6.3. Wire feed unit.
Check the wire feed unit at regular intervals. The feed roller wire guide plays an important part in obtaining consistent results. Poor
wire feeding affects welding. Clean the rollers weekly, especially the feed roller groove, removing all metallic dust deposits. Whilst the feed roller is
removed blow compressed air through the wire path to remove any debris.
6.4. Changing Wire Feed Roller
IMPORTANT:
(Refer to section 3.21)
Make sure that the wire feed rollers, the wire guide hose and the contact tip of
the torch match the diameter and type of wire to be used and ensure that these parts are fitted correctly.
6.5. Contact Tip.
The contact tip is a consumable item and must be replaced when the hole becomes enlarged or oval. The contact tip
MUST
be kept
free from spatter to ensure an unimpeded flow of gas.
6.6. Gas Cup.
The gas cup must also be kept clean and free from spatter. Build up of spatter inside the gas cup can cause a short circuit at the contact tip
which will result in either the fuse blowing on the printed circuit card, or expensive machine repairs. To keep the contact tip free from spatter, we
recommend the use of Sealey Anti-Spatter Spray (MIG/722307) available from your Sealey Dealer.
PROBLEM
POSSIBLE CAUSE
REMEDY
1. Power source stops.
Overheating protection activated due to overload.
Protection automatically resets when transformer has cooled (about 15 min).
2. No weld current, fuses blowing.
Rectifier blown.
Replace rectifier.
3. No weld current.
Bad connection between clamp & workpiece.
Break in earth lead.
Break in gun lead.
Clean or grind contact surface and weld area.
Repair or replace earth lead.
Repair or replace gun, lead.
4. Feed motor not working.
Fuse blown.
Gear damaged or worn.
Motor defective.
Replace fuse.
Replace gears.
Replace motor (contact service agent).
5. Wire does not feed, feed roller rotates.
Pressure roller incorrectly adjusted.
Dirt, copper, dust, etc, have collected in gun liner.
Gas cup (nozzle) or tip defective.
Deformed wire.
Adjust tension.
Clean the liner using compressed air. If too much dirt, replace the swan neck.
Replace gas cup (nozzle) and/or tip.
Check roller tension and adjust it if necessary.
6. Wire feeds unevenly.
Dirt, etc, guide hose/swan neck.
Gas cup (nozzle) or tip defective.
Gas cup (nozzle) spattered.
Feed roller groove clogged.
Feed roller groove deformed.
Pressure roller tension too slight.
Clean the guide hose/swan neck using compressed air.
Replace gas cup (nozzle) and/or tip.
Clean or replace gas cup (nozzle).
Clean feed roller.
Replace feed roller.
Adjust tension.
7. Unstable arc.
Incompatible settings.
Impurities in weld area
Worn or defective gas cup (nozzle).
Check settings.
Clean and/or grind workpiece.
Replace gas cup (nozzle).
8. Porous weld.
No gas.
Gas cup clogged.
Draft blowing away shielding gas.
Rusty or dirty joints.
Torch too far from, or at wrong angle to, work.
Gas leak.
Dirty workpiece.
Open gas cylinder, regulate gas flow.
Clean or replace cup.
Screen off welding site or increase gas flow.
Clean or grind the workpiece.
The distance from gas cup to workpiece should be 8-10mm.
Check hoses, connections and torch assembly.
Clean.
9. Electrode sticking in gas cup (nozzle).
Worn or defective gas cup (nozzle).
Electrode deformed.
Wire speed too slow.
Replace gas cup (nozzle).
Check roller tension.
See recommendations for wire speed.
10. Irregular weld bead.
Torch incorrectly held.
Wire weaving in weld pool.
Use correct torch angle.
Check roller tension and adjust as needed.
11. Weld bead too narrow and raised.
Weld current too high.
Weld speed too low
Increase power and wire speed.
Move gun slower and weave a little more.
12. Weld bead too wide.
Weld current too high.
Weld speed too low.
Arc too long.
Decrease power and wire speed.
Move gun faster and weave less.
Bring gun closer to workpiece.
13. Poor penetration.
Weld current too high.
Weld speed too low.
Arc too long.
Increase power and wire speed.
Bring gun closer to workpiece.
14. Excessive penetration.
Weld current too high.
Weld speed too slow.
Incorrect distance of torch to workpiece.
Decrease power and wire speed.
Move gun faster.
Torch distance should be 8-10mm.
15. Fuse blowing.
Tension too great.
Gas cup contact tip clogged.
Release tension (see Section 3).
Clean gas cup and contact tip (see Section 5).
16. Coils of wire on reel overlap, or wire is
oxidised. Coils break or fall under wheel.
Tension to loose or tight. Coil damaged or wire
twisted.
Reset tension. Change wire reel.
17. Wire runs through gun but there is no
welding current.
Defective contactor.
Worn contacts of contactor regulator.
Regulation switch problem.
Faulty rectifier.
Fault on electronic circuit of contactor.
Work cable not connected correctly.
Check coil ends, change coil if necessary.
Check, clean contacts, change if oxidation is present.
Check secondary voltage for each switch setting.
Disconnect rectifier from secondary, check each diode goes one way only.
If not change rectifier.
Change control module.
Connect work clamp directly to workpiece. Check wire is in good condition and making
good contact with clamp.
7. TROUBLESHOOTING
MIG/SGT15.V2 & MIG/SGT15/12.V2 - 1 - 21/12/07
