Description Of Controls - GT WTU 457 Mode D'emploi

DESCRIPTION OF CONTROLS

Fig. 8
Mains switch ON / OFF
"Machine operational" indicator
light comes on when mains switch is set to position "1"
Welding current regulator
Outer scale: the welding current may be steplessly adjusted from 5-
450A or 5-650A.
The inner scale (1-10) serves as an approximate guide to welding
current levels when remote control units are used. The remote control
units FR1-1, FR2-1, FR3-1 and FR4-1 are also equipped with scales
from 1-10, thus making it possible to use them in combination with all
machines in the WTU series.
Selector switch ELECTRODE / ARC-AIR
a) ELECTRODE position
- manual electrode welding, or
- TIG-welding = constant-current characteristic "CC"
b) ARC-AIR position - for use with
- arc-air gouging
- filler-wire welding = falling characteristic
(see chapter arc-air gouging)
STANDARD / ELECTROTECT SELECTOR SWITCH
STANDARD switch position = constant-current characteristic. When
welding with e.g. basic electrodes, the short-circuit amperage only
increases very slightly in the instant of droplet transfer. When the
electrode "sticks" to the workpiece (= short circuit), the amperage
increases to the nominal current (i.e. the welding-amperage value
previously set on the scale). The electrode burns out and can no longer
be used.
ELECTROTECT switch position = constant-current characteristic with
automatic current cut-out in short circuit.
If the welding voltage drops below 15 V, e.g. when the electrode sticks
to the workpiece (= short circuit), the welding current is automatically
reduced to a minimum. In this situa-tion, the electrode can easily be
detached from the workpiece without burning out and without any
damage to the electrode coating. (This is a great advantage in welding
training situations). After the electrode is detached from the workpiece,
the full ignition voltage is reapplied.
Selector switch for INTERNAL - EXTERNAL welding current setting
INTERNAL setting
- The desired welding current is set using the welding current regula-
teur on the machine
EXTERNAL setting
- The desired welding current is set using remote control units
FR1-1 / FR2-1 / FR3-1 / FR4-1
Connecting socket for remote control
Remote control operation:
- Plug in remote control cable plug and fix on using a swivel nut
42V / 400VA ~ socket (option)
The 42V~ safety voltage socket means that hand lamps and electrode
driers can be plugged in in conditions of increased electrical danger
10A overload cut-out (option)
Overload protection for 42V~ socket
Digital ammeter (option)
- for indicating the actual welding amperage value
Fig. 9
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