CT6844
CT6844-05
AC/DC CURRENT PROBE
Instruction Manual
EN
. 2018
Oct
CT6844A961-02 18-10H
Revised e
Warranty
Warranty malfunctions occurring under conditions of normal use in
conformity with the Instruction Manual and Product Precautionary
Markings will be repaired free of charge. This warranty is valid for a
period of three (3) years from the date of purchase. Please contact
the distributor from which you purchased the product for further
information on warranty provisions.
Introduction
Thank you for purchasing the HIOKI Model CT6844, CT6844-05 AC/
DC Current Probe. To obtain maximum performance from the device,
please read this manual rst, and keep it handy for future reference.
Inspection
When you receive the device, inspect it carefully to ensure that
no damage occurred during shipping. In particular, check the
accessories and cables. If damage is evident, or if it fails to operate
according to the specications, contact your dealer or Hioki
representative.
Precautions during Shipment
Handle the device carefully so that it is not damaged due to a
vibration or shock.
Safety
This device is designed to conform to IEC 61010 Safety Standards,
and has been thoroughly tested for safety prior to shipment.
However, using the instrument in a way not described in this
manual may negate the provided safety features. Before using the
instrument, be certain to carefully read the following safety notes.
Mishandling during use could result in injury or death,
as well as damage to the device. Be certain that you
understand the instructions and precautions in the
manual before use.
dition 2
DANGER
1 2 3 4
WARNING
With regard to the electricity supply, there are risks of
electric shock, heat generation, re, and arc discharge
due to short circuits. If persons unfamiliar with electricity
measuring instrument are to use the
instrument, another person familiar with such instruments
must supervise operations.
Notation
In this manual, the risk seriousness and the hazard levels are
classied as follows.
Indicates an imminently hazardous situation
DANGER
WARNING
CAUTION
that will result in death or serious injury to the
operator.
Indicates a potentially hazardous situation
that may result in death or serious injury to the
operator.
Indicates a potentially hazardous situation that
may result in minor or moderate injury to the
operator or damage to the device or malfunction.
Safety Symbols
Indicates hazardous high voltage.
Provides warning that negligent safety check or incorrect
operation presents a signicant hazard that could result in
electrical shock, burn injury, or even death to the user.
Indicates the prohibited action.
Indicates the compulsory action.
Symbols Afxed to the Device
Indicates cautions and hazards. When the symbol is
printed on the device, refer to a corresponding topic in the
Instruction Manual.
Indicates that only insulated conductors suited to the
voltage of the conductor under test can be measured.
Symbols for Various Standards
Indicates the Waste Electrical and Electronic Equipment
Directive (WEEE Directive) in EU member states.
Indicates that the product conforms to regulations set out
by the EU Directive.
Usage Notes
Follow these precautions to ensure safe operation and to obtain the
full benets of the various functions.
DANGER
Do not use the device to measure bare conductors.
Doing so may result in a short-circuit or electrical shock.
Make measurements at a location on an insulated wire
that has a suitable amount of insulation for the circuit
voltage.
The maximum measurable 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. Do not measure
currents in excess of the derating curve. Doing so may
result in device damage or malfunction, re, or burns due
to sensor heating.
CAUTION
Do not place foreign objects between the jaws or insert
•
foreign objects into the gaps of the sensor head. Doing so
may worsen the performances of the sensor or interfere with
clamping action.
• When the connected instrument’s power is turned off, do
not apply current to the sensor. Doing so may damage the
device.
• Avoid stepping on or pinching cables, which could damage
the cables insulation.
Be careful to avoid dropping the device or otherwise
•
subjecting them to mechanical shock, which could damage
the jaw and adversely affect measurement.
• Do not touch the cores with the jaw opened. If the cores are
subject to static electricity, the device may be damaged.
Keep the jaw closed when not in use, to avoid accumulating
•
dust or dirt on the facing core surfaces, which could interfere
with clamp performance.
When the power to conductors to be measured is turned
•
on or off, a current owing through the lines can exceed
considerably the maximum allowable current of the device.
This could result in damage to the device. Make sure that
there is not any over-current.
• When disconnecting the output connector, be sure to
release the lock before pulling off the connector. Forcibly
pulling the connector without releasing the lock, or pulling
on the cable, can damage the connector.
• The cable is hardened under the 0°C or colder environment.
Do not bend or pull it to avoid tearing its shield or cutting
cable.
Installation Environment
WARNING
Installing the device in inappropriate locations may cause
a malfunction of device or may give rise to an accident.
Avoid the following locations:
• Exposed to direct sunlight or high temperature
• Exposed to corrosive or combustible gases
• Exposed to a strong electromagnetic eld or
electrostatic charge
• Near induction heating systems (such as high-
frequency induction heating systems and IH cooking
equipment)
• Susceptible to vibration
• Exposed to water, oil, chemicals, or solvents
• Exposed to high humidity or condensation
• Exposed to high quantities of dust particles
Overview
The CT6844 and CT6844-05 are openable and closable clamp
current sensors that are designed to measure AC and DC currents
of up to 500 A at a high level of precision.
They offer excellent frequency characteristics (amplitude and phase)
as well as excellent temperature characteristics (sensitivity and
offset) and can be used not only for current measurement, but also
for high-precision power measurement.
Usage with Other Hioki Products
This device is used in connection with a dedicated instrument (Hioki
product).
Refer to “Combined accuracy and conditions” specied in the
specications for details.
Maintenance and Service
To clean the device, wipe it gently with a soft cloth moistened with
•
water or mild detergent.
Measurements are degraded by dirt on the mating surfaces of the
•
jaw, so keep the surfaces clean by gently wiping with a soft, dry
cloth.
Names of Parts
Top
Jaw
Side
Output
connector
Current direction indicator
Clamp lever
CT6844-05
Output connector
Lock lever
Demagnetization button
(DEMAG)
Label
Bottom
Zeroadjustment
knob (0 ADJ)
Options
9705 Conversion Cable*1, 9318 Conversion Cable*1,
CT9900 Conversion Cable*1, CT9901 Conversion Cable*
The Conversion Cable makes it possible to connect to and use
with products that cannot be directly connected to the CT6844 or
CT6844-05. (Refer to “Connection example”)(No gures are added
to the accuracy.)
CT9902 Extension Cable*2(5 m), CT9903 Extension Cable*1 (5 m)
• Single sensor cable, 5 m extension (max. 10 m extension).
• Up to two extension cable is connectable. (If three or more
extension cables are connected to the device, its performance is
not guaranteed)
• Add the following values to each of the accuracy per cable:
Amplitude accuracy: ±0.1% rdg. (DC ≤ f*
±0.5% rdg. (1 kHz < f*
Phase accuracy: ±(0.1 × f*
*1: For CT6844, *2: For CT6844-05, *3: frequency
3
kHz)° (1 kHz < f*3)
3
≤ 1 kHz)
3
)
Connection Example
Host instrument
CT6844
9318
CT9901
9705
9318
CT6844-05
Cannot be directly connected to any parenthesized models.
A module is required.
Refer to “Combined accuracy and conditions” specied in the
specications.
CT9900
3390, 3390-10, 9602
(3193-10), 3334-10
78971 (MR88477,
MR8827, MR8740)
8940 (8860-50)
PW6001, PW3390,
CT9555, CT9556,
CT9557
2
Measurement
NO
Input current [A rms]
T
Pre-operation Inspection
Verify that the device operates normally to ensure that no damage
occurred during storage or shipping. If you nd any damage, contact
your authorized Hioki distributor or reseller.
Check Items Solution
Is there any wiring break
involving the output
connector or sensor base?
Is the cable insulation
torn?
Is there any cracking or
damage on the jaw?
Do not place conductors carrying currents with frequencies
of 10 kHz or higher in close proximity to the jaw, even if the
device does not clamp them. Current owing through nearby
conductors may cause self-heating of the jaw, damaging the
device.
This device has the protective resistance (output resistance)
in the signal output circuit. To monitor the output signal, it is
recommended to use a measuring instrument, such as digital
multimeter, that has an input resistance of 1 M
Procedures
Attach the device to the host instrument that is
1
powered off.
Turn on the host instrument.
2
Perform a demagnetization (DEMAG) and/or zero-
3
adjustment (0 ADJ) (if needed).
Refer to “Demagnetization (DEMAG) and Zero-adjustment
(0 ADJ).”
Release the jaw lock (UNLOCKED will appear).
4
Open the jaw.
5
Clamp only one conductor to be measured and close
6
the jaw.
• Check that the tips of jaw are engaged each other.
• If the current direction indication is oriented against the
current direction, a polarity of output signal is reversed.
Source side
Conductor
Current
direction
indicator
7
8
9
10
11
Current
direction
Lock the jaw (LOCKED will appear).
Slide the clamp lever.
Start measurement.
On completion of the measurement, remove the device
from the conductor.
Turn off the host instrument.
Detach the device from the host instrument.
If any, proper measurement cannot be
made. Discontinue use and contact your
authorized Hioki distributor or reseller.
If there is any damage, electric shock
may result. Discontinue use and have
the sensor Is there any cracking or
repaired.
CAUTION
or higher.
Ω
Load
side
OK
5
6
NO
7
4
Slide the lock lever.
5 6 7 8
NO
Demagnetization (DEMAG) and Zero-Adjustment
(0 ADJ)
Immediately after the power is turned on or an over-current
exceeding the rated current is input, an offset can be output.
Because the offset behaves as an error during DC current
measurement, perform a demagnetization and/or zero-adjustment,
going through the following procedure.
Open the jaw and press
1
the demagnetization
(DEMAG) button.
Demagnetization (DEMAG) button
Open and close the jaw several times and check if
2
the offset output is stabilized, observing the host
instrument display.
Lock the jaw (LOCKED will appear).
3
Perform a zero-adjustment by turning
4
the zero-adjust knob (0 ADJ), observing
the offset output displayed on the host
instrument display.
No zero-adjustment can be performed while any current is input.
•
• Because offset output varies with the surrounding environment
and the ambient temperature (terrestrial magnetism and other
devices that generate magnetic elds), perform the zero-
adjustment at the same location at which measurements will be
made.
• If the device is connected to an host instrument with a zero
correction function, align the notch of the zero-adjustment knob
with the upper center.
• Mechanical shock, for example from dropping the instrument,
may cause the offset to shift.
• If no zero-adjustment can be completed, perform
demagnications (DEMAGs) several times with the jaw
remaining closed.
• When measuring a DC or low-frequency (1 kHz or less) current
of small magnitude, you can increase sensitivity on a relative
basis by wrapping the conductor several times around the jaw.
Wrapping the conductor 10 times will cause the device to output
a signal equal to 10 times the measured current.
• In the high-frequency domain,
when the high-potential side
of a circuit (the High side) is
clamped, measured values
may be affected by commonmode noise.
• 1.5 MHz harmonic noise arising from the operating principle can
be emitted.
• Place the clamped conductor to be measured as close to the
jaw center as possible. Separate other conductors from the
device as far away as possible. Measuring large currents with a
frequency of 1 kHz or more or locating unclamped conductors
carrying 500 A or more of such high-frequency currents close to
the jaw can cause increases in errors or waveform distortions.
High
Source Load
Current
Low
Notch
Specications
Accuracy
f.s. Maximum display value or scale length (Rated current)
rdg. Reading value (The value currently being measured and
indicated on the measuring instrument)
The specs of the CT6844-05 are the same as those of the CT6844
except the output connector and options.
Operating
environment
Indoors, Pollution Degree II, altitude up to
2000 m (6562 ft.)
Operating
temperature and
humidity
Storage temperature
and humidity
Standards Safety: EN61010
Dielectric strength 4260 V AC (current sensitivity: 1 mA), 50
Product warranty
period
Rated current 500 A AC/DC
Output voltage 4 mV/A
Maximum input
current
Output resistance 50
Temperature
and humidity for
guaranteed accuracy
Guaranteed accuracy
period
Guaranteed
accuracy period from
adjustment made by
Hioki
Accuracy
Sine wave input; Conductor at center position; Connected with
Model 9555-10; Not including each effect; Measuring instrument
that has an input resistance of 1 M
Amplitude accuracy (Dened at the rated value or less and within
the derating curve; The accuracy dened for the frequency range
of DC < f < 5 Hz is the design value)
Phase accuracy (Dened at the rated value or less and within the
derating curve; The accuracy dened for the frequency range of
DC < f < 10 Hz is the design value)
Frequency Amplitude Phase
DC ±0.3% rdg.±0.02% f.s.* −
DC < f ≤ 100 Hz ±0.3% rdg.±0.01% f.s. ±0.1°
100 Hz < f ≤ 500 Hz ±0.3% rdg.±0.02% f.s. ±0.2°
500 Hz < f ≤ 1 kHz ±0.5% rdg.±0.02% f.s. ±0.5°
1 kHz < f ≤ 5 kHz ±1.0% rdg.±0.02% f.s. ±1.0°
5 kHz < f ≤ 10 kHz ±1.5% rdg.±0.02% f.s. ±1.5°
10 kHz < f ≤ 50 kHz ±5% rdg.±0.02% f.s.
50 kHz < f ≤ 100 kHz ±15% rdg.±0.05% f.s.
100 kHz < f ≤ 200 kHz ±30% rdg.±0.05% f.s.
* An accuracy of ±0.02% f.s. is accomplished after the offset voltage
is adjusted within a range of ±0.2 mV.
Offset adjustable range ±2 mV
Emitted noise 5 mV pp or less (100 kHz or less)
Temperature
coefcient
Effect of conductor
position
Effect of external
electromagnetic eld
Effect of magnetic
Effect of commonmode voltage
Effect of radiated
radio-frequency
electromagnetic eld
Effect of conducted
radio-frequency
electromagnetic eld
Measurable conductor
diameter
-40°C to 85°C (-40.0°F to 185.0°F), 80% RH
or less (no condensation)
-40°C to 85°C (-40.0°F to 185.0°F), 80% RH
or less (no condensation)
EMC: EN61326
Hz/60 Hz, for 1 minute, between jaw and
output connector of cable
3 years
Within the derating curve
(±5%)
Ω
0°C to 40°C (32.0°F to 104.0°F), 80% RH or
less
1 year, opening and closing of the jaw: up to
10000 times
1 year, opening and closing of the jaw: up to
10000 times
or higher
Ω
±(0.5 + 0.1 ×
f kHz)°
-40°C to 0°C and 40°C to 85°C
Amplitude sensitivity: ±0.01% rdg./°C or less
Offset voltage: ±0.005% f.s./°C or less
±0.1% rdg. or less (input current of 100
A, DC to 100 Hz, with the use of a 10 mm
diameter wire)
100 mA or less (value scaled to the input, in
a DC or 60 Hz magnetic eld of 400 A/m)
75 mA or less (value scaled to the input,
after 500 A DC input)
0.05% f.s. or less (1000 V rms, DC to 100
Hz)
6% f.s. at 10 V/m
6% f.s. at 3 V
20 mm or less
φ
Supply voltage ±11 V to ±15 V (tracking)
±300 mA or less
Power capacity
Rated power 7 VA or less (When measuring a current of
Dimensions Approx. 153W×67H×25D mm
Mass Approx. 400 g (14.1 oz.)
Cable length Approx. 3 m
Output connector
CT6844: Hioki PL23 (Male)
CT6844-05: Hioki ME15W (Male)
Accessories Mark bands (×6), Carrying case, Instruction
Options
For CT6844
For CT6844-05
(When measuring a current of 500 A with a
frequency of 55 Hz, while ±12 V power is
supplied)
500 A with a frequency of 55 Hz, while ±12
V power supplied)
(6.02"W×2.64"H×0.98"D) (excluding
protrusions or cable)
manual
CT9900 Conversion Cable
CT9903 Extension Cable
9318 Conversion Cable
9705 Conversion Cable
CT9901 Conversion Cable
CT9902 Extension Cable
Combined accuracy and conditions
Combined accuracy = Accuracy of CT6844(-05) + Accuracy of
combined product (Power factor: 1)
Combined product
CT9555,CT9556,CT9557
Sensor Unit
PW3390 Power Analyzer CT9900 –
PW6001 Power Analyzer CT9900 –
9602 AC/DC Clamp Input Unit
3334-10 AC/DC Power HiTester – CT9901
8940 F/V Unit
8971 Current Unit
9555-10 Current Unit – CT9901
3390, 3390-10 Power Analyzer – CT9901
*1: Add the sensor unit output accuracy to the combined accuracy
when one of the addition functions, that is, RMS output or
TOTAL OUTPUT, is used.
*2: Add ±0.1% rdg. to the combined accuracy.
*3: The sensor recognition methods vary according to the Memory
HiCorder settings (refer to the manuals of Memory HiCorder to
be connected).
1 k
100
：Ambient Temperature
A
DC 720 A
10
DC 1
*1
*2
*3
*3
500 A
10 100 1 k 10 k 100 k 1 M
Frequency derating curve
Required option
CT6844 CT6844-05
CT9900 –
– CT9901
9705+9318
9318 CT9901+9318
2 kHz
500 A
CT9901+9705+9318
-40℃≦TA≦85℃
20 kHz
100 A
Frequency [Hz]
200 kHz
20 A
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