【What is different? Between Impulse Noise and Electrical Fast
Transient Burst】
The Inquiry about "a distinction between an impulse noise simulator (following and our company
model INS series) and a Fast transient Burst simulator (following and our company model FNS
series)" is one of the major questions in a lot of quries from customers.
Herewith the difference is focused and presented.
The phenomenon which are reproduced and backgraound
Both INS and FNS reproduce phenomenon of back electromotive energy noise which may be
generated in ON/OFF of power supply switching (like a gas insulated braker and/or
electromagnetism relay, etc.).
INS was introduced by Mr. Manohar L.Tandor (at that time worked in I.B.M) as a simulator of the
high frequency noise to data processing apparatus in the 1960s, and the computer maker of those
days adopted it in the 1970s, and it spread widely.
FNS is indicated as a basic standard of the immunity type test which reproduces the malfunction
by the noise phenomenon of switching ON/OFF and adopted not only in Europe but also
world-wide. The 1st edition of Standard for this test was issued as IEC801-4 in IEC TC65
(Industrial Process Controls) in 1988.
Then, in order to adopt to all the electric devices,
IEC1000-4-4 was issued in 1995. Moreover, in order to differenciate the numbering between ISO
and IEC, “60000” has been added to the Stadanrd number. Consequently, it has been named as
IEC61000-4-4.
output waveform
Rise time / the pulse width
[INS] It is a rectangular wave whose pulse width is 50ns-1μs and rise time is less than 1ns.
<Entire waveform +2kV >
500V/ div
<At rise up less than 1ns>
400ns/ div
500V/ div
1
1ns/ div
Copyright(c) 2009 Noise Laboratory Co., Ltd.
[FNS] It is a triangular wave whose pulse width is 50ns and rise time is 5ns..
<Entiire waveform +2kV >
500V/ div
<At rise up
40ns/ div
500V/ div
less than 5ns>
4ns/ div
- Repetition intervals (Image and figure comparison)
[INS]
[FNS]
Variable till 10ms-999ms *1
Variable till 0.5μs-999Ms *2
*1 : 4kV type of INS is 16ms-999ms.
*2 : Guaranteed accuracy is 5kHz - 100 kHz (IEC standard requirement).
Frequency characteristic
[INS] Including broadband noise frequency more than 1GHz.
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[FNS] The frequency components ceases below 400MHz.
Output voltages
[INS] Maximum voltage is available up to 4,000V.
Although there is no specific provisions, the measure test voltage is basically
2,000V and it may be increased to 3,000V for taking some margin into the
account.
[FNS] Maximum voltage is available up to 4,800V.
IEC Standard requires up to 4,000V..
Noise injection method
[INS] To power lines : Normal mode (between a lines-line), and common mode
(between a line - grounds)
To signal lines : Magnetic field coupling and/or capacitive coupling which use
clamps
Featuring Normals mode injection taking power supply conditions in Japan into the account
[FNS] To power lines :ONLY commonmode (between a line-ground
To signal lines : Capacitive coupling which uses clamp
Conforming Standards and Guide line
[INS] NECA TR-28 (Nippon Electric Control Equipment Industries Association)
JEM-TR177 (Japan Electrical Manufacturers' Association)
JEC0103_2005 (Institute of Electrical Engineers)
The individual industry and manufacturers private standards (Automobie,
Consumer equipments, Industrial equipments, etc.)
[FNS] IEC61000-4-4 (International Electrotechnical Commission)
JIS C 61000-4-4 (Japanese Industrial Standards Committee)
The individual industry and manufactueres private standards (automobile etc.)
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Conclusion
Both the Impulse Noise test and Electrical Fast Transient Burst (EFT/B) test purpose withstand
test for back electromotive energy noise which may be generated in ON/OFF of power supply
switching.
The repetition frequency of EFT/B tests is very fast, and it is broadly adopted based on provision
of international standard IEC61000-4-4 to world-wide including Japan as JIS C 61000-4-4.
On the other hand, although the Impulse Noises tests are not requested In international
standards, it is standardized in some Japanese authorized committees or associatons as it is
descrived in the above for point of the view “it enables to verify immunity quantitativeness against
the noise in spreaded broad band range and such rectangular waved impulse noise immunity test
which can compare with the actual recordd in the markets should be standardized”
.
Therefore, the simulator has been popularly used by Japanese electrical manufacturers even they
establish the factilites in overseas contries and carry on the test there. The rise time must be
more rapid and frequency component lasts until higher range than EFT/B test and the tests both in
normal mode and common mode can be done.
Those can realize more severe tests than EFT/B
test and tests in normal mode because of Japanese real power supply condtions. The reasons
cause worth of the impulse noise tests in addition to EFT/B tests.
Eventually, there are many Japanese manufacturers keep on doing both EFT/B and impulse
noise tests in order to maintain and improve their products quality.
[INS and a FNS comparative table]
PARAMETER
INS (IMPULSE NOISES)
FNS(EFT/B NOISE) *3
Rectangular (square)
Triangular
Rise times
Less than 1ns
5ns
The pulse width
50ns-1000ns
50ns
Output voltages
Max. 4000V
Max. 4800V
Max 100Hz *4
Max 2MHz *5
Frequency components
Including high frequency more than 1GHz
400MHz or less
Test mode (To power lines)
Common mode / Normal mode
Only common mode
Test mode (To signal lines)
Capacitive coupling / magnetic field coupling
Capacitive coupling
Output waveform
Repetition frequency
Conforming Standard or
NECA TR-28
IEC61000-4-4
Guildline
JEM-TR177
JIS C 61000-4-4
JEC 0103_2005
Individual industry standards or
Individual industry standards or private
private standards
standards
User
Mainly Japanese
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Worldwide
Copyright(c) 2009 Noise Laboratory Co., Ltd.
* 3: EFT/B noise : Abbreviated name of Electrical Fast transients Burst noise
* 4:100Hz is specification of the simulator whose output voltages is 2kV. (In case of 4kV output simulator, this
parameter can be 60Hz)
* 5: The requirement of the Standards is 100kHz.
<< Difference between old model and current model in Impluse Noise Simulator (INS series)>>
Digitals controlling circuits are built in the current ones (The old ones are controlled with analog
oscillation circuits)
Therefore, there may be difficulty to take same tests results between the old ones and current ones
due to slight dispersion of the noise generation timing, etc. even the rise up time of the waveforms
and pulse durations are identical. It is recommended that scheming and devising problemless
transfer from the old ones to the current ones with the simultaneous using for a while.
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Copyright(c) 2009 Noise Laboratory Co., Ltd.