Forney 373 Multi Process Welder User Guide

Forney 373 Multi-Process Welder

Specifications

• Wire spool support (MIG): 0.024 in (0.6 mm) – 0.035 in (0.9 mm) wire diameter spools
• Spool sizes mentioned: 8 in (200 mm) and 4 in (100 mm)
• MIG drive roll marking target: visible markings for 0.030 in – 0.035 in wire diameter
• Solid wire MIG gas flow: approximately 20 – 35 CFH
• Input power (120V operation—generator safe): at least 4000W continuous output; no low-idle; max 5% Total Harmonic Distortion (THD)
• Extension cord (MIG/TIG/STICK—stated): #12 AWG or larger; maximum length 25 ft (8 m)

Usage Instruction

1. Read the user manual first before operating.
2. Set polarity: Solid Wire DCEPG round – Jumper +. Flux-core Wire DCEN Ground + Jumper –
3. Install Wire Spool 0.024” (0.6mm) – 0.035” (0.9mm) diameter
   • 8” (200mm) wire spool
   • 4” (100mm) wire spool
4. Set drive roll: Ensure drive-roll shows the correct wire diameter is visible when the drive roll is installed, 0.030”- 0.035”.
   • Face the appropriate groove towards the inside of machine
   • For additional wire diameters, additional drive rolls are needed.
5. Set Drive-roll Pressure: For proper tension, align the tops of the screw and nut together
6. Attach gas, if necessary: Solid wire MIG requires shielding gas, set the gas flow to approximately 20 – 35 CFH
7. Ground Workpiece: Connect ground clamp to clean, bare metal.
8. Connect to 120V Input Power
   • Generator safe: Use power source with 4000W of continuous output, no low-idle, 5% THD max.
   • Extension cord: #12 AWG or larger, 25’ (8m) or shorter.
9. Select Process: (For TruSet™, see back.)
10. Adjust Settings: Adjust wire feed speed and voltage. See chart on welder for correct settings.
11. Feed Wire: Remove consumables and depress trigger until wire comes out. Replace consumables.
12. Begin Welding: With contact tip 1/4” from metal, depress trigger completely to initiate arc.

TruSet™ MIG

1. Select, TruSet™
2. Follow steps 1-9 of the Manual MIG setup.
3. Push button under GAS MIX to cycle through the available wire type and shielding gas options, choose appropriate combination.
4. Push button under WIRE DIAMETER to cycle through the available wire diameter options, choose the appropriate diameter.
5. Adjust the RIGHT KNOB to cycle through the available workpiece thickness, choose the appropriate thickness.
6. The machine will set optimal voltage and WFS. Continue with step 11 of the Manual MIG setup.
7. The automatic settings can be trimmed up or down with the left knob if you want to refine the weld settings.

Expert-Tech Tips:

• Best performance is at a trim setting between -5 and +5.
• Step up to the next material thickness to get more penetration.

1. Read user manual
2. Set polarity: All TIG welding is done electrode negative.
   • Always DCEN
   • Ground +
   • Electrode Holder –
     
3. Ground Workpiece: Connect ground clamp to clean, bare metal.
4. Attach gas line on torch to shielding gas: TIG welding requires shielding gas; 100% argon is recommended.
5. Connect to 120V Input Power
   • Generator safe: Use power source with 4000W of continuous output, no low-idle, 5% THD max.
   • Extension cord: #12 AWG or larger, 25’ (8m) or shorter.
6. Select Process
7. Adjust Amperage: See Settings Chart in manual for recommended amperages based on material thicknesses.
8. Open Gas Valve: You must manually control your shielding gas. Be sure to close after ending the arc.
9. Begin Welding: Use a lift arc technique to start the arc.

1. Read user manual
2. Set polarity: Refer to the electrode manufacturer recommendation for polarity
   • Usually DCEP
   • Ground –
   • Electrode Holder +
3. Ground Workpiece: Connect ground clamp to clean, bare metal.
4. Connect to 120V Input Power
   • Generator safe: Use a power source with 4000W of continuous output, no low-idle, 5% THD max.
   • Extension cord: #12 AWG or larger, 25’ (8m) or shorter.
5. Select Process
6. Turn knob to adjust Amperage: Refer to the electrode manufacturer recommendation for amperage.
7. Begin Welding

Troubleshooting

MIG TROUBLESHOOTING TIPS

Do not weld aluminum

• This machine cannot connect to a spool gun, which is recommended for aluminum.
• Workpiece Grounding: Connect the ground clamp to clean, bare metal. No rust, paint or other coatings. Attach the ground clamp directly to the workpiece if you are experiencing issues.
• Too much spool tension: Wire from spool to drive should relax with a slight curve after feeding.
• Incorrect drive roll pressure
  • Too little pressure = Roll can slip, and feed can be erratic
  • Too much pressure = can crush wire, causing wire feeding problems and welder damage
• Frequently tripping circuit breaker or exceeding duty-cycle
  • Trying to weld single pass on material larger than 1/4” (6mm) thick is not possible with this machine. Multi-pass recommended for thicker materials.
  • Welder should be the only thing plugged into the circuit.
• Low weld output or poor fusion
  • Usually due to low input power.
  • Welder should be the only thing plugged into the circuit.
  • Avoid using extension cords. If one must be used, it must be #12 AWG or larger; 25’ (8m) or shorter.
  • Generators must be 4000W continuous output and not have a low-idle function (or have it disabled).
• Duty cycle exceeded or insufficient airflow. Allow machine to cool.
• Incorrect input power. Verify power source is 120V+/- 10%.
• Gun is triggered when machine is powered on. Release trigger.

TIG TROUBLESHOOTING TIPS

Aluminum welding

• Output is DC only, which is not recommended for TIG welding aluminum.
• Workpiece Grounding: Connect the ground clamp to clean, bare metal. No rust, paint or other coatings. Attach the ground clamp directly to the workpiece if you are experiencing issues.
• Frequently tripping circuit breaker or exceeding duty cycle
  • The welder should be the only thing plugged into the circuit.
• Duty cycle exceeded or insufficient air flow. Allow machine to cool.
• Incorrect input power. Verify power source is 120V+/- 10%.
• Electrode is shorted or stuck to workpiece. Separate the electrode from the workpiece.

STICK TROUBLESHOOTING TIPS

• Workpiece Grounding: Connect the ground clamp to clean, bare metal. No rust, paint or other coatings. Attach the ground clamp directly to the workpiece if you are experiencing issues.
• Frequently tripping circuit breaker or exceeding duty cycle
  • The welder should be the only thing plugged into the circuit.
• Duty cycle exceeded or insufficient airflow. Allow machine to cool.
• Incorrect input power. Verify power source is 120V+/- 10%.
• Electrode is shorted or stuck to workpiece. Separate the electrode from the workpiece.

FIND MORE INFORMATION AT FORNEYIND.COM

QUESTIONS OR TROUBLE?
Contact Forney Industries at 1-800-521-6038, customerservice@forneyind.com, forneyind.com