Gas Flows From The Torch, The Pilot Arc Does Not Light (High Frequency Missing) - Cebora POWER PLASMA 3100 Service Manual

CEBORA S.p.A.

3.3.6 - Gas flows from the torch, the pilot arc does not light (high frequency missing).

Some of the following tests may be checked only in the second after pressing the torch start
HF OSCILLATOR TEST.
HF board (22), discharger SC1 discharges at regular intervals, for approximately one second,
q
with start button pressed.
♦ Check connections between HF board (22) and torch; more specifically, between
TP5 and the torch electrode conductor, terminal E of J6 and nozzle conductor.
♦ Check torch cable; if worn or damaged or losing its insulation, replace.
♦ Check electrode and torch nozzle; replace if worn or damaged.
♦ Make sure that the gas pressure in the torch plasma chamber is not too high. If
necessary, check the operation of the pressure regulator (E) and pressure gauge
(F), and observe the technical specifications (see Instructions Manual).
♦ Go to par. 3.3.7.
♦ Check the distance between the tips of the discharger SC1 (correct value = 0.9 mm.).
♦ Make sure the HF transformer (T2) is correctly fixed on HF board (22), especially that the
primary winding is not interrupted. If necessary reset the original connection or replace HF
board (22).
FOR THE FOLLOWING TESTS DISCONNECT THE CONNECTOR J3 ON THE HF
BOARD (22) TO PREVENT HIGH FREQUENCY FROM BEING GENERATED.
CONTACT TIP VOLTAGE TEST.
HF board (22), connector J6-E and TP5 (gnd) = fig. 5.2.1, with start button pressed (open
q
circuit nozzle voltage, interrupted after approximately 300 msec., for missing pilot arc
current).
♦ Go to par. 3.3.7.
HF BOARD (22) POWER SUPPLY TEST.
HF board (22), connector J4 and patch terminal disconnected from J3 (gnd) = fig. 5.2.2, with
q
start button pressed (HF board (22) power supply voltage, interrupted after approximately 300
msec., for missing pilot arc current).
♦ Check the wiring between J3 and J4 HF board (22) and transformer TF2 on power
board (35).
3.302.089
NOTE
button, due to failure by the pilot arc to strike.
Correct?
NO
WARNING
Correct?
YES
Correct?
YES
YES
NO
NO
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31/05/02