Jasic EVO 2.0 EM-160C, Operator'S Manual

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GUIDE TO MIG/MAG WELDING
Before starting any welding activity ensure that you have suitable eye protection and
protective clothing. Also take the necessary steps to protect any persons within the welding
area.
Burn Back
In the event that the welder was to stop welding and all functions of the machine stopped simultaneously
then the consumable filler wire would in all likelihood freeze in the weld pool. In order to avoid this
happening the burn back feature is present on most machines.
This facility may be built in or an adjustable control. It will allow the power and gas shield to be
maintained on the consumable filler wire when it has stopped feeding thereby burning clear of the weld.
In some equipment the burn back is preset within the control circuits others offer an external variable
control feature to adjust the time of delay.
Other Controls
Other common control features are latching or 2T/4T where the welding can either in 2T mode press the
torch trigger to weld and release to stop or in 4T press and release the torch trigger to start, weld without
holding the trigger on and stop by pressing and releasing the trigger again. This is particularly useful when
carrying out long welding runs.
Crater fill controls are available on many machines. This allows the crater at the end to be filled helping
eliminate welding defects.
A spot welding timer will allow the time of the weld to be set and after the time has expired the operator
will have to release the torch switch to restart the weld.
MIG/MAG system checks
Shielding gas nozzle
This nozzle must be periodically cleaned to remove weld spatter. Replace if distorted or squashed.
Contact Tip
Only a good contact between this contact tip and the wire can ensure a stable arc and optimum current
output; you must therefore observe the following precautions:
•
The contact tip hole must be kept free of grime and oxidation (rust).
•
Weld spatter sticks more easily after long welding sessions, blocking the wire flow, the tip must
therefore be cleaned often and replaced if necessary.
•
The contact tip must always be firmly screwed onto the torch body. The thermal cycles to which the
torch is subjected can cause it to loosen, thus heating the torch body and tip and causing the wire to
advance unevenly.
MIG Torch Wire Liner
This is an important part that must be checked often because the wire may deposit copper dust or tiny
shavings. Clean it periodically along with the gas lines using dry compressed air. The liners are subjected
to constant wear and tear and therefore must be replaced after a certain amount of time.
Wire Drive System
Periodically clean the set of feeder rollers to remove any rust or metal residue left by the coils. You must
periodically check the entire wire feeder group: feed arms, wire guide rollers, liner and contact tip.