Fr 4-1 Remote Control Unit; Welding Start-Up - GT WTU 457 Mode D'emploi

FR 4-1 REMOTE CONTROL UNIT

Fig. 14
The FR4-1 is used with manual electrode and TIG welding.
Since a pre-set amperage is not always ideal for the entire duration of a
welding task, pulsating direct current is often used, so that the welder can
continue welding without having to alter
the current setting. For example, when pipes are being welded in cramped
conditions, the amperage often needs to be corrected. Should tempera-
tures rise too high, there is a danger that liquid metal will begin to drop from
the welding pool. Too low, and the workpiece material will not melt
sufficiently.
Function: A relatively low welding current (pulse current I
steep up-slope to a considerably higher value (pulse current I
again after a pre-set period (pulse current time t
current I ), a process which repeats itself over and over again. This is only
2
possible when a specially designed current source is used.
During this welding process, small sections of the weld zone melt and
solidify quickly. A seam of this type is thus considerably easier to manage
than one with a large welding pool. This technique is also used for TIG-
welding thin sheet metal. Each fusion point overlaps the next, thus forming
a neat and regular seam. When the TIG pulsing technique is used for
manual welding, the welding rod is applied at each current peak.
Description of pulsed arc operating mode
For this operating mode the tumbler switch
position. The pulse current I
to MAX by means of the dial . The corres-ponding pulse current time t
can be preselected (from 0,1 to 2 seconds) using the control dial situated
immediately above this . The LED control lamp
the presence of pulse current I . The dial
1
current I (basic current) as an absolute value from MIN to MAX. The
2
necessary pulse current time t
2
background current is indicated by the LED control lamp
Description - standard operating mode
For this operating mode the tumbler switch
position. The pulse function is thus deactivated and the remote control unit
operates using continuous current. The LED control lamp
remains ON. The welding current may be steplessly adjusted from MIN to
MAX using the regulator dial .
Connection of remote control unit: see FR1-1 remote control unit
) rises via a
2
) and drops
1
) to the basic setting (pulse
1
must be switched to the
can be steplessly adjusted from MIN
1
lights up to indicate
is used for adjusting the pulse
is fixed by means of the dial
.
must be shifted to the
lights up and

WELDING START-UP

Fig. 15
Einstellvorgang
- Plug the manual electrode cable and earth cable into current sockets
and (which way round will depend on the type of electrode - as stated
by the electrode manufacturer). Latch them in firmly by turning them
clockwise.
- Plug in mains plug
- Shift the mains switch
- The green control lamp
- The air fan should be operational: (check that air is being emitted at the
rear of the machine).
- Shift selector switch
- Shift selector switch
position
- If welding without a remote control unit, shift selector switch
internal position
- If using remote control unit, connect remote control cable at position
(selector switch
- Preselect welding current INTERNAL or EXTERNAL
- Welding may now be started
WELDING
Settings
Table 2 gives the ampacity limits for the most important electrode diame-
1
ters, as well as rules of thumb for calculating them. The values given are
only valid for unalloyed and low-alloy core rods and for the stated electrode
lengths. For root-welding, vertical-up and overhead welding the welder
should use the lower limit. For fillet-welding in horizontal and flat positions
and also for vertical-down welding, the amperage is set near to the upper
. The
limit.
Electrode Ø mm 2.0
Length mm 250/300
Amperage A 40-80
Rule-of-thumb min. 20 x Ø
for amperage max. 40 x Ø
Table 2 Amperages, as dictated by electrode diameter
11
from "0" to "1"
indicates that the machine is operational.
to ELKTRODE position
into either the STANDARD or ELEKTROTECT
at EXTERNAL)
3.25
2.5 4.0
350/450
350 350/450
50-100 90-150 120-200 180-270
min. 30 x Ø
max. 50 x Ø
to
6.0
5.0
450
450
220-360
min. 35 x Ø
max. 60 x Ø