Hot start (MMA electrode)
Hot start is a function which helps to establish the arc
at the start of MMA electrode welding. When the
electrode touches the workpiece the start current is
increased by a pre-set percentage of the welding current
and for a period of 0.5 seconds.
Current
0.5 sec.
Adjusted
current
Welding
start
This percentage can be set from 0 to 100% (but cannot
exceed the maximum output of the machine), and after
the initial surge the current falls to the welding current.
When established as an automated parameter the value
is set at 25%.
Gas pre-flow time (MIG/MAG)
Gas pre-flow time is the time for which shielding
gas flows before an arc is established and this in
order to ensure that the arc is fully protected from atmos-
pere. In MIG/MAG welding the pre-flow time is the time
from activating the torch trigger until the wire feed starts.
The pre-flow time can be set to between 0 and 10
seconds, and when set as an automated parameter the
value is 0.2 seconds. Soft start can be disconnected by
setting the gas pre-flow time to 0.0 seconds.
Slope-down (MIG/MAG)
The slope-down period is the time between the
end of welding and when the arc is finally
extinguished, and is initiated when the torch trigger is
activated as the weld is completed.
In MIG/MAG synergic welding the current reduces from
the welding current to the lowest current in the synergic
program. When the current is automatically reduced to
the lower current condition, the other synergic para-
meters controlled by current are also changed in
relation to the current. If welding with 4-times trigger
control then welding at the lower current continues for
as long as the trigger is held. The slope-down period
can be pre-set to between 0 and 99.9 seconds and
when set as an automated parameter has a value of 0
seconds.
Burn back (MIG/MAG)
The burn back function of the machine prevents
the welding wire sticking to the workpiece at the
end of a weld. Burn back time is the period after current
slope-down and wire feed have stopped and before the
arc is extinguished. Burn back time can be adjusted
between 0.05 and 0.5 seconds and when set for an
automated parameter the value is calculated during
welding.
Gas post-flow time (MIG/MAG)
Gas post-flow time is the time for which shielding
gas continues to flow after the arc is ex-
tinguished. The time can be set between 0 and
60 seconds and has a value of 3 seconds if set as an
automated parameter.
Extra contribute
from hot-start
Time
Pulse welding
If the pulse time is set at 0.0 ms the pulse
welding mode is switched off and all other pulse para-
meters are unavailable. All other values of pulse time
make pulse welding and its parameters available.
The following diagram illustrates the various pulse
welding parameters.
Current
Pulse time
Pulse
current
Base
ms
current
The pulse time within a pulse period is that time for which
welding takes place at the higher (pulse) current. For the
rest of the pulse period welding is at the set base current
(MMA electrode) or the base voltage (MIG/MAG).
Base current (MMA electrode)
Base current is set as a value between 0 and
100% of the adjusted current (= pulse current).
Pulse frequency
(MMA electrode, MIG/MAG)
The pulse frequency identifies the number
of pulses per second and can be adjusted between 1
and 999 Hz depending on the pulse time.
The controls over pulse frequency and pulse time are
such that it is not possible to set a pulse period which is
shorter than the pulse time. The pulse period is
calculated by dividing one second by the pulse
frequency.
Pulse time
(MMA electrode, manual MIG/MAG)
Pulse time can be set within 0.1 and 99.9 ms - depending
on the pulse frequency setting. The pulse time cannot be
set to a value longer than the pulse period.
ADDITIONAL FUNCTIONS
Connection and disconnection of the
Robot Interface
If the machine is fitted with a Robot Interface
then some parameters and functions will be able to be
controlled from this unit. The Robot Interface can be
introduced to the system by pressing at the same time
the AUTO key pad and the key pad above the left hand
display window. The displays then show
Control from the Robot Interface can be disconnected by
pressing at the same time the AUTO key pad and the key
pad under the left hand display window. The displays
then show
. Full information on the Robot Inter-
face is contained in the separate operating manual.
Display of wire consumption (MIG/MAG)
The machine calculates how much wire has been used
since the last zero position and displays this information if
both key pads are pressed at the same time. Wire
consumption is measured in metres.
20
1/Pulse frequency = Pulse period
Time
.