Lincoln Electric SVM157-A Feeding Wire Electrode Making a Weld, Idle Roll Pressure Setting

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B-5		OPERATION			B-5
FEEDING WIRE ELECTRODE			MAKING A WELD
	WARNING		1. Check that the electrode polarity is correct for the
				process being used, then turn the power switch
When triggering, the electrode and drive mecha-
				ON.
nism are electrically “hot” relative to work and
ground and remain “hot” several seconds after the			2. Set desired arc voltage tap and wire speed for the
gun trigger is released.				particular electrode wire, material type and thick-
				ness, and gas (for GMAW) being used. Use the
NOTE: Check that drive rolls, guide plates and gun				Application Chart on the door inside the wire com-
parts are proper for the wire size and type being used.				partment as a quick reference for some common
Refer to Table C.1 in Accessories section.				welding procedures.
1. Turn the Readi-Reel or spool until the free end of the			3. Press the trigger to feed the wire electrode through
	electrode is accessible.			the gun and cable and then cut the electrode within
				approximately 3/8" (10 mm) of the end of the con-
2. While securely holding the electrode, cut off the bent				tact tip [3/4" (20 mm) Outershield® ].
	end and straighten the first six inches. (If the elec-		4. If welding gas is to be used, turn on the gas supply
	trode is not properly straightened, it may not feed
	properly through the wire drive system).			and set the required flow rate (typically 25-35 CFH;
				12-16 liters/min).
3. Release the pressure on the idle roll by swinging the			5. When using Innershield electrode, the gas nozzle
	adjustable pressure arm down toward the back of
	the machine. Lift the cast idle roll assembly and			may be removed from the insulation on the end of
	allow it to sit in an upright position. Leave the outer			the gun and replaced with the gasless nozzle. This
	wire guide plate installed. Manually feed the wire			will give improved visibility and eliminate the possi-
	through the incoming guide bushing and through the			bility of the gas nozzle overheating.
	guide plates (over the drive roll groove). Push a suf-		6. Connect work cable to metal to be welded. Work
	ficient wire length to assure that the wire has fed into
	the gun and cable assembly without restriction.			clamp must make good electrical contact to the
	Reposition the adjustable pressure arm to its origi-			work. The work must also be grounded as stated in
	nal position to apply pressure to the wire.			“Arc Welding Safety Precautions”.
4. Press gun trigger to feed the electrode wire through				WARNING
	the gun.
			When using an open arc process, it is necessary
IDLE ROLL PRESSURE SETTING
			to use correct eye, head, and body protection.

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The optimum idle roll pressure varies with type of wire, wire diameter, surface conditions, lubrication, and hardness. As a general rule, hard wires may require greater pressure, and soft, or aluminum wire, may require less pressure than the factory setting. The opti- mum idle roll setting can be determined as follows:

1.Press end of gun against a solid object that is elec- trically isolated from the welder output and press the gun trigger for several seconds.

2.If the wire “birdnests”, jams or breaks at the drive roll, the idle roll pressure is too great. Back the adjustment knob out 1/2 turn, run new wire through gun, and repeat above steps.

3.If the only result was drive roll slippage, loosen the adjustment knob on the conductor plate and pull the gun cable forward about 6" (15 cm). There should be a slight waviness in the expose wire. If there is not waviness, the pressure is too low. Tighten the adjustment knob 1/4 turn, reinstall the gun cable and repeat the above steps.

7.Position electrode over joint. End of electrode may be lightly touching the work.

8.Lower welding helmet, close gun trigger, and begin welding. Hold the gun so the contact tip to work distance is about 3/8" (10 mm) [3/4" (20 mm) for Outershield].

9.To stop welding, release the gun trigger and then pull the gun away from the work after the arc goes out.

10.When no more welding is to be done, close valve on gas cylinder (if used), momentarily operate gun trigger to release gas pressure, and turn off POWER MIG 200.

POWER MIG 200