Irregular Pilot Arc Starts, Unstable Pilot Arc - Cebora 961 Service Manual

CEBORA S.p.A.

3.3.5 - Irregular pilot arc starts, unstable pilot arc.

PLASMA GAS PRESSURE TEST.
Gas pressure correct in the plasma chamber of the torch.
♦ Make sure that solenoid valve EL1 (7) = opened, during the pilot arc.
♦ 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 (see Instruction
Manual and Sales Catalog).
♦ Make sure that the air fitting (B) inserted in the pressure regulator (E) has a
threaded part no longer than 6 - 8 mm (1/4" - 5/16"), to avoid a possible regulator
(E) malfunction.
♦ Make sure that the pressure regulator (E) and pressure gauge (F) are working
properly; replace if defective.
♦ Make sure there are no occlusions in the gas hoses of the power source.
♦ With power source off, check the resistance of resistor (36). Corrected value = 1,4 ohm. If not
correct replace resistor (36).
♦ Make sure the internal parts of the torch are properly isolated, including the cables, and if in
doubt replace the entire torch.
♦ Check the electrode, swirl ring and torch nozzle; replace if worn or damaged.
♦ With power source off, make sure the pilot arc firing ram inside the torch is working properly,
by manually supplying the ELT (6) air conduit. If you find a firing ram in defective working
conditions replace it or replace the complete torch.
3.302.170
Correct?
YES
NO
14
06/07/04