Section 6:Troubleshooting; Basic Troubleshooting; Solving Problems Beyond The Welding Terminals - Thermal Arc Fabricator 281 Service Manual

SECTION 6:
TROUBLESHOOTING

6.01 Basic Troubleshooting

The basic level of troubleshooting is that which can be
performed without special equipment or knowledge,
and without removing the covers from the Power
Supply.
If major components are faulty, then the Power Supply
should be returned to an Accredited Thermal Arc
Service Agent for repair.
6.02 Solving Problems Beyond the
Welding Terminals
The general approach to fix Gas Metal Arc Welding
(GMAW) problems is to start at the wire spool then
work through to the MIG torch. There are two main
areas where problems occur with GMAW:
1. Porosity
When there is a gas problem the result is usually
porosity within the weld metal. Porosity always stems
from some contaminant within the molten weld pool
which is in the process of escaping during solidification
of the molten metal.
Contaminants range from no gas around the welding
arc to dirt on the work piece surface. Porosity can be
reduced by checking the following points:
1. Gas cylinder contents and flow meter.
a. Ensure that the gas cylinder is not empty
and the flow meter is correctly adjusted to
20-25CFM (15 litres per minute).
2. Gas leaks
a. Check for gas leaks between the regulator/
cylinder connection and in the gas hose to
the Power Source.
3. Internal gas hose in the Power Source.
a. Ensure the hose from the solenoid valve to
the MIG torch adaptor has not fractured and
that it is connected to the MIG torch adaptor.
4. Welding in a windy environment.
a. Shield the weld area from the wind or
increase the gas flow.
Manual No. 0-4880B
FABRICATOR 281 WELDING MACHINE
5. Welding dirty, oily, painted, oxidized or greasy
plate.
a. Clean contaminates off the plate
6. Distance between the MIG torch nozzle and the
work piece.
a. Keep the distance between the MIG torch
nozzle and the work piece to a minimum.
7. Maintain the MIG torch in good working order.
a. Ensure that the gas holes are not blocked and
gas is exiting out of the torch nozzle. Refer to
WARNING below
b. Do not restrict gas flow by allowing spatter to
build up inside the MIG torch nozzle.
c. Check that the MIG gun O-rings are not
damaged.
Disengage the drive roll when testing for gas
flow by ear.
2. Inconsistent wire feed
Wire feeding problems can be reduced by checking the
following points:
1. Wire spool brake is too tight.
a. Feed roller driven by motor in the cabinet will
slip.
2. Wire spool brake is too loose.
a. Wire spool can unwind and tangle.
3. Worn or incorrect feed roll size.
a. Use 'U' groove drive feed roll matched to the
aluminum wire size you are welding. Use 'V'
groove drive feed roll matched to the steel
wire size you are welding. Use 'knurled V'
groove drive feed roll matched to the flux
cored wire size you are welding.
4. Misalignment of inlet/outlet guides.
a. Wire will rub against the misaligned guides
and reduces wire feedability.
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!
WARNING
TROUBLESHOOTING