Schloder SFT 1400 User manual

OPERATION MANUAL
BURST-GENERATOR
SFT 1400

Manual SFT 1400 page 2
OPERATION MANUAL
BURST-GENERATOR
SFT 1400
290708
Warning:
This apparatus generates high voltages which may cause danger to life for persons with a cardiac
pacemaker. This is for persons with a cardiac pacemaker an unavoidable dangerous equipment. The
local and national and all applicable safety regulations must be obeyed for operation of this unit.
Operation of this unit is only allowed to an experienced electric technician, see VDE 0104.

Manual SFT 1400 page 3
Contents
1. Introduction .............................................................................................................................4
2. Burst definitions .....................................................................................................................4
3. Description of functions.........................................................................................................5
3.1. General.....................................................................................................................................5
3.2. Security instructions ..............................................................................................................5
3.3. Front panel functions .............................................................................................................6
3.4. Connectors on the rear ..........................................................................................................8
3.5. Test in conformity to the standards......................................................................................9
3.6. Test according to the standard / data-lines .......................................................................10
3.7. Test with all parameters free adjustable ............................................................................10
3.8. Polarity selection ..................................................................................................................11
3.9. Coupling network..................................................................................................................11
3.10. Pulse output ..........................................................................................................................12
3.11. Self check / measurements..................................................................................................13
3.11.1. Monitor output .........................................................................................................................13
3.11.2. Output High Voltage................................................................................................................13
3.12. Special functions with the key "special"............................................................................14
3.12.1. Special function continuous burst ...........................................................................................14
3.12.2. Special function IFM mode / increasing frequency mode.......................................................14
3.12.3. Special function DFM mode / decreasing frequency mode....................................................15
3.12.4. Special function real burst ......................................................................................................15
3.12.5. Special function sweep ...........................................................................................................16
3.13. Memory function ...................................................................................................................17
3.13.1. General description.................................................................................................................17
3.13.2. Examples on the usage of the memory key............................................................................17
4. Burst test field.......................................................................................................................18
4.1. About what's written in the standard .................................................................................18
4.2. Recommendation for the setup of a testing corner ..........................................................19
5. Limits of parameters.............................................................................................................20
6. Putting into operation...........................................................................................................20
7. Technical data .......................................................................................................................21
7.1. Generator unit .......................................................................................................................21
7.2. Coupling network..................................................................................................................21
7.3. General...................................................................................................................................21
8. Calibration .............................................................................................................................22
9. Scope of delivery ..................................................................................................................22
9.1. Basic model...........................................................................................................................22
9.2. Options and accessories .....................................................................................................22
10. Block schematic SFT 1400...................................................................................................23

Manual SFT 1400 page 4
1. Introduction
This test generator simulates quick transient noise interference’s as they are defined in various standards
(see IEC 61000-4-4, EN 61000-4-4.).
In reality this noise interference’s are mostly generated when switching inductive loads. Significant for this
interference’s is a very short rise time (within the range of nano seconds) of the single pulses and the
high repetition rate within the burst packet.
Hence each single pulse generates a wide RF-interference-spectrum up to 300 MHz. The line-bound
interference-effect will be increased by a RF-interference due to short antenna length.
Increasing the number of single pulses within the burst-packet and the herewith resulting addition effect
will influence both, analogue and digital circuits.
The easy operation and the clearly arranged front panel with the generator settings allows a timesaving
and optimized testing in the fields of:
•Research and design:
Test with fixed standard values and investigation with variable settings (search for worst case)
•Quality assurance:
Test with fixed standard values, manual adjustable or automatic test procedure by remote computer
control.
•Service:
Handy unit and easy to be operated
2. Burst definitions
drawing 1
designation param. standard definition variable setup on SFT 1400
burst duration a
15 ms ±20% at 5 kHz
0,75 ms ±20% at 100 kHz
(correspond to 75 pulses
/package)
0,01 - 100 ms *1
burst period b 300 ms ±20 % 10 - 1000 ms *1
burst frequency c 5 kHz or 100 kHz
up to 4 kV
100 Hz - 125 kHz
up to 5 kV
pulse amplitude U 0,5 / 1 / 2 / 4 kV 200 V - 5000 V (into 10 V steps)
pulse rise-time tr5 ns ±30 %
pulse width (50 Ohm)
pulse-width (1 kOhm) tw
50 ns ±30 %
50 ns, -15ns/+100 ns
*1: the SFT 1400 automatically
concerns the units. maximum
power restrictions
impedance Z 50 Ω±2 %

Manual SFT 1400 page 5
3. Description of functions
3.1. General
The burst generator SFT 1400 exists of a generator module and a coupling network. The generator
module itself has a power supply, a control module and a high voltage module.
Generatorteil / generator module
Netz / mains
Netzteil
power supply
µP - Steuerung
µP - control
HV - Schalter
HV - switch
Prüflings-
einspeisung
EUT feeding
Einkoppel - Netzwerk
coupling network
Prüflings-
anschluß
EUT supply
drawing 2
3.2. Security instructions
Warning: This apparatus generates high voltages.
This generator must be operated only with approved protection-earth-power jacks. Cutting the protection-
earth-lead may cause danger to life and is therefore forbidden. The units enclosure and the grounding
jacks are joined to the protection-earth-conductor.
When the unit shows damagements and a dangerless operation is not ensured it has to be retired from
operation and must be protected against unauthorized operation.
Also when the mains are disconnected it is possible to have lethal high voltages inside of the test
generator (capacities). Servicing this generator should only be done by a well experienced specialist
which has good knowledge of this generator.
The interference generator SFT 1400 is according to its specifications only to be used for
laboratory operation in an industrial surrounding.
The coupling network has no internal fuses, the user has to provide proper fusing for the test object and
the coupling network according to its power consumption. Fuse size must not exceed 16 A, see also
technical data.

Manual SFT 1400 page 6
3.3. Front panel functions
drawing 3
[ 1] Ground jack.
[ 2] Laboratory jacks for EUT connection.
[ 3] Protected earth outlet for EUT connection.
[ 4] Polarity of the burst packet: positive, negative or alternating.
[ 5] External or manual trigger release.
[ 6] Selection key for the period-time, linked with the display left (time in ms). Adjustment of parameters
by turning the digital potentiometer [8].
[ 7] Selection key for the test-time, linked with the display left (time in s). Adjustment of parameters by
turning the digital potentiometer [8].
[ 8] Digital potentiometer.
[ 9] Selection of the special functions. The following functions are activated by repeated pressing:
Continuous burst: packet length meets test time, period see chapter 5.
IFM: increasing burst frequency in one packet with fixed pulse-voltage.
DFM: decreasing burst frequency in one packet with fixed pulse-voltage.
Real burst: increasing burst frequency with decreasing pulse-voltage.
Sweep: randomized changes of burst frequency and pulse-voltage.
[10] Jack for interface cable, both connectors are parallel.
[11] Activation of the interface-mode.
[12] Activation of the memory function.
[13] Selection key for the duration-time, linked with the display left (time in ms). Adjustment of
parameters by turning the digital potentiometer [8].
[14] Selection key for the frequency, linked with the display left (frequency in kHz). Adjustment of
parameters by turning the digital potentiometer [8].
[15] LED for "CWG active", necessary for the connection with the surge-generator CWG 500.

Manual SFT 1400 page 7
[16] Displays for the memory mode.
[17] Display for the pulse-voltage (Voltage in kV). Adjustment of parameters by turning the digital
potentiometer [8]. The selection-LED’s in the keys [6], [7], [13] or [14] must not burn.
[18] Coupling selection for the paths L, N and PE.
[19] Display for the phase orientation with a red and a green lamp.
[20] Output to control the optional 3-phase coupling network CWG 520.
[21] HV-output for the connection of a capacitive coupling clamp or an external 3 phase coupling
network.
The settable parameters as there are voltage, spike frequency, burst-duration and burst period are
displayed on LED-displays. The operation modes of the key functions will be displayed by LED’s in the
appropriate switch.

Manual SFT 1400 page 8
3.4. Connectors on the rear
Abbildung 4
[30] Electronic feeding for the SFT 1400 with RF-suppression filter.
[31] Ground jack.
[32] Internal serial bus for the operation of several Schlöder test generators in one setup
[33] Operational input for an EUT's failure supervision.
[34] Jacks for EUT-feeding

Manual SFT 1400 page 9
3.5. Test in conformity to the standards
The basic standard for interference-immunity-tests is given in IEC 61000-4-4 and EN 61000-4-4.
Contents of the mentioned standards are identical. The burst tests are described and defined in part 4 of
the a./m. standards.
For the tests according to the standards the four test-levels are pre-defined in the unit's memory. The
access on these information’s starts by pressing the memory-key [12]. A quick press on this key shows
the in the lower display [16] the storage location number. The upper display [16] shows the operation
mode . By turning the digital potentiometer [8], the memory location can be selected. The memory
locations 1 - 4 correspond with the test levels 1 - 4. A second pressing of the memory-key [12] returns the
values into the RAM. More detailed description of the memory function You will find in chapter 3.12.
In the four displays voltage [17], frequency [14], duration [13] and period [6] the parameter according to
IEC 61000-4-4 appear as following:
step voltage frequency duration period
1 500 V 5 kHz 15 ms 300 ms
2 1000 V 5 kHz 15 ms 300 ms
3 2000 V 5 kHz 15 ms 300 ms
4 4000 V 5 kHz 15 ms 300 ms
Select the mode of coupling with the coupling select switches [18] (see also chapter 3.12 - coupling
network) and define the polarity with switches [4]. Now start an automatic test procedure with trigger key
[5]. There are two different operation modes:
Single event:
•Selection by pressing and holding the key [7] "test time" and simultaneously quickly turning the digital
potentiometer [8] to the left, the display "test time" shows "|" in the left segment.
•Values for frequency and duration to the lower border (press and hold the corresponding key and turn
the digital potentiometer [8] quick to the left) cause the selection of a single spike, otherwise a single
packet is released by pressing the trigger-key [5].
Automatic release:
•The display "test time" [7] shows the pre-selected time or the remaining time during the test.
•The release starts by pressing the trigger-key [5] and ends after the run-down of the test time or
another pressing of the trigger-key [5].
•If the trigger-key [5] is pressed longer than one second during the test there will be a pause. The
display "test time" blinks and there are no further pulses released until the trigger-key [5] is pressed
again.
•Continuous operation (not continuous burst) is selected by pressing and holding the key "test time" [7]
and simultaneously quickly turning the digital potentiometer [8] to the right. The display "test time"
s h o w s " - - - -" .
The function of the trigger key [5] may be remote controlled via BNC-input: permanent grounding of this
TTL-input makes continuous operation. Short time (less than burst period) grounding fires a single burst
packet.

Manual SFT 1400 page 10
3.6. Test according to the standard / data-lines
The tests on data- and signal-lines with a capacitive coupling clamp are defined in the standard
IEC 61000-4-4 in that way the pulse-voltage is divided by to referred to the pulse-voltage at mains-
coupling. So the test levels 1 - 4 are defined with the voltages 250V, 500V, 1000V and 2000V.
While the pulse is released the interference signal is fed to the jack [21] where the capacitive coupling
clamp (SFT 410) is connected via the high-voltage cable SFT 430. The coupling selection keys [18] have
to be switched off so the interference signal is effective without any impair.
The lines to be tested are placed between the coupling-plates of the coupling clamp SFT 410 and the
hood is closed. This is the only possibility to test according to the standard. A touch with the coupling
plate (while the hood is opened) with the hand would cause a capacitive decoupling to ground via the
human body and improves the result unwanted.
3.7. Test with all parameters free adjustable
The adjustment of the test parameters is done by pressing the key referring to the display of the desired
parameter and turning the digital potentiometer [8].
NOTICE: If you press simultaneous the selection key and turning the potentiometer, the displayed step
wide will be expand.
All parameters should be adjusted in a certain sequence: voltage, frequency, duration, period, test
time. This makes sure that no adjustments have to be repeated because of the automatic
correction in the maximum parameter's definition.
Output voltage: the keys [17]
•Adjustable from 200 V to 5000 V, displayed in kV.
•In all tests this voltage can be varied in 10V-steps.
Spike frequency: key [14]
•Variable setting possible from 0,1 kHz up to 125 kHz.
Burst duration: key [13]
•Setting possible from 0,01 ms to 100 ms.
Depend on the spike frequency and the burst duration. The Generator SFT 1400 automatically
considers the maximum unit's power capability (see chapter 5).
The display is off if mode “continous burst” is activated.
Burst period: key [6]
•Range of setting from 10 ms to 1000 ms.
Depend on the spike frequency and the burst duration. The Generator SFT 1400 automatically
considers the maximum unit's power capability (see chapter 5).
test time: key [7]
•Setup from single event [, ] until 9900 sec. or. continuous test [----]

Manual SFT 1400 page 11
3.8. Polarity selection
The polarity of the generated pulses will be selected by using the keys [4]:
Positive
•Key "+" is pressed, key "Alt" not pressed.
•The burst packets, dependant from the present parameters, will be generated with positive sign.
Negative
•Key "-" is pressed, key "Alt" not pressed.
•The burst packets will be generated with negative sign.
Alternating
•Key "Alt" pressed together with "+" or "-".
•The burst packets will be generated alternating with positive and negative sign when one of the keys.
According to which one of the keys [+] or [-] is pressed the polarity of the first packet is defined.
•The shortest burst period in this mode is 300 ms.
•All other parameters are settable in the given limits due to the available maximum unit power. The
burst generator takes the keying ratio in account and provides proper display readings.(see ch. 5, lim.
of parameters)
•The changeover switching of relays, needed for this function, does not influence the shape of the
pulses: Switching the relays is done before firing the pulses by the semiconductor switch.
3.9. Coupling network
The coupling network is used to superpose the pulses of the test-generator to the power leads of the
testing object. This is done by using discrete coupling capacities of 33 nF and with an appropriate
dielectric strength according to IEC 61000-4-4.
The coupling circuit is configured by using the keys [18], following circuits can be realized:
•Phase (L) + Neutral (N) ⇒Earth, known as common mode or asymmetrical coupling.
•Protection earth ⇒earth,
PE of the test object is decoupled from the mains by means of a choke. The pulses are directly
coupled to the PE of the test object.
•Phase (L) ⇒Earth.
•Neutral (N) ⇒Earth.
The filter in the coupling network provides a high impedance for the fast test-pulses and therefore isolates
the common mains from the interference pulses and protects other electronic devices used close to the
test generator. (see also block circuit diagram ch.10).
It should not be neglected or forgotten: Noise level in the proximity of the test generator is much higher
than normal, it is recommended to use the test generator in a shielded room or faradays cage.
The coupling network has no internal fuses, the user has to provide proper fusing for the test object and
the coupling network according to its power consumption. Fuse size must not exceed 16 A, see also
technical data ch.7.

Manual SFT 1400 page 12
3.10. Pulse output
The FISCHER coaxial HV-jack provides the burst voltage and may be used as follows:
•Monitoring the pulses with the SFT 450 - 100:1 attenuator / 50 Ω. See also chapter 3.11.2.
•Connecting the connector cable SFT 430 to the capacitive clamp SFT 410. Direct capacitive coupling
to signal or I/O-leads is mostly not possible because this would falsify their signals, therefore coupling
is made using the capacitive clamp which couples along a distance of 1 m. The generator SFT 1400
can be connected to both sides of the capacitive clamp SFT 410.
•Connecting the connector cable SFT 431 to the 3-phase coupling network CWG 520. Since the test
generator SFT 1400 uses a 1-phase coupling network, the test of 3-phase objects requires a 3-phase
coupling network.

Manual SFT 1400 page 13
3.11. Self check / measurements
3.11.1. Monitor output
This BNCoutput connector [20] may be used to check the present parameters like frequency, burst
duration, burst period and other functions. An oscilloscope with a small bandwidth allows to check this
TTL-output signal.
3.11.2. Output High Voltage
The high voltage connector [21] provides the ability to check the burst signals amplitude and its waveform
resp. its consistency of measuring values. This can be done with the SFT 450- 100:1 / 50 Ωattenuator.
The source impedance of the generator is 50 Ω. For a physically accurate measurement the HV output
has to be closed with 50 Ωso the voltage divider divides the output voltage by two.
To protect the inputs of a scope, inside the SFT 450 is found an additional attenuator 100:1. The SFT 450
divides the HV output once by two (because of the 50 Ω) and additionally with the factor 100:1.
Depend on the used scope input You get the following relations:
a) 200 ÷1 with the SFT 450 and a high impedance scope input
b) 400 ÷1 with the SFT 450 and a 50 Ω−impedance of the scope input
These relations are valid only for signal sources with an source impedance of 50 Ωand an attenuation of
100:1. For signal sources with a varying source impedance mind the dividing relation Ri/Ra.
Checking the values of a single pulse as there are voltage, rise time, and pulse width is recommended to
be done with an analogue oscilloscope having a bandwidth of 400 MHz. A good solution would be a
Tektronix model 7834 with Y-amplifier type 7A26, input terminated with 50 Ω, alternative with a 50 Ω
amplifier type 7A19 and Tektronix TDS 680 B.

Manual SFT 1400 page 14
3.12. Special functions with the key "special"
The special functions of the SFT 1400 can be selected by pressing the key "special" [9]. The yellow LED
inside the key displays the mode. All operation-modes are placed sequentially, every press on the key [9]
switches to the next function. Following special functions are realized:
Continuous burst: packet length corresponds with the test time.
IFM: increasing frequency in one packet with remaining pulse-voltage.
DFM: decreasing frequency in one packet with remaining pulse-voltage.
Real burst: increasing pulse-voltage with decreasing burst frequency.
Sweep: randomized frequency variation.
3.12.1. Special function continuous burst
Display memory: display off
Display frequency: adjustment as desired selectable
Display duration: display off
Display period: - - -
Display test time: adjustment as desired selectable. At display "|" (left side) there will be only a
pulse release while pressing the trigger-key [5].
At the function continuous burst the pulses with a duration time that meets the test time are coupled to
the EUT. This is a very high stress for the EUT since it is a simple "energy view". Test with continuous
burst can be used for example to track saturation effects in chokes. If the EUT shows any influence the
user will change to the variable test mode according ch. 3.7 to find the details of incompatibility and the
exact reasons for this.
The maximum frequency depends on the voltage:
voltage range Pulse / paket max max. frequency
0,20 - 2,00 kV 500 5 kHz
2,01 - 3,00 kV 500 3 kHz
3,01 - 5,00kV 500 1,5 kHz
3.12.2. Special function IFM mode / increasing frequency mode
Display memory: display off
Display frequency:
Display duration: 15.0
Display period: adjustment as desired selectable
Display test time: adjustment as desired selectable
The burst frequency is varied continuously within one burst packet from 8,1 to 100 kHz. The burst
duration is fixed to 15 ms and shown in the display duration [13]. The period can be varied according to
the adjusted voltage:
≤2000 V from 50 ms until 1000 ms.
> 2000 V until 3000 V from 83 ms until 1000 ms.
> 3000 V until 5000 V from 166 ms until 1000 ms.
Using this test mode makes it easy to investigate resonance or saturation effects in the tested device. If
the EUT shows any influence the user will change to the variable test mode according ch. 3.7 to find the
details of incompatibility and the exact reasons for this.

Manual SFT 1400 page 15
3.12.3. Special function DFM mode / decreasing frequency mode
Display memory: display off
Display frequency:
Display duration: 15.0
Display period: adjustment as desired selectable
Display test time: adjustment as desired selectable
The burst frequency is varied continuously within one burst packet from 100 to 8,1 kHz. The burst
duration is fixed to 15 ms and shown in the display duration [13]. The period can be varied according to
the adjusted voltage:
≤2000 V from 50 ms until 1000 ms.
> 2000 V until 3000 V from 83ms until 1000 ms.
> 3000 V until 5000 V from 166ms until 1000 ms.
Using this test mode makes it easy to investigate resonance or saturation effects in the tested device. If
the EUT shows any influence the user will change to the variable test mode according ch. 3.7 to find the
details of incompatibility and the exact reasons for this.
3.12.4. Special function real burst
Display memory:
Display frequency:
Display duration: 15.0
Display period: adjustment as desired selectable
Display test time: adjustment as desired selectable
The burst frequency is varied continuously within one burst packet from 5 to 100 kHz and back to 5 kHz.
Simultaneously the pulse-voltage is varied from the value shown in display voltage [17] down to 0 V and
back to the original value (see drawing 5). The burst duration is fixed to 10 ms and shown in the display
duration [13]. The period can be varied according to the adjusted voltage:
≤2000 V from 120 ms until 1000 ms.
> 2000 V until 3000 V from 200 ms until 1000 ms.
> 3000 V until max. 3400 V from 400 ms until 1000 ms.
This test mode simulates the natural burst phenomena. At the natural phenomena a decrease of the
pulse-voltage comes simultaneously with the decreasing of the burst frequency. If the EUT shows any
influence the user will change to the variable test mode according ch. 3.7 to find the details of
incompatibility and the exact reasons for this.
drawing 5

Manual SFT 1400 page 16
3.12.5. Special function sweep
Display memory: Display off
Display frequency:
Display duration: 7.50
Display period: adjustment as desired selectable
Display test time: adjustment as desired selectable
The burst frequency is varied by random within one burst packet from 5 to 100 kHz. Simultaneously the
pulse-voltage is varied by random between the value shown in display voltage [17] and 0 V. The burst
duration is fixed to 7,5 ms and shown in the display duration [13]. The period can be varied according to
the adjusted voltage:
≤2000 V from 60 ms until 1000 ms.
> 2000 V until 3000 V from 100 ms until 1000 ms.
> 3000 V until max. 3400 V from 200 ms until 1000 ms.
This test mode simulates bouncing of an electrical contact for example in relay controls. If the EUT shows
any influence the user will change to the variable test mode according ch. 3.7 to find the details of
incompatibility and the exact reasons for this.
drawing 6 drawing 7
Window from burst packet sweep burst packet sweep

Manual SFT 1400 page 17
3.13. Memory function
3.13.1. General description
With the aid of the memory key [12] up to 25 settings can be stored and recalled. All variable parameters
and the key positions are fixed for recall.
The first pressing of the memory key activates the memory function. Depend on the holding duration one
of three functions can be called up:
a) memory recall: display [16 upper] shows .
key [12] pressed up to 1 second
b) store setting: display [16 upper] shows .
key [12] pressed between 1 and 2 seconds
c) clear setting: display [16 upper] shows .
key [12] pressed longer than 2 seconds
The display [16 lower] shows the number of the actual setting, it can be changed by turning the digital
potentiometer. Setting 00 is always equivalent with the unit setting before pressing the memory key.
The settings 1 to 25 are random access. An empty memory cell leads to display "- - - -" in [6], [7], [13] and
[14].
Another pressing of the memory key activates the selected command and the leaves the memory
function. If setting number "00" was selected, no changes in the memory are made.
3.13.2. Examples on the usage of the memory key
1. Recall data from the memory, e.g. memory cell 3
•Activate function "recall" by pressing key [12].
•Shuttle to memory cell 3 shown in the display [16 lower] with the aid of the poti [8]. The desired values
are shown in the displays.
•Press memory key again. The generator is in the operation mode again and the values of memory cell
3 are ready to use.
2. Save data, e.g. memory cell 12
•First adjust the desired values at the generator.
•Activate function "store" by pressing and holding the key [12] for 1 - 2 seconds.
•Shuttle to memory cell 12 with the aid of the poti [8].
•Press memory key again. The generator is in the operation mode again and the values saved in the
memory cell 12 are shown in the displays.
3. Delete date, e.g. memory cell 20
•Activate function "clear" by pressing and holding the memory key for longer than 2 seconds.
•Shuttle to memory cell 20 with the aid of the poti [8].
•Press memory key again. The generator is in the operation mode again and the values shown before
activating the memory mode are shown again. While exiting the memory mode, memory cell 20 is
deleted.

Manual SFT 1400 page 18
4. Burst test field
4.1. About what's written in the standard
drawing 8
In the standard IEC 61000-4-4 the setup of the test bed is described with the drawing above. Following
requirements have to be met:
•The EUT is located on a ground plane and insulated from it by a foundation of 10 cm thickness. For
table sets this distance can be up to 1 meter (= table).
•The laboratory floor is covered with a earthen ground plane from copper or aluminium with a thickness
of at least 0,25 mm. Other metals may be used with a thickness of at least 0,65 mm. The ground
plane has to rise above the EUT at least 50 cm on each side and must be bigger than 1 m².
•The EUT is set up according to its functions and earthen as desired in the installation instructions.
Further ground connections are not allowed. Between the laboratory wall and other metal parts must
be a distance of 50 cm.
•While using a coupling clamp keep a distance of at least 50 cm to the walls. The distance between
coupling clamp and EUT must not be more than one meter.

Manual SFT 1400 page 19
4.2. Recommendation for the setup of a testing corner
drawing 9
As described above the conformity tests should be made in a Faraday’s cage. To reduce the expend of
tests in the development, we suggest the setup of a testing corner. Such a corner can be located in the
usual development laboratory or - even better - in the cellar, where the iron reinforce makes a good
shielding. If the test corner is located in the laboratory it is worth to construct moveable metal screens to
protect other devices in the room. These metal screens have to connected (separable) with the ground
plane.
•The table with a high of 80 cm has to be all out of wood and must not have any metal parts like nails
or mountings. Such wooden tables can be found typically at local workshops of handicapped people
or prison joiner's workshops.
•The metal plates must be connected with low impedance, either by welding or with copper tape. The
ground plate on the table is to be connected with the ground plane.

Manual SFT 1400 page 20
5. Limits of parameters
The design of the generator SFT 1400 makes it superior to the pre given values of IEC 61000-4-4, it will
exceed a lot of values in a wide range. But there are limits for some settable parameters of the generator
due to its limited power which will are described below:
A Variable voltage
voltage [kV] max. frequency
cont. burst [kHz]
max. pulses / sec max. pulses /
packet
0,20 - 2,00 5 5000 500
2,01 - 3,00 3 3000 500
3,01 - 5,00 1,5 1500 500
B Alternating operation
Like Pt. "A", the minimum burst period must be 300 ms.
6. Putting into operation
1. Provide mains connection for the generators power supply, use power connector on the rear of
the generator, 230 V / 50 Hz.
2. Provide additional ground connection on one of the ground connectors on the rear or front side
of the unit. Ground connectors are marked with the ground sign.
3. Connect the cable for the test objects supply to the 3 connectors on the units rear side, first the
3 safety-connectors, then the protection-earth power plug. On DC-applications one can use
appropriate laboratory cables. On 230 V AC applications the power plug must be in a position that
the green lamp [19] is on, this ensures that phase (L) is connected to the connector [L].
4. Connect the test object to the wall-protection-earth-power outlet or the laboratory connectors.
5. Switch the mains switch on the rear on.
6. Select the desired operation mode with the memory function [12]. Use the potentiometers
in the variable mode to set the desired parameters.
7. Select desired polarity with the selector [4], positive, negative or alternating.
8. Select the desired coupling mode with selectors [18].
9. Pressing the key [5] "Trigger". After pressing the trigger-key [5] the interference pulses are
superposed according to the adjusted coupling and the other parameters to the mains of the EUT.
To stop the burst test the trigger-key [5] must be released.