Iwatsu SS-540 Instruction Manual

Instruction Manual
Current Probe
SS-540/SS-550
Ⓒ2021 IWATSU ELECTRIC CO., LTD. All rights reserved．
Contents
Contents
Introduction ··················································································· 1
Safety Precautions ······································································· 1
Note ································································································ 11
Checking packed materials ························································· 11
Components ·················································································· 11
Management of instrument ························································· 12
Repair and sending instrument to be repaired ························ 12
Cleaning of instrument ································································ 12
Chapter 1 Overview ······································································ 13
1.1 Summary ··········································································· 13
1.2 Features ············································································ 13
1.3 Part Names ······································································· 14
1.4 Part Functions ··································································· 14
1.5 Specifications ···································································· 16
1.5.1 Instrument specifications ········································· 16
1.5.2 Certification standards ············································· 21
1.5.3 Recommended Power Supply and Oscilloscopes ·· 21
Chapter 2 Operation ····································································· 22
2.1 Preparations for Measurement ········································· 22
2.2 Demagnetizing and Zero Adjustment ······························· 23
2.3 Measuring methods ·························································· 26
Contents
Chapter 3 Daily check and calibration······································· 32
3.1 Maintenance ······································································ 32
3.2 Periodic Calibration ··························································· 32
3.3 Inspection ·········································································· 33
1
Introduction
• Thank you for purchasing this instrument of IWATSU
ELECTRIC CO., LTD. We hope that you will enjoy it for
years to come.
• Please read this manual carefully before attempting to use
the instrument. Store the manual in a safe place so it can be
referred to when necessary.
Safety Precautions
Throughout this manual, the symbol
(Warning) and
(Caution) are used to indicate points that must be observed to
ensure safety and prevent injury and property damage. Be
sure to read these points carefully and observe all precautions.
Symbols indicating the need for caution also appear on the
instrument itself.
Symbols in this manual (
Warning
Caution
Note
Warning
Caution and Note)
Indicates that failure to observe this precaution may lead to
death or serious injury.
Indicates that improper use may lead to injury or damage to
the instrument.
Provides instruction or advice regarding unit functions or
operation.
Symbols on the instrument
Warning
Indicates the need to refer to the instruction manual before
use in order to prevent injury and equipment damage.
Indicates that the instrument can be operated with direct
current (DC) or alternating current (AC).
Indicates that the instrument can not be set and detached in
the active circuit.
2
Precautions
• Due to our continuing efforts to improve performance and
functions, the information in this manual is subject to change
without notice.
• Unauthorized reproduction of the contents of this manual is
strictly prohibited.
• If you have any questions about this instrument, contact
Iwatsu office or our sales distributors.
Revision History
• April 2021: 1st edition
KMLA00291
3
Read this page to ensure proper safety. (to be continued)
Warnings
• Do not use this instrument in an environment with
explosive gases.
This may result in explosion.
• If you notice smoke, foul odor or abnormal noise,
immediately turn off the power supply of all equipment
with which this instrument is connected, and then
detach this instrument from the insulating target
conductor to be measured.
Continued use under these circumstances may result in electric
shock or fire. Contact Iwatsu office or our sales distributors for
repair. Do not attempt to repair this instrument yourself.
• Turn off the power to the insulating target conductor to
be measured before attaching or detaching sensor head
part of this instrument to or from the insulating target
conductor to be measured.
Failure to do so is very dangerous for targets to be measured that
use high current.
• Do not use this instrument to measure exposed
conducting lines.
This may result in electric shock, short-circuiting or equipment
damage. (The clamp core and shield casing are not insulated.)
• Use caution not to wet this instrument or allow entry of
water or foreign objects into.
Continued use under these circumstances may result in an
electric shock, fire, or failure. If water, foreign objects, or other
substances enter this instrument or the instrument is wet with
water, immediately turn off the power supply of all equipment with
which this instrument is connected, and then detach this
instrument from the insulating target conductor to be measured.
After that, contact Iwatsu office or our sales distributors for repair.
4
Read this page to ensure proper safety. (to be continued)
Warnings
• Do not handle this instrument if your hands are wet.
This may result in electric shock, fire or equipment damage.
• Do not touch the plug of the power cord if your hands
are wet.
This may result in electric shock.
• Be careful not to damage the insulating sheath of the
insulating target conductor to be measured.
• Make sure the oscilloscope connected to the BNC
output connector on the current probe is used with the
protective earth.
See "1.5.3 Recommended Power Supply and Oscilloscope" on
page 21 for our company instruments that fit this description.
• Do not use this instrument if the unit case is damaged.
This may result in electric shock. If the unit case is damaged,
contact Iwatsu office or our sales distributors for repair.
• Connect only the recommended power unit to this
instrument.
Use of power units not suited may result in fire or equipment
damage. See 1.5.3 "Recommended Power Supply and
Oscilloscopes" on page 21.
• Confirm that any dust does not adhere to the power plug
before inserting surely it into the power supply
receptacle.
Dust may result in electric shock, fire, or malfunction.
• Do not place this instrument in an area there frequent
vibrations or impacts occur.
If this instrument is dropped or overturned, it may cause a
physical injury or a malfunction.
5
Read this page to ensure proper safety. (to be continued)
Warnings
• When handling power cords and sensor cables:
This may result in fire, electric shock, or equipment damage. If the
power cord is damaged, contact Iwatsu office or our sales
distributors for repair.
⋅ Do not attempt to fabricate power cord and sensor cable.
⋅ Do not pull power cord and sensor cable by the cable. Always
grasp the plug.
⋅ Do not bend power cord and sensor cable.
⋅ Do not heat power cord and sensor cable.
⋅ Do not twist power cord and sensor cable.
⋅ Avoid getting power cord and sensor cable wet.
⋅ Do not bind power cord and sensor cable together.
⋅ Do not place heavy objects on top of power cord and sensor
cable.
• Do not use this instrument in a highly
environment where condensation may occur.
humid
If using, an electric shock or fire, or failure may occur.
• Do not put on this instrument a container that water,
medicine, etc. has entered or a small metallic object.
If not, an electric shock or fire may occur. If this instrument is wet
with water, or metal and other objects enter the instrument,
immediately turn off the power supply of all equipment with which
this instrument is connected, and then detach this instrument from
the insulating target conductor to be measured. After that, contact
Iwatsu office or our sales distributors for repair.
• When thunder begins, pull out the power plug of a
device or the AC adaptor to which this instrument is
connected from the outlet. Then, detach this instrument
from the target to be measured, and do not use it.
Lightning may be a cause of an electric shock, fire, or failure.
6
Read this page to ensure proper safety. (to be continued)
Warnings
• Do not use this instrument when it has failed.
Using a failed main unit or, cable or AC adaptor may be a cause
of an electric shock or fire. In the event of a failure, contact Iwatsu
office or our sales distributors for repair.
• Do not attempt to modify or disassemble the unit.
This may result in electric shock, fire or equipment damage.
Requests to repair the unit may be refused if unauthorized
modifications have been made.
• This instrument SS-540 and SS-550 might not be able to
be used at the same time because there are restrictions
on power consumption in the probe power on the
oscilloscope side according to the measured current.
Refer to page21 and page27 for details.
• The BNC ground of this instrument is connected to an
electric ground through the power supply such as PS-52
or PS-54 to prevent danger. Use the equipment only for
the floating measurement when executing the floating
measurement.
When the ground terminal of the instrument is connected to a
ground besides the earth potential, this instrument, the equipment
and the circuit to be measured must be damaged because the
equipment that connects this instrument is connected to a ground.
Moreover, there must be danger of getting an electric shock.
Oscilloscope etc.
Wrong example
This instrument
(Current probe)
Power supply
7
Read this page to ensure proper safety. (to be continued)
Cautions
• Do not supply current that exceeds the maximum
continuous input range.
The values are derived from the rise in temperature caused when
the unit heats up during measurement. Do not input the current
that exceeds this. This instrument might be damaged. Moreover,
the maximum input range differs depending on the frequency of
the current being measured. See Figure 1.5.1 "Instrument
Specifications".
• When current exceeding the maximum continuous input
range is supplied, the sensor unit will heat up, triggering
an internal protective interlock that will prevent normal
output.
If this happens, cut off the input immediately (either by removing
the sensor from the insulating target conductor to be measured or
by setting the input current to zero). Then wait for a sufficient
amount of time for the unit to cool before resuming normal
operation.
• At high temperatures, the overcurrent protection circuit
in the unit may cause the protective interlock to operate
at current levels that are below the maximum
continuous input range.
• Do not subject the instrument to sudden rapid changes
in temperature, mechanical stress or shocks.
This may damage the instrument and the sensor head and result
in equipment failure.
• Keep the sensor head closed unless you are clamping
the insulating target conductor to be measured in
preparation for measurement.
Leaving the sensor head open may damage the sensor head.
8
Read this page to ensure proper safety. (to be continued)
Cautions
• Before moving this instrument, make sure that the
power supply plug is disconnected from the power
supply receptacle and that the sensor head, output
terminal (BNC) cable and other external connection lines
are removed.
Failure to do so will damage the sensor head or cable, causing an
electrical shock, fire, or failure.
• When handling the sensor head, be sure to observe the
following precautions:
⋅ The contact end of the sensor head is precision-polished.
Handle the unit carefully to avoid damaging this surface.
Scratches on the surface may adversely affect performance.
⋅ The end of the sensor head must be kept clean, as dirt on the
surface will adversely affect performance. If the surface
becomes dirty, wipe it clean with a soft cloth or the like.
• When removing the connector from the output terminal,
first unlock the connector, grasp the connector and pull
to remove.
Failure to remove the connector in this manner may damage the
terminator.
• Do not store or use this instrument in direct sunlight or
in environments that are subject to high temperatures,
high humidity or condensation.
Use or storage at other than the rated conditions may result in
warping due to heat, impaired insulation, or unit failure.
The proper temperature and humidity levels for use and storage
are listed below.
⋅ Operating temperature: 0 to +40°C, no dew condensation
⋅ Operating humidity: below the moisture amount of 80%RH
⋅ Storage temperature: -10 to +50°C, no dew condensation
⋅ Storage humidity: below the moisture amount of 80%RH
9
Read this page to ensure proper safety. (to be continued)
Cautions
• For your safety, when this instrument is not used for a
long time, remove the power plug of this instrument
from the power supply receptacle.
• Do not leave
environments.
this
instrument
in
wet
or
dusty
This may result in electric shock, fire or equipment damage.
• Do not leave this instrument in a place exposed to lamp
soot or steam generated by counters, humidifiers, etc.
If not, an electric shock, fire, or failure may occur.
• Securely insert the power plug into the power supply
receptacle.
• Hold the power plug part when removing the power
supply cord from the power supply receptacle.
Pulling on the power cord will damage the cord. This may be a
cause of an electric shock, fire, or failure.
• For your safety, remove the power plug of this instrument
from the power supply receptacle, make sure that the
sensor head, output terminal (BNC) cable and other
external connection lines are removed before
maintenance. In addition, wipe off with a dry cloth when
water droplets are attached.
If not, an electric shock or failure may occur.
10
Read this page to ensure proper safety.
Cautions
• Before transporting this instrument, house this
instrument in the accessory soft (for SS-540) or hard (for
SS-550) case, and then pack the housed instrument in
the packing material used at the time of purchase, or the
packing material or better.
This instrument may fail if a large vibration or impact is applied
during transportation, possibly causing a fire. If you do not have a
proper packing or shock-absorbing material for transportation,
contact Iwatsu office or our sales distributors. If transportation is
to be handled by a forwarding agent, display "Contains a
precision machine" on each side of the packing box.
• We recommend to order Iwatsu office or our sales
distributors for periodical inspection and calibration
once a year or so.
11
Note
An accurate measurement can not be likely to be done in the
vicinity the generation of a strong magnetic field and strong
electric fields such as the transformer, the large current circuits,
and the wireless machines.
Checking packed materials
When receiving this instrument, check the packed materials while
referring to the following “Components.” If there is a missing item
or an item damaged during transportation, immediately contact
Iwatsu office or our sales distributors.
Components
 Main unit
…………..1
 Accessories (See the accessories table below.)
Accessories table
Quantities
(SS-540)
Quantities
(SS-550)
Hard case
-
1
Soft case
1
-
Items
Instruction Manual (this document)
1
1
Sheet for China RoHS
1
1
Cable tie
1
1
12
Management of instrument
When disposing of this instrument, it must be recycled or
disposed of properly in accordance with local laws or regulations.
When disposing of it, request a recycling company to dispose of it
in accordance with local laws or regulations.
Repair and sending instrument to be repaired
If a failure occurs, send the instrument to Iwatsu office or our
sales distributors.
When sending an instrument to be repaired, clearly write the
instrument name, serial number (in the label on the rear of this
instrument), description of the failure, and the name, division, and
telephone number of the responsible person.
Cleaning of instrument
When you take the dirt of this instrument, wipe with a soft and dry
cloth or wipe with a dry cloth after you wipe with a soft cloth etc.
to contain water, and the soapless soap.
Never use neither medicines of thinner, benzine, acetone, ether,
ketone, alcohol, and the gasoline system, etc. nor the detergents
that contain them.
This instrument is likely to transform, and to discolor.
13
Chapter 1 Overview
1.1 Summary
This instrument is connected directly to the BNC input terminal
on an oscilloscope or other waveform monitoring unit. This
makes it easy to measure current waveforms by simply
clamping it onto an insulating target conductor to be measured.
1.2 Features
⋅ Highly accurate current detection
⋅ Easy current measurement
⋅ Broadband frequency bandwidth
SS-550 : DC - 100MHz
SS-540 : DC - 50MHz
⋅ Compact unit capable of measuring low current
⋅ Simple protection function from excessive input
⋅ Unique development by using thin film Hall element
Chapter 1 Overview
14
1.3 Part Names
• External View
1.4 Part Functions
① Open-close lever
Used to open and close the sensor head. Be sure to use
this lever to open and close the sensor head.
② Sensor head
Clamps the insulating target conductor to be measured and
detects the current level. The sensor head is made up of a
molded part, ferrite, Hall element and other parts that have
been precision-machined and assembled. Be sure to
handle the sensor head carefully, as it may be damaged by
Chapter 1 Overview
15
sudden violent changes in ambient temperature,
mechanical stress, shocks and so on.
③ Demagnetizing switch (DEMAG)
Used to eliminate magnetization from the magnetic core
generated when the power is turned on and off or caused
by excessive input. Be sure to do this before starting
measurement.
④ Zero adjustment dial (ZERO ADJ)
Used to compensate for offset voltage, temperature drift
and the like with this instrument.
⑤ Rough-adjustment trimmer
Used only when adjustment with the zero adjustment dial is
not possible.
⑥ Output connector
Outputs the measured current waveform at a steady rate
(0.1 V/A). The connector is plugged into the BNC input
terminal on the oscilloscope.
⑦ Power plug
This plug is inserted into the power supply receptacle of the
PS-52 or PS-54 power supply and the like to provide power
to the sensor and terminator.
Chapter 1 Overview
16
1.5 Specifications
1.5.1 Instrument specifications
Table1, Figure1 and Figure2 indicate SS-550 instrument
specifications. Table2, Figure3 and Figure4 indicate SS-540
instrument specifications.
The following values indicate unit performance 30 minutes
after the power has been turned on in an ambient environment
of 23°C ± 5°C.
Chapter 1 Overview
17
Table1. SS-550 Instrument specifications
Frequency bandwidth
Rise time
Waveform response
Maximum continuous input
current range
Maximum peak current value
Output voltage rate
Amplitude accuracy
Noise
Power consumption
Power supply voltage
Temperature/humidity range
(operating)
Temperature/humidity range
(storaged)
Location for use (operating)
Accuracy warranty period
Product warranty period
Temperature characteristic of
sensitivity
External magnetic field
Measurable conductor
Measurable conductor diameter
Cable or cord lengths
External dimensions
Weight
Accessories
DC to 100 MHz (−3 dB)
3.5 ns or less
Sag: 3 % or less (for 1kHz rectangular waveform)
Overshoot: Within ±20 % (for the step waveform in rise
time of 0.8 ns)
30 Arms (See Figure1 Derating by Frequency.)
50 A peak (in the non-continuum)
0.1 V/A
±1.0 % rdg. ± 1 mV : to 30 Arms
±2.0 % rdg.
: 30 Arms to 50 Apeak
(for DC or within the range of AC 45 to 66 Hz)
2.5 mArms or less. (for measuring instrument with 20
MHz bandwidth)
5.3 VA or less
DC ±12 V±0.5 V
0 °C to +40 °C (no dew condensation),
below the moisture of 80 % RH
−10 °C to +50 °C (no dew condensation),
below the moisture of 80 % RH
Indoor use, Pollution Degree 2 and at the altitude of
2000 meters or less
1 year (Opening/Closing up to 10,000 times)
1 year
Within ±2 % (for the input of 50 Hz and 30 Arms within
the range of 0 °C to +40 °C)
Equal to 5 mA or less (for DC, 60 Hz and 400 A/m of AC
magnetic field)
Only for insulated target conductor
φ 5 mm or less
Sensor cable 1.5 m ±0.1 m
Power cord
1.0 m ±0.1 m
Sensor part: 175 (W) × 18 (H) × 40 (D) mm (±2 mm)
Terminator part: 27 (W) × 55 (H) × 18 (D) mm (±2 mm)
240 g ± 20 g
Instruction manual (1), Hard case (1)
Sheet for China RoHS (1), Cable tie (1)
Chapter 1 Overview
18
35
Maximum input current [A]
30
25
20
15
10
5
10
100
1k
10k
100k
1M
10M
100M
Frequency [Hz]
Figure 1. Derating by Frequency (SS-550)
10
Ħ
Input impedance [ ]
1
100m
10m
1m
100
1k
10k
100k
1M
10M
100M
Frequency [Hz]
Figure 2. Input Impedance (SS-550, sample characteristics)
Chapter 1 Overview
19
Table2. SS-540 Instrument specifications
Frequency bandwidth
Rise time
Waveform response
Maximum continuous input
current range
Maximum peak current value
Output voltage rate
Amplitude accuracy
Noise
Power consumption
Power supply voltage
Temperature/humidity range
(operating)
Temperature/humidity range
(storaged)
Location for use (operating)
Accuracy warranty period
Product warranty period
Temperature characteristic of
sensitivity
External magnetic field
Measurable conductor
Measurable conductor diameter
Cable or cord lengths
External dimensions
Weight
Accessories
DC to 50 MHz (−3 dB)
7 ns or less
Sag: 3 % or less (for 1kHz rectangular waveform)
Overshoot: Within +10 %/-20 % (for the step waveform
in rise time of 3 ns)
30 Arms (See Figure3. Derating by Frequency.)
50 A peak (in the non-continuum)
0.1 V/A
±1.0 % rdg. ± 1 mV : to 30 Arms
±2.0 % rdg.
: 30 Arms to 50 Apeak
(for DC or within the range of AC 45 to 66 Hz)
2.5 mArms or less. (for measuring instrument with 20
MHz bandwidth)
5.6 VA or less
DC ±12 V±0.5 V
0 °C to +40 °C (no dew condensation),
below the moisture of 80 % RH
−10 °C to +50 °C (no dew condensation),
below the moisture of 80 % RH
Indoor use, Pollution Degree 2 and at the altitude of
2000 meters or less
1 year (Opening/Closing up to 10,000 times)
1 year
Within ±2 % (for the input of 50 Hz and 30 Arms within
the range of 0 °C to +40 °C)
Equal to 20 mA or less (for DC, 60 Hz, and 400 A/m of
AC magnetic field)
Only for insulated target conductor
φ 5 mm or less
Sensor cable 1.5 m ±0.1 m
Power cord
1.0 m ±0.1 m
Sensor part: 175 (W) × 18 (H) × 40 (D) mm (±2 mm)
Terminator part: 27 (W) × 55 (H) × 18 (D) mm (±2 mm)
230 g ± 20 g
Instruction manual (1), Soft case (1)
Sheet for China RoHS (1) , Cable tie (1)
Chapter 1 Overview
20
10
100
1k
10k
100k
1M
10M
100M
Frequency [Hz]
Figure 3. Derating by Frequency (SS-540)
Figure 4. Input Impedance (SS-540, sample characteristics)
Chapter 1 Overview
21
1.5.2 Certification standards
Safety
EN61010-2-032
EMC
EN61326-1
1.5.3 Recommended Power Supply and Oscilloscopes
The following Iwatsu Instruments are recommended for use
with this instrument:
• Power Supply
⋅ PS-52, PS-54
• Recommended Oscilloscopes
⋅ Probe power PS-52 or PS-54 becomes unnecessary if
Probe power option DS-579 (Total current consumption of
the current probe can be used within the range of 750mA or
less.) of product of our company that can be used as power
supply for probe, Digital oscilloscope ViewGoII series that
can attach DS-579, and power connector conversion cable
are used together, and it is possible to use them slimly and
compactly.
If you have any questions about this instrument, contact Iwatsu
office or our sales distributors.
Chapter 1 Overview
22
Chapter 2 Operation
2.1 Preparations for Measurement
1. Prepare this instrument and the recommended power
supply and oscilloscope or other waveform monitoring
instrument.
Note
⋅
This instrument output is terminated internally. It should be
used with an oscilloscope whose input impedance is 1 MΩ
or greater. Measurement accuracy cannot be guaranteed
if the input impedance is 50Ω.
2. Set the switch of the recommended power supply to the
OFF position and connect the power cord.
3. Insert the power plug for this instrument into the power
supply receptacle on the recommended power supply.
4. Set the recommended power supply switch to the ON
position and check to make sure that the power lamp on
the front panel lights up.
Chapter 2 Operation
23
2.2 Demagnetizing and Zero Adjustment
Notes
⋅
⋅
Immediately after the power is turned on, this instrument
will heat up, in some cases causing considerable offset
voltage drift. This should stabilize almost completely in
about thirty minutes.
When conducting continuous measurement, please note
that the offset voltage will drift due to the ambient
temperature, etc.
1. Set the oscilloscope input to GND and adjust the trace to
the zero position.
2. Set the oscilloscope input coupling to DC.
3. Plug the output connector on this instrument into the input
terminal on the oscilloscope and check to make sure it is
locked securely in position.
Chapter 2 Operation
24
Cautions
• When removing the output connector, release the lock
and then grasp the connector and pull to remove. Never
try to forcibly remove the connector without first
releasing the lock. Also, never pull the cable, as this
may damage the terminator.
• When connecting this instrument to an input terminal
that is not a BNC terminal, make sure that the polarity is
correct.
• Do not demagnetize while this instrument is clamping an
insulating target conductor to be measured.
Demagnetizing causes current to flow into the insulating
target conductor to be measured, which may damage
parts in the circuit to be measured.
Demagnetizing
Insulating target conductor
• Check that the insulating target conductor to be
measured is not clamped when supplying power to this
instrument for the same reason. Demagnetized
waveforms may generate when supplying electric
power.
Chapter 2 Operation
25
4. Without clamping this instrument to the insulating target
conductor to be measured, press the open/close lever until
the "UNLOCK" marking disappears. Then check to make
sure that the sensor head is securely closed.
5. Press the DEMAG switch on the terminator. The process
takes about one second. A demagnetizing waveform is
output while demagnetizing is in progress.
6. Turn the zero adjust dial on the terminator and adjust the
trace to the zero position.
7. If you were not able to adjust the trace to the zero position
in the previous procedure 6, turn the rough adjustment
trimmer and adjust the trace so it is within the adjustment
range of the zero adjustment dial.
Chapter 2 Operation
26
2.3 Measuring methods
1. Check to make sure that all safety requirements have been
satisfied and all preparations for measurement (as
described in the previous section) are complete.
2. Pull the open/close lever on the sensor unit to open the
sensor head.
3. Make sure the arrow on the sensor head showing the
direction of current flow matches the direction of the current
flow to be measured. Then clamp the insulating target
conductor to be measured so the conductor is in the center
of the clamp window.
4. Press the open/close lever on the sensor head unit until the
"UNLOCK" marking is not visible. Check to make sure that
the open/close lever is locked securely and the sensor
head is tightly closed.
5. You may now monitor the current waveform on the
oscilloscope. The output sensitivity of this instrument is 0.1
V/A. Convert the voltage sensitivity values on the
oscilloscope to current sensitivity values. For example, if
the voltage sensitivity on the oscilloscope is 10 mV/div, the
current sensitivity will be 100 mA/div.
Chapter 2 Operation
27
Notes
⋅
⋅
When using this instrument, note that these two
instruments may not be used simultaneously with the
PS-52 POWER SUPPLY, depending on the current to be
measured.
The current consumption of this instrument depends on
the current value to be measured. Use the instrument
within the range where the total of the current
consumption of it is 600mA or less. Refer to Figure 5 (for
SS-540) or Figure 6 (for SS-550).
Current to be measured (A)
Figure 5. Current consumption* vs. current to be measured (typical for SS-540)
*The sum total of a positive and negative current consumption
Current to be measured (A)
Figure 6. Current consumption* vs. current to be measured (typical for SS-550)
*The sum total of a positive and negative current consumption
Chapter 2 Operation
28
Cautions
• The maximum continuous input range is determined by
the temperature rise when this instrument heats up
during measurement. Do not apply current that exceeds
this range, as this may damage this instrument.
• The maximum continuous input range will differ
depending on the frequency of the measured current.
See the graphs in section 1.5.1 "Instrument
Specifications" (on page 16).
• When current in excess of the maximum continuous
input range is applied, the sensor will heat up, triggering
the internal protective interlock and preventing normal
output. If this happens, immediately cut off the input
(either by removing the sensor from the insulating target
conductor to be measured or by setting the input
current to zero). Then wait a sufficient amount of time
for the unit to cool before resuming normal operation.
• At high temperatures, the overcurrent protection circuit
in the unit may cause the protective interlock to operate
at current levels that are below the maximum
continuous input range.
Chapter 2 Operation
29
Cautions
• When it keeps inputting the electric current that exceeds
the range of the continuous maximum input or the
protection function is frequently operated, this
instrument might be damaged.
• In addition to the maximum continuous input range,
there is a value listed under "During non-continuous
input" in the Instrument Specifications:
SS-550 / SS-540
Maximum continuous input range: 30 Arms
During non-continuous input: 50 Apeak
When using this instrument, make sure the effective
value does not exceed the maximum continuous input
range. The specifications during non-continuous input
indicates that the upper limit for the response is 50
Apeak.
• Always use the open/close lever to open the sensor
head. Pushing up the top core with the sensor head
locked may damage the open/close mechanism.
• Do not apply pressure to the sensor head in the
direction shown in the figure below.
Do not press in this direction
Locked
Chapter 2 Operation
30
Note 1
⋅
Do not place any unclamped conductor with an electric
current of a frequency of 10 kHz or more near the sensor
head.
Current flowing in the conductor nearby may heat up the
sensor head and cause its temperature to rise, leading to
damage to the sensor.
For example, when one side of a go-and-return conductor
is clamped and the other side is also placed near the
sensor head as shown in the diagram, even if the electric
current is lower than the consecutive maximum current,
electric currents in both sides will heat up the wires and
raise the temperature, thereby causing damage to the
sensor.
Chapter 2 Operation
31
Note 2
⋅
⋅
⋅
Resonance may be generated depending on the
frequency of the current being measured. This will not
affect measurement.
In some cases, the position of the insulating target
conductor to be measured in the clamp window may affect
measurement. Make sure the insulating target conductor
to be measured is in the center of the clamp window.
When measuring signals containing high frequency
components, the measurements may be affected if the
side of the cable with high potential is clamped. Always
clamp the low potential side.
Generator
⋅
Load
Accurate measurements may not be obtained near
transformers, cables carrying strong current and other
objects that generate a strong magnetic field, or near radio
transmitters or other equipment that generates a strong
electrical field.
Chapter 2 Operation
32
Chapter 3 Daily check and calibration
3.1 Maintenance
• Cleaning
If the exterior becomes dirty, gently wipe away the dirt with a
soft cloth moistened with water or a diluted neutral
detergent. Be careful not to use the solvents and cleaners
listed below, as this may cause discoloration or other
damage.
You may use the following:
⋅ Water or (diluted) neutral detergent
Do not use the following:
⋅ Alcohol, gasoline, acetone, lacquer, ethyl alcohol, paint
thinner, or solvents containing ketones
If the sensor head gets dirty, gently wipe away the dirt with a
(dry) soft cloth or the like.
3.2 Periodic Calibration
This instrument must be inspected and calibrated periodically
to ensure that signals are measured correctly. For periodical
calibration, contact Iwatsu office or our sales distributors. We
recommend that this instrument is calibrated about once a
year.
Chapter 3 Daily check and calibration
33
3.3 Inspection
1. Set the oscilloscope input to GND and adjust the trace to
the zero position.
2. Set the oscilloscope input coupling to DC.
3. With the sensor head on the current probe completely
closed, connect this instrument (SS-540 or SS-550) to the
oscilloscope and press the DEMAG switch. Immediately
after the switch is pressed, a sine wave of approximately
300 mVp-p will be output, gradually becoming attenuated
and stopping after a few seconds. Check to make sure that
this occurs.
4. Turn the zero adjustment dial and check to make sure that
the trace is at the zero position.
Chapter 3 Daily check and calibration
Contact Us
Overseas Sales Sect., Sales Dept. No.2
Address
: 1-7-41 Kugayama, Suginami-ku,
Tokyo 168-8501, Japan
Phone
: +81 3 5370 5483
Facsimile
: +81 3 5370 5492
Web Site
E-mail
: http://www.iti.iwatsu.co.jp/index_e.html
: [email protected]