Lincoln Electric SAM400, SAM650 manual Toggle Switch, Contactor, Electrode Polarity Switch

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.

CAUTION

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