Tweco 190 MIG Thermal Arc Fabricator - Manual (Page 39)

FABRICATOR 190 WELDING MACHINE
Manual No. 0-4838 4-3 OPERATION
1. Handle Bar
2. Thermal Overload Indicator: The critical component
for thermal protection are the rectifier stack and the
transformer, which are fitted with thermal overload
protection devices. If the overload is activated then
the machine should be left to cool for approximately
15 minutes before resuming welding. If the Power
Source is operated within its duty cycle, the thermal
overload will not activate. Refer to section 2.10 for an
explanation of duty cycle and section 2.13 for the
power supply specifications.
WARNING
When the On/Off Power Switch Indicator is
lit, the machine is connected to the primary
input supply voltage and the internal electrical
components are at primary input voltage
potential.
3. On/Off Power Switch: The indicator light is provided
to indicate when the Fabricator 190 is connected to
the Input Power Supply Voltage. With the switch in
the Off position the auxiliary power and the fan
are turned off and the switch is illuminated to indicate
that the primary power is still present.
4. Wirespeed Control: The Wirespeed Control knob
controls the wire feed speed which is adjustable from
80 to 800 IPM.
5. Spot Timer Control: The spot time duration is set by
the Spot Timer Control knob, and is only activated
with the mode selector switched to Spot position.
When the Mode Selector switch is switched to the
Spot position, the Spot Timer Control knob controls
the duration of a single spot weld. The timer is
adjustable from .5 to 4.5 seconds.
6. Mode Selector Switch: The Mode Selector switch
selects the method of welding.
CONTINUOUS: This mode of welding is used to
weld two or more components together with a
continuous weld. When the MIG gun trigger
switch is depressed welding commences. When
the MIG gun trigger switch is released welding
ceases.
SPOT: This mode of welding is used to weld two
plates together at a desired location by melting
the top & bottom plates together to form a nugget
between them. The spot time period is set by the
Spot Timer Control knob.
7. Output Voltage Control Switch: The Output Voltage
Control Switch sets the voltage level to the welding
terminals. The output voltage is increased when the
switch is rotated in the clockwise direction.
CAUTION
The Output Voltage Control switch MUST NOT
BE SWITCHED during the welding process.
8. Positive Welding Current Terminal: Welding current
flows from the Power Supply via this heavy duty
terminal. Shown with terminal knob removed. The
knob must be firmly secured before attempting to
weld.
9. Gun Polarity Lead: This lead selects the welding
voltage polarity of the electrode wire. Attach it to
the positive welding terminal (+) when using steel,
stainless steel or aluminum electrode wire . Attach
the Gun Polarity Lead to the negative welding
terminal ( - ) when using gasless flux cored
electrode wire. If in doubt, consult the manufacturer
of the electrode wire for the correct polarity.
10.Positive and Negative Welding Terminal Knobs
Welding current flows from the Power Supply via the
heavy duty terminals. The knobs must be firmly
secured before attempting to weld.
CAUTION
Loose welding terminal connections can cause
overheating and result in failure of the
terminals.
11.Negative Welding Current Terminal: Welding current
flows from the Power Supply via this heavy duty
terminal. Shown with terminal knob removed. The
knob must be firmly secured before attempting to
weld.
12.Gun Connector: This is the receptacle into which the
MIG gun is connected. It accepts a #4 Tweco style
gun.
13.Gun Trigger Switch Amphenol Receptacle: The Gun
Trigger 4-pin receptacle is used to connect the two
wires from the MIG gun to the Fabricator 190. Only
pins A and B are used for this. To make connections,
align keyway, insert plug, and rotate threaded collar
fully clockwise. Refer to Figure 4-3.