Irregular Pilot Arc Starts, Unstable Pilot Arc - Cebora PLASMA PROF 80 Service Manual

CEBORA S.p.A.

3.3.8 - Irregular pilot arc starts, unstable pilot arc.

PLASMA GAS PRESSURE TEST.
Gas pressure correct in the plasma chamber of the torch.
♦ Check for the presence of gas at the intake fitting (B) and make sure that the
pressure and flow rate in the intake line meet specifications.
♦ Make sure that the threaded part of the fitting (B) inserted in the pressure
regulator (E) is no more than 6 - 8 mm (1/4" - 5/16") long, to avoid any possible
malfunction of the regulator (E).
♦ Make sure that the pressure regulator (E) and pressure gauge (F) are working
properly.
♦ Make sure there are no occlusions in the gas hoses of the power source.
♦ Make sure that solenoid valve EL1 (37) = open, and solenoid valve EL2 (37) =
closed, during the pilot arc. If necessary, perform the tests PILOT ARC
SOLENOID VALVE EL1 (37) TEST, par. 3.3.4, and TRANSFER ARC
SOLENOID VALVE EL2 (37) TEST, par. 3.3.9.
♦ Check presence of the flow regulator on the solenoid valve EL1 (37).
PILOT ARC CURRENT TEST.
Setting board (19), connector J2, terminals 4 and 2 (gnd) = fig. 5.2.3 (pilot arc current signal)
with start button pressed and pilot arc lit.
♦ Regular pilot arc operation.
♦ Carry out the test in par. 3.3.6.
♦ Check for the presence of the three phases of supply voltage on terminals TP1, TP2, TP3 of
power board (20).
♦ Check the wiring of the primary and secondary windings of the transformer (50), considering
that any connection other than the one shown in the diagram in par. 5.1 is to be considered
incorrect and may cause additional damage to the power source components.
♦ Check the wiring between J3 setting board (19) and voltage change on the transformer (50).
In particular make sure that the connection of each individual wire has been made as shown in
the diagram in par. 5.1.
♦ Check the condition of the windings of transformer (50), especially making sure that there are
no signs of overheating or dents in the winding columns that may lead to partial short-circuits
in the pins. If necessary, replace the transformer (50).
♦ Check connections between central adapter (12), HF transformer (23), choke (44) and
terminal TP5 of power board (20). If you find loose connections, tighten and replace any
components with damaged terminals.
♦ Check the condition of the central adapter (12), the torch cable, and the internal parts of the
torch. If you find short-circuits or isolation leaks, restore the original isolation or replace the
damaged components.
♦ Check the electrode, swirl ring and torch nozzle; replace if worn or damaged.
3.302.167
Correct?
YES
Correct?
NO
NO
YES
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25/06/04