Tweco 251 Thermal Arc Fabricator - Manual (Page 26)

FABRICATOR 251
INSTALLATION 3-4 Manual No. 0-4847
3.06 Quick Setup
CAUTION
To obtain adequate air flow and cooling for
the Power Supply components, the four
wheels must be fitted. Alternatively, the Power
Supply may be raised 5.5" (140 mm)from the
floor using supports that do not restrict
airflow.
NOTE
The steps in this subsection are intended for
individuals experienced in the set up of this
type welder. More detailed setup instructions
are in the 3.07 and following subsections.
1. Connect the work lead to the negative (-) socket
(positive + for Self Shielded Flux Cored Wire)
2. Connect the GUN lead to the positive (+) socket
(negative - for Self Shielded Flux Cored Wire)
NOTE
See section 3.15 "Polarity Changeover" for
more detail and exceptions!
3. Position a gas cylinder on the rear tray and se-
cure to the Power Supply cylinder bracket with
the chain provided. If this arrangement is not used
then ensure that the gas cylinder is secured to a
building pillar, wall bracket or otherwise securely
fixed in an upright position.
!
WARNING
If the gas cylinder is not secured to the cylin-
der tray, the power supply must be kept from
moving to avoid over-extending the gas hose
which can result in personal injury, damage
to the power supply, flow meter and gas cyl-
inder.
4. Fix the cable stowage hook to the Power Supply
cylinder bracket with the bolts provided.
5. Fit the gas Regulator/Flow Meter to the gas cylin-
der and connect the gas hose from the rear of the
Power Supply to the Flow Meter outlet.
6. The machine is fitted with a .035/.045” vee groove
feed roll suited for hard wire. Change this feed
roll if required to fit your chosen wire size.
7. Fit the electrode wire spool to the wire reel hub
located behind the electrode wire compartment
door.
8. Fit the TWECO Weldskill MIG gun and trigger wires
through/to the front of the unit.
9. Remove the contact tip from the gun.
10. With the gun lead reasonably straight, feed the
wire through the wire drive rolls and gun.
11. Fit the appropriate contact tip and replace insula-
tor and nozzle.
3.07 Installation of Shielding Gas
(GMAW) Process
NOTE
Shielding Gas is not required if the unit is used
with self shielded FCAW (flux cored arc weld-
ing) wires
1. Cylinder positioning: Block the wheels of the unit so
it cannot roll. Carefully stand the cylinder on the tray
and with one foot, press against the bottom of the
cylinder to assure it is against the back of the unit.
Chain the cylinder in place. (Refer to Figure 3-2 for
Wheel Kit cylinder installation)
2. Cracking: Remove the large metal cap on top of the
cylinder by rotating counter clockwise. Next remove
the dust seal. Position yourself so the valve is pointed
away from you and quickly open and close the valve
for a burst of gas. This is called “Cracking” and is
done to blow out any foreign matter that may be
lodged in the fitting. (Figure 3-2.)
3. Fit Regulator/Flow Meter to cylinders: Screw the
regulator into the appropriate cylinder. (Figure 3-2)
The nuts on the regulator and hose connections are
right hand (RH) threaded and need to be turned in a
clockwise direction in order to tighten. Tighten with a
wrench.
CAUTION
Match regulator to cylinder. NEVER CONNECT
a regulator designed for a particular gas or
gases to a cylinder containing any other gas.
4. Attach supplied gas line between the regulator output
and the desired input at the rear of the power supply
depending on Spool Gun or MIG Gun use. (Refer to
Figure 3-2 and 3-12).