Operation Manual

3.2 MMA welding

In manual metal arc (MMA) welding, the ller material is melted from the electrode to the

weld pool. The rate of welding current is selected on the basis of the electrode size and

welding position. The arc forms between the electrode tip and work piece. The melting

electrode coating forms a gas and slag shield, which protects the molten metal in transfer

to the weld pool and during solidication. As the slag solidies over the hot weld metal, it

prevents weld metal oxidation. This slag coating is removed after welding e.g. with a chipping

hammer. When removing the slag coating, ensure you protect your eyes and face with suitable

equipment.

For more info, visit www.kemppi.com > Welding ABC.

3.2.1 Filler materials and equipment

Minarc Evo 180 can be used with all electrode types suitable for DC welding. Electrode sizes

for the unit are listed in Technical data section later in this manual.

1. Follow the welding specications given on the electrode package.

2. Before you start welding, check that you have selected the correct welding process.

3. Check that the welding cable and earth cable connections are hand tight. If a cable

connection is loose, it will result in a decrease of welding performance, overheating of

the connection, and it may aect your product warranty cover.

4. Select and mount the correct electrode type rmly in holder.

3.2.2 Earth return cable and clamp

If possible, always x the earth return cable and clamp directly to the welding work piece.

1. Clean the connection surface of earth clamp from paint, dirt and rust.

2. Connect the clamp carefully so that contact surface is as large as possible.

3. Finally check that the clamp remains fastened.

3.2.3 Manual metal arc welding (MMA)

Select your required welding parameters according to the manufacturer’s ller material

recommendations and the joint to be welded.

1. Select the required polarity (+ or –) of welding current cable (normally + ) and

return current cable (normally –) according to the ller material manufacturers

recommendations.

2. Select MMA welding mode by pressing the process selection button on the control

panel.

3. Select a suitable welding current by adjusting the current adjustment knob.

4. Make a small test weld to check the selections made.

Minarc Evo 180