Snap-On TIG 250 AC-DC, Руководство по обслуживанию

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CEBORA S.p.A.
6
The snubber board (6) also includes the load resistors for SCR1 and SCR2 (47), which make
it possible for SCR1 and SCR2 (47) to function correctly even with an open circuit power
source, and the capacitor C1, which helps strike the arc in DC mode.
The connector (13) on the rear panel of the power source is connected to the pressure switch
on the cooling unit; it is connected in series to the thermostats on transformer (46) and inductor
(50), on the same alarm line that reaches the control board (40). When the cooling unit is not
connected, it is necessary to make a bridge on connector (13) between terminals 1 and 3, to
prevent the power source from remaining blocked.
The fan (45), to cool the power elements of the power source, is powered directly by terminal
board (52) and therefore always at 230 Vac.
On the front panel is the connector board (49), which acts as an interface for the power source
input and output signals. It dialogues directly with the control board (40) and contains the filters
to eliminate disturbances on the power source input and output signals.
These signals include:
−
Power source start, from torch trigger.
−
External adjustment of the welding current via external potentiometer.
The signals processed by the electronic boards and present at their connectors are listed in the
tables in chapter five of this manual.
3.302.221 15/01/07