Lincoln Electric Power Mig 255 Svm144 B Users Manual

2015-02-09

• Master Table of Contents
• Safety
• Section A - Installation
• Section B - Operation
• Section C - Accessories
• Section D - Maintenance
• Section E - Theory of Operation
• Section F - Troubleshooting & Repair
• Symptoms
  • Major Physical or Electrical Damage is Evident
  • Machine is dead — no open circuit voltage output and no wire feed when gun trigger is pulled. The machine display may be lit.
  • No open circuit voltage output but wire feeds normally when gun trigger is pulled.
  • Wire feeds but welding output is low causing wire to “stub”. Welds are “cold”. Machine cannot obtain full rated output of 200 amps at 28 volts.
  • The output voltage and wire feed is present continuously or pulsing when gun trigger is NOT activated.
  • The output voltage is present continuously when gun trigger is NOT activated.
  • No control of arc voltage. Wire feeding is normal.
  • There is no gas flow when gun trigger is pulled. Wire feeds and weld voltage is present.
  • The machine stops feeding wire while welding.
  • No control of wire feed speed. Other machine functions are normal
  • There is no wire feed when gun trigger is pulled. Normal open circuit voltage is present.
  • The arc is unstable and or “hunting”.
  • Weld bead is narrow or ropy. May have porosity with electrode stubbing into plate.
  • The contact tip seizes in the gas diffuser.
  • The welding arc is variable and sluggish.
  • The arc striking is poor.
• Section G - Electrical Diagrams