Schaffner NSG 438 User Manual
NSG 438
601-241D
User Manual
NSG 438
ESD Simulator
NSG 438
Contents
1 Explanation of the symbols used in this manual.........................1
2 Safety.............................................................................................2
3 Introduction...................................................................................4
3.1. Electrostatic discharge (ESD)..........................................................4
3.2. Simulation.......................................................................................4
3.3. Effects on the EUT...........................................................................7
4 The NSG 438 system.....................................................................8
4.1. The generator..................................................................................9
4.1.1. Function modules............................................................................9
4.1.2. Block diagram................................................................................10
4.1.3. Operating elements.......................................................................12
4.2. System components......................................................................14
4.2.1. Battery charger / power supply unit................................................14
4.2.2. Options..........................................................................................15
4.2.3. Discharge networks.......................................................................15
4.2.4. Remote triggering..........................................................................16
4.2.5. Interlock.........................................................................................18
4.2.6. Measurement adapters..................................................................22
5 Commissioning............................................................................23
5.1. Function test..................................................................................23
6 Operation.....................................................................................25
6.1. Switching on..................................................................................25
6.2. Battery monitoring..........................................................................26
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6.3. Operation and settings...................................................................27
6.3.1. Display mode.................................................................................28
6.3.2. Voltage..........................................................................................29
6.3.3. Polarity..........................................................................................30
6.3.4. Counter.........................................................................................30
6.3.5. Repetition......................................................................................31
6.3.6. Settings.........................................................................................32
6.3.7. Language......................................................................................32
6.3.8. Device info....................................................................................32
6.3.9. Discharge......................................................................................32
6.3.10. Threshold......................................................................................33
6.3.11. ISO-Selftest...................................................................................34
6.3.12. Level.............................................................................................35
6.3.13. Program........................................................................................35
6.3.14. Trigger button................................................................................36
6.3.15. Continuous operation.....................................................................36
7 Test procedures...........................................................................37
7.1. Standard-compliant procedures.....................................................37
7.2. Other situations.............................................................................32
8 Verification of the pulse data......................................................39
9 Typical pulse data........................................................................40
10 Maintenance.................................................................................41
10.1. Calibration.....................................................................................41
10.2. Exchanging the R-C network.........................................................42
10.2.1. Reduction of pulse repetition rate at increased capacity.................43
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10.3. Repairs..........................................................................................43
10.4. NSG 438 System error messages ................................................. 44
10.5. Disposal........................................................................................ 45
11 Technical specifications..............................................................46
12 ESD standards.............................................................................48
13 Warranty.......................................................................................49
14 Ordering information...................................................................50
15 Addresses....................................................................................51
Manufacturer
Schaffner EMV AG
Nordstrasse 11, 4542 Luterbach/Switzerland
www.schaffner.com
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1 Explanation of the symbols used in this manual
Please take note of the following explanations of the symbols used in order
to achieve the optimum benefit from this manual and to ensure safety
during operation of the equipment.
The following symbol draws your attention to a circumstance where nonobservation of the warning could lead to inconvenience or impairment in
the performance.
Example:
This connection must not be confused with the main
power input
The following symbol draws your attention to a circumstance where nonobservation of the warning could lead to component damage or danger to
the operating personnel.
Example:
Never connect or disconnect the pistol while system is
performing a test
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2 Safety
This item of equipment, together with its accessories,
works at high voltages of up to 30kV. Any careless
handling or non-observance of the operating
instructions can have dangerous consequences.
The NSG 438 generator is not a toy! It is a professional tool and belongs
only in the hands of specialists and appropriately trained personnel.
When powered by its own batteries the generator can be active even
without any power cable being connected.
The instrument must not be switched on unless a correctly connected
earth or earth cable (pulse current return path) is in place. The original
earth cable supplied with the instrument is to be used. Any replacement
cables must be fabricated in such a way that they cannot be accidentally
connected to a mains outlet socket. Do not touch the test finger! There is a
danger of an unpleasant electric shock if the instrument is switched on
(LC-display active).
Only trained personnel may operate the instrument.
Personnel fitted with a heart-pacemaker must not operate
the instrument nor approach the test rig while it is in
operation.
These operating instructions form an integral part of the instrument and
must be available to the operating personnel at all times.
The instrument must not be used for any purpose other than testing the
ESD immunity of electronic equipment.
The construction of the generator is not designed for use in an explosive
environment.
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Each electrostatic discharge produces powerful
electromagnetic interference.
Nearby electronic equipment can be seriously disrupted
unless the appropriate counter-measures are taken.
Perform ESD tests preferably in a shielded room.
If a network needs to be exchanged, the test has to be
stopped first, followed by a waiting time of at least 5s
to ensure the voltage being internally discharged.
The rechargeable batteries in the base station must not be short-circuited
under any circumstances. They must only be recharged with the original
charging unit supplied with the generator. Should they have to be
replaced, kindly observe the relevant recommendations for their correct
disposal.
The instrument must not be opened. Repairs, maintenance work and
internal adjustments are only to be carried out by a qualified service
engineer. Use the instrument only in dry surroundings. Any condensation
that occurs must be allowed to evaporate before putting the generator into
operation. Long periods of exposure to sunlight and excessive warming by
external energy sources are to be avoided.
Do not continue to use the instrument should any mechanical damage
occur. The instrument's housing and the cable have both an insulating and
a screening function, which can only be assured while the housing is
intact. Return a damaged generator to a Schaffner service centre
immediately for repair.
Schaffner EMV AG Luterbach, Switzerland and the associated sales
organization accept no responsibility for personal or material damage nor
for any consequential damage that results from irresponsible operation of
this instrument.
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3 Introduction
Under appropriate ambient conditions, both material objects and even the
human body itself can become charged with electrical energy. This effect
is due to "electrostatics", a phenomenon that has been known since the
earliest times. Thales von Milet (600 BC) noticed how amber attracted very
light particles when it was rubbed. Touching a charged item against a
conductive object leads to a charge equalization through a spark
discharge, which produces a brief but powerful electro-magnetic field.
3.1. Electrostatic discharge (ESD*)
This effect can be explained as follows: Two insulating substances with
differing dielectric constants become charged when rubbed together, i.e.
one material gives electrons to the other one. This effect is known as
electrostatic charging. The same can happen to a person. When
somebody walks around in a dry atmosphere on carpet while wearing
shoes with good insulating properties, a charge of several thousand volts
can be built up. If, now, that person comes close to a conductive surface,
the charge that he or she is carrying flows away through a hefty spark
discharge.
The high equalizing current that flows, and the associated large
electromagnetic field that hence results, can cause electronic devices
(computers, terminals, process controllers, vehicle electronics, solid state
devices, credit or memory cards, etc.) to malfunction or even be destroyed.
* ESD = electrostatic discharge
3.2. Simulation
A systematic investigation of electronic equipment and installations to
determine their electromagnetic compatibility (EMC) is, today, a necessity
if one is not prepared to suffer the economic disadvantages that could
otherwise ensue. As a logical consequence, appropriate testing is now a
legal requirement for the sale of electronic products within the EU.
The ESD-test plays an important role in the range of interference
sensitivity tests. It simulates frequently occurring effects and guides the
development engineer to any weak spots in an instrument or item of
equipment through a combination of high voltage and high frequency
properties.
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A simulation device must be constructed such that it reproduces practical
conditions realistically. Furthermore, the results obtained (interference
sensitivity threshold) must be reproducible.
The interference immunity of an instrument is not only dependent on its
construction, it is also largely dependent on the quality or the consistency
of the mass production techniques used. Knowing this has led to the
demand for individual testing or at least random sample testing.
Further weak spots, which could affect the overall interference immunity,
can arise through the assembly of instruments into complete systems
because of the installation method used, the cabling and the earthing. An
ESD check on systems is therefore also prescribed. Such tests provide
valuable information about the immunity of the system to effects that occur
only sporadically under operating conditions and hence represent difficult
to detect sources of disruption.
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The ESD generator NSG 438 fulfils the requirements of numerous
applications in an ideal manner, thus:
Ergonomic shape For non-tiring use
Operation Operating elements and display always in
view of the user. Constant check on the test
values.
Battery-powered Independence from a mains power feed.
Carrying case Generator and its accessories can be readily
packed and conveniently transported.
Microprocessor-control All the functions are "on-board", including a
pre-settable counter, pre-programmed test
values, discharge voltage measurement, etc.
Precision The test parameters are maintained precisely
for reliably reproducible tests.
Flexibility The specifications prescribed in the standards
are more than fulfilled in every respect. The
instrument also offers many additional handy
features.
Safety The high voltage generator is automatically
deactivated if the instrument remains unused
for a period of time.
Long-term operation Automatic long-term operation for stationary
applications with the generator mounted on a
tripod.
Application field Development optimization, type-approval,
EMC certification, batch testing (individually),
testing of fully installed systems.
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3.3. Effects on the EUT
The most significant interference components of an electrostatic discharge are
of a high frequency nature. The interference paths and effects have to be
assessed in the range from about 30MHz to multi-GHz.
The extremely rapid rise time of a discharge affects an object under test
mostly through:
§ magnetic HF-coupling between electrical conductors in the
electronics and the discharge current path.
§ electrical coupling between the discharge current and signal
lines. A discharge current to the EUT flows proportionally through
all the associated conductors (earth, mains, data lines,
screening, etc.) according to their relative impedance.
Malfunctions in insufficiently immune electronic equipment and systems
make themselves apparent through:
§ program crashes
§ blocking of command sequences
§ incorrect commands, statuses or data being further processed
§ partial system resets (e.g. only in peripheral modules, which lead
to errors that the system does not recognize)
§ disturbance or destruction of interface modules
§ destruction of insufficiently protected MOS components.
ESD (electrostatic discharge) testing usually shows up all the weak spots
in the HF-range of a piece of equipment simultaneously. The uses to which
the NSG 438 ESD simulator can be put hence go way beyond those called
for in standard-conform applications.
This instrument provides the engineer with a means to detect sources of
error caused by unsuitable earthing, poor ground connections, insulation
problems, etc.
The generator also serves as a reliable aid for localizing hidden wiring
faults during acceptance trials on installations.
Use can also be made of the instrument as an insulation tester to
determine the breakdown voltage of switches, relay contacts, insulators,
etc.
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4 The NSG 438 system
By using the latest materials, construction methods and manufacturing
techniques for the robust housing shell, together with highly insulated
modules, the newest high voltage technology, the touch-sensitive
operating panel and a control unit built using the SMD-technique, it has
been possible to integrate all the functions that a comprehensive simulator
system should offer into one compact instrument.
Professional industrial designers have ensured an optimized ergonomic
concept. The instrument, with its well-balanced handgrip, sits comfortably
in the user's hand and guarantees non-tiring operation. Both the operating
elements and the display window remain in view of the user while work is
in progress.
The NSG 438 offers optimal freedom of movement around the work-place
and is an ideal test instrument not just for the development engineer but
also for quality control purposes, system tests and for investigations in the
field.
As supplied in the basic set, the system is equipped with a 150pF / 330Ω
discharge network for the IEC / EN 61000-4-2 (2001) standard.
The discharge voltage of up to 30kV for both Air-Discharges and ContactDischarges ensure a comfortable test margin over and above the levels
called for in the standards.
The instrument is well equipped to cope with other (and future) standards.
The accessories include various networks and test fingers that can be
attached by the user himself.
The basic set contains everything necessary for general use. A rich
assortment of accessories for special tasks is available such as a remote
triggering unit, further discharge networks, an ergonomically shaped
carrying case, a tripod adapter, test fingers, etc.
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4.1. The generator
The NSG 438 generator is modularly constructed from a number of
discrete function units.
4.1.1. Function modules
The base station contains the battery supply, the high voltage generator
and regulator as well as several safety features.
The pistol houses the interchangeable pulse network, high voltage relay,
the exchangeable test finger, measuring electronics and the touchsensitive input / display panel.
Pistol
Display and
touch-panel
Network
(exchangeable)
Pistol stand
On/Off button and
emergency off switch
Base station
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4.1.2. Block diagram
The various function units are shown in the block diagram:
Block diagram of the base station:
µP Control Unit
Buzzer
High Voltage
active
Communication to
Discharge Pistol
Meas.
Circuit
High Voltage to
Discharge Pistol
High Voltage
Generator
+ / -
Interlock Unit
Communication to
the PC (Opto Link)
External Trigger
EUT Fail
Interlock IN
Interlock OUT
24 VDC
PSU and Battery
Power On Power Batt. Status
Interlock
Interlock
Reset
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Block diagram of the pistol:
The microprocessor controls and monitors all the generator functions:
§ Touch-panel entries are checked for plausibility. Unacceptable
entries are rejected and an acoustic warning notifies the user of
the error.
§ Values entered are clearly shown on the large display screen.
Further information shows the operating status and the counter
settings.
§ The battery charge state is continuously monitored. The display
warns if there is a tendency towards low voltage. The
instrument's functions are inhibited once the battery voltage is
insufficient to guarantee the pulse parameters.
§ High voltage generation is dynamically controlled by the
processor. Varying load conditions, supply voltages, etc. can
thus be taken into account and have no effect on the pulse
parameters.
High Voltage
Manual Trigger
Communication to
the Base Station
Discharge Network
Display with
Touch - Panel
µP Control Unit
High Voltage
Relay
Test Finger
Buzzer
Tip Ident.
Network Ident.
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§ The instrument switches itself off automatically if it is not used for
a while. The pulse parameters and operating mode remain
stored and ready for re-use.
§ The charge voltage to the network is kept constant as long as the
trigger is active. The high voltage is discharged internally when
the trigger is reset.
§ If no discharge occurs when set for an Air-Discharge and the
trigger is active, the processor waits for about 15s then autonomously resets the trigger and discharges the network internally
with simultaneous acoustic warning.
§ A measurement facility detects an actual valid discharge and
shows it on the display.
§ Pulse triggering is monitored. Once an arc has occurred the
network is discharged internally so that no further arcing is
possible.
4.1.3. Operating elements
Apart from the trigger button itself (pulse triggering), all the operating
elements, test-relevant setting and user information are presented on the
touch-sensitive display panel facing the operator.
The NSG 438 is switched on and off with the main power switch. The
significance of the elements in the display field can be seen in the
following picture. Further information can be found in section “Operation”.
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