5 OPERATION
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Connect the return cable to the remaining welding terminal on the power source. Secure the
return cable's contact clamp to the work piece and ensure that there is good contact.
5.4
Overheating protection
The welding power source has a thermal overload trip which operates if the temperature
becomes too high, interrupting the welding current and lighting a yellow indicating lamp on
the front of the power source. The thermal overload trip resets automatically when the
temperature has fallen.
NOTE!
If the utilization of the power source is to high it might get
overheated. See permissable load in the TECHNICAL
DATA chapter in this manual.
If the air inlet or outlet is blocked or get clogged with
unwanted material the power source might get
overheated. Make sure that the airflow through the power
source is not blocked.
5.5
MMA welding
5.5.1
Striking the arc
MMA welding may also be referred to as welding with coated electrodes. Striking the arc
melts the electrode, and its coating forms protective slag.
If, when striking the arc, the tip of the electrode is pressed against the metal, it immediately
melts and sticks to the metal, rendering continued welding impossible. Therefore, the arc has
to be struck in the same way that you would light a match. Quickly strike the electrode
against the metal and then raise it to give an appropriate arc length (approx. 2 mm). If the arc
is too long, it will crackle and split before finally going out completely. Once the arc has been
struck, move the electrode from left to right. The electrode should be at an angle of 60° to the
metal.
5.5.2
Manipulation of electrode
In MMA welding, there are three motions to being matched in the end of electrode: the
electrode moving to the molten pool along axes [1]; a small oscillation maybe neccessary to
achieve the desired width of the melt pool [2]; the electrode moving along welding way [3].
The operator can choose the manipulation of electrode based on welding joint sharp, welding
position, electrode spec, welding current and operation skill, etc.
