Lincoln Electric IDEALARC SP-255 Operator's Manual page 15

are held closed. The left pair will automatically contin-
ue to increment or decrement the selection above it at
a slow, steady rate as long as the key is pressed. The
center and right pairs will continue to increment and
decrement the selections above them at a slow rate,
but then the rate will gradually increase until it
becomes very rapid. This allows rapid setting from a
small quantity to a large quantity or vice versa while
maintaining an excellent resolution (i.e., 50 IPM to 600
IPM). However, when the trigger is closed, the
changes will be at a steady, moderate rate to allow for
proper "on the fly" control.
START MODE SELECTIONS
The SP-255 permits selection of Fast/Slow Run-In
wire feed speed as well as adjustment of the start
striking voltage, to optimize arc starting, using the
starting screen display.
The starting screen (see Figures below) is
displayed by pressing and holding both the
PROCESS key and the TIMERS OFF key at
the same time.
FIGURE 1
1. Run-In Speed
The SP-255 is factory set for FAST run-in
(Figure 1) where the wire feed will accelerate
directly to the preset speed. SLOW run-in will
initially feed at 50 IPM until welding current is
sensed, or for 2 seconds if feeding without
welding (loading wire).
SLOW run-in may be selected using the left
arrow keys which will toggle the starting screen
display to SLOW (Figure 2) or back to FAST
(Figure 1).
FIGURE 2
2. Start Voltage
The START voltage setting (Figure 1 or 2) may
be offset from the factory programmed level
(00%) by up to ±30% above or below pro-
grammed level using the right arrow keys, or
from the gun thumbswitch by positioning the
screen cursor beneath the START display using
the IPM-VOLTS key. (see "Gun Switch Keys" in
this section).
OPERATION
3. Spool Gun Start Mode
If using optional spool gun mode (see "Making
a Weld with the Spool Gun" in Accessories sec-
tion), the RUN-IN portion of the starting screen
is not functional and will not be displayed. The
START voltage is adjusted as described above
(Figure 3).
The starting screen is exited by pressing any
key on the keypad except TIMERS OFF, IPM-
VOLTS or any Arrow key. Closing Gun Trigger
will also not clear the starting screen.
NOTE: It is not necessary to repeat the above
procedure each time the unit is powered up.
That is, the unit will remember the start mode
settings from the previous power down and
return you to that same state upon your next
power up. thus, you need only perform the
above procedure when you want to change the
start mode settings.
When saving to Memory locations 1-5, the start
mode at the time of saving will be saved into
the memory location as well. Thus, the operator
should be aware that when recalling a memo-
rized procedure, he is also recalling particular
start mode which will override any present start
mode setting and remain in effect until either
the mode is changed using the above proce-
dure or until a memorized procedure containing
another start mode is recalled.
PROCESS (WIRE/GAS) KEY
This key is used to display the Wire Type, Wire
Diameter, and Welding Gas. Each combination of wire
and gas dictates a unique relationship between the
wire feed speed and the arc voltage. The SP-255
uses this unique relationship, along with the metal
thickness, to set the proper values of wire feed speed
and arc voltage. Therefore, it is very important that
the wire type, wire diameter, and welding gas on
the display match the actual wire type, wire diame-
ter, and welding gas being used for the weld.
Left arrow keys—set Wire Type
FIGURE 3
JAN96 IDEALARC SP-255
B-3