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PATON
®
PSI PRO 315 A 400 V DC MIG/MAG TIG/MMA
4.4.2. TIG-4T CONTACTLESS ARC STARTING FUNCTION
This function of the control button on the welding torch is used if the welding unit contains an external
module for contactless arc starting (oscillator) with an integrated gas supply valve.
The control button on the welding torch is connected directly to the oscillator. When the control button
of the welding torch is pressed, this function is performed in such a manner as the
TIG-2T
contactless
arc starting function
(see Section 4.3.2),
but with two differences.
According to the first difference
, at the start of welding, when the control button is held down (t1)
after the first pressing, the weld area has been purged with gas before welding, and the high-voltage
arc starting has been provided, the initial current (for forming a pilot arc) is constant (instant of time
t2), and only when the button is released, the welding current will increase to the set operational
current value. Therefore, the button is not to be pressed during the welding with the set operational
current.
According to the second difference
, at the end of the welding, when the control button is held down
(instant of time t3) after the second pressing, the welding current will decrease linearly to the crater
welding current value and then is constant until the button is released. When the button is released, the
welding current will decrease linearly, the welding unit will be switched off (instant of time t4) and the
weld area will be purged with gas. After these operations, the gas supply valve will be closed.
ATTENTION!
The oscillator must contain a device for protecting the output
of the welding unit against electric breakdown caused by a high-voltage
discharge generated at the instant of time of arc starting. Before the operation,
activate the protective device.
4.5. INITIAL CURRENT (PILOT ARC CURRENT) SETTING
This function facilitates the arc starting in a welding process with the use of a welding torch. The
function allows the welding process to be started at low welding current, which only support the
welding process without increasing heat input to the weld and without burning through the workpiece.
In the
TIG-4T
welding process, it is reasonable to heat the weld area before welding. By default, the
initial current
[PRIMARY ARC]
value is 15 A.
The procedure for changing the values of the operational parameters of the welding unit is described in
Section 6.1.
4.6. LINEAR INCREASE OF WELDING CURRENT
This function provides the economic consumption of an electrode, promotes the extension of the
service life of the welding torch, and facilitates the use of the welding torch. This function prevents the
spillage of molten metal in the welding pool. Additionally, during the period
[TIME UP ARC]
of linear
increase of the welding current, it is possible to accurately locate the welding torch in the weld area, as
the arc starting point is initially not always is located in the weld area. It is reasonable to heat the weld
area. By default, the period of linear increase of welding current is 1.0 s.
The procedure for changing the values of the operational parameters of the welding unit is described in
Section 6.1.