12
Lift the gas cylinder carefully onto the tray at the rear of
machine. Fasten the cylinder securely using the supplied
chain. Attach gas hose to a gas regulator on gas cylinder.
For normal operation using the GunMaster 250, gas flow
should be set to approximately 21 - 25 cfh. Avoid excessive
gas flow as this can lead to weld defects. (Gas is not
required when using self shielded/gasless wires)
Gas flow can be checked without welding by setting the
voltage selector switch on the front of the machine in the
upright position pointing to the gas flow symbol. In this
position gas flow can be checked and the welding lines
purged without wire feeding or welding voltage being pre-
sent.
Joint Preparation
The joint to be welded must be prepared. During welding,
those parts of the workpiece are heated by the arc and
melt, this molten material mixes with the weld metal of
the wire or electrode. To make sure that fusion is good
and to avoid impurities in the molten pool, it is necessary
to clean the surfaces of the joint carefully. Therefore, use
a wire brush to remove rust, paint and other forms of
contamination where welding is to be carried out. The
area to be welded must also be dry.
Fit-up between the parts to be welded together must be
adjusted so that the joint gap is uniform from end to end.
In the case of light-gauge materials, welding can either
be done from one side or both, depending on the strength
required. For heavier materials, start with a root bead
and then fill up the joint with a sufficient number of passes.
A new welding process commences when the
trigger is pulled again. Max plate thickness
when spot welding is about 14 gage. If the
plates are of different thickness, weld from
the thin side.
Interval (Stitch) Welding (
- - -
)
This form of welding is particularly suitable
when working with very thin or inferior plate
or when the gap size is large since it gives
a cooler weld.
The spot welding control knob is used to
set the welding time. The interval time
control knob is used to set the pause time.
Both welding time and pause time can be set
steplessly between 0.2 and 2 sec. For welding
voltage and wire feed speed settings, see the
recommendation table on page 14.
Pull the trigger to start the welding process.
When the set welding time has elapsed,
the process is automatically interrupted and
starts again after the pause time has
elapsed.
The process continues as long as the
trigger is pulled. The molten pool of metal
is cooler and the risk of burning through
is considerably reduced.
Burn-back Time
The Power Compact has adjustable
burnback time from 0-250ms. This is
preset when supplied from ESAB. The
potentiometer is located inside the
machine above the feed unit. Use a small
screwdriver and adjust carefully.
How To Select Welding Data
– Seam Welding
VOLTAGE
WIRE
FEED SPEED
Switch the power supply on by means of
the main switch. This will cause the light-
emitting diode in the switch to light up.
Set the voltage-setting switch to the correct
position1-10.(see recommendation table
on page 13).
Note!
Do not adjust the voltage control while
welding. Stop welding, click switch to
new position and begin welding again.
The recommendation table also shows
the best inductance output for
connection of the return cable.
Set the wire feed speed (current) with the
potentiometer graded 1-10.
(See recommendation table on page 14)
Note!
Wire feed speed (current) can be adjusted
while welding.
Pulling the trigger on the gun starts the welding process,
releasing the trigger stops it.
First do a sample weld on a clean piece of plate.
According to the results adjust as follows:
Caution! In most cases, the preset value should be used.
SPOT WELD
TIME
STITCH WELD
TIME
BURN BACK
POT
Spot Welding (•••)
In most cases, spot welding is done from one
side to join two overlapping plates.
For spot welding purposes, the gun must
be fitted with a spot welding nozzle.
If spot welding is required, use the spot
welding control knob to set time. The spot
welding time can be set steplessly
between 0.2 and 2 sec. For welding
voltage and wire feed speed settings, see
the recommendation table on page 13.
Pull the trigger. When the set spot weld
time has elapsed, the process is
automatically interrupted without the
trigger needing to be released.
ON
OFF
