Avoiding Wire Feeding Problems | Lincoln Electric SVM170-A instruction

B-9	OPERATION	B-9

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WARNING

When using an open arc process, it is necessary to use correct eye, head, and body protection.

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

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

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

11.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 255C.

AVOIDING WIRE FEEDING

PROBLEMS

Wire feeding problems can be avoided by observing the following gun handling procedures:

a.Do not kink or pull cable around sharp corners.

b.Keep the gun cable as straight as possible when welding or loading electrode through cable.

c.Do not allow dolly wheels or trucks to run over cables.

d.Keep cable clean by following maintenance instructions.

e.Use only clean, rust-free electrode. The Lincoln electrodes have proper surface lubrication.

f.Replace contact tip when the arc starts to become unstable or the contact tip end is fused or deformed.

g. Keep wire reel spindle brake tension to minimum required to prevent excess reel over-travel which may cause wire "loop-offs" from coil.

h. Use proper drive rolls and wire drive idle roll pressure for wire size and type being used.

FAN CONTROL

The fan is designed to come on automatically when a weld arc is established. The fan will stay on for a minimum of 6 minutes after the weld arc is terminated. The fan will also stay on when the machine’s welding and feeding are disabled during thermostatic over temperature protection. (See Welding Thermal

Overload Protection)

INPUT LINE VOLTAGE PROTECTION

High Line Voltage — If the line voltage exceeds 125% of rated input voltage, the output will be reduced to the lower level to protect voltage rating of the capacitor bank.

Low Line Voltage — You may not be able to get maximum output from the machine if the line voltage is less than rated input. The unit will continue to weld, but the output may be less than what is set.

WIRE FEED OVERLOAD

PROTECTION

The POWER MIG 255C has solid state overload protection of the wire drive motor. If the motor becomes overloaded, the protection circuitry turns off the wire feed speed weld outputi and gas solenoid. Check for proper size tip, liner, and drive rolls, for any obstructions or bends in the gun cable, and any other factors that would impede the wire feeding.

To resume welding, simply pull the trigger. There is no circuit breaker to reset, as the protection is done with reliable solid state electronics.