REHM TIGER 170 Instructions De Service page 8

„ + " Marking on the welding current socket
3.2
The „ + " sign indicates the positive pole of the welding power source. The earth cable is
connected to this socket when TIG welding.
„ – " Marking on the welding current socket
3.3
The „ - " sign indicates the negative pole of the welding power source. The torch is
connected to this socket when TIG welding.
4 Mains power supply
The welding unit must be fitted with the correct mains supply plug which fully complies with
the International electrical standards and the local electrical regulations. The unit must only
be operated with fuses or circuit breakers with a maximum current rating of 16A. When the
mains power is switched on, the mains ON/OFF switch on the back of the unit is illuminates.
If the TIGER 170 is switched ON and OFF frequently (in quick succession), the unit may
automatically switch over to the power supply protection mode. In this mode, the unit cannot
be re-started and the green indicator lamp flashes. If this occurs, switch the unit OFF and
wait for approx. 2 minutes. The unit can then be restarted.
5 Installation
Care should be taken during installation of the unit to ensure that the ventilation slots are not
covered and the area where the machine is to be used affords a protection classification of
IP23.
6 Description of Welding processes
6.1 TIG Welding
6.1.1 Principle of the TIG welding process
The unit supplies a current up to 170 A DC for the TIGER 170 and 210 A for the TIGER 210
for TIG welding. The mains current limiting function is inactive during the TIG welding mode.
Despite the higher output current, the power drawn from the mains supply is lower than
required for stick electrode welding; the mains fuse is therefore unlikely to trip-out during TIG
welding.
During TIG welding, a welding arc is established between a tungsten electrode and the
workpiece. The shielding gas normally used is an inert gas such as pure Argon, Helium or a
mixture of both.
The negative pole of the power supply is connected to the tungsten electrode, the positive
pole is connected to the workpiece. The tungsten electrode is the conductor and the current
carrier (non-consumable electrode). The filler metal required is fed manually in the form of a
rod or by a separate cold wire feed unit. The tungsten electrode, and the welding pool is
protected from the atmosphere by the inert shielding gas supplied from the gas nozzle.
GB
6