Printed .............................	App3-1
Appendix 4.	Terminology ..................................................................................	App4-1
Appendix 5.	Explanation of Reactive Power Method ........................................	App5-1
Appendix 6.	Settings Check Sheet ...................................................................	App6-1
Index ...............................................................................................................		Index-1

8	IM CW140-E

Chapter 1. Product Overview

1.1 Product Overview

The CW140 clamp-on power meter is basically designed for measuring root- mean-square voltage and current rms values and thereby electric energy. With its computing capabilities, the CW140 can measure and analyze a wide variety of parameters related to electric power.

This section explains the features of the CW140 and shows a schematic diagram representing the functions of the CW140. It also explains the screen views (i.e., measuring objects) presented by each measurement mode of the CW140.

Features

●Supports a variety of measurement modes and continuous measurement.

The CW140 has four measurement modes which support continuous measurement.

•Instant Measure mode (logging)

•Electric Energy Measure mode (integration)

•Demand Measure mode (demand measurement)

•Harmonics Measure mode (logging)

● Efficient Measurement using the Wh Key

This feature simplifies operations required for the Electric Energy Measure mode most often used.

● Supports a variety of wiring methods.

•Supports single-phase two-wire systems, single-phase three-wire systems, three-phase three-wire two-current systems, three-phase three-wire threecurrent systems, and three-phase four-wire systems.

•Supports dual-load systems in a single-phase two-wire, single-phase threewire, or three-phase three-wire configuration (except when in the Harmonics

Measure mode).

● Data Management

•Measured values or measurement settings can be stored in internal memory or on a 3.5-inch floppy disk inserted in an optional floppy drive attached externally to the CW140.

•Allows simultaneous data saving to internal memory and a floppy disk, or copying internal memory data to a floppy disk.

•An optional printer connected externally to the CW140 allows you to print

measured values or measurement settings.

● Communication

With an RS-232-C interface, it is possible to transfer data to or receive measurement settings from a personal computer. The CW140 stores measurement data in CSV format, facilitating data processing (such as creating graphs) using commercial spreadsheet software.

● Setting Operations

•Easy-to-operate Display Screen

You can easily change settings by selecting items highlighted on the screen using Range keys, Cursor key, and function keys.

● Settings Check Sheet

The settings check sheet in Appendix 6 lists required setting items for each measurement mode. Use this sheet for reference and to improve efficiency when making settings in the field.

1

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1-1

1.1Product Overview

Schematic Function Diagram

		key								key
TOP MENU
				(Chapter 5)			(Chapter 6)
screen
				System Setting			File Handling
				mode Screens
							mode
				1/2 and 2/2

(Chapter 10)

					Electric Energy
	(Chapter 8)	(Chapter 9)	(Chapter 11)	(Chapter 12)	Measure mode
					conditions
	Instant Measure	Electric Energy	Demand Measure	Harmonics		Last condition
						Setting condition 1
	mode	Measure mode	mode	Measure mode
						Setting condition 2
				(Graph display)	set
	Logging	Integration	Demand	Logging
					Saving	Setting condition 3
	Condition setting	Condition setting	Condition setting	Condition setting		Setting condition 4

Averaging function (Section 7.6)
Scaling function (Section 7.7)	Internal		Storage of data and setup conditions		D/A
Low-pass filter function (Section 7.5)	memory		Reading of setup conditions
					output
Frequency measurement
Wiring check function (Section 7.2)					(Optional)

Power failure handling function (Chapter 16) Auxiliary functions (Chapter 17)

Clock

Language selection (Japanese, English) Hold of on-screen readings

NiMH battery recharging LCD contrast

LCD backlight

Beep (confirmation of key operation) Key locking

Power-saving mode System reset

Low battery indicator Testing backup batteries

	(Chapter 15)
RS-232C interface
for personal computer or printer		External trigger function
	(Section 17.3)	(Section 14.2)
	Event input function
Floppy disk drive unit	(Section 14.3)
(connected externally)
(Section 17.2)

1-2	IM CW140-E

1.1 Product Overview

On-screen Information (Data Items) Provided by Each Measurement Mode

In each measurement mode, you can measure and calculate on-screen data

items, as shown below.

Instant Measure mode (Chapter 8)

Rms voltage value (V)

Rms current value (A)

Active power (W)

Reactive power 1 and 2 (Var)

1:With reactive power meter method

2:Without reactive power meter method Apparent power (VA)

Power factor Phase angle (°) Frequency (Hz)

Three-phase unbalance factor (%) (for three-phase wiring only)

	Electric Energy Measure mode	Active power (Wh)
	(Chapter 9)
		Regenerative power (Wh)
		Lagging reactive power (Varh)
		Leading reactive power (Varh)

Demand Measure mode (Chapter 11)

Indication During Demand Interval Indication at the End of Demand

•Maximum demand and its time

•Demand of one demand period earlier

•Electric energy integrated since the start of demand

•Electric energy integrated during the present demand period

•Power factor

•Load factor

•Remaining time of demand interval

•Maximum demand and its time

•Average of respective demands

•Electric energy integrated from the start to the end of demand

•Average power factor

•Average load factor

Harmonics Measure mode Analysis of 1stthrough 13th-order harmonics

(Chapter 12)

Table displays	• Voltage/current	Rms value, harmonic content, phase angle
		Total rms value (All-RMS)
		Total harmonic distortion
		IEEE (relative to fundamental wave);
		CSA (relative to total rms value)
		Fundamental wave frequency
	• Power	Power value, power content, power phase angle
		Total power value
		Total power factor
		Fundamental wave frequency
Graph displays
	• Voltage/current	Rms value, harmonic content, phase angle
	• Power	Power value, power content, power phase angle

(The CW140 does not support the Harmonics Measure mode when wired to

2-system load.)

NOTE

The CW140 can show a screen of instantaneous values whether it is in the Electric Energy Measure mode or the Demand Measure mode.

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1-3

Chapter 2. Components, Their Use and Overrange, and Error Indications

2.1 Front Panel and Connector Block

<Connector Block>

			L	L		L	L
			1		2	3		4
N	v1	v2	v3	N		N	N	N
			L	N L	N	L 1 N L 2 N L 3 N L 4 N

		<Side View>		<Front View>
					INPUT / OUTPUT
		AC adapter		CLAMP ON POWER METER
		jack
Battery charge
LED indicator	(7.24)	switch
NiMH battery)
(for optional		Power
	184
			F 1	F 2	F 3	F 4	F 5
		START KEY LIGHT		Wh	ESC		ENTER
		&STOP	LOCK
			V	A	W		TOP MENU
		65 (2.56)		206 (8.11)

Unit: mm (approx. inches)

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2-1

2.2 Operation and Functions Keys

Status LED indicator* for continuous measurement

LIGHT

ESC

Name	Key Symbol			Description
Function keys				Set data appropriate for information				Display
	to			shown in their respective
				corresponding fields along the
				bottom edge of the display.
START&STOP				Starts/stops logging when the CW140 is in the Instant Measure or Harmonics Measure
key				mode.
				Starts/stops integration when the CW140 is in the Electric Energy Measure mode.
				Starts/stops demand when the CW140 is in the Demand Measure mode.
Backlight key				Turns on/off the backlight.
	LIGHT			Holding this key down for more than 3 seconds places the CW140 in a key
				lock state. To cancel the state, hold this key down again for more than 3
				seconds.
Watt-hour key				Allows you to measure electric energy easily without selecting the Electric
				Energy Measure mode from the TOP MENU screen.
Escape key				Cancels such data as setup conditions.
		ESC
Enter key				Confirms such data as setup conditions.
Cursor key				Moves the cursor through on-screen data items so an item can be selected.
V Range key				Shows/resets the voltage range.
				(You can change the setpoint with a function key.)
A Range key				Shows/resets the current range.
				(You can change the setpoint with a function key.)
Wiring key				Shows/resets the setting of a wiring method.
				(You can change the setting with a function key.)			Also see "Checking Wiring."
TOP MENU key				Changes the display to the TOP MENU screen for selecting each
				measurement mode.

* Status LED indicator: Remains lit when the CW140 is performing continuous measurement (whether the meter is in a stand-by state or taking measurements) in each measurement mode.

2-2	IM CW140-E

2.3Connecting Input Signals to Be Measured and External Input Terminals

● Terminal Assignments

Voltage input terminals

Current (clamp) input terminals

L

L

L

L

CH

1

CH

2

CH

3

CH

4

N

v1

v2

v3

N

N

N

N

FDD

L

N

L

N

L 1 N L

2 N L 3 N L

4 N

RS-232C

LOGIC INPUT

START/STOP

D/A OUTPUT

Connector for connection with	Event input terminals		D/A output terminals
an external floppy disk drive unit			(optional)

External control (trigger) input terminals

RS-232C connector for printer/personal computer

Event input terminals:	Receive ON/OFF signals from equipment
	under test.

External control input terminals: Receive START/STOP signals informing

	of the start and end of logging,
	integration or demand measurement.
D/A output terminals:	Terminals for D/A output
	(not available if the CW140 is not
	equipped with a D/A output option).

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2-3

2.3Connecting Input Signal Lines to Be Measured and External Input Terminals

●Connection of Input Signal Lines to Be Measured and External Input Terminals (Example)

Ring marker

Current clamp

Voltage probe (red/yellow/blue)

Voltage probe (black)

WARNING

•Thoroughly read Section 3.3, "Precautions for Wiring the Circuit Under Test."

•When wiring the CW140, turn off the circuit under test.

It is extremely dangerous to connect or disconnect measuring lead wires without turning off the circuit under test.

•Be extremely careful not to connect any voltage-mode circuit to the current input terminals or any current-mode circuit to the voltage input terminals. Miswiring can result in not only damage to the circuit or equipment under test but also an injury to personnel.

•The CW140 can be connect to a maximum of four voltage input probes or four current-sensing clamps. Do not connect any probe or clamp that is not necessary for measurement.

•Do not use any other probes or current-sensing clamps than those supplied with the CW140.

•Before connecting a current-sensing clamp to the CW140, make sure the H and L polarities are correctly identified.

●Differentiating among Voltage Input Probes and among Current-

sensing Clamps

• Voltage Input Probes

Probe for Input terminal N: Black (one)

Probes for Input terminals V1 to V3: Three different colors: Red, Yellow and Blue.

• Current-sensing Clamps

Clamps for Input terminals CH1 to CH4: Differentiated by ring markers of four different colors

2-4	IM CW140-E

2.3 Connecting Input Signal Lines to Be Measured and External Input Terminals

● Use of Ring Markers (Standard Accessories)

Attach ring markers of the same color to both the terminal connection side and alligator clip side of a voltage input probe or to both the terminal connection side and clamping side of a current-sensing clamp. This enables you to differentiate between the input signal lines.

CAUTION

Be careful not to damage a probe when attaching ring markers.

● Connection of External I/O Terminals

Signal wire

Tool such as a flat-tip screwdriver

● Connection Procedure

Insert the signal wire into the hole while pressing the rectangular area at the bottom of the external I/O terminal using such a tool as a flat-tip screwdriver. Removing the screwdriver from the terminal fixes the signal wire in place.

CAUTION

•Do not apply voltages outside the allowable input voltage range (-0.5 to 5.5 V), otherwise the input circuit may be damaged.

•When wiring the CW140, be careful not to mistake an input terminal for an output terminal.

● Applicable Signal Wires

Standard wire: φ1.0 single-core wire (AWG18) or 0.75 mm2 stranded wire Adaptable wire: φ0.4 to 1.0 single-core wire (AWG26 to 18) or 0.35 to 0.75

mm2 stranded wire (AWG22 to 20) with a minimum strand diameter of 0.18 mm; typical length of stripping = 10 mm

● Applied Terminals

LOGIC INPUT: Event input terminals (receive ON/OFF signals from equipment under test)

START/STOP: Terminals for inputting signals informing the start and end of logging, integration or demand measurement.

D/A OUTPUT: Terminals for D/A conversion output (optional)

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2-5

2.4Overrange and Other Marks Shown during Measurement

● Overrange Indications during Measurement

: Conditions for current overrange indication

This mark appears if the sampled value exceeds 300% of the rated current range or if the rms value of the measured current exceeds 110% of the rated range. If a fixed range is used, step up the range.

: Conditions for voltage overrange indication

This mark appears if the sampled value exceeds 300% of the rated voltage range or if the rms value of the measured voltage exceeds 110% of the rated range. If a fixed range is used, step up the range.

TIP

•The current overrange mark appears if an input signal to one of the terminals CH1 to CH4 satisfies the conditions noted above.

•The voltage overrange mark appears if an input signal to one of the terminals V1 to V3 satisfies the conditions noted above.

Indication of Overrange Marks When Auto-ranging Is Used

The CW140 steps up or down the range, as discussed in Section 7.3, "Ranges and Number of Digits." Then, the CW140 shows the or mark if the conditions noted above become true under the maximum range.

Indication of OR Symbol

The CW140 shows the OR symbol, instead of a usual four-digit value, if the result of measurement (calculation) satisfies the conditions noted above.

(If a fixed range is used, step up the range.)

Indication of OR Symbol When Auto-ranging Is Used

The CW140 steps up or down the range, as discussed in Section 7.3, "Ranges and Number of Digits." Then, the CW140 shows the OR symbol if the conditions noted above become true under the maximum range.

WARNING

The CW140 shows an overrange mark under the maximum range only if the input level exceeds the maximum allowable input level. Do not apply any input level higher than the maximum allowable input level.

2-6	IM CW140-E

2.4 Overrange and Other Marks Shown during Measurement

CAUTION

When measuring an input signal level exceeding the rated range, use a voltage transformer (VT) or a current transformer (CT) - scaling function. When using a VT or CT, thoroughly read Section 3.5, "Wiring the Circuit under Test Using External VT/CT."

● Frequency-related Overrange Indications

Normal measurement: The measurement range is from 45 Hz to 1 kHz.

The display shows "----" if the input signal is below 40 Hz or above 1.2 kHz.

Three-phase unbalance factor measurement:

The measurement range is from 45 to 440 Hz.

The display shows "----" if the input signal is below 40 Hz or above 440 Hz.

Harmonics measurement: The measurement range is from 45 to 65 Hz.

The display shows "----" if the input signal is below 40 Hz or above 70 Hz.

● Indications When the Measured Value Is Too Small

If either a voltage or current input level is below 0.4% of the rated range, the CW140 gives the readings noted below. If a fixed range is used, step down the range.

Reactive power 2 and apparent power: Read zero (0).

Power factor and phase angle: Read as "----".

If the level of active power or reactive power is below 0.7% of the rating, the reading is displayed as shown below.

Active power or reactive power: Read zero (0). The integration stops.

In harmonics measurement, the display reads as shown below if the input level of a frequency-measuring device is below 10% of the rated range.

All measurement data items: Read as "----".

If the voltage, current or power harmonic content in harmonics measurement is below 0.1%, the phase angle of a harmonic component of that order reads as "----".

TIP

Even if the instantaneous value overrange occurs and the OR symbol appears in the electric energy measure mode, the integration processing continues. In this case, the level of accuracy of the on-screen integrated value may become inaccurate (about two times) that of the rated accuracy.

NOTE

If continuous measurement (logging, integration, or demand) is performed when in AUTO range, the range will be fixed to the value when the START&STOP key is pressed.

2

Overview Product

IM CW140-E

2-7

2.4Overrange and Other Marks Shown during Measurement

●Other Marks

Screen View

: Appears if the demand exceeds the reference power level.

: Denotes the scaling function.

Appears if either the VT or CT ratio is set at a value other than 1. : Appears when the reactive power method is used.

: Appears when display hold is enabled.

: Appears when a current overrange occurs.

: Appears when a voltage overrange occurs.

: Appears when the CW140 is configured so that data is stored in internal memory.

: Appears when the CW140 is configured so that data is stored on a floppy disk.

: Appears when the CW140 is configured so that data is output to a printer.

: Appears when the battery becomes low (low-battery mark).

: Appears when an AC adapter is used.

: Appears when the CW140 is in a key lock state.

TIP

•The Floppy Disk mark is only effective if an optional external floppy disk drive is used.

•The Printer mark is only effective if an optional external printer is used.

•The Low-Battery mark appears if either an optional NiMH battery pack or alkaline batteries are used.

•The (Low-Battery mark) and (AC Adapter mark) indications share the same position of view on the display.

2-8	IM CW140-E

Chapter 3. Precautions for Safe Measurement

3.1 Handling Precautions

If you are a first-time user, be sure to read "Precautions for Safe Use of the Instrument" on pages 4 and 5.

●Do not place any load on the instrument.

Do not place any other equipment of a vessel filled with water on the instrument. Otherwise, the instrument may become defective.

●Moving the instrument

Before moving the instrument, make sure the power cord and all other cables are disconnected. When moving the instrument, hold it with both hands.

●Input Terminals

Do not bring any electrified substance close to the signal terminals. Otherwise, the internal circuitry may be destroyed. Do not apply any mechanical shock to the signal terminals. Otherwise, such impact may be transformed into electrical noise and input to the instrument.

●Protection of Case and Operation Panel

Do not spray any volatile chemical on the case or operation panel. Do not leave any rubber or vinyl product in contact with the instrument for a prolonged period. Otherwise, the instrument may be discolored or deformed.

●Cleaning

When cleaning the case and/or operation panel, disconnect the power cord from the outlet. Then, wipe the surfaces of the case and/or operation panel with a soft clean cloth. Do not use chemicals such as benzine or paint thinner. Otherwise, the instrument may be discolored or deformed.

●Display Screen

When the instrument is shipped from the factory, the display screen is covered with a protective film. Remove the film before you begin using the instrument.

The LCD backlight lasts a approximately 10,000 hours when kept turned on at room temperature. If it is used longer than that period, the brightness may drastically decrease. If this occurs, the backlight needs to be replaced. Contact the vendor from which you purchased the instrument.

3

Measurement Safe for Precautions

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3-1

3.1Handling Precautions

●After Use

After use, disconnect the power cord from the outlet.

●Long Absence of Use

If the instrument will not be used for a prolonged period, remove the batteries (AA-size alkaline batteries or NiMH battery pack) from the instrument.

Precautions for Use of the Clamp

CAUTION

•The clamping CT (current transformer) is precision assembled to ensure high performance. When using the clamp, do not apply any intense mechanical shock, vibration or force to the clamping CT.

•If dust or any other foreign matter gets in the clamping CT, do not shut the clamping cores tight. First remove the dust and then make sure the clamping cores on both sides close smoothly.

3-2	IM CW140-E

3.2 Installation Procedure

Install the instrument in a location that satisfies the following conditions.

● Ambient Temperature and Humidity

• Ambient temperature: 5°C to 40°C

• Ambient humidity: 35 to 80% RH (no condensation)

● Operating altitude

2000m max. above sea level

● Level Location

Do not install the instrument in an unstable or inclined location. Otherwise, this may result in the failure to obtain precision measurements.

● Do not install the instrument in a location that is:

•exposed to direct sunlight or close to a heat source;

•close to such a noise source as high-voltage equipment or a motive power supply;

•exposed to a relatively large amount of lampblack, steam, dust or corrosive gas;

•exposed to frequent mechanical vibration;

•close to a source of strong electromagnetic fields; or

•unstable.

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Measurement Safe for Precautions

IM CW140-E

3-3

3.3Precautions for Wiring the Circuit under Test

WARNING

•When wiring the instrument or the instrument is turned off, turn off the circuit under test.

It is extremely dangerous to connect or disconnect measuring lead wires without turning off the circuit under test.

•Be extremely careful not to connect any voltage-mode circuit to the current input terminals or any current-mode circuit to the voltage input terminals. Miswiring can result in not only damage to the circuit or equipment under test but also an injury to personnel.

•Do not apply any input level higher than the following to the voltage or current input terminals.

• Maximum allowable input (continuous)

Voltage input:		600 Vrms
Current input:		250 Arms	Clamp A (96030)
		625 Arms	Clamp C (96031)
	* 700 Arms		Clamp B (96032)

* Refer to Section 19.2, “Specifications of Current Clamps” for details.

In addition to the maximum allowable input, the rated input levels are specified as shown below.

Voltage ratings: 150, 300 and 600 V

Current ratings: 20, 50, 100 and 200 A		Clamp A (96030)
	50, 100, 200 and 500 A	Clamp C (96031)
	200, 500 and 1000 A	Clamp B (96032)

•If using an external VT (voltage transformer) or CT (current transformer), make sure the transformer can adequately withstand the voltage being measured.

•Be careful not to allow the secondary stage of the CT to become open-circuited while the CT is being electrified. Otherwise, a high-voltage may develop on the secondary stage, causing extreme danger.

•The maximum allowable input voltage range of the external input terminals (external control input and event input terminals) is specified as –0.5 to 5.5 V.

Do not apply voltages exceeding this range, otherwise the input circuitry may be damaged.

(When wiring the input terminals, be careful not confuse them with the optional D/A output terminals.)

•Do not use any probes or clamps other than those voltage input probes or dedicated clamps supplied together with the CW140.

•Do not use a clamp with any non-insulated conductors.

TIP

After wiring the CW140, it is necessary to perform setting/operation for the wiring method using the

WIRING key.

SEE ALSO

Section 7.1, "Wiring," for details on how to set the wiring method.

3-4	IM CW140-E

3.4 Diagrams of Basic Wiring
This section explains the methods of basic wiring using illustrations.
				Current-sensing clamp		3
(1)	1φ2W	S 1			L
		O
					O
		U				SafeforPrecautions
		R N			A
		C			D
		E
		Voltage input terminals	N V1	CH1	Current input terminals	Measurement
				I1	On-screen symbol
(2)	1φ3W	S 1			L
		O
					O
		U
		R N			A
		C			D
		E 2

	Voltage input terminals			N	V1	V2	CH1 CH2		Current input terminals
							I1	I2	On-screen symbol
(3)	3φ3W2i	S 1	R						L
		O
									O
		U	S
		R 2							A
		C	T						D
		E 3

Voltage input terminals	N V1	V3		CH1	CH3	Current input terminals
				I1	I3	On-screen symbol

TIP

In the case of a current-sensing clamp, the symbol of a current input terminal shown on the CW140 main

unit differs from that shown on the display, as indicated in the figures above.

IM CW140-E

3-5

Power supply side (SOURCE)

3.4 Diagrams of Basic Wiring
(4)	3φ3W3i	S 1		R	L
		O
					O
		U	2	S
					A
		R
		C		T	D
		E 3

	Voltage input terminals			N	V1	V3	CH1 CH2 CH3			Current input terminals
							I1	I2	I3	On-screen symbol
(5)	3φ4W		R
	S	1								L
	O		S
	U 2									O
	R	3	T							A
	C									D
	E N N

Voltage input terminals	N V1 V2 V3		CH1 CH2 CH3	Current input terminals
			I1 I2 I3	On-screen symbol

When connecting the current-sensing clamp, make sure the following polarities and clamp position are correctly identified.

1 When connecting to

the CW140 main unit: Conductor

H and L polarities		cable
2 The clamp should be
positioned	in	the
direction from		the
power source side to
the load	side,	as
indicated	by	the

	arrow.	Load side	Connector on the main unit
		(LOAD)

WARNING

In addition to using the checking wiring function, be sure to verify the actual wiring connections.

3-6	IM CW140-E

								3.4 Diagrams of Basic Wiring
- 2-system load		-
(6)	1φ2W×2	S	1						L
		O							O
		U
									A
		R N
		C							D
									2
		E								3
	Voltage input terminals			N	V1		CH1 CH2		Current input terminals	forPrecautions
									L
									O
									A
									D
									1
							I1	I1-2	On-screen symbol	Safe
(7)	1φ3W×2	S	1						L	Measurement
		O							O
		U
									A
		R N
		C							D
									2
		E 2
									L
									O
									A
									D
									1
	Voltage input terminals			N	V1	V2	CH1 CH2 CH3 CH4		Current input terminals
							I1	I2-1 I1-2 I2-2	On-screen symbol
(8)	3φ3W×2	S	1 R						L
		O	S						O
		U
									A
		R	2
		C	T						D
									2
		E 3

L

O A D 1

Voltage input terminals						Current input terminals
	N V1	V3		CH1 CH2 CH3 CH4
				I1 I3-1 I1-2 I3-2		On-screen symbol

IM CW140-E

3-7

3.5Wiring the Circuit under Test Using External VT/CT

WARNING

•When using an external CT, be careful not to allow the secondary stage of the CT to become open-circuited while the primary stage is being electrified. Otherwise, a high voltage may develop on the secondary stage, causing extreme danger.

•The current under test flows through the bold lines shown in the figure below. For these lines, use wire that has an adequate margin of current-carrying capacity.

If the maximum voltage or current level being measured exceeds the maximum measurement range of the CW140, use an external VT and/or CT. This strategy enables the measurement of voltage or current levels above the maximum range.

If the maximum voltage level exceeds 600 V, attach an external VT. Then, connect the secondary stage of the VT to the voltage input terminals.

If the maximum current level exceeds the following value, attach an external CT. Then, connect the secondary stage of the CT to the currentsensing clamp.

200 A, when clamp A (20, 50, 100 and 200 A) is used 500 A, when clamp C (50, 100, 200 and 500 A) is used 1000 A, when clamp B (200, 500 and 1000 A) is used

Example of 1φ2W

	S
	O 1			L
	U			O
	R			A
	C N			D
	E	V	L
	VT			CT
	Voltage	v		Current
	transfomer			transfomer

Voltage input terminals	N	V1		CH1		Current input terminals

TIP

•The CW140 can show the primarystage value even if the scaling function is applied using VT/CT.

SEE ALSO

Section 7.7, "Scaling Function," for details on how to use VT/CT.

•The lowest current range of the CW140 main unit itself is 20 A on full scale and the accuracy also depends on this value. Note therefore that if a CT is used and its secondary output is too small when compared with 20 A, then the error ratio will become higher.

3-8	IM CW140-E