HBS 93-10-0702A, Operating Manual, Page: 27 / 78

ARC 800 Order No. BA 93-10-0702A Issue 01.03.08 27
– At the beginning of the welding process, the welding element (stud) in the welding
gun is lifted clear off the workpiece by a lifting device (solenoid). An initial switched
current triggers a pilot arc of a low current power (see position 2). Then the main arc
ignites between the face area of the welding element and the workpiece.
– The main arc burns at the set current during the welding time preselected at the
power unit. The selected welding energy must match the requirements of the
selected welding element. The energy of the arc melts the face of the welding element
and the workpiece (see position 3).
– At the end of the preset welding time, the stud is mechanically moved to the
workpiece. On plunging into the weld pool, the two weld zones join and solidify. The
contact of stud and workpiece extinguishes the arc in a short-circuit and the main
current is switched off.
– The weld zone solidifies and cools down. The welding element is now welded to the
workpiece over its entire cross-section of the welding element (see position 4). As
soon as the weld metal is cooled down, the welding gun can be carefully withdrawn
from the welding element. When using shielding gas, the shielding gas flow is
switched off with the withdrawal of the welding gun. If a ceramic ferrule is used, it can
be removed by light hammer blows.
The welding range of drawn-arc stud welding is about 3 to 25 mm diameter when using
mild steel/stainless steel. Welding elements with rectangular cross-section should not
exceed a ratio length : width of about 5 : 1. All technical information and adjustment
values are based on the use of welding elements which correspond with current
standards (see appendix).
Variations on Drawn-Arc Stud Welding
Item Drawn-arc stud welding with
ceramic ferrule/ring
Drawn-arc stud welding with
shielding gas
Short-cycle stud welding
with shielding gas
Capacitor-discharge stud
welding with drawn-arc
Diameter
welding element d
[metric mm (imperial)] 3 - 25
(#4 or 12 gage to 1") 3 - 12 (16)
(#4 or 12 gage to 1/2" (5/8") 3 - 12
(#4 or 12 gage to 1/2") 2 - 8
(14 gage to 5/16")
Max. current I [A] 3000 2500 1500 5000
Welding time t [ms] 50 - 2000 50 - 2000 5 - 100 3 - 10
Energy source Welding rectifier
Welding transformer
Welding rectifier
Welding transformer Welding rectifier Capacitor
Weld pool protection Ceramic ferrule CF Shielding gas SG Shielding gas SG
No protection NP No protection NP
Material welding
element S 235
CrNi steel
Aluminum (up to 12 mm/0,47") S 235
CrNi steel
Aluminum (up to 12 mm/0,47") S 235
CrNi steel
Brass (with shielding gas) S 235
CrNi steel
Aluminum, brass, copper
Workpiece surface Metallic bright
(rolling skin, rust film)
Metallic bright
(rolling skin, rust film) Metallic bright,
galvanized, light oiled Metallic bright,
galvanized, light oiled
Min. thickness of
workpiece ¼ d
min. 1 mm (0,04") 1/8 d
min. 1 mm (0,04") 1/8 d
min. 0,6 mm (0,02") 1/10 d
min. 0,6 mm (0,02")
Adjustable parameters Welding current
I [A] = 80 x d
(up to 16 mm/0,63")
Welding current
I [A] = 80 x d
(up to 16 mm/0,63") Welding current
I [A] = 100 x d
(up to 12 mm/0,47") Charging voltage
Welding time
t [ms] = 20 x d
(up to 12 mm/0,47") Welding time
t [ms] = 20 x d
(up to 12 mm/0,47") Welding time Ignition point / lift
Lift
(arc length) Lift
(arc length) Lift
(arc length) Spring pressure
(plunging speed)
Plunging depth Plunging depth Plunging depth Plunging depth