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CT6710
Instruction Manual
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Hioki CT6710, CT6711 Instruction Manual

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CT6710
CT6711
CURRENT PROBE
Instruction Manual

Aug. 2020 Revised edition 1 CT6710A961-01 20-08H
EN
Measurement Procedure
Be sure to familiarize yourself with the “Usage Notes”
section (p. 8), each instruction of use, and safety notes presented at the beginning of each instruction of use.
Inspecting the Device Before Use
Preparing for Measurement
• Provide power to the device.
• Connect the termination unit to your waveform measuring instrument.
• Execute demagnetization and automatic zero-
adjustment.
Measuring Currents
• Clamp the sensor around a conductor to be measured.
• Measure a current.
Finishing Measurement
CT6710A961-01
(p. 26)
(p. 28)
(p. 41)
(p. 65)
Connection Example
Waveform measuring instrument
H
Power source
Load
See “Example of connection to the circuit to be measured” (p. 49).
L
Model 3269 Power Supply
Contents
Introduction .....................................................................................1
Notations ......................................................................................... 2
Checking Package Contents ......................................................... 5
Safety Notes .................................................................................... 7
Usage Notes .................................................................................... 8
1 Overview 13
1.1 Product Overview ...................................................13
1.2 Product Features ....................................................14
1.3 Name and Function of Each Part ..........................16
Termination unit .................................................................... 16
Junction box (keys, LEDs) .................................................... 18
Sensor .................................................................................. 20
1.4 Specications of Lighting Up / Blinking LEDs ..... 22
2 Current Measurement 25
2.1 Inspecting the Device Before Use ......................... 26
2.2 Preparing for Measurement ................................... 28
Providing power to the CT6710/CT6711 ............................... 29
Executing demagnetization and automatic
zero-adjustment .................................................................... 33
2.3 Measuring Currents ................................................ 41
How to measure a current .................................................... 50
To measure a low current ..................................................... 58
To measure a current accurately .......................................... 60
When the device has entered protection mode .................... 62
2.4 Finishing Measurement .......................................... 65
1
2
3
4
Index
i
Contents
3 Specications 69
3.1 General Specications ........................................... 69
3.2 Specications of Input, Output, and
Measurement ........................................................... 71
Basic specications .............................................................. 71
Specications of accuracy .................................................... 73
3.3 Specications of Functionality .............................. 75
3.4 Typical Characteristics ...........................................77
Frequency characteristics ..................................................... 77
Frequency derating curve ..................................................... 78
Input impedance ................................................................... 80
Consumption current ............................................................ 81
Inuence of common-mode voltage ...................................... 82
4 Maintenance and Service 83
4.1 Troubleshooting ......................................................84
Before sending back your device for repair .......................... 85
4.2 Errors ....................................................................... 88
Types of errors ...................................................................... 89
4.3 Cleaning ................................................................... 96
4.4 Disposal ................................................................... 97
Index 99
Warranty
ii

Introduction

Introduction
Thank you for choosing the Hioki CT6710, CT6710 Current Probe. To ensure your ability to get the most out of this device over the long term, please read this manual carefully and keep it available for future reference.
Each model o󰀨ers a di󰀨erent frequency band listed below:
Model CT6710: DC to 50 MHz Model CT6711: DC to 120 MHz
The following manuals are provided along with these models. Refer to manuals relevant to your purpose.
• Current Sensor Operating Precautions
Information on the device for safe operation
• Instruction Manual (this document) Basic instructions and specications of the device
Please review the separate “Current Sensor Operating
Precautions” before using the device.
Target audience
This manual has been written for use by individuals who use the product in question or who teach others to do so. It is assumed that the reader possesses basic electrical knowledge (equivalent to that of someone who graduated from the electrical program at a technical high school).
1

Notations

Notations
Safety notations
This manual classies seriousness of risks and hazard levels as described below.
Indicates an imminently hazardous situation
DANGER
WARNING
CAUTION
that, if not avoided, will result in death or serious injury.
Indicates a potentially hazardous situation that, if not avoided, could result in death or serious injury.
Indicates a potentially hazardous situation that, if not avoided, could result in minor or moderate injury.
NOTICE
IMPORTANT
NOTE
Indicates a high-voltage hazard. Failure to verify safety or improper handling of the device could lead to electric shock, burn injury, or death.
2
Indicates potential risks of damage to the supported product (or to other property).
Indicates information or content that is particularly important from the standpoint of operating or maintaining the device.
Indicates useful advice concerning device performance and operation.
Indicates an action that must not be performed.
Indicates an action that must be performed.
Symbols shown on the device
Indicates the presence of a potential hazard. For more information about locations where this symbol appears on device components, see the “Usage Notes” section (p. 8), warning messages listed at the beginning of operating instructions, and the accompanying document entitled “Current Sensor Operating Precautions.”
Indicates that the device can only be used at a location on an insulated wire with su󰀩cient insulation for the
circuit voltage.
Symbols for various standards
Indicates the Waste Electrical and Electronic Equipment Directive (WEEE Directive) in EU member states.
Indicates that the product complies with standards imposed by EU directives.
Notations
3
Notations
Others
*
Indicates additional information is described below.
Bold
Indicates the names of the control keys.
Accuracy
Hioki denes tolerances for measured values in terms of percentage of reading, as indicated below.
Reading (Displayed value) Indicates the value the measuring instrument
rdg.
displays. Tolerances for reading errors are expressed in percent of reading (% of reading, % rdg).
4

Checking Package Contents

Checking Package Contents
When you receive the device, inspect it to ensure that no damage occurred during shipment. Pay particular attention to keys and connectors. If you nd any damage or discover that the device does not perform as indicated in its specications, please contact your authorized Hioki distributor or reseller.
Check that the package contents are correct. The carrying case contains the current probe, Instruction Manual, and Current Sensor Operating Precautions.
Carrying case
(Accessory)
Model CT6710/CT6711 Current Probe
Instruction Manual
(Accessory)
Current Sensor Operating Precautions
(0990A901)
(Accessory)
5
Checking Package Contents
Option
The option below is available for the device. To order an option, please contact your authorized Hioki distributor or
reseller.
Options are subject to change. Check Hioki’s website for the
latest information.
Model 3269 Power Supply

The 3269 Power Supply can provide the power to up to two probes of the CT6710/CT6711. (The 3272 Power Supply cannot be used as a power supplying unit for the CT6710/CT6711.)
Precautions for transportation
• Store packaging materials for future use. You will need the packaging materials when shipping the device.
• Transport the device in its carrying case.
6

Safety Notes

Safety Notes
The device has been designed in accordance with the IEC 61010 safety standard, and its safety has been veried by means of testing prior to shipment. However, failure to follow the information in this manual could render safety-related functionality provided by the device ine󰀨ective. Please review the safety information below before using the device.
DANGER
Read this manual carefully and ensure you
understand its contents before using the
device.
Improper use of the device could result in serious bodily injury or damage to the device.
WARNING
If using an electrical measuring instrument
for the rst time, seek instruction from an individual with electrical measurement experience rst.
Failure to do so may lead to electric shock, overheating, re, arcing due to a short-circuit, or other hazards.
7

Usage Notes

Usage Notes
Be sure to follow the precautions listed below in order to use the device safely and in a manner that allows it to function e󰀨ectively. Use of the device should conform not only to its specications, but also to the specications of all accessories, options, and other equipment in use.
DANGER
Do not use the device for measuring bare
conductors.
Take measurements at a location on an
insulated wire with su󰀩cient insulation for the
circuit voltage.
Doing so may result in electric shock or a short-circuit.
8
Usage Notes
DANGER
Do not remove any covers of the sensor,
junction box, and termination unit.
The internal components of the device carry high voltages and may become very hot during operation. Touching them could cause electric shock or burns.
Do not connect the device to the primary side
of a distribution panel.
If a short-circuit occurs on the primary side, an unrestricted current ow can damage the device and facilities, resulting in serious bodily injury. Even if a short-circuit occurs on the secondary side of the distribution panel, the panel will interrupt the short-
circuit current.
Do not use the device in powerful magnetic
elds.
Doing so could cause the sensor to become abnormally hot, resulting in bodily injury, damage to the device, or re.
Follow all operating precautions for a
waveform measuring instrument or any other measuring instruments to which this device is
connected.
Failure to observe this could cause serious bodily injury or damage to these instruments.
9
Usage Notes
Do not use the device to measure circuits that
Do not install the instrument in locations such
WARNING
exceed the ratings or specications of the
device.
Doing so could cause damage to the device or overheating, resulting in bodily injury.
as the following:
• In locations where it would be subject to direct
sunlight
• In locations where it would be subject to high
temperatures
• In locations where it would be exposed to corrosive
or explosive gases
• In locations where it would be exposed to water, oil,
chemicals, or solvents
• In locations where it would be exposed to high
humidity or condensation
• In locations where it would be exposed to powerful
electromagnetic radiation
• Close to objects carrying an electric charge
• In locations with an excessive amount of dust
• Close to inductive heating devices (high-frequency
inductive heating devices, IH cooktops, etc.)
• In locations characterized by a large amount of
mechanical vibration
• Close to HF power supply units
Doing so could cause damage to the device or cause it to malfucntion, resulting in bodily injury.
10
Usage Notes
WARNING
Ensure that the insulation on the cords is
undamaged and that no bare conductors are improperly exposed before using the device.
Any damage to the cords leads to electric shock. Contact your authorized Hioki distributor or reseller for
repair.
CAUTION
Do not place the device on an unstable stand
or angled surface.
Doing so could cause the device to fall or overturn,
resulting in bodily injury or damage to the device.
Properly connect the device to a circuit to
be measured and your waveform measuring
instrument.
Improperly connecting them could cause electric shock or damage to the circuit, device, or your instrument.
11
Usage Notes
Do not store or use the device in locations
Do not apply force in the directions shown in
Do not
apply force.
Keep the upper jaw locked in place when the
NOTICE
subject to abrupt temperature changes.
Doing so could damage the sensor heads.
the gure below while the upper jaw is locked
in place.
Opening lever position
when the upper jaw is
locked in place
Doing so may damage the retracting/extending
mechanism.
device is not in use.
Leaving the upper jaw unlocked will cause dust or dirt to settle on the facing core surfaces, resulting in damage to the device.
12
1

Overview

1.1 Product Overview

Model CT6710/CT6711 is a clamp-on current probe that features high current-detection sensitivity and broad frequency band. The probe uses three current ranges to detect current waveforms from 1 mA to 50 A. You can directly connect the termination unit to a BNC input
terminal of your waveform measuring instrument such as
an oscilloscope and recorder, and then clamp the sensor around a conductor to be measured to observe current
waveforms easily.
Sensor (p. 20)
Junction box (p. 18)
Termination unit (p. 16)
1
13
Product Features

1.2 Product Features

Clamp-on sensor heads (p. 21)
The clamp-on sensor heads allow current measurement without the need to make physical contact with a conductor to be measured or to disconnect it. You can observe current waveforms while maintaining the ow of
electric current.
Sliding jaw retracting/extending mechanism
(p. 21)
This feature lets you easily retract, extend, and lock the upper jaw in place to clamp the sensor around a conductor to be measured.
Easy-to-connect output terminal (p. 17, p. 38)
Insert the output terminal into a BNC input terminal on your waveform measuring instrument to connect the termination unit.
Warning LED lights (p. 18)
The warning LEDs alert you to an overload (indicating that an input current value exceeds the rated current of the device) or jaw-unlocked condition (indicating that the upper jaw has not been locked in place).
14
Product Features
Three current measurement ranges (p. 53)
You can choose from the three ranges according to the magnitude of the current to be measured. This feature lets you observe a wide range of currents, from 1 mA to 50 A.
Broad frequency band (p. 71)
Model CT6710: DC to 50 MHz Model CT6711: DC to 120 MHz
Demagnetizing and automatic zero-adjustment functions (p. 33)
You can use a single key to demagnetize the magnetic cores and correct variations in o󰀨set voltage, both of which are required before measuring.
Protection mode (p. 62)
The device automatically enters protection mode to prevent damaging itself when overheating.
1
15
Name and Function of Each Part

1.3 Name and Function of Each Part

Termination unit

See p. 34 and p. 35.
Top view
1 2
5
16
3
4
6
Name and Function of Each Part
Output terminal
1
The device converts a captured current waveform into a voltage waveform by multiplying a particular rate according to a specied current range and outputs the voltage
waveform from this terminal. Connect this terminal to a BNC input terminal of your waveform measuring instrument.
Unlock lever
2
To disconnect the output terminal, pull on the termination unit
while simultaneously pulling this lever.
Vents
3
The unit has the vents on the sides and bottom. Do not clog
them.
Serial number
4
The serial number consists of nine digits. The rst two digits indicate the year of manufacture, while the second two digits indicate the month of manufacture. Do not remove this sticker as the number is important.
Power plug
5
Power is provided to the CT6710/CT6711 through this plug.
Connect this plug with the 3269 Power Supply.
Shell
6
Pull on the power plug while simultaneously pulling this shell
to disconnect the plug.
1
You can easily connect and disconnect the termination unit with two ngers
even when multiple termination units
are connected to a waveform measuring
instrument.
17
Name and Function of Each Part

Junction box (keys, LEDs)

4
5
6
7
1
8
DEMAG / AUTO ZERO key
1
Hold down (about 1 s)
Press momentarily
(less than 0.5 s)
(Higher range) key (p. 53)
2
Switch over to a next higher current range.
(Does not switch from the 30 A range to the 0.5 A range)
(Lower range) key (p. 53)
3
Switch over to a next lower current range.
(Does not switch from the 0.5 A range to the 30 A range)
18
2
3
Top view
Performs demagnetization followed by automatic zero-adjustment. (p. 33)
Performs automatic zero-adjustment alone. (p. 40)
Name and Function of Each Part
POWER LED (green light)
4
• Lights up when the power is on (p. 31). (Normal operation)
• Rapidly blinks when a checksum error has occurred (p. 95).
OVERLOAD LED (red light)
5
• Flashes three times when demagnetizing or automatic zero­adjustment cannot be performed (p. 91).
• Rapidly blinks when an overload state is detected (p. 90), the device has entered protection mode (p. 62), or a checksum error has occurred (p. 95).
JAW UNLOCKED LED (red light)
6
• Lights up when the upper jaw is unlocked.
• Flashes three times when demagnetizing or automatic zero-
adjustment cannot be performed (p. 91).
• Rapidly blinks when the device has entered protection mode (p. 62) or a checksum error has occurred (p. 95).
DEMAG / AUTO ZERO LED (orange light)
7
• Slowly blinks when demagnetization or automatic zero­adjustment has not yet been performed (p. 33).
• Lights up when demagnetization and automatic zero­adjustment are
• Goes out when demagnetization and automatic zero­adjustment have been completed (p. 39).
• Flashes three times when demagnetization and automatic zero-adjustment cannot be performed (p. 91).
• Rapidly blinks when the device has entered protection mode (p. 62) or a checksum error has occurred (p. 95).
RANGE LEDs (green lights)
8
• Lights up when its current range is chosen (p. 53). (Normal operation)
• Blinks rapidly when the device has entered protection mode (p. 62) or a checksum error has occurred (p. 95).
in execution
(p. 39).
1
19
Name and Function of Each Part

Sensor

NOTICE
Do not store or use the device in locations
subject to abrupt temperature changes.
Do not apply force or mechanical shock to the
device.
Do not subject the device to static electricity.
Doing so could damage the device.
4
2
See p. 41.
1
3
4
20
5
6
See p. 41.
When the upper jaw is unlocked
See p. 41.
Top view
Name and Function of Each Part
Jaws
1
Clamp this part around a conductor to be measured by operating the opening lever, which allows the upper jaw to slide (retract/extend).
Sensor aperture
2
A conductor to be measured must pass through this
aperture.
Sensor heads
3
The sensor heads, located inside the jaws, detects currents.
Current direction indicator
4
Clamp the sensor around the conductor such that the direction this arrow indicates matches the current direction of a conductor to be measured.
JAW UNLOCKED indicator
5
If this indicator appears, the upper jaw is not locked in place.
Opening lever
6
To retract and extend the upper jaw, always operate this lever. This lever allows you to retract and lock the upper jaw
in place.
1
21
Specications of Lighting Up / Blinking LEDs
1.4 Specications of Lighting Up /
Blinking LEDs
: Lighting up : O󰀨 : Blinking
Device state LED
Automatic
zero-
adjustment
1 − − (On start-up)
2 Not performed Not detected (Initial state)
In execution
3
(Incl. demag.)
In execution
4
(excl. demag.)
5 Completed Not detected (Before use, normal state )
6 Completed Exceeds prescribed level −
7 Not performed Exceeds prescribed level −
8 Completed Not detected Upper jaw unlocked
9 Completed Exceeds prescribed level Upper jaw unlocked
10 Not performed Not detected Upper jaw unlocked
11 Not performed Exceeds prescribed level Upper jaw unlocked
12 − *1 *1
13 − −
14 − −
Overload Others
− (No range keys available)
− (No range keys available)
Excess heat detected in
junction box*
ROM checksum error at
power-on (CPU failure)
2
*1. When the DEMAG / AUTO ZERO key is pressed under any one of the
following conditions (p. 91):
• The upper jaw is unlocked.
• An overload has been detected whether or not the upper jaw is locked in place.
• A current exceeding 0.5 A rms has been detected whether or not the
upper jaw is locked in place.
*2. Press any key to restore the device. The ranges cannot be switched until
the device is restored. See “When the device has entered protection mode” (p. 62).
Green
POWER
Rapidly
22
Specications of Lighting Up / Blinking LEDs
: Lighting up : O󰀨 : Blinking
Red Red Orange Green
OVERLOAD JAW UNLOCKED
1 s 1 s 1 s 1 s 1 s 1 s 1
LED
DEMAG / AUTO
ZERO
Slowly*
30 A 5 A 0.5 A
4
RANGE
3
Rapidly*
3
Rapidly*
3
Rapidly*
3
Rapidly*
Rapidly
ashes 3 times
Rapidly
Rapidly
*3. Blinks at 250-ms intervals. (duty ratio: 50%) *4. After the device is turned on and then all LEDs light up for 1 second, the
DEMAG / AUTO ZERO LED blinks, which indicates that demagnetization
or automatic zero-adjustment has not yet been performed.
*5. Even when demagnetization or automatic zero-adjustment has not yet
been performed, the device that has detected an overload and that with the upper jaw unlocked leave the DEMAG / AUTO ZERO LED unlit.
 
Rapidly
ashes 3 times
Rapidly
Rapidly
5
*
5
*
Rapidly
ashes 3 times
Rapidly
Rapidly
Specied range only 4
Specied range only 5
Specied range only 6
Specied range only 7
Specied range only 8
Specied range only 9
Specied range only 10
Specied range only 11
Specied range only 12
Rapidly 13
Rapidly 14
1
2
3
23
Specications of Lighting Up / Blinking LEDs
24

Current Measurement

2
Do not clog the vents on the sides and bottom
of the termination unit (p. 16).
Doing so could cause internal overheating of the termination unit, resulting in bodily injury, re, or damage to the device.
Do not pile the junction box (p. 18) on
another.
Do not cover the junction box with a cloth.
Doing so could cause internal overheating of the junction box, resulting in bodily injury, re, or damage to the device.
IMPORTANT
Do not drop the device. Do not subject the device to an impact. Do not place any foreign object between the facing
core surfaces of the sensor heads.
Do not scratch the facing core surfaces between the
sensor heads.
Do not touch the facing core surfaces. Do not insert any foreign object into the gap around
the sensor heads.
Doing so could adversely a󰀨ect the measurement accuracy and the retracting/extending mechanism.
WARNING
2
25
Inspecting the Device Before Use

2.1 Inspecting the Device Before Use

Check the device for any damage that may have occurred during storage or shipping, and verify proper operation before use. If you nd any damage or failure, contact your authorized Hioki distributor or reseller. See “Before sending back your device for repair” (p. 85).
Items to prepare
• Model CT6710/CT6711 Current Probe
• Model 3269 Power Supply (available as an option)
• Waveform measuring instrument (such as oscilloscope
and recorder)
Connecting the CT6710/CT6711 to a Hioki Memory HiCorder with a power supply module for current probes (option) installed allows the CT6710/CT6711 to operate without the 3269 Power Supply. For more information, contact your authorized Hioki distributor or reseller.
IMPORTANT
Use a waveform measuring instrument (such as
oscilloscope and recorder) with an input impedance of
1 MΩ or more.
The output of the device is internally terminated. Accurate measurement is not possible with waveform
measuring instruments with an input resistance of 50
.
Ω
26
Inspecting the Device Before Use
Inspecting appearance and functionality of the device and condition of conductors to be
measured
Are the sensor, junction box, and termination unit damaged?
No
Yes
ZHave the device repaired.
Damage can cause electric shock.
2
Is the insulation of each
cord damaged?
No
Provide power to the device. (p. 29)
Do the seven LEDs light up for about one second after the device is turned on?
Yes
Is the insulation of
each conductor to be measured damaged?
No
The inspection is
completed.
Yes
O󰀨 or
blinking
Yes
ZHave the device repaired.
Damage can cause electric shock.
ZHave the device repaired.
The device is damaged.
Do not clamp the sensor
around any damaged conductor.
27
Preparing for Measurement

2.2 Preparing for Measurement

WARNING
Turn o󰀨 all equipment before connecting the
device.
Failure to do so can cause electric shock or a short-
circuit.
CAUTION
Before connecting the power cord to the inlet
on the rear panel of the 3269 Power Supply, verify that the supply voltage you plan to use falls within the supply voltage range noted on the 3269.
Supplying a voltage that falls outside the specied range to the 3269 could damage the CT6710/CT6711 or the 3269, causing bodily injury.
NOTICE
Always operate the opening lever to retract,
extend, and lock the upper jaw.
If you retract, extend, or lock the upper jaw directly by hand, the sensor may be damaged.
28
Preparing for Measurement

Providing power to the CT6710/CT6711

IMPORTANT
Do not allow the total consumption current of the
current sensors connected with the 3269 Power Supply to exceed the rated output current of the 3269.
The consumption current of the CT6710/CT6711 depends on current under measurement. One unit of the 3269 can simultaneously provide power to up to two current probes (the CT6710/CT6711) each of which measures a current with the maximum rated current value. For information about the consumption current, see “Consumption current” (p. 81) in “Typical
Characteristics.”
The 3272 Power Supply, which does not have su󰀩cient current capacity, cannot activate the CT6710/CT6711.
2
29
Preparing for Measurement
How to provide the power to the CT6710/CT6711
Ensure that the POWER switch of the 3269
1
Power Supply is set to OFF.
Connect the power cord to the power inlet on the
2
back of the 3269 Power Supply.
Slide the opening lever
3
of the sensor toward the lower jaw until the JAW
UNLOCKED indicator is
hidden.
The upper jaw will be locked
in place.
Do not clamp the sensor around any
conductor.
Connect the power plug
4
of the CT6710/CT6711 to the power receptacle of the 3269 Power Supply.
30
Power receptacle
Preparing for Measurement
Set the POWER switch of the 3269 Power Supply
5
to the ON position.
The LEDs of the CT6710/CT6711 and the 3269 will light up or blink as follows:
Model 3269
The POWER indicator will light up.
Model CT6710/CT6711
All LEDs will light up for 1 s, and then the CT6710/ CT6711 will operate as follows:
• The POWER LED will light up.
• The DEMAG / AUTO ZERO LED will blink slowly.
Green will light up
Orange will blink slowly
Keep the upper jaw locked in place while the
POWER LED lights up.
2
31
Preparing for Measurement
Wait for 30 minutes or more.
6
Wait at least 30 minutes after starting to supply power
to the CT6710/CT6711 to accurately measure a current before executing demagnetization and automatic zero­adjustment. See “Executing demagnetization and automatic zero-adjustment” (p. 33).
Do not execute demagnetization and
automatic zero-adjustment or measure current immediately after starting to supply power to the CT6710/CT6711.
An o󰀨set voltage may increase due to the heat generation of the CT6710/CT6711.
32
Preparing for Measurement
Executing demagnetization and automatic zero­adjustment
WARNING
Do not hold down the DEMAG / AUTO ZERO
key when the sensor is clamped around a
conductor under measurement.
Conductor under measurement
Do not hold down the key.
Doing so will start magnetization, causing bodily injury or damage to the circuit under measurement.
2
33
Preparing for Measurement
Do not subject the connection to force. Do not rotate the output terminal while the
termination unit is connected with a waveform
measuring instrument.
Doing so could damage the output terminal on the
termination unit or the BNC input terminal on the waveform measuring instrument.
Do not short-circuit the output terminal Do not apply voltage to the output terminal.
Doing so could damage the device.
NOTICE
34
Preparing for Measurement
NOTICE
Arrange the termination unit and a BNC
input terminal of your waveform measuring instrument in a straight line when connecting
the termination unit.
Failure to do so may damage the output terminal.
When connecting the output terminal to an
input terminal that is not a BNC terminal
through a conversion plug, make sure that the polarity is as follows:
BNC center contact: Positive Outer conductor: Ground potential
(or negative)
Failure to do so may damage the device and your
waveform measuring instrument.
2
35
Preparing for Measurement
What is demagnetization?
The magnetic core can be magnetized, which results from turning power on and o󰀨, inputting an excessively large current, or other factors. Executing demagnetization
eliminates magnetic charges.
What is automatic zero-adjustment?
Automatic zero-adjustment corrects variations in the o󰀨set voltage caused by factors such as the device-specic o󰀨set voltage and variations in temperature.
When the DEMAG / AUTO ZERO LED blinks slowly, execute demagnetization and automatic zero-adjustment. The DEMAG / AUTO ZERO LED blinks slowly in the following states:
• The power supply to the CT6710/CT6711 just started.
• A current exceeding the rated current was inputted to
the device, but this condition was resolved. (The current value fell below the rated value or stopped. Otherwise, the sensor was removed from the conductor under measurement.)
During demagnetization (with the DEMAG / AUTO ZERO LED lit), the device outputs a demagnetization waveform (which attenuates over time) from its output terminal. This waveform, which appears on a waveform measuring instrument, may be asymmetric along the horizontal axis; however, this does not represent a device malfunction.
36
Preparing for Measurement
How to execute demagnetizing and automatic
zero-adjustment
IMPORTANT
Do not move the sensor during demagnetization or
automatic zero-adjustment.
Disturbance (such as external magnetic elds and temperature changes) may prevent demagnetization or automatic zero-adjustment from being completed
normally.
Slide the opening lever
1
of the sensor toward the lower jaw until the JAW
UNLOCKED indicator is
hidden.
The upper jaw will be locked
in place. The JAW UNLOCKED LED will go out.
2
Set the input coupling of your waveform
2
measuring instrument to GND, then adjust the zero position of the display.
Do not clamp the sensor around any
conductor.
37
Preparing for Measurement
Set the input coupling of the waveform
3
measuring instrument to DC.
Connect the output
4
terminal of the termination unit to a BNC input terminal of
the waveform measuring
instrument.
• Insert the output terminal straight.
• Insert the output terminal
until it clicks so that it is securely locked in position.
The connection can be established with the unlock lever of the termination unit pointing up, regardless of whether the pair of the locking studs in the BNC input terminal on the waveform measuring instrument is xed in the horizontal or
vertical orientation.
38
Vertical Horizontal
Hold down the DEMAG /
5
AUTO ZERO key on the
junction box for about 1
second.
Preparing for Measurement
The DEMAG / AUTO ZERO LED will light up.
Demagnetization and automatic zero-adjustment will
start.
After the completion, the DEMAG / AUTO ZERO LED
will go out.
Green will light up
Orange will light up
Green will light up
Orange will go out
Hold down
2
39
Preparing for Measurement
If the DEMAG / AUTO ZERO LED ashes three times, the device cannot perform demagnetization or automatic zero­adjustment.
ZImplement the remedy described on the following page.
“Demagnetizing / automatic zero-adjustment unavailable” (p. 92)
To halt demagnetization or automatic zero-adjustment
on the middle of its execution
ZPull the unlock lever toward you to unlock the upper
jaw.
When you halt demagnetization or automatic zero­adjustment, re-execute demagnetization and automatic zero-adjustment before taking a measurement.
To execute automatic zero-adjustment alone (without executing demagnetization)
ZPress the DEMAG / AUTO ZERO key momentarily (Do
not hold down the key). (p. 18)
40
Measuring Currents

2.3 Measuring Currents

Be sure to read the following sections and perform the steps described there before taking measurements: “2.1 Inspecting the Device Before Use” (p. 26) “2.2 Preparing for Measurement” (p. 28)
Follow all operating precautions for your waveform measuring instrument or any other measuring instrument.
DANGER
Do not cause a short-circuit between the wire
to be measured and another wire with the
metallic parts of the tips of the sensor.
Doing so can cause arc ash, resulting in serious bodily injury or damage to the device or other equipment.
Do not measure any current in excess of the
derating curve.
Doing so can cause overheating of the device, resulting in bodily injury, re, or damage to the device.
See “Frequency derating curve” (p. 78).
The maximum measurement current varies with the
frequency, and the current that can be measured continuously is limited. Operating the device at less than this limitation is referred to as derating.
2
41
Measuring Currents
Do not subject the ground side of other input
terminals to a di󰀨erent potential when you use one of the following waveform measuring instruments:
• an instrument that does not provide
electrical insulation between its input
terminals and chassis
• an instrument that does not provide
electrical insulation among its input terminals
H
Power source
Load
DANGER
L
Waveform measuring instrument
Load
Model 3269 Power Supply
If you do so, a short-circuit current will ow through the 3269 Power Supply and the CT6710/CT6711 from the ground terminal, causing electric shock or damage to the CT6710/CT6711 and the 3296.
See the gure in “Example of connection to the circuit to be measured” (p. 49) for a proper connection.
42
Measuring Currents
DANGER
Ensure that the insulation on a conductor is
not worn or damaged before clamping the sensor around the conductor to be measured.
Take care not to damage the insulation when
clamping the sensor around the conductor.
Damage to the conductor insulation can cause electric shock.
Connect the CT6710/CT6711 to the 3269 Power
Supply and a waveform measuring instrument (oscilloscope or recorder) before clamping the device around a live line to be measured.
Failure to do so may cause electric shock or a short-
circuit.
2
43
Measuring Currents
While measuring a high-frequency current
or a current that includes high-frequency components, keep hands and other body parts away from the jaws.
Eddy current loss may cause heating of the sensor heads. Failure to do so could re or damage to the measurement target and device, resulting in burns.
Keep away any cords and other parts, which
include the cords of the device, from the
conductor under measurement.
Dielectric heating may cause heating of cords and other parts, resulting in burns.
WARNING
44
Measuring Currents
CAUTION
Do not place any conductor carrying a current
with a frequency of 10 kHz or more close to the jaws even when the sensor is not clamped
around a conductor.
A current owing through conductors near the sensor may heat up the sensor heads, leading to damage to the device, resulting burns.
When the device is clamped around one of the go­and-return conductors and the other conductor is placed close to the jaws, self-heating of both currents will synergistically heat up the sensor heads even if the electric current is lower than the maximum rated
current.
Do not place conductors not to be measured close
to the jaws.
2
45
Measuring Currents
Do not prevent heat radiation from the device. Do not input a current that exceeds the
maximum rated current value*.
An temperature increase in the device cause burns, damage to the device, or a short-circuit.
Never input a current that exceeds ±50 A even
momentarily.
Doing so can damage the device, resulting in bodily injury. See “Maximum peak current” (p. 72).
Do not exceed the maximum rated current,
regardless of the blinking state of the
OVERLOAD LED.
Doing so can damage the device, resulting in bodily injury.
Overload warnings are detectable in a frequency band of DC and 45 Hz to 66 Hz (sine wave). When measuring a current with a frequency outside the frequency detection band, the overload warning function may not work properly. See “Frequency characteristics” (p. 77).
CAUTION
* The maximum rated current has been specied in
light of a temperature increase caused by self-heating during measurement. The maximum rated current varies depending on the frequency of the current under
measurement.
See the gures in “Frequency derating curve” (p. 78).”
46
Measuring Currents
CAUTION
Use the device for measuring currents much
lower than the maximum rated current value if an ambient temperature is relatively high or a current to be measured can contain frequency
components other than the fundamental.
Self-heating could cause burns or damage to the device even if the current under measurement is lower than the maximum rated current.
The maximum rated current is dened as a recommended value for when a sine-wave current is inputted to the device at the temperatures and humidity specied for the guaranteed accuracy. See “Frequency derating curve” (p. 78).
Connect the device and other probes properly
to a circuit to be measured and your waveform
measuring instrument.
Improperly connecting them could cause electric shock or damage to the device, other probes, and instrument.
2
47
Measuring Currents
Do not subject the sensor to high voltage,
including static electricity.
Doing so may damage the device.
Do not pass a current through a conductor
under measurement when the 3269 Power Supply or your waveform measuring instrument is o󰀨.
Doing so may damage the device and instrument.
Keep the upper jaw locked in place except the
following occasions:
• When clamping the sensor around a
conductor to be measured
• When removing the sensor from the
conductor.
Leaving the upper jaw unlocked can damage the device.
NOTICE
48
Measuring Currents
Example of connection to the circuit to be
measured
The gure below illustrates a connection between the device and a measuring instrument with non-isolated input terminals equipped,
such as a general oscilloscope.
Waveform measuring instrument
H
Power source
Load Load
L
Model 3269 Power Supply
The 3269 Power Supply can provide the power to up to two probes of the CT6710/CT6711.
Connecting the CT6710/CT6711 to a Hioki Memory HiCorder with a power supply module for current probes (option) installed allows the CT6710/CT6711 to operate without the 3269 Power Supply. For more information, contact your authorized Hioki distributor or reseller.
2
49
Measuring Currents

How to measure a current

IMPORTANT
Do not place the sensor close to a heat source. Do not roughly operate the opening lever to lock the
upper jaw.
Do not subject the jaws and opening lever to force. Do not subject the sensor aperture to force while the
sensor is clamped around the conductor.
Changes in ambient temperature and an impact on the sensor head can cause uctuations in the o󰀨set voltage, resulting in an adverse e󰀨ect on the
measurement accuracy.
Be sure to execute demagnetization and automatic
zero-adjustment before taking measurements.
Failure to do so can adversely a󰀨ect the measurement
accuracy.
See “Executing demagnetization and automatic zero­adjustment” (p. 33).
50
Pull the opening lever of
1
the sensor toward you to retract the upper jaw.
Clamp the sensor
2
around a conductor to be
measured.
• Have the current direction indicator match the direction of the current to be measured.
• Place the conductor at the center of the sensor aperture.
Slide the opening lever
3
toward the lower jaw until
the JAW UNLOCKED indicator is hidden.
The upper jaw will be locked
in place. The JAW UNLOCKED LED will go out.
Measuring Currents
2
Low-potential side
(Ground potential
side)
High- potential side
51
Measuring Currents
Check the LEDs on the junction box.
4
The POWER LED
and one of
light up.
There is no error.
Go on to step
Z
.
5
The OVERLOAD LED blinks rapidly.
The device has detected a measurement current in excess of the level dened for the current range. See “Overload” (p. 90).
When you use the 30 A range
Immediately remove the sensor from the conductor
Z
under measurement.
When you use the 0.5 A range or 5 A range
Switch a higher current range.
Z
IMPORTANT
• The instrument may be unable to properly detect overload states immediately after the current range has changed.
• The currents for which an overload state can be detected are DC and sine waves with frequencies of 45 Hz to 66 Hz. The device is unable to detect the currents listed below as an overload state.
- Currents that exceed the dened level on a momentary basis
- High-frequency currents that exceed the dened level
the RANGE LEDs
Any other LEDs lights up or blinks.
A di󰀨erent error is occurring.
See “4.2 Errors” (p. 88) to identify a reason and take
Z
necessary measures.
52
Measuring Currents
Press the  (higher range) key or  (lower range)
5
key to choose a current range.
• Choose a current range with a maximum peak current higher than the peak value of a current under
measurement.
See “Maximum peak current” (p. 72). If the peak value of the current under measurement exceeds the maximum peak current of the chosen current range, the output waveform will be saturated or distorted, preventing you from correctly observing the current
waveform.
• You need to choose a current range according to the level
of the current under measurement to minimize an adverse e󰀨ect of noise on observation of the current waveform. The following table shows the recommended current ranges for each of the levels of currents under measurement.
Electric current level
Recommended current
±5 A to ±50 A 30 A (0.1 V/A)
±0.5 A to ±5 A 5 A (1 V/A)
±1 mA to ±0.5 A 0.5 A (10 V/A)
range
(Output rate)
2
53
Measuring Currents
Convert a voltage sensitivity of the waveform
6
measuring instrument into a current sensitivity.
Using the following formula can convert a voltage sensitivity
(unit: V/div) specied on the waveform measuring instrument into a current sensitivity (unit: A/div).
S
=
S
/
R
I
V
O
S
: Current sensitivity (A/div)
I
S
: Voltage sensitivity (V/div)
V
R
: Output rate (V/A)
O
Example
When your waveform measuring instrument with its voltage
sensitivity set at 10 mV/div measures a current that has an RMS value of 1 mA
1 mA/div
0.5 A range (10 V/A) 5 A range (1 V/A)
S
= (10 ×10-3) / 10
I
= 1 × 10
-3
(A/div) = 10 ×10-3 (A/div)
S
I
54
10 mA/div
= (10 × 10-3) / 1
Measuring Currents
IMPORTANT
After you measured a current that exceeds the
maximum rated current value of each current range, re-execute the demagnetization and automatic zero­adjustment.
The sensor heads have been magnetized, causing
incorrect current measurements.
See “Executing demagnetization and automatic zero­adjustment” (p. 33).
IMPORTANT
When you measure high-frequency currents, the position of the conductor under measurement in the sensor aperture may vary the magnitude of load applied to the circuit under measurement, adversely a󰀨ecting the measurement accuracy. See “Input impedance” (p. 80).
The following methods can minimize the adverse e󰀨ect:
• Straighten the conductor under measurement as long as possible.
• Clamp the sensor at the center of the straight portion of the
conductor as close as possible.
• Arrange the conductor at the center of the sensor aperture as close as possible.
• Do not wind the conductor around a jaw.
2
55
Measuring Currents
IMPORTANT
When you measure high-frequency currents, Clamping the sensor around the high-potential side of a circuit may cause common-mode noise to a󰀨ect the measurement accuracy adversely. See “Inuence of common-mode voltage” (p. 82).
As needed, reduce the frequency band of the waveform measuring instrument, or clamp the sensor around the low­potential side conductor.
H
NO
Power source
Load
L
Displayed values can frequently uctuate due to induction potential even when no voltage is applied. This, however, is
not a malfunction.
56
OK
Measuring Currents
NOTE
• Depending on the amplitude and frequency of a current under measurement, the sensor heads may emit a resonant sound. Such a sound may also be emitted during demagnetization. This, however, does not represent a device malfunction.
• If foreign matter adheres to the facing core surfaces on the sensor heads and thus creates a slight gap between the upper and lower sensor heads, the sensor heads may emit a resonant sound.
ZRemove any foreign matter by following the cleaning
method. See “4.3 Cleaning” (p. 96).
• An increase in the resonant sound while the device is in use may indicate that the gap between the upper and lower heads has widened. The gap may adversely a󰀨ect the measurement accuracy. Calibrating the device is recommended. See “Maintenance and Service” (p. 83).
2
57
Measuring Currents

To measure a low current

When measuring low DC or low-frequency low AC, you can increase the current-detection sensitivity of the device in the
following way.
How to measure a low current
Coil a single conductor to be measured into
1
several loops with a diameter of 200 mm or
more.
Clamp the sensor around the loops in a bundle.
2
This will make the conductor pass through the sensor
aperture one time more than the loop count consecutively
in one direction.
Arrange the loops radially as shown on the
3
following page.
Measure the current.
4
58
Measuring Currents
As shown in the gure below, clamping the sensor around the seven loops in a bundle allows the conductor to pass through the sensor aperture eight times, which increases the voltage of the output signal by a factor of eight.
200 mm or more
Arrange loops radially.
φ
2
High-potential
side
Low-potential
side
(Grounded side)
59
Measuring Currents

To measure a current accurately

Retracting and extending the upper jaw can cause an o󰀨set voltage of several millivolts. Perform the steps described below before measuring a current to measure it accurately.
How to measure a current accurately
Hold down the DEMAG /
1
AUTO ZERO key on the
junction box for about 1
second.
The DEMAG / AUTO ZERO
LED will light up. Demagnetization and automatic zero-adjustment will
start.
After the completion, the
DEMAG / AUTO ZERO LED
will go out.
Wait for about 5 minutes.
2
The uctuation in the o󰀨set voltage will stabilize.
Operate the opening
3
lever of the sensor back
and forth to retract and
extend the upper jaw 4 or 5 times.
60
Hold down
Before execution, orange blinks or
goes out.
Slide the opening
4
lever toward the lower jaw until the JAW
UNLOCKED indicator is
hidden.
The upper jaw will be locked with the upper and lower sensor heads arranged in
position relative to each other.
The JAW UNLOCKED LED will go out.
Momentarily press the
5
DEMAG / AUTO ZERO
key on the junction box. (Do not hold down the key.)
Measuring Currents
2
The DEMAG / AUTO ZERO
LED will light up. Automatic zero-adjustment will be performed alone.
After the completion, the
DEMAG / AUTO ZERO LED
will go out.
Measure a current.
6
See “How to measure a current” (p. 50).
Press
(Do not hold down)
61
Measuring Currents

When the device has entered protection mode

To protect the device against self-generated heat, it enters protection mode when the temperature of the junction box exceeds a specied level.
Green lights up
Reds blink rapidly
Orange blinks rapidly
Greens blink rapidly
In protection mode, the device cannot correctly measure any current. Moreover, you cannot switch the current ranges. When the device has entered protection mode, follow the procedure presented on the following pages to restore it to
normal operation.
If the device has entered protection mode, it is recommended to re-calibrate it because internal components may have been subjected to thermal stress.
62
How to restore the device
Pull the opening lever of
1
the sensor toward you to retract the upper jaw,
and remove the sensor from the conductor under measurement.
Slide the opening
2
lever toward the lower jaw until the JAW
UNLOCKED indicator is
hidden.
The upper jaw will be locked
in place.
Wait for a while to let the junction box cool down
3
to a normal temperature.
Measuring Currents
2
63
Measuring Currents
Press any key.
4
One of the RANGE LEDs (of the range used before the device entered protection mode) will light up, and the device will get back to normal.
The DEMAG / AUTO ZERO
LED will blink slowly.
Perform demagnetization
5
and automatic zero­adjustment.
See “Executing
demagnetization and automatic zero-adjustment” (p. 33).
Press
any key
64
Finishing Measurement

2.4 Finishing Measurement

NOTICE
Do not pull the cord to unplug the output
terminal.
Doing so can damage the cord and output terminal.
Hold the termination unit and disconnect the
output terminal while pulling the unlock lever toward you.
2
65
Finishing Measurement
To disconnect the power plug of the device,
do not pull the cord.
Do not twist the power plug.
Doing so could damage the cord and the power
receptacle of the 3269 Power Supply.
While holding the shell (p. 17), pull the
power plug out.
Pulling the shell lets the plug be unlocked, so you can disconnect the plug from the power receptacle.
NOTICE
66
How to nish measurement
Pull the opening lever of
1
the sensor toward you to retract the upper jaw,
and remove the sensor from the conductor under measurement.
Slide the opening
2
lever toward the lower jaw until the JAW
UNLOCKED indicator is
hidden.
The upper jaw will be locked
in place. The JAW UNLOCKED LED will go out.
Disconnect the
3
termination unit from the BNC input terminal on
the waveform measuring
instrument.
Finishing Measurement
2
While pulling the unlock lever,
pull out the termination unit straight.
67
Finishing Measurement
Set the POWER switch of the 3269 Power Supply
4
in the OFF position.
Disconnect the power
5
plug of the CT6710/ CT6711 from the 3269 Power Supply.
Hold the shell (p. 17) of
the power plug when you
disconnect it.
Do not pull the cord. Do not twist the power plug.
Unplug the power cord of the 3269 Power Supply
6
from the outlet.
68
Specications
3
Unless otherwise specied, each specication item is applied to both Model CT6710 and Model CT6711. Items with a model number, “(Model CT6710)” or “(Model CT6711),” indicated are applicable to each model. Each item is specied for the device operated at 23°C±5°C (73°F±9°F) and 80% RH (no condensation), 30 minutes elapses after the device is turned on before use.
3.1 General Specications
Operating environment
Indoor, Pollution Degree 2, Operating altitude up to 2000 m (6562 ft.)
Operating temperature and humidity
0°C to 40°C (32°F to 104°F), 80% RH or less (no condensation)
Storage temperature and humidity range
−10°C to 50°C (14°F to 122°F), 80% RH or less (no condensation)
Standards Safety: EN61010
EMC: EN61326
Measurable conductors
Insulated conductors
Measurable diameter of conductors
5 mm or less in diameter
3
69
General Specications
Power supply External power supply (Model 3269)
Rated supply voltage: ±12 V DC ±0.5 V Maximum rated power: 7.8 VA (For current probe only, when measuring 30 A rms continuously)
Consumption current
See “Consumption current” (p. 81) in “3.4
Typical Characteristics.”
Dimensions • Sensor
Approx. 155W × 18H × 26D mm (6.10″W × 0.71″H × 1.02″D)
• Junction box Approx. 45W × 120H × 25D mm (1.77″W × 4.72″H × 0.98″D)
• Termination unit
Approx. 29W × 83H × 40D mm (1.14″W × 3.27″H × 1.57″D)
Excluding BNC connector or protrusions
Mass Approx. 370 g (13.1 oz.)
Cord lengths • Between sensor and junction box
Approx. 1500 mm (59.06″)
• Between junction box and termination unit Approx. 150 mm (5.91″)
• Power cord Approx. 1000 mm (39.37″)
Product warranty period
1 year
Accessories Option
See “(Accessory)” (p. 5) and “Option” (p. 6).
70
Specications of Input, Output, and Measurement
3.2 Specications of Input, Output, and
Measurement
Basic specications
Frequency band
DC to 50 MHz (−3 dB) (Model CT6710) DC to 120 MHz (−3 dB) (Model CT6711) See “Frequency characteristics” (p. 77) in “3.4
Typical Characteristics.”
Rise time (10% to 90%)
7.0 ns or less (Model CT6710)
2.9 ns or less (Model CT6711)
Delay time (the time lag between the input signal with a rise time of 1 ns and the output signal)
30 A range: 12 ns (typical) 5 A range: 12 ns (typical)
0.5 A range: 13 ns (typical)
Current range (output rate)
30 A range (Rate: 0.1 V/A) 5 A range (Rate: 1 V/A)
0.5 A range (Rate: 10 V/A)
3
71
Specications of Input, Output, and Measurement
Maximum rated current*
Maximum peak current
Noise 75 µA rms or less (Typical: 60 µA rms)
Input impedance
*1. Depending on the ambient temperature and measurement
conditions, internal overheating can result in an overload condition, limiting the maximum rated current lower than those specied here.
*2. The device requires to cool down for 10 times the length of time
the current was inputted.
1
30 A range: 30 A rms 5 A range: 5 A rms
0.5 A range: 0.5 A rms Derating is needed as input frequency
increases.
See “Frequency derating curve” (p. 78) in “3.4
Typical characteristics.”
Specied for currents of DC and sine wave
30 A range: ±50 A peak
(maximum duration of input: 2 s*2)
5 A range: ±7.5 A peak
0.5 A range: ±0.75 A peak (less than 10 MHz) ±0.3 A peak (10 MHz or more)
(For only the probe with the 0.5 A range, connected with a measuring instrument that has a frequency band of 20 MHz)
See “Input impedance” (p. 80) in “3.4 Typical
characteristics.”
72
Specications of Input, Output, and Measurement
Specications of accuracy
Accuracy warranty conditions
• Accuracy warranty period 1 year (until the upper jaw has been retracted and locked up to 10,000 cycles)
• Guaranteed accuracy period after adjustment made by Hioki
0.5 year
• Temperature and humidity for guaranteed accuracy
23°C±5°C (73°F±9°F), 80% RH or less
• Warm-up time At least 30 minutes
• Power voltage range
±12 V DC ±0.5 V
Amplitude accuracy*
*3. Unless there is any change in the state of the facing core
surfaces, which includes scratches, adhesion of foreign objects,
or any change in the operating environment.
3
30 A range: ±3.0% rdg. ±1 mV (Typical: ±1.0% rdg. ±1 mV
[for 10 A rms or less]) 5 A range: ±3.0% rdg. ±1 mV (Typical: ±1.0% rdg. ±1 mV)
0.5 A range: ±3.0% rdg. ±10 mV (Typical: ±1.0% rdg. ±10 mV) For a direct current and a sine-wave current with frequencies of 45 Hz to 66 Hz within the maximum peak current value of each current
range
3
73
Specications of Input, Output, and Measurement
Temperature characteristics of sensitivity*
±2.0% rdg. or less After automatic zero-adjustment was executed, in the temperature range except 23°C±5°C, under the following input conditions: 30 A range: AC with 50 Hz, 30 A 5 A range: AC with 50 Hz, 5 A
0.5 A range: AC with 50 Hz, 0.5 A
E󰀨ect of radiated radio-frequency electro-magnetic eld
±10 mA or less at 3 V/m
E󰀨ect of conducted radio-frequency electro-magnetic eld
±10 mA or less at 3 V
E󰀨ect of external magnetic eld
20 mA or less (Model CT6710)
(DC and 60 Hz, in a magnetic eld of 400 A/m)
5 mA or less (Model CT6711)
(DC and 60 Hz, in a magnetic eld of 400 A/m)
*3. Unless there is any change in the state of the facing core
surfaces, which includes scratches, adhesion of foreign objects,
or any change in the operating environment.
*4. The values of the temperature characteristics of sensitivity are
added to the amplitude accuracy.
3, *4
74
Specications of Functionality
3.3 Specications of Functionality
Demagnetizing and automatic zero-adjustment functions
When the upper jaw is not locked in place, an overload is detected, or an inputted current exceeds the values listed below, the functions are not available.
0.50 ±0.25 A rms
(DC and sine wave with frequencies of 45 Hz to 66 Hz)
• Demagnetizing and automatic zero-adjustment
Operation: Executes demagnetization and
automatic zero-adjustment.
Means: Hold down the DEMAG / AUTO
ZERO key (1 s).
• Automatic zero-adjustment
Operation: Executes automatic zero-
adjustment alone.
Means: Press the DEMAG / AUTO ZERO
key.
Jaw-unlocked detection
When the upper jaw is not locked in place, the
JAW UNLOCKED LED lights up.
3
75
Specications of Functionality
Overload detection
• Typical sampling frequency: 7.8125 kHz
• Typical checking cycle: 500 ms
Breakdown
Typical sampling period: 400 ms Typical computing-and-judging period:
100 ms
(1) Excess of rated current level
When the input current exceeds the following
level, the OVERLOAD LED blinks rapidly. 30 A range: 32.5 ±2.5 A rms 5 A range: 5.25 ±0.25 A rms
0.5 A range: 0.525 ±0.025 A rms
(For all the ranges, the target currents are of
DC and sine wave with frequencies of 45 Hz
to 66 Hz) (2) Excess of specied temperature
Detects an internal temperature anomaly and
issues an alert by blinking all of the LEDs
except the POWER LED.
Typical specied-temperature: 80°C
Typical hysteresis: 10°C
Recovery means: Press any key. Then,
the device requires demagnetization and automatic zero-adjustment.
Specications of lighting up / blinking LEDs
See “1.4 Specications of Lighting Up / Blinking LEDs” (p. 22).
76
Typical Characteristics
0.5 A range (10 V/A)
Gain (dB)
Frequency
(Hz)
0.5 A range (10 V/A)

3.4 Typical Characteristics

All of the characteristics shown in this section are typical.

Frequency characteristics

30
20
10
5 A range (1 V/A)
0
−10
Gain (dB)
30 A range (0.1 V/A)
−20
−30
−40
1 10 100 1 k 10 k 100 k 1 M 10 M 100 M
Fig. 1 Frequency characteristics (Model CT6710)
30
20
10
5 A range (1 V/A)
0
−10
30 A range (0.1 V/A)
−20
−30
−40
1 10 100 1 k 10 k 100 k 1 M 10 M 100 M
Fig. 2 Frequency characteristics (Model CT6711)
Frequency (Hz)
3
77
Typical Characteristics

Frequency derating curve

Figures 3 and 4 show the derating curves with a sine-wave current inputted in the temperature and humidity range for the guaranteed accuracy. If the ambient temperature (T rises or the current under measurement contains high­frequency components, the device temperature will rise, and thus its continuously inputtable current value and frequency
will lower.
)
A
78
Typical Characteristics
35
Maximum input current (A)
TA = 23°C, Sine wave
35
Maximum input current (A)
30
25
20
15
10
5
0
100 1 k 10 k 100 k 1 M 10 M 100 M 1 G
Frequency (Hz)
Fig. 3 Derating curve according to frequency (Model CT6710)
30
25
20
15
10
5
0
100 1 k 10 k 100 k 1 M 10 M 100 M 1 G
Frequency (Hz)
30 A range
5 A range
3
30 A range
5 A range
TA = 23°C, Sine wave
Fig. 4 Derating curve according to frequency (Model CT6711)
79
Typical Characteristics

Input impedance

The location where the sensor is clamped will exhibit impedance as shown in Figs. 5 and 6, which inserts a load in a circuit under measurement. In particular, take this characteristic into account when measuring a high-frequency
current.
1
0.1
0.01
Input impedance (Ω)
0.001 100 1 k 10 k 100 k 1 M 10 M 100 M 1 G
Fig. 5 Input impedance (Model CT6710)
1
Frequency (Hz)
0.1
0.01
Input impedance (Ω)
0.001 100 1 k 10 k 100 k 1 M 10 M 100 M 1 G
Fig. 6 Input impedance (Model CT6711)
80
Frequency (Hz)

Consumption current

1.2
Input current (A)
Consumption current (A)
Fig. 7 Consumption current (with the 30 A range specied)
Typical Characteristics
1
0.8
0.6
0.4
0.2
0
0 10 20 30 40 50
DC
AC
3
81
Typical Characteristics
V
/ V
(dB)
Frequency (Hz)
Inuence of common-mode voltage
The gure below indicates the ratio of common-mode voltage (external noise voltage) applied to a conductor under measurement positioned in the sensor aperture and the
resulting output voltage.
−40
−60
−80
−100
c
−120
O
−140
−160
−180 10 100 1 k 10 k 100 k 1 M 10 M
VO: Output voltage (V) VC: Common-mode voltage (V)
Fig. 8 Inuence of common-mode voltage
82
0.5 A range 5 A range 30 A range
30 A range

Maintenance and Service

4
WARNING
Do not attempt to modify, disassemble, or
repair the device yourself.
Attempting the above may cause bodily injury or re.
Calibration
The calibration interval depends on factors such as operating conditions and environment. Please determine the appropriate calibration interval based on your operating conditions and environment and have Hioki calibrate it accordingly on a regular basis.
4
83
Troubleshooting

4.1 Troubleshooting

If damage is suspected, read “Before sending back your device for repair” (p. 85) and check the device as described. If this cannot resolve problems, contact your authorized Hioki distributor or reseller.
When transporting the device, be sure to observe the following precautions:
• Remove the CT6710/CT6711 from the 3269 Power Supply.
• Include a memo that describes the problem in detail.
• Pack the device in the packaging in which it was initially
delivered and double-pack it.
Damage that occurs during transportation is not covered by
the warranty.
84
Troubleshooting

Before sending back your device for repair

Symptom
No waveform is displayed on the waveform measuring
instrument.
Z
Z
If the issue has not been resolved, the device may be
malfunctioning.
Z
A resonant sound is emitted from the sensor heads.
This does not a󰀨ect the measurement accuracy. The sensor head may emit a resonant sound depending on the amplitude and frequency of the current under
measurement.
The resonant sound emitted from the sensor heads becomes louder.
Calibration of the device is recommended because the gap may adversely a󰀨ect the measurement accuracy. The gap between the upper and lower sensor heads may have increased.
Cause, remedy
/
Re-execute demagnetization and automatic zero­adjustment. (p. 33) Make sure that the input coupling of the waveform measuring instrument is set to DC. (p. 38)
Have the device repaired.
4
85
Troubleshooting
Symptom
Cause, remedy
/
Demagnetization and automatic zero-adjustment
cannot be performed.
Demagnetization or automatic zero-adjustment has not
been completed normally.
Under the following conditions, demagnetizing and automatic zero-adjustment cannot be performed. Alternatively, demagnetization or automatic zero­adjustment has not been completed normally.
• The upper jaw is unlocked.
• An overload has been detected whether or not the
upper jaw is locked.
• A current exceeding 0.5 A rms has been detected whether or not the upper jaw is locked.
Implement the remedy described on the following
Z
pages: See “Demagnetizing / automatic zero-adjustment unavailable” (p. 92). Then, re-execute demagnetization and automatic zero-adjustment. See “Executing demagnetization and automatic zero­adjustment” (p. 33).
When demagnetization or automatic zero-adjustment has not been normally completed even with the sensor not clamped around any conductor and the upper jaw locked in place, the device may be malfunctioning.
Send the device for repair.
Z
86
Troubleshooting
Symptom
The waveform outputted during the demagnetization is asymmetric along the horizontal axis.
This does not represent a device malfunction.
Z
Cause, remedy
/
After demagnetization and automatic zero-adjustment
are completed, make sure that the zero position on
the waveform measuring instrument is appropriate.
4
87
Errors

4.2 Errors

If an error occurs, the LEDs on the junction box will light up or blink. See “1.4 Specications of Lighting Up / Blinking LEDs” (p. 22). When an error occurs, remedy the error according to measures described on the following pages. If the device needs to be repaired, contact your authorized Hioki distributor or reseller.
88
Errors

Types of errors

You can identify the type of an error with the LED indicators displayed on the junction box.
Protection mode
Green lights up
Reds blink rapidly
Orange blinks rapidly
Greens blink rapidly
The abnormal internal temperature was detected in the junction box, and thus the device has entered protection mode.
Follow the procedure on the following page.
Z
“When the device has entered protection mode” (p. 62)
4
Calibration of the device is recommended. Internal components may have been subject to thermal stress.
89
Errors
Overload
Green lights up
Red blinks rapidly
Red lights up or goes out
Orange goes out
One of greens lights up
The input current exceeding the specied level of each current range is detected.
When you use the 30 A range
Immediately remove the sensor from the conductor under
Z
measurement.
When you use the 0.5 A range or 5 A range
Switch a higher current range.
Z
90
Errors
IMPORTANT
• The instrument may be unable to properly detect overload states immediately after the current range has changed.
• The currents for which an overload state can be detected are DC and sine waves with frequencies of 45 Hz to 66 Hz. The device is unable to detect the currents listed below as an overload state.
- Currents that exceed the dened level on a momentary basis
- High-frequency currents that exceed the dened level
• Although external magnetic elds may cause the OVERLOAD
LED to blink while the upper jaw is retracted, this does not indicate an issue with the device.
4
91
Errors
Demagnetizing / automatic zero-adjustment unavailable
Green lights up
Reds ash 3 times
Orange ashes 3 times
One of greens lights up
Demagnetizing and automatic zero-adjustment cannot be performed; otherwise, demagnetization or automatic zero­adjustment has not been completed normally. The device must be in the following conditions:
• The upper jaw is unlocked.
• An overload has been detected whether or not the upper
jaw is locked.
• A current exceeding 0.5 A rms has been detected whether or not the upper jaw is locked.
Depending on the LED status exhibited after the three
Z
blinks, implement the remedy described on the following pages. After that, re-execute demagnetization and automatic zero-adjustment (p. 33).
92
LED status after three ashes
Green lights up
Red goes out
Red lights up
The upper jaw is unlocked.
Slide the opening lever of the sensor toward the
Z
lower jaw until the JAW UNLOCKED indicator is hidden to lock the upper jaw in place.
Errors
Red blinks rapidly
Red lights up or goes out
An overload is detected.
Remove the sensor from the conductor under
Z
measurement.
Then, slide the opening lever of the sensor toward the lower jaw until the JAW UNLOCKED indicator is hidden to lock the upper jaw in place.
Green lights up
4
93
Errors
Green lights up
Red lights up or goes out
Red goes out
A current exceeding 0.5 A rms has been detected.
Remove the sensor form the conductor under
Z
measurement.
Then, slide the opening lever of the sensor toward the lower jaw until the JAW UNLOCKED indicator is hidden to lock the upper jaw in place.
94
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