Fimer TT255 AC/DC Manuel D'emploi page 39

ADJUSTMENTS AND SETTINGS:
Button 9 controls the current and the machine
power.
Button 10 adjusts the welding settings on the
screen:
2t-4t-4bilevel: Used to set the operating mode to 2
times or 4 times.
2t: In 2t operating mode pressing the button caus-
es the protective gas to be released; when the
electrode is raised from the piece the electric arc is
struck, with the initial current and/or ramp-up,
which remains on for the entire time the button is
held down. When the button is released the
machine starts the ramp-down of the current
and/or the final current, if set.
4t: In the 4t operating mode, when the button is
pressed for the first time the protective gas is
released, then when the electrode is raised from
the piece the electric arc is struck.
The current delivered corresponds to the initial cur-
rent parameter as long as the button is not
released, then the machine performs the ramp-up
if set. The next time the button is pressed the
machine performs the ramp-down of the current, if
set, and the final current (until the button is
released), and then the post gas phase. If the but-
ton is released immediately the machine performs
the ramp-down of the current (if set) and then the
post gas phase.
4bi: This operation is similar to the 4t mode with
the only difference that pressing the torch button
for short periods (< 1s) during welding (after the ini-
tial ramp) cause the passage of the current from
the first level I1 to the second level I2; holding the
button down (> 1s) causes the start of the end of
the weld (ramp-down and/or final current if set).
2nd level current: If the value 4bi of the 2t-4t-
4bilevel parameter is selected this makes it possi-
ble to set the 2nd level current as a percentage of
the welding current.
Start current: Used to set the value to which the
welding current is raised immediately after the
electric arc has been struck.
Start time: Used to set the time for which the cur-
rent determined by the initial current parameter is
applied.
In 4t/4bi mode (if the spot weld parameter is equal
to 0) this time has no effect and the initial current is
maintained as long as the torch button is held
down.
Slope up: Used to set the duration of the ramp-up
of the welding current.
Slope down: Used to set the duration of the ramp-
down of the welding current.
End current: Used to set the value which the
welding current reaches at the end of the ramp-
down.
End time: Used to set the time for which the cur-
rent determined by the final current parameter is
applied.
In 4t/4bi mode this time has no effect and the initial
current is maintained as long as the torch button is
held down.
Post gas time: Used to set the time of gas deliv-
ery after the welding current has stopped.
Pulse mode: Used to activate (Hz) or deactivate
(OFF) the pulse welding mode; with the pulse
welding mode active (Hz) the machine delivers the
welding current for a certain time and the current
determined by the base current parameter for
another period of time. The number of current
impulses per unit time is given by the value of the
frequency parameter.
The pulsation is activated only during the welding
phase and not during the initial/final current phas-
es or during the ramps.
Background current: Used to set the base cur-
rent used during generation of the pulses.
Pulse frequency: Used to set the number of cur-
rent impulses per unit time when the pulse welding
mode is active.
Pulse balance: This represents the percentage of
time for which the welding current is applied when
the pulse welding mode is active.
Water pump: Used to switch on (ON) or switch off
(OFF) the water pump unit if present.
Remote: Used to switch on (ON) or switch off
(OFF) the remote control of the intensity of the cur-
rent delivered.
Min current: Used to set the minimum output cur-
rent when the remote control is at the minimum
adjustment value.
Spot welding: Used to set (if other than 0) the
maximum duration of the weld.
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