High-Frequency (Hf) Ignition; Welding With Hf Ignition; Welding Without Hf Ignition; Pulsing - REHM INVERTIG.PRO COMPACT 240 DC Betriebsanleitung

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3.7

High-frequency (HF) ignition

The push button [19] is used to select the HF ignition of the arc in TIG welding,
where the display LEDs [20] show whether the high-frequency is activated or
deactivated
3.7.1

Welding with HF ignition

The REHM TIG welding units are fitted with HF ignition units as standard. When
using the "Electrode" setting, the HF ignition function
automatically.
The HF ignition unit enables, thanks to the pre-ionisation of the air, when direct
and alternating current welding, the contact free ignition of the arc between the
electrode and the work piece, which prevents tungsten inclusions and thus
welding faults. In both cases, after the successful ignition, the HF ignition unit is
deactivated again automatically. The re-ignition of the arc when alternating
current welding as described in Chapter 3.5.14 is carried out without the HF
ignition unit. This reduces the radiation of electrical interference fields and even
enables alternating current welding without HF ignition as is already familiar from
direct current welding (see Chapter 3.7.2).
When the setting is " ", the HF ignition unit is ready for operation. When igniting
the arc, the electrode is held approximately 3-5 mm above the work piece. When
pressing the torch button, a high voltage impulse ionises the area and creates
the arc. The contact free ignition means that tungsten inclusions in the welding
seam are prevented. When welding, after the successful ignition, the HF ignition
unit is deactivated again automatically.
3.7.2

Welding without HF ignition

When welding under direct or alternating current, a contact ignition can be
carried out (lift arc). The high-frequency function is deactivated for this purpose.
To ignite the arc, the electrode is put in place, and the torch button is pressed.
When the electrode is lifted up, the arc ignites as programmed and without
causing wear to the pointed electrode. This can be a beneficial option when
working on sensitive electronic objects (for example, in hospitals, repair welding
to CNC controlled machines) when a danger is posed by the interference cause
of high-frequency pulses.
3.8

Pulsing

With the press button [21] you can select the welding procedure without pulsing,
conventional pulsing and high-frequency pulsing. The display LEDs [22] show the
selected pulse type by lighting up (see Chapter 3.5.7).
Functional description
is deactivated