Operating Steps, Starting the Welder | Lincoln Electric SVM 117-A

B-7	OPERATION	B-7
	OPERATION

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SETTING IDLE ROLL PRESSURE

The idle roll pressure wing screw is set at the factory backed out 2-1/2 turns from full pressure. This is an approximate setting. The optimum idle roll pressure varies with type of wire, wire diameter, surface condi- tions, lubrication, and hardness. As a general rule, hard wires may require greater pressure, and soft, or aluminum wire, may require less pressure than the fac- tory setting. The optimum idle roll setting can be deter- mined as follows:

1.Push the end of gun against a solid object that is electrically isolated from the welder output.

2.Press the gun trigger for several seconds.

a.If the wire "birdnests", jams, or breaks at the drive roll, the idle roll pressure is too great. Back the wing screw out 1/2 turn, run new wire through gun, and repeat steps 1 and 2.

b.If the drive roll slips, loosen the wing screw on the conductor block and pull the gun cable for- ward about 6" (15 cm). There should be a slight waviness in the exposed wire. If there is no waviness, the pressure is too low. Tighten the wing screw 1/4 turn, reinstall the gun cable, and repeat steps 1 and 2.

OPERATING STEPS

WARNING

Before operating the machine, be sure you have all the materials needed to perform the work. Be sure you are familiar with and have taken all possible safety precautions before starting the work. It is important that you follow these operating steps each time you use the machine.

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STARTING THE WELDER

1.Turn the POWER switch to ON. This illuminates the red LED pilot light.

2.Select the correct voltage and wire speed for the welding process required.

3.Operate the gun trigger for welder output and to energize the wire feeder motor.

NOTE: When the POWER SWITCH is ON, the fan motor is thermostatically controlled to provide cooling for the transformer and other components only when the machine needs cooling. When the machine does not require fan cooling the fan does not run, such as when first turned on, when welding at low current, or at low duty cycle procedures.

CHANGING RUN-IN MODE (Later models only)

The WIRE-MATIC 250 is factory set for slow run-in mode. This means the machine will initially feed wire at 50 IPM until output current is sensed or for 2.0 sec- onds, whichever occurs first. After which it will accel- erate to the preset wire feed speed.

In the Fast run-in mode, the machine will accelerate directly to the preset wire feed speed.

ENTER FAST RUN-IN MODE

1.Turn POWER SWITCH to OFF on front panel of WIRE-MATIC 250.

2.Turn the WIRE SPEED CONTROL POTEN- TIOMETER KNOB fully clockwise to maximum.

3.Close the gun trigger switch and turn the POWER SWITCH to ON.

a.The gas solenoid will actuate four times to sig- nal that the unit has entered the fast run-in mode. The gun trigger need only be closed until the first gas solenoid actuation is heard.

NOTE: Arc starting characteristics may be effected when using the fast run-in mode since normal starting processes are being overridden.

ENTER SLOW RUN-IN MODE

1.Turn POWER SWITCH to OFF on front panel of WIRE-MATIC 250.

2.Turn the WIRE SPEED CONTROL POTEN- TIOMETER KNOB fully counterclockwise to mini- mum.

3.Close the gun trigger and turn the POWER SWITCH to ON.

a.The gas solenoid will actuate two times to sig- nal that the unit has entered the slow run-in mode. The gun trigger need only be closed until the first gas solenoid actuation is heard.

OPERATION