maxiMIG 250/300
Operating manual
Page 23
16. Operation / Welding
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Installation of the welding unit
When installing the machine, allow for sufficient space for inlet and outlet cooling air so that the rated duty cycle
will be attained.
The machine should not be exposed to moisture, welding spatter or spark rays caused by grinding work.
- Mains connection
To be carried out only by a qualified electrician!
Connect mains plug to mains cable as specified on the rating plate. The yellow-green lead is provided for PE
earth conductor. The three phases (black, brown, blue) may be con-nected to L1, L2, and L3 at random.
-
Connection of shielding gas cyclinder
Put the cylinder in place near to the shielded-arc welding unit and secure with chain.
Connect cylinder pressure reducer and check that all connections are tightly sealed.
-
Connection of welding torch hose pack
Connect hose pack to central adapter.
Ensure excellent contact between all connections within the welding circuit,
i.e. workpiece, torch connection and contact tip nozzle. Bad contact causes high transition
resistance which leads to overheating and poor quality of the weld.
- Connection of workpiece cable
When clamping the workpiece into its holder, choose an appropriate spot without paint or rust for good
conductivity
17. Welding
To obtain a high-quality weld, it is of great importance to select the right voltage step with optimum wire feed rate
and gas flow.
- Setting of cyclinder pressure reducer
Set the shielding gas flow rate at the pressure reducer on cylinder (6- 18 l/min). The gas flow rate depends
chiefly on the welding amperage.
- Loading of welding wire
Select the welding wire according to the material being welded. Mount the appropriate contact tip nozzle and
wire feed rollers. For more details see chapter 5 "wire feed".
- Select weld grade via weld-grade switch
Do not switch during welding operation
to avoid damage to the grade switch.
Adjust wire feed rate
(see chapter 13. control elements)
Start welding process by pressing torch trigger.
