Lincoln Electric IM557 manual Idle Roll Pressure Setting, Gas Guard Regulator Setting

B-9	OPERATION	B-9
Idle Roll Pressure Setting

The idle roll pressure is set at the factory, backed out three turns from full pressure on 4-roll feeders. This is an approximate setting. For small wire sizes and aluminum wire up to 9 or 10 turns out may be required to minimize “birdnesting”. The optimum idle roll pres- sure varies with type of wire, surface condition, lubri- cation, and hardness. The optimum idle roll setting can be determined as follows:

1)Release the incoming idle roll pressure arm, then 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 pressure setting out 1/2 turn, run new wire through gun, and repeat above steps.

3)If the only result is drive roll slippage, disengage the gun locking nut, and pull the gun cable forward about 6” (150mm). There should be a slight wavi- ness in the exposed wire. If there is no waviness, the pressure is too low. Increase the pressure set- ting 1/4 turn, reconnect the gun, tighten the locking nut, and repeat the above steps.

4)After the outgoing pressure is set, determine how many turns away from full pressure the setting is. Set both idle roll tensions to this setting. Engage both idle rolls before welding. In most applications, best wire feeding will occur when both idle roll pressures are set the same.

Gas Guard Regulator Setting

1)With the gas supply shut off, the Gas Guard regu- lator flow adjusting key should be set to maximum (full clockwise) which is rated to be 60 SCFH (28 lts/ min).

2)Adjust gas supply flow rate for a level higher than will be required, then adjust Gas Guard flow adjusting key counterclockwise to the desired gas flow rate.

SYNERGIC 7 & 7H