Lincoln Electric TIG 275 - Manual (Page 27)

B-10 OPERATION B-10
SETUP GUIDELINES FOR TIG WELDING
WITH AN AMPTROL
Both the Hand and Foot Amptrols work in a similar
manner. They are meant to be used for remote current
control for TIG welding using the machine
’ s 2-Step
trigger mode (See Item 12).
The Amptrol is capable of controlling the output of the
Precision TIG over the range between the level preset
by the
Minimum Output control when the Amptrol is at
its inactivated state, and the level preset by the
Maximum Output control when the Amptrol is at fully-
activated state.
It is important to note that even with the Precision TIG ’ s
new MicroStart TM Technology, some tungstens may be
difficult to start at the low (2 amps) minimum rating of
the machine. Rather than guessing where to depress
the Amptrol to start the arc reliably, the
Minimum
Output control allows presetting the exact level, so
reliable starts, as well as minimum crater-fill levels, can
be consistently obtained at the minimum Amptrol (inac-
tivated ) state.
FIGURE B.6 shows Precision TIG setup
for TIG welding with an Amptrol.
USING THE START PEDAL FOOT AMPTROL (K870-1)
To further enhance reliability of consistently obtaining
this minimum level just after the Amptrol
’ s start switch
is closed, or just before it opens for crater-fill, the new
K870-1 Start Pedal Foot Amptrol is available. Its
independent start pedal on control pedal provides two-
stage foot action to easily feel start switch closure at
minimum output level for precise arc start and crater
control. Also, an adjustable heel stop helps assure
comfortable foot location.(See Figure B.5)
Currently available TIG foot pedal controls combine the
arc start switch actuation in the same pedal action with
the output control variable resistance. This technique
provides no independent tactile feel of where the arc
start switch actuates, and at what control level, for con-
sistent TIG starting. Nor does it provide a way for con-
sistent crater-fill control to feel at what decreasing con-
trol pedal position the arc start switch will re-open
causing arc out.
PRECISION TIG 275
PREFLOW
Fixed 0.5 sec
or x2
START TIME
Manual
in 4-Step
UPSLOPE
Fixed<0.5 sec
w/o Amptrol
MINIMUM OUTPUT
(Start) SETTING
Adjustable 2-50A
MAXIMUM OUTPUT
SETTING
Adjustable 2-Max.A
Amptrol or Remote
(PEAK) Range
2 or 4-STEP
Trigger
Closed
4-STEP
Trigger
1 ST Open
4-STEP Trigger
Re-closed or
2-STEP Trigger
Opened
4-STEP Trigger
Re-opened
after
Downslope Time
DOWNSLOPE
Adjust 0 —10 sec
w/ Advan. Panel
(Fixed 0 sec w/o)
POSTFLOW
Adjust 2-60 sec
or x2
CRATER-FILL
LEVEL
Advanced
Panel Select:
Mach. Min.
or
MIN. Setting
(as w/o Panel)
With PULSE ON
No Pulsing
During Upslope Time
or
When Downslope
Drops Below
Background Setting
% ON TIME
Adjustable
5-95%
PULSE FREQ.
Adjustable
0.1-20 pps
BACKGROUND
Adjustable
MIN.Setting -100% Peak
CRATER-FILL TIME
Manual in 2/4-Step
w/ Restart Disabled
TIG WELD CYCLE CHART
SEE ITEM 12 SEE ITEM 12
SEE ITEM 12 SEE ITEM 12
SEE ITEM 7
SEE ITEM 9
SEE ITEM 17
SEE ITEM 16
SEE ITEM 15 SEE ITEM 14
SEE ITEM 7
SEE ITEM 12
SEE ITEM 9
SEE ITEM 7
SEE ITEM 6
SEE ITEM 6 & 7
SEE ITEM 12 & TIG
Welding Features