CEBORA S.p.A.
17
3.3.6
- In TIG mode, gas flows from the torch, the arc does not strike (no high frequency).
HF OSCILLATOR TEST.
Via the control panel, set TIG operation with HF (ex.: Leds L and G lit).
Correct?
HF board (42), discharger SP2 emits discharges at regular intervals, with start button pressed.
NO
YES
♦
Check the connections between secondary windings of the power transformer
(46), thyristor group (47), inductor (50), AC/DC selector switch (30), HF
transformer (28) e output terminals (-)(AB) e (+)(AC) of the power source. If you
find loose connections, tighten them and replace any components with damaged
terminals.
♦
Check operation of the AC/DC selector switch (30), making sure the closing
sequence of the contacts matches the table in the electrical diagram in par. 5.1.
♦
Make sure that there is no short-circuit between terminals J1 and J2 of HF board
(42) or in the connection of the primary circuit of HF transformer (28).
♦
Check the integrity of the HF-filter board (41), particularly the status of the 3
capacitors, the earth connection of the board, and the connections between
terminals TP1 of HF-filter board (41) with (+)(AC) output terminal of the power
source and TP2 of HF-filter board (41), with the shared point between inductor
(50) and HF transformer (28). If you find damaged components or connections,
replace HF-filter board (41).
♦
Make sure that the output terminals (+)(AC) and (-)(AB) of the power source
(gifas) are not in isolation leak, thus that there are no high voltage surface
discharges. Replace with new ones if necessary.
♦
Check the torch and torch cable; if worn or damaged, replace.
♦
Go to par. 3.3.7. (open circuit operation).
♦
Make sure the connection between terminals J1 and J2 of HF board (42) with the primary
circuit of the HF transformer (28) is not broken. If necessary, restore the connection or replace
HF transformer (28) and/or HF board (42).
♦
Check the distance between the tips of the discharger SP2 (correct values = 0.85 mm.).
HF BOARD (42) COMMAND TEST.
WARNING
FOR THIS TEST
DISCONNECT THE CONNECTOR J3
ON HF BOARD (42) TO
PREVENT HIGH FREQUENCY GENERATION.
Correct?
HF board (42), connector J4, terminals 1 - 2 = approximately 30 Vac, with start button
pressed.
YES
NO
♦
Check the wiring between J4 HF board (42) and J9 control board (40).
♦
With power source off, temporarily disconnect connector J4 from HF board (42)
and check the resistance between terminals 1 - 2 of J4 on HF board (42). Correct
values = >Mohm in both directions. If incorrect replace HF board (42). If in short-
circuit, also replace control board (40).
3.302.221
15/01/07
Summary of Contents for TIG 250 AC-DC
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