TECNA TE 500 User manual

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TABLE OF CONTENTS
TOPICS PAGE
TE500 WELDING CONTROL UNIT 5
MAIN FEATURES 5
CONTROL UNIT SWITCH-ON 6
CONTROL UNIT PROGRAMMING 7
DESCRIPTION OF THE PARAMETERS 9
CONFIGURATION MENU 13
STEPPER MENU 15
CURRENT STEPPER OPERATING MODE 16
INSTALLATION MENU 21
PROGRAM COPY MENU 23
PROGRAM SEQUENCE MENU 24
PROGRAM SEQUENCE EXAMPLE 26
CHECK INPUT MENU 28
PANEL LEDs 29
COMMANDS ON THE PANEL 30
SELF-CALIBRATION PROCEDURE 31
SELECTION OF THE WORK PROGRAM 32
WORK MODES 33
CONSTANT CURRENT OPERATING MODE 34
DESCRIPTION OF THE WORK CYCLE 35
MEASUREMENT OF THE WELDING CURRENT AND THE CONDUCTION ANGLE 36
WELDING ANALYSIS 37
WELDING CURRENT AND CONDUCTION ANGLE LIMITS 38
COMPENSATION OF THE SECONDARY CURRENT 39
WELDING SPOTS COUNTER FUNCTION 39
SERIAL INTERFACE RS-232 ITEM 50214 (Option) 40
SERIAL INTERFACE RS-485 ITEM 50209 (Option) 42
INTERFACE FOR PROPORTIONAL VALVE ITEM 50220 (Option) 43
INTERFACING WITH AUTOMATIC SYSTEMS 44
DOUBLE STROKE FUNCTION 45
DESCRIPTION OF SIGNALS ON TERMINAL BOARD 46
MESSAGES LIST 48
FIRST INSERTION DELAY ADJUSTMENT 51

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The TE500 is a microprocessor-based welding control unit for resistance welders. The task of the
welding control unit is to manage the welder components, in particular the controlled diodes that carry
out the welding current control.
It is possible to store up to 63 different welding programs, 31 of which are recalled directly from an
external device. Each program comprises 18 programmable parameters that describe the work cycle.
In addition to the plain 4-stage welding cycle, the control unit allows the running of welding processes
with pre-welding current, post-welding current, slope and pulses.
WELDING CONTROL UNIT TE 500
MAIN TECHNICAL DATA
2
3
2
1
4
MADE IN ITALY
• Simplified programming via 6 keys and a backlit alphanumeric LCD.
• Synchronous control with controlled diodes, phase control current adjustment.
• Storage of 63 welding programs, 31 recallable from the outside.
• 26 programmable parameters for each program.
• Slope, pulses, pre-weld, post-weld functions and adjustment of the welding times in half-periods.
• Display of the RMS welding current measurement in kA and relative angle of conduction.
• Dual operating mode: standard and constant current.
• Welding current or angle of conduction limits.
• Double stroke function.
• Stepper function to compensate the electrodes wear with programmable curve.
• Counter for the performed welding spots.
• Compensation function of the secondary current for welding oxidized sheets and rods.
• Single and automatic cycle. WELD and NO-WELD function.
• Adjustment of first insertion delay.
• Control of 4 solenoid valves 24 Vdc max. 5 W with self-protected output.
• Auto-regulation at mains frequency 50/60 Hz.
• Serial data transmission by means of opto-isolated RS232 or RS485 ports.
• Output for optional proportional solenoid valve.
• Key for selecting foot control or two-hand control.
• Selectable languages: Italian, English, French, German and Spanish.
• Possibility of upgrading control unit Firmware via appropriate software.

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CONTROL UNIT SWITCH-ON
It must be pressed every time the control unit is powered. When the key is pressed all the devices
connected to the VAUX are powered, such as for example, any double stroke valves.
As soon as the welding control unit is turned on, the display shows the primary mains frequency and the
software version of the program.
After a few seconds, the TE500 is set to a waiting condition until the Restart key is pressed.
This key enables the control unit’s commands and outputs.
Before starting any welding operations, first program the welding data and set some general operating
parameters of the welder.
Before pressing the key it is important to check that it will not cause
injury/damage to people or equipment.
SUPPLY FREQUENCY
50 Hz.
TECNA TE500 2.31
WELD CONTROL UNIT
PUSH KEY[//]
RESTART TO CONTINUE
009
k

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The programming parameters of the control unit are divided into different menus as shown in the
drawing above:
_ PROGRAMMING
_ CONFIGURATION
_ STEPPER
_ INSTALLATION
_ PROGRAM COPYING
_ INPUT CHECK
_ PROGRAM SEQUENCES
To begin the programming operations, turn the key in the PROG position and be aware of some of the
fundamental features of the control unit.
Arrow ">" on the left-hand side of the display indicates the cursor’s position.
Use keys dand fto move the cursor up and down whereas keys hand gare used for entering and
exiting from the menu selected by the cursor.
Use keys aand sto set the value of the parameter indicated by the cursor.
PROGRAMMING MENU
The "Programming" menu contains all the parameters associated with the welding cycle, the times and
the currents by means of which to carry out the welding process.
CONTROL UNIT PROGRAMMING
TE500 VER. 2.31
>PROGRAM DATA
SETUP MENU
STEPPER MENU
The first choice to make is the number of the program to be used. Choose among the 63 storable
programs using the aand skeys.
Then proceed with the next parameters moving with the dand fkeys, adjusting the desired value
always using the aand skeys.
As such all the parameters will be set to the desired value for carrying out the welding process. Keep in
mind that there is no need to confirm the set data item that is stored automatically after the adjustment.
Parameters can have several values, according to the type of parameter. The minimum and maximum
limits of each parameter are shown in the following table.
PROGRAM DATA
>PROGRAM NUMBER 01
WORK MODE IK
CONTROL MODE CUR

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There are few special conditions:
• If OFF TIME is set to (0), the welding control unit will work in single cycle.
• If OFF TIME is set to (99), the welding control unit will carry out the min. current compensation with a
value lower than 2.0 kA (see paragraph "COMPENSATION OF THE SECONDARY CURRENT")
• By setting the PRE-WELD parameter to zero, the pre-weld is not carried out.
• By setting the POST-WELD parameter to zero, the post-weld is not carried out.
PARAMETER DESCRIPTION VALUE RANGE
WORK MODE WORK MODE IK - PW%-FIX
CONTROL MODE CONTROL MODE NO - CURR - DEG
1 SQUEEZE 1 1s1 SQUEEZE TIME 01 - 99 cycles
2 SQUEEZE SQUEEZE TIME 00 - 99 cycles
3 PRESSURE WELDING PRESSURE 00 - 99 cycles
4 FORGE DELAY FORGING TIME 00 - 99 cycles
5 PRE-WELD PRE-WELD TIME 00.0 - 99.5 cycles
6 PRE-POWER PRE-WELD CURRENT 05 - 99%
7 COLD I COLD 1 TIME 00 - 50 cycles
8 SLOPE UP SLOPE UP TIME 00 - 25 cycles
9 WELD 1 WELDING TIME 00.5 - 99.5 cycles
10 POWER 1
CURRENT 1 WELDING CURRENT 5 - 99% 1.0 - 90.0 kA
11 COLD 2 COLD 2 TIME 01 - 50 cycles
12 N. IMPULSE NUMBER OF IMPULSES 00 - 09
13 SLOPE DOWN SLOPE DOWN TIME 00 - 25 cycles
14 COLD 3 COLD 3 TIME 00 - 50 cycles
15 POST-WELD POST-WELD TIME 00.0 - 99.5 cycles
16 POST-POWER POST-WELD CURRENT 05 - 99%
17 HOLD TIME HOLD TIME 01 - 99 cycles
18 OFF TIME DWELL TIME 00 - 99 cycles
19 CURR MIN MIN LIMIT IN CURRENT 1.0 - 90.0 kA
20 CURR MAX. MAX. LIMIT IN CURRENT 1.0 - 90.0 kA
21 ANGLE MIN MIN LIMIT IN DEGREES 001° - 180°
22 ANGLE MAX. MAX. LIMIT IN DEGREES 001° - 180°
WORK PROGRAM PARAMETERS TABLE
If CONTROL MODE is activated it will be possible to have additional parameters, namely:
if the CONTROL MODE parameter is set to CURR, otherwise
if the parameter is set to DEG.

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All the following parameters that indicate times are expressed in periods, also called mains cycles. The
mains frequency defines the duration of a period.
Mains frequency of 50 Hz 1 period = 20 ms
Mains frequency of 60 Hz 1 period = 16.6 ms
WORK MODE
The WORK MODE parameter defines the mode for adjusting the welding current of the program: either
power percent (PW%), constant current (IK) or fixed (FIX). Welding time WELD 1 is carried out
according to the adjustment mode set in this parameter. PRE-WELD and POST-WELD times are
always run with the power percent or fixed adjustment.
CONTROL MODE
The CONTROL MODE parameter permits to select the control mode of the desired welding current.
NO No control is performed on the supplied welding current.
CUR TE500 permits to set the welding current min. and max. limits.
DEG TE500 permits to set the min. and max. limits of the welding current conduction angle.
For further information, please read the relevant paragraph.
SQUEEZE 1
The 1st SQUEEZE time or first squeeze determines the time needed by the electrode to move down.
If a pneumatic circuit is present with low-pressure squeeze, such time is that which determines the
duration of the squeeze at low pressure, i.e. the interval of time that elapses from the beginning of the
head descent to the application of the welding force. The set value must be long enough to allow the
electrodes to reach the workpiece to be welded.
In a standard pneumatic circuit, such time is the interval from the beginning of the head descent to the
beginning of the welding. The set value must be long enough to allow the electrodes to achieve the
proper clamping force, before the welding begins.
During the first squeeze time, it is possible to end the cycle if the start cycle signal is deactivated.
SQUEEZE Optional
The SQUEEZE time is a wait time like that of the 1st SQUEEZE. It is necessary for welding machines
with low-pressure squeeze functions. In this case, such time determines the interval from the
application of the welding force onto the electrodes (energizing of the SV2 valve) to the beginning of the
welding. It should be long enough to allow the electrodes to achieve the proper clamping force before
the welding begins. An inadequate adjustment of such time produces sparks among the electrodes and
the sheet when the welding begins, causing quality inconsistencies. If the welding machine does not
contemplate low-pressure squeeze, deactivate this parameter (see Installation Menu). Otherwise it will
be added to the 1st squeeze time. If the start cycle signal is deactivated, during the squeeze time, the
sequence is interrupted.
DESCRIPTION OF THE PARAMETERS

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PRESSURE Optional
This parameter, expressed in bar, expresses the welding pressure value. The set value must be such
that it guarantees a proper clamping force during the welding cycle. An inadequate adjustment of such
value produces sparks between electrodes and sheet when the welding begins.
FORGE DELAY Optional
The FORGE DELAY parameter is used exclusively with pneumatic circuits that contemplate the forging
function. Such function permits to increase the electrode force during the welding cycle.
The parameter describes the time that elapses from the beginning of the welding process to the
application of the forging force onto the electrodes by means of solenoid valve SV3. If the value is set
to zero the forging function is disabled, valve SV3 will be activated at the beginning of the squeezing
phase.
PRE-WELD
The PRE-WELD parameter indicates the duration of a current flow that can be carried out before the
welding process so as to pre-heat the workpiece to be welded. This parameter is expressed by three
digits since it can be set with half-period precision. If this parameter is set to 0, the pre-weld will not be
carried out. Pre-weld is carried out with a current adjustment equivalent to that indicated in the PRE-
POWER parameter (PRE-WELD CURRENT).
PRE-POWER (PRE-WELD CURRENT)
The value expressed in this parameter indicates the power used for carrying out the pre-weld.
COLD 1
The COLD 1 parameter indicates the time that elapses from the pre-weld (PRE-WELD) to the weld
(WELD 1).
If the pre-weld is deactivated (that is, when PRE-WELD time = 0), this cooling time is not carried out.
SLOPE UP
The SLOPE UP parameter describes the time for attaining the programmed welding current value. The
starting value of this slope always corresponds to the minimum current, whereas the final value
corresponds to the current value set at parameter CURRENT 1 (WELDING CURRENT). The slope
inclination is automatically calculated by the microprocessor according to the set values. The SLOPE
UP time is added to the welding time (WELD 1).
WELD 1 (WELDING TIME)
The WELD 1 parameter indicates the welding current flow duration. It is carried out with the same
power value set at parameter CURRENT 1 (WELDING CURRENT). When the pulse operating mode is
activated, this parameter indicates the duration of each pulse. This parameter is expressed by three
digits since it can be adjusted with half-period precision.

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CURRENT 1 (WELDING CURRENT)
The value indicated in CURRENT 1 shows the current adjustment used for carrying out the welding
process.
Depending on the adjustment mode selected by means of the WORK MODE parameter, this value
indicates either the current percent adjustment (PW%, power percent adjustment), or the required
welding current value expressed in kA (IK, constant current adjustment).
N. IMPULSE (NUMBER OF IMPULSES)
The N. IMPULSE parameter indicates the number of impulses used for carrying out the welding
process. The duration of each impulse corresponds to the time set in parameter WELD 1 (WELDING
TIME).
COLD 2 (COLD 2 TIME)
The COLD 2 parameter is used in the pulse operating mode; it indicates the time that elapses from a
welding impulse to the next one.
SLOPE DOWN
The SLOPE DOWN parameter is a welding time that is added at the end of the welding process: it
enables to decrease the welding current from the value set at CURRENT 1 down to the minimum value.
The slope inclination is automatically calculated by the microprocessor according to the set values. The
SLOPE DOWN time is always added to the welding time.
COLD 3 (COLD 3 TIME)
The COLD 3 parameter indicates the time that elapses from the welding process (WELD 1) to the post-
weld (POST-WELD).
POST-WELD
The POST-WELD parameter indicates the duration of a current flow that can be carried out after the
welding time in order to enable a more gradual cooling of the welded workpiece. This parameter is
expressed by three digits since it can be adjusted with half-period precision. If this parameter is set to 0
the post-weld is not carried out. The post-weld is carried out with the current adjustment set in the
POST-POWER parameter.
POST-POWER
The value expressed in this parameter indicates the post-welding power.
HOLD TIME
The HOLD parameter indicates the time that elapses from the end of the welding process to the
opening of the electrodes. It allows a quicker cooling of the welding spot and prevents the spot from
being stimulated before being properly cooled.
OFF TIME (DWELL TIME)
The OFF TIME parameter indicates a welder wait time, namely the one that elapses from one welder
cycle to the next one when the welder is working in automatic cycle. When this value is set to zero, the
welder always works in single cycle; if it is set to another value, the welder will work in the automatic
cycle.
When the welder works in single cycle, the control unit carries out a single welding cycle each time it
receives a start cycle signal. When the welder works in automatic cycle, the welder goes on executing
welding cycles until the start cycle signal is released.
By programming this parameter to 99 the welding current compensation function is activated (see the
relevant paragraph).

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CURR MIN / ANGLE MIN (MINIMUM CURRENT LIMIT OR CONDUCTION ANGLE)
The meaning of this parameter depends on the control mode selected in the CONTROL MODE
parameter.
When the control unit is set to current control mode (CONTROL MODE=CUR), this parameter fixes a
minimum current value. For each weld, the TE500 monitors that the welding current supplied by the
welder is higher than the value set at this parameter; if it is lower, an error message will be displayed
(see the relevant paragraph).
When the control unit is set to degree control mode (CONTROL MODE=DEG), this parameter fixes a
minimum conduction angle value. For each weld, the TE500 monitors that the maximum welding
current conduction angle supplied by the welder is higher than the value set at this parameter; if it is
lower, an error message will be displayed (see the relevant paragraph).
If the CONTROL MODE parameter is set to NO (no control on the welding current), the parameter is not
displayed during the programming phase.
CURR MAX. / ANGLE MAX. (MAXIMUM CURRENT LIMIT OR CONDUCTION ANGLE)
This parameter expresses different data according to the control mode selected at the CONTROL
MODE parameter:
When the control unit is set to current control mode (CONTROL MODE=CUR), this parameter fixes a
maximum current value. For each weld, the TE500 monitors that the welding current supplied by the
welder is lower than the value set in this parameter; if it is higher, an error message will be displayed
(see the relevant paragraph).
When the control unit is set to degree control mode (CONTROL MODE=DEG), this parameter fixes a
maximum conduction angle value. For each weld, the TE500 monitors that the maximum welding
current conduction angle supplied by the welder is lower than the value set in this parameter; if it is
higher, an error message will be displayed (see the relevant angle).
If the CONTROL MODE parameter is set to NO (no control on the welding current), the parameter is not
displayed during the programming phase.é

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The "Configuration" menu contains those parameters that are used for enabling or disabling a function
of the control unit.
PARAMETER DESCRIPTION VALUE RANGE
START1 PRG Start cycle 1 program 00 - 63
START2 PRG Start cycle 2 program 01 - 63
PRINTER SPOT Welding spots print ALL - GOOD - BAD
STOP BAD SPOT Number of spots for out-of-limit stop 0 - 9
PROG SEQUENCE Program sequence activation ON - OFF
AMMETER CAP. Ammeter capacity 40 - 90 kA
CALIBRATION Self-calibration procedure ON - OFF
LANGUAGE Language for describing parameters ITA-ENG-SPA-DEU-FRE
CONFIGURATION MENU
START CYCLE 1
This parameter indicates the program number to be run when the cycle is activated from the start cycle
1 command. The value of the program also includes 0 which, if set, allows the control unit to work with
the program that is active in the setting.
START CYCLE 2
This parameter indicates the program number to be run when the cycle is activated from the start cycle
2 command.
SPOTS PRINT
With this parameter, if the serial port is setup for print (see "Installation" paragraph), the user can
choose which welding spots to be printed. It is possible to print all spots or only the spots whose
current value remains within the set limits or those with out-of-limits values.
OUT-OF-LIMITS SPOTS STOPPING FUNCTION
Parameter STOP SPOTS permits to program the control unit so that it stops when out-of-limits welding
spots are performed. The set value indicates the number of consecutive "out-of-limits" welding spots
after which the machine stops. The limit error occurs when a welding spot is carried out with values
either higher or lower than the limits set in parameters CURR MIN and CURR MAX. To set the value
use keys aand s ; the value can be set from 0 to 9.
If the value is set to zero, this function is deactivated; in this case, the welder does not stop even in
case of "out-of-limits" welding spots.
PROGRAM SEQUENCE
The sequence type operation is activated with this parameter. If this parameter is set to ON, the menu
for setting the program sequences will appear in the list of the main menus.
CONFIGURATION MENU PARAMETERS TABLE
---CONFIGURATION---
>START CYCLE1 10
START CYCLE2 06
SPOTS PRINT OFF

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AMMETER CAPACITY
This parameter indicates the ammeter capacity of the control unit. Keep in mind that the capacity refers
to simple harmonic currents and as such overflow conditions might occur even with effective current
values lower than the nominal value of the carrying capacity and this depends on the sensitiveness of
the connected transducer.
CALIBRATION
Set this parameter to ON for starting the self-calibration procedure. For further information refer to the
relevant paragraph.
LANGUAGE
With this parameter the user programs the language in which the control unit should display both the
parameters to be set and the error messages.

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The "Stepper" menu contains parameters associated with the current stepper operations.
PARAMETER DESCRIPTION VALUE RANGE
TOTAL STEPS Number of incremental steps 01 - 07
SPOTS 1 Spots step 1 0 - 10000
INCREMENT-1 % Percent increment step 1 0 - 50
SPOTS 2 Spots step 2 0 - 5000
INCREMENT 2 % Percent increment step 2 0 - 50
SPOTS 3 Spots step 3 0 - 5000
INCREMENT 3 % Percent increment step 3 0 - 50
SPOTS 4 Spots step 4 0 - 5000
INCREMENT 4 % Percent increment step 4 0 - 50
SPOTS 5 Spots step 5 0 - 5000
INCREMENT 5 % Percent increment step 5 0 - 50
SPOTS 6 Spots step 6 0 - 5000
INCREMENT 6 % Percent increment step 6 0 - 50
SPOTS 7 Spots step 7 0 - 5000
INCREMENT 7 % Percent increment step 7 0 - 50
STEPPER MENU PARAMETERS TABLE
NUM. OF INCREMENTS
This parameter indicates how many segments are to be created for implementing the stepper curve.
Only the parameters that describe the desired function will be displayed in relation to the set value.
SPOTS 1,2,3,...
Each of these parameters indicates the number of spots of which the associated segment is composed.
INCREMENT 1,2,3,...
These parameters indicate the current stepper percent to be attained upon the completing of the spots
set in the associated segment.
STEPPER MENU
--- STEPPER ---
>NUM. INCREMENTS 01
SPOTS 1 4000
INCREMENT 1 12%

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The stepper function enables to compensate the wear of the electrodes that affects the quality of the
welding spots. When the electrode diameter is enlarged, the contact section area between the
electrode and the workpiece to be welded increases and, as a consequence, the welding current
density (Ampere/mm2) decreases. If the current is maintained at a fixed value throughout the whole
electrode life, it will be noticed that the quality of the last spots is poorer than the first ones. The stepper
function is used for overcoming this problem. It gradually increases the current adjustment during the
welding process when the diameter of the electrodes increases: this enables to maintain a constant
current density.
This function is suitable especially when using the control unit in constant current mode.
Nevertheless, it also works when the control unit operates in percent adjustment mode, but it is
not active in FIX mode.
An increment curve is programmed to describe the pattern of the current during the electrodes' life.
This curve is described by one or more segments for each of which the number of welding spots and
the associated current increment in percent are programmed.
After it has been set, the current increment is applied to all the welding programs used.
The current or conduction angle limits, if used, increment by the same percent. The same holds true for
the pre-weld and post-weld current adjustments.
If the set welding (or power) current values are changed during the process, the control unit takes them
into consideration and re-calculates the welding conditions.
If modifications are made to the programmed stepper curve, the control unit clears the counter and
therefore the starting diameter of the electrodes must be reset.
SIMPLIFIED USE OF THE STEPPER FUNCTION (LINEAR INCREMENT)
The stepper function can be used in a simplified manner by programming a simple percent increment
for a specific number of welding spots that are to be carried out with the same electrodes.
The user must know the service life of the electrodes in order to adjust these parameters. To do this
run some welding tests with new electrodes before they are replaced. Under these two conditions the
currents, required for carrying out the welding spots of the required quality, are assessed. The change
in percent is calculated and then it is set in the control unit.
The parameters that allow the carrying out of the stepper function are entered in the "Stepper" menu.
The instructions for programming these parameters are outlined in the relevant paragraph.
For the "simplified" use of the stepper function, always set parameter STEPS INCREM to 1 (since the
segment to be programmed is only one). Enter the number of welding spots to be carried out in
parameter SPOTS 1, i.e. the foreseen life span of the electrodes. Enter the percent increment to be
achieved in parameter INCREMENT 1.
CURRENT STEPPER FUNCTION

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Example:
After having run the welding tests, the result was that the usable life of the electrodes = 2000 welding
spots. Another fact that ensued was that the required current for new electrodes = 15 kA, whereas after
2000 welding spots the diameter increase of the electrodes requires a current of 19 kA.
Therefore calculate the change in percent as follows:
Consequently the following parameters are set in the "Stepper" menu:
%26100
151519
100% =×
−
=×
−
=rentinitialcur rentinitialcurendcurrent Change
PARAMETER DESCRIPTION VALUE
STEPS INCREM Number of segments for stepper function 1
SPOTS 1 First segment spots number 2000
INCREMENT1 First segment increment percent 26%
The welding program should be adjusted for carrying out the first welding spot followed by the
adjustment that permits to obtain the required current with the starting electrode diameter: 15 kA.
Now the welding process can begin. Current will vary conforming to the set increment rule. The graph
below shows its pattern.
INITIAL CURRENT = 15 kA
END CURRENT = 19 kA
INCREMENT PERCENT = 26 %
NUMBER OF WELDING SPOTS = 2000
CURRENT INCREMENT DURING PRODUCTION
0
2
4
6
8
10
12
14
16
18
20
0 500 1000 1500 2000
NUM BER OF WELDING SPOT S
WELDING CURRENT (k
A
Upon having completed all 2000 welding spots the TE500 stops the production cycle and displays the
following message:
22
------STOP------
MAX. N. of SPOTS
At this point the operator replaces the electrodes (or resets their original diameter) and clears
the spots counter to clear stepper calculations. The TE500 resets the initial work parameters
and begins a new increment phase.

18 /52
In the aforesaid work method, a linear welding current increment is used during the whole life span of
the electrodes. In actual fact the increase of the contact section of the electrode on the sheet is not
linear but has a pattern that is similar to the one shown in the graph below.
COMPLETE USE (NON-LINEAR INCREMENT CURVE)
As such the use of the linear increment is an approximation which nonetheless permits to achieve good
results in most applications. However when the user wishes to achieve utmost constancy during work
conditions, a non-linear increment curve can be set that is described by defining a certain number of
segments.
This type of adjustment requires an adequate knowledge on how electrodes wear and on the
parameters required during their life. Consequently many welding spot tests are necessary for
assessing the work conditions in different moments of the electrodes' life.
The increment curve is set by assessing a certain number of linear segments. The number of welding
spots and the desired increment are assessed for each segment.
The STEPS INCREM parameter determines the number of segments to be inserted in the increment
curve. Enter the number of welding spots that make up the segment in the “SPOTS n” parameters.
Enter the corresponding percent increment to be achieved in the “INCREMENT n” parameter.
The programming procedure is outlined in the "Stepper" menu paragraph.
IDEAL PATTERN
REAL PATTERN
WITH SET INCREMENT
CURVE
CURRENT
NUMBER OF WELDING SPOTS
IDEL PATTERN
REAL PATTERN
WITH LINEAR INCREMENT
CURRENT
NUMBER OF WELDING SPOTS

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SPOTS PERFORMED REQUIRED CURRENT
0 (initial electrode diameter) 15 kA
700 17.8 kA
1800 19.5 kA
3000 20.2 kA
4000 (final electrode diameter) 20.7 kA
The following parameters are consequently set in the "Stepper" menu:
Example:
After a number of welding tests, the ensuing life of the electrodes resulted to be 4000 welding spots and
the following current values are required during the different moments of the electrodes' life.
Therefore calculate the duration (in number of welding spots) and the percent increment of each
segment.
Keep in mind that the percent increment must always be calculated in relation to the beginning of the
segment being examined.
spots700=0-700=1segmentofDuration
spots1100=700-1800=2segmentofDuration
spots1200=1800-3000=3segmentofDuration
spots1000=3000-4000=4segmentofDuration
%19100
15 158.17
1001% =×
−
=×
−
=rentinitialcur rentinitialcurendcurrent segmentChange
%10100
8.17 8.175.19
1002% =×
−
=×
−
=rentinitialcur rentinitialcurendcurrent segmentChange
%4100
5.19 5.192.20
1003% =×
−
=×
−
=rentinitialcur rentinitialcurendcurrent segmentChange
%3100
2.20 2.208.20
1004% =×
−
=×
−
=rentinitialcur rentinitialcurenecurrent segmentChange
PARAMETER DESCRIPTION VALUE
TOTAL STEPS Number of segments per stepper function 4
SPOTS 1 Number of spots of the first segment 700
INCREMENT1 Increment percent of first segment 19%
SPOTS 2 Number of spots of the second segment 1100
INCREMENT2 Increment percent of second segment 10%
SPOTS 3 Number of spots of the third segment 1200
INCREMENT3 Increment percent of third segment 4%
SPOTS 4 Number of spots of the fourth segment 1000
INCREMENT4 Increment percent of fourth segment 3%

20 /52
The welding program should be adjusted for carrying out the first welding spot followed by the
adjustment that allows the achieving of the required current with the starting diameter of the electrodes:
15 kA.
Now the welding process can begin. Current will change according to the programmed increment rule.
The graph below shows its pattern.
CURRENT (kA
)
NUMBER OF WELDING SPOTS
SEGMENT 1
SEGMENT 2
SEGMENT 3 SEGMENT 4
40003000200010000
15
14
13
16
17
18
19
20
21
22
17.8 kA
19.5 kA 20.2 kA20.7 kA
700
1800 3000