B-3
OPERATION
B-3
c. Be sure the wire feeder is properly set for
constant or variable voltage as appropri-
ate.
2. ML-2, ML-3, MN-1, LN-4, LN-5 and LN-6
Wire Feeders
This power source can be used with these
obsolete wire feeders. Write to the factory
for specific connections.
3. Other Wire Feeders
This power source can be used with wire
feeders manufactured by other companies.
The connection must be determined by the
customer for the specific equipment being
used.
Auxiliary power available for wire feeder
operation is described under “Auxiliary
Power” in this section of the manual. To
operate the SAM contactor, connect the
appropriate wire feeder control circuit to
close the circuit from #2 to #4 on the SAM
terminal strip.
TOGGLE SWITCH
This switch is located on the front of the control panel
at the top of the nameplate. Set the switch to “Variable
Voltage” or “Constant Voltage” as appropriate for the
welding process to be used. See Control Panel operat-
ing illustrations in this section of the manual.
CONTACTOR
The output contactor is automatically in the welding cir-
cuit when the machine is properly connected to a
Lincoln® wire feeder through the “Connect to Auto.
Equipment” stud. It closes only when the wire feeder is
welding. The contactor is not in the welding circuit
when using the ‘Stick’ stud.
ELECTRODE POLARITY SWITCH
Select electrode negative (straight) or electrode posi-
tive (reverse) polarity as needed. On the SAM-400,
this switch must also be set for either constant or vari-
able voltage welding as appropriate.
DO NOT SWITCH WHILE WELDING.
CURRENT AND VOLTAGE CONTROLS
Constant Voltage Welding
The SAM-400 “Current Control” is NOT in the circuit
when the ‘Electrode Polarity’ switch is set for constant
voltage welding.
Set the open circuit voltage (OCV) needed for the par-
ticular application with the “Constant Voltage Control”
located to the left of the nameplate. Adjust the final
welding voltage with either the wire feeder voltage con-
trol or the “Portable Field Control”. Set the welding cur-
rent with “Amps” or “Wire Feed Speed” control on the
wire feeder.
Low Range Feature (SAM400 K1279-1 only) --
Extends the output voltage range of the SAM400
welder down to 12 volts for constant voltage welding.
The maximum output current is not to exceed the rat-
ing of the machine. The Low Range Feature provides
a two-position manual switch which allows the operator
to set his machine for normal welding or for low voltage
welding. Factory installed only.
On the SAM650 connect the “Tap” lead inside the
machine to the appropriate “Innershield” stud for”Min.
(Flat) Slope.” “Med. Slope” or “Max. Slope”. Low voltage
(below 20 volts) low current welding often requires
“Max. Slope” to adjust the weld metal droplet size for
minimum spatter and to control puddle fluidity and
bead shape. Innershield and other spray transfer type
processes generally operate with “Med. Slope”.
A Hot Start circuit on all models operates automatical-
ly whenever the toggle switch is set on “Constant
Voltage.” It increases the open circuit voltage by sev-
eral volts until the arc is established -- then the voltage
automatically drops to normal welding voltage. When
the wire feeder is started before the arc is started, the
voltmeter indicates a voltage several volts higher than
welding voltage. To read actual welding voltage, the
arc must be established.
Constant Voltage Welding With Variable Inductance
Control: SAM-400 Only.
Variable inductance or slope control is usually desir-
able for low voltage (below 20 volts) applications and is
sometimes useful in other constant voltage jobs.
To introduce this control into the circuit, set the
“Electrode Polarity” switch to “Variable Voltage” and the
toggle switch to “Constant Voltage”. Then the “Current
Control” acts as the variable inductance control.
Normally this control must be kept within the 8 to 1
o’clock range.
SAM400 & 650
CAUTION
