CHIEF MultiMig 621 Manuel D'instructions page 7

7- Pof (post-gas).
The adjustment may range from 0 to 30 seconds.
8- Acc (soft-start ).
The adjustment may range from 0 to 100%.
It is the wire speed, expressed as a percentage of the
speed set for the welding, before the wire touches the
workpiece.
This adjustment is important in order to always achieve
good starts.
Manufacturer setting «Au»: automatic.
The value can be changed using the knob AN. If, once
changed, you wish to return to the original settings,
press the key AV until the abbreviation «Au» reappears on
the display AM.
9- BB (Burn-back).
The adjustment may range from 4 to 250ms. Serves to
adjust the length of the wire leaving the contact tip after
welding. The higher the number, the more the wire burns.
Manufacturer setting «Au» automatic.
If, once changed, you wish to return to the original settings,
press the key AV until the abbreviation «Au» reappears on
the display N.
10- L (impedance).
The adjustment may range from -9.9 to +9,9. Zero is the
number set by the manufacturer:if the number is negative,
the impedance decreases and the arc becomes harder; if
increased, it becomes softer.
11- dP ( Double pulse)
This type of welding varies the current intensity between
two levels and may be included in all synergic processes.
Before setting, it is necessary to make a short bead to
determine the speed closest to the type of welding that
you will be doing. This determines the reference speed.
To activate the function proceed as follows:
A)- Activate the function by turning knob AN until the
abbreviation On reappears on the display AM.
B)- Turn knob AI fino uni tl the abbreviation FdP reappears
(double pulse frequency) on the display AL. The display
AM reads the abbreviation OFF.
Turn the knobAN to select the working frequency
(adjustment from 0.5 to 5 Hz). The selected value is shown
on the display AM.
C) Turn knobAI until the abbreviation ddP (difference in
m/min of the double pulse) is displayed.
Turn the knob AN to select the meters per minute (range
from 0.1 to 3m/min) that will be added to and subtracted
from the reference speed (default 1m/min).
D)Turn the knob AI until the display shows the the
abbreviation tfP. This is the duration of the highest wire
speed, thus the highest current. It is expressed as a
percentage of the time gained from the Fdp frequency
(see figure 3).
Turn knob AN to adjust the percentage. Range between
25 and 75% (default 50%).
E)-Turn knobAI unitl the display shows the abbreviationAdP
(arc length of the highest current). Range between -9.9
and 9.9% (default 0).
When welding, check that the arc length is the same for
both currents; turn the AN knob to correct it if necessary.
Note: it is possible to weld within the double pulse
functions.
DdP= 0,1÷3 m/min
tdP = 25÷75% di
T = 1/ Fdp (0,5÷5 Hz)
Once these adjustments have been made, to return to the
control panel normal display briefly press key AE.
Should it be necessary to adjust the arc length of the
lowest current/lowest speed, adjust the arc length of
the reference speed. When the reference speed moves,
the previous settings must also be repeated for the new
speed.
12- PP (push-pull).
By using Push-Pull torch function PPF (Push Pull Force)
is enabled which adjusts the drive torque of the push-pull
motor in order to make the wire feed linear. The adjustment
may range from 99 to -99 and is done through knob AN..
Standard adjustment is 0.
13- Ito. (Inching time out).
The purpose is to stop the welding machine if the wire
flows after starting with no passage of current.
The wire flow from the welding torch can be adjusted
from 5 to 50 centimeters by means of knob AN. When
this function is restored, it may be activated (On) or cut
off (Off).
14- Fac. (factory).
The purpose is to return the welding machine to the
original settings provided by the manufacturer. With the
function selected, the display AM shows noP = restores
the welding machine to the original settings disregarding
the stored programs, Prg = deletes all stored programs
and ALL = restores the welding machine to the original
settings.
To save the desired function press the button AV, the
abbreviation shown on the display AM will begin flashing;
after a few seconds, a sound will confirm that it has been
saved.
6 INSTALLATION
The welding machine must be installed by skilled
personnel. All connections must be made in full
compliance with current safety laws.
Reference
speed
T
Fig. 3
7