Multiple Arc System Considerations; Basic Modes Of Operation (Cc / Cv - Lincoln Electric POWER Wave AC/DC 1000 Operator's Manual

B-8
MULTIPLE ARC SYSTEM
CONSIDERATIONS
Large scale SAW applications often employ multiple
arcs to increase deposition rates. In multiple arc sys-
tems, magnetic forces created by like and opposing
weld currents of adjacent arcs can result in arc inter-
action that can physically push or pull the arc columns
together. To counteract this effect, the phase relation-
ship between adjacent arcs can be adjusted to alter-
nate and equalize the duration of magnetic push and
pull forces. This is accomplished by the use of an
optional K2282-1 Power Wave System Interface,
which not only synchronizes the arcs, but also
enables adjustment of the phase relationship between
them. Ideally, the net result is a cancellation of the
interacting forces.
FIGURE B.2
- - -
+ + +
- - + + +
PUSH PUSH PUSH
FIGURE B.3
CAUTION
Never simultaneously touch electrically "hot"
parts in the electrode circuits of two different
welders. The electrode to electrode no load volt-
age of multiple arc systems with opposite polari-
ties can be double the no load voltage of each arc.
Consult the Safety information located at the front
of the Instruction Manual for additional informa-
tion.
------------------------------------------------------------------------
OPERATION
+ + + + + + + + + +
- - - - - - - - -
PULL PULL PULL
Lead Arc Lead Arc
Trail Arc Trail Arc
POWER WAVE® AC/DC 1000
BASIC MODES OF OPERATION
CONSTANT CURRENT (CC)
• Operator presets Current and desired Voltage.
• The Power Source:
- Goal is to maintain a constant arc length.
- Drives a constant Current.
- Synergically Controls WFS to Maintain Voltage
at the desired Set point.
• Arc Length is proportional to Voltage.
• Traditionally used for larger diameter wires and
slower travel speeds.
CONSTANT CURRENT (CC)
AMPS
CURRENT HELD
CONSTANT
WIRE FEED
SPEED VARIED
MAINTAIN CONSTANT
ARC LENGTH
CONSTANT VOLTAGE (CV)
• Operator presets Wire Feed Speed and desired
Voltage
• The Power Source:
- Goal is to maintain a constant arc length.
- Commands constant wire feed speed
- Synergically Controls Current to Maintain
Voltage at the desired Set point
• Arc Length is proportional to Voltage
• Traditionally used for smaller diameter wires and
faster travel speeds.
CONSTANT VOLTAGE (CV)
AMPS
CURRENT VARIED
WIRE FEED SPEED
HELD CONSTANT
MAINTAIN CONSTANT
ARC LENGTH
B-8
AND
Extension
Heating= Vir
Total Electrical
Stick out
TO
V= Vir+Varc
Arc Length= Varc
AND
Extension
Heating= Vir
Total Electrical
Stick out
TO
V= Vir+Varc
Arc Length= Varc