Lincoln Electric IDEALARC DC-1500 Service Manual page 15

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To Set for Machine or Remote Control
The output can be controlled either at the wire feeder or the
DC-1500. When the NL Option Kit is installed, however, out-
put is controlled only from the K775 Remote Con-trol usually
mounted at the wire feeder.
To adjust the output from the wire feeder, set the toggle
switch on the front of the DC-1500 to "Output Control
Remote". To adjust the output using the DC-1500 "Output
Control" rheostat, set this switch to "Output Control at DC-
1500".
To Set the Welder Output
With the toggle switch set to "Output Control at DC-1500",
rotating the "Output Control" rheostat on the DC-1500 from
1 to 10 increases the machine output from minimum to max-
imum. The same full range control is set from the wire feed-
er or K775 when the toggle switch is set to "Output Control
Remote".
Set the output as required by the welding procedures.
Mode Switch
The toggle switch labeled CV Innershield, CV submerged
arc, VV submerged arc, is used to select the proper welder
characteristics for the process being used.
NOTE: Some machines say "VV" for variable voltage while
other machines use the terminology "CC" for constant cur-
rent.
The CV Innershield Mode permits the DC-1500 to produce
essentially a flat output characteristic that can be varied from
approximately 20 to 60 volts. In this position the dy-namic
characteristics of the machine under welding con-ditions pro-
vides optimum welding characteristics for Innershield weld-
ing and other open arc processes.
The CV Submerged Arc Mode also produces an essentially
flat output characteristics that can be varied from approxi-
mately 20 to 60 volts. The dynamic characteristics of the CV
Submerged Arc Mode are such that excellent submerged arc
welding can be obtained for most procedures that previously
required a constant current type power source.
The VV Submerged Arc Mode permits the DC-1500 to pro-
duce a constant current output characteristic through the
range of 200A-28V to 1500A-60V with an open circuit voltage
of 45 to 98 volts. Although almost all submerged arc welding
can now be done in the CV mode, the VV mode
able for those procedures where VV (CC) may still be desir-
able.
Set-up for Various Processes
Selection of mode switch position — There are several gen-
eral rules to follow in the selection of the mode switch posi-
tion.
1. Use the CV Innershield mode for all Innershield weld-ing.
2. Use the CV Submerged Arc mode for most submerged
arc welding. However, some high speed welding pro-
cedures may perform better on the CV Innershield mode.
OPERATION
3. The VV (CC) mode is available for high current, large
puddle submerged arc procedures that cannot be done
as well with the constant voltage mode.
4. Air Carbon Arc Gouging or Cutting — For air carbon arc
gouging, the constant voltage Innershield mode is used
with the output control set between 4 and max. depend-
ing on the application, carbon size, etc. Up to
start with the machine control set at 4 and increase as
required for long cable lengths. With
short (100') cable lengths can lead to occasional tripout of
the protection circuit when the carbon is shorted to the
work. Cutting back the output setting will reduce the short
circuit current and minimize tripping. Longer cable lengths
do an even better job since this also reduces the short cir-
cuit current but even more significantly permits raising the
open circuit voltage (by increasing control setting) for
smoother operation. See the table below for optimum
cable size and length.
Carbon Typical
Size Current Range
1 / 600-1000 Amps
2
5 / 800-1200 Amps
8
If ever longer leads are used and the output control is
already set on max., the unit has reached its maximum air
carbon arc capability.
3 / " carbons are not recommended for use with the
4
1500 because the high surge currents that occur with this
diameter can cause the DC-1500 fault protection circuitry
to trip the machine off the line, if the operator does not
gouge in such a way to limit the currents.
General Set-Up Procedures When Using DC-1500 and
Lincoln Automatic Head NA-3
(Read the following and refer also to the chart on page 9.)
1. NA-3 — The NA-3 should be set for the mode being used
on the power source. If using either of the CV modes, the
NA-3 VV board switch should be set for CV. If the power
source is used in the VV mode, then the NA-3 VV board
mode switch should be placed in the VV position.
All NA-3's when used with the DC-1500 are capable of
cold starting with the variable voltage board mode switch
in VV. Cold starting permits the wire to be inches down to
the work, automatically stop and automatically energize
the flux hopper valve. All NA-3's made after September
1976, are capable of cold starting on either CV or VV set-
is avail-
tings of the variable voltage board switch.
IDEALARC® DC-1500
1 / " carbons,
2
1 / " and 5 / " carbons,
2 8
Combined Total
Electrode and
Electrode
Work Lead Length
and Work
(Min) (Max) Lead Size
250' 825' 2 — 4/0
375' 925' 3 — 4/0
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DC-