Gas Flows From The Torch, Pilot Arc Does Not Start (No High Frequency) - Cebora PLASMA PROF 123 ACC Service Manual

CEBORA S.p.A.

3.3.7 - Gas flows from the torch, pilot arc does not start (no high frequency).

NOZZLE VOLTAGE TEST.
Power board (56), terminal TP6(or terminal 1 of igbt module)(gnd) and terminal J4(+) on
sensor board (52) = fig. 5.2.2a (+280 Vdc approximately, contactor (55) closed) nozzle
voltage with pilot arc off, for 2.5 seconds (pilot arc maximum time), with start button pressed.
♦ Go to par. 3.3.6.
VOLTAGE PRESENCE ON HF BOARD (27) TEST.
HF board (27), terminals CN2(+) and CN3(-), voltage = fig. 5.2.3a (+280 Vdc
approximately) voltage on HF board (27) with pilot arc off, for 2.5 seconds (pilot arc
maximum time), with start button pressed.
♦ Check the wiring between CN2 - CN3 of HF board (27) and terminals 1 - 4 of J1
on sensor board (52).
♦ Check the wiring between J1 terminal on power board (56), nozzle resistor (33),
contactor (55) and J4 terminal on sensor board (52). If you find loose connections,
tighten and replace any damaged components.
♦ Check for continuity between terminal J4 and terminal 4 of J1 on sensor board
(52). If interrupted reset the connection and replace sensor board (52), if
necessary.
♦ Check wiring between TP7 terminal of power board (56), choke (35), HF
transformer (50), TP2 terminal on HF-filter board (32), TP4 terminal on HF-filter
board (32) and terminal 1 of J5 on sensor board (52). If loose connections are
found, tighten them and replace any damaged components.
♦ Check for continuity between terminal 1 of J5 and terminal 1 of J1 on sensor
board (52). If interrupted reset the connection.
♦ Check resistor (33). Correct value = 1.5 ohm. If incorrect, replace it.
♦ Replace sensor board (52) and/or HF-filter board (32).
HF OSCILLATOR TEST.
HF board (27), discharger SCI1 discharges at regular intervals.
♦ Make sure that connection between terminals CN1 and CN4 of HF board (27),
and HF transformer (50) primary circuit is not interrupted.
♦ Check distance between discharger SCI1 tips (correct distance = 0.95 mm).
♦ Replace HF board (27).
3.302.269
Correct?
YES
Correct?
YES
Correct?
YES
NO
NO
NO
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12/04/2012