Lincoln Electric IM983 RED-D-ARC DC655e (CE) - Manual (Page 22)

B-7 OPERATION B-7
CV MODE CURRENT-LIMITING
CV MIG and CV Sub-Arc modes employ electronic
current limiting to limit excessive short circuit output
current which can result in undesirable arc character-
istics or nuisance over current protection shutdown
(see Machine Protection section).
As shipped, the DC655e (CE) is set for “Hi” current
limiting, which maintains constant voltage until the
welding current exceeds a level proportional to the
voltage setting, then falls off linearly at about 10 volts
per 100 amps to a limited short circuit current. “Lo”
current limiting provides the same short circuit current,
but the arc voltage begins to linearly fall off at lower
current, at about 5 volts per 100 amps.
“Hi” is recommended for all CV processes, especially
for CV subarc and CV arc gouging, but “Lo” tends to
“soften” the arc more when welding NR203Ni 1% on
the Low Inductance (-) terminal. If “Lo” is desired,
switch #4(right-most) of the DIP switch located on the
lower-center of the DC655e (CE) Control PC board
needs to be switched from up (Hi) position to down
(Lo) position.
CC MODE ARC FORCE
Arc Force provides extra weld current which linearly
increases as the welding voltage decreases below a
level determined by the constant current setting. The
Arc Force control knob, located behind the latched
cover, adjust Arc Force from “Min” (no current
increase) to “Max” (about 9A/V increase).
A general guideline for CC welding is to set Arc Force
to “Mid” position (#5) and increase (typically no more
than to #7) as necessary to prevent “stubbing” or
“pop-outs” while welding. This higher Arc Force is rec-
commended espicially for low end 6010 stick welding.
CC MODE HOT START
Hot start is built-in for CC mode stick and carbon arc
starting. Hot Start provides an extra weld current
“boost” at the arc strike which increases with higher
current settings. This Hot Start level exponentially
decays to the weld current setting in a few seconds.
Adjustment of the Hot Start shouldn’t be necessary,
but an unsealed trimmer (R81) is provided on the
DC655e (CE) Control PC Board to adjust hot start.
Full counter-clockwise adjustment will reduce Hot
Start to zero.
CC MODE ARC GOUGING
The DC655e (CE) is rated for air carbon arc gouging
with up to 3/8” (10mm) diameter carbons. CC mode
gouging is often preferred over CV mode for cutting
control, but some Arc Force may be required to avoid
carbon stubbing.
DC655e (CE) (RED-D-ARC)
VOLTS
AMPS
CV OUTPUT
"HI" Current Limit
"Lo" Current Limit
High
Setting
Low
Setting
VOLTS
AMPS
CC OUTPUT
Min. Arc Force
Hot Start
OCV
Low
Setting
Hi
Setting
Max. Arc Force
1 2 3 4
Switch #4 "Hi"CV Current
Limit (as shown)
Switch #3 is for test
purposes and is to
be down
DIP Switch
See Machine Shutdown section
for use of switch #1 and #2. Note:
CC Hot Start
Trimmer
DC655e Control PC Board