Operation; Control Function - ESAB Heliarc 252 Instruction Manual

SECTION 3
3.1 CONTROL FUNCTIONS
(Refer to Fig. 3-1)
A. Power On-Off (I-O) Switch (S1). Switch is located on the rear panel. In the
OFF position, the power source is electrically shut down. In the ON position,
Power On light on front control panel will light and power is being provided
to all circuits in the power source.
B. CONTACTOR Switch (S3). T his 3-position toggle switch sets the operational
modes which can be used. In the STICK position (with the toggle UP), the
solid-state contactor circuits immediately energize, and welding power is
continuously present at the output terminals. In the TIG REMOTE position
(toggle at mid-position), the solid-state contactor and other tig sequencing
circuits are controlled by a remote device (foot or torch switch) through the
Remote Control receptacle. In TIG position (toggle down) the contactor is
always on.
C. Current Control (Panel-Remote) Switch (S5). This 2-position toggle
switch determines the location from which welding current will be oper-
ated; PANEL position from the power source Weld Current potentiometer,
or REMOTE position from an optional foot or hand control that plugs into
the Remote Control receptacle. When the REMOTE position is selected,
the optional remote control will vary the welding current, but only within the
range preset on the power source Weld Current potentiometer (R3).
D. Remote Control Receptacle (J2). This receptacle allows you to plug-in
a remote accessory (i.e., foot or hand control) to provide remote current
and/or contactor control, depending on the Panel/Remote selection of panel
switches described in Items B and C above.
E. Current Selector Switch (S2). A 3-position switch offers a choice of AC,
DCSP, or DCRP output current to suit your particular welding applications.
Placing the switch in its DCSP mode causes the output terminals to assume
the following polarities; work is positive, and torch/electrode is negative. Con-
versely, when the switch is in DCRP; work is negative and torch/electrode
is positive. Do not change the position of this switch while welding or
under load.
F. Current Control (R3). This control provides adjustment of welding current.
The panel-faced dial provides an accurate reference for presetting and/or
adjusting the control.
G. High Frequency Selector Switch (S4). A 3-position toggle switch controls
high frequency.
The functional positions are: Off -- no high frequency (this is the normal posi-
tion for all stick welding or scratch start TIG), Continuous -- high frequency
is provided throughout the entire welding cycle (this is the normal position
for all AC Tig welding), and Start -- high frequency initiates immediately and
cuts off when the arc is established (this last position is normal for most DC
Tig welding applications).
H. Post Flow Control (R2). This control provides a timed (from 3 to 30 sec-
onds) post-flow of shielding gas after the welding arc is broken.
23

OPERATION