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

CEBORA S.p.A.

3.3.7 - Gas flows from the torch, the pilot arc does not light (nozzle voltage missing).

Some of the following tests may be checked only in the second after pressing the torch start
FOR THE FOLLOWING TESTS DISCONNECT THE CONNECTOR J3 ON THE HF
BOARD (22) TO PREVENT HIGH FREQUENCY FROM BEING GENERATED.
NOZZLE 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. 3.3.6.
POWER BOARD (35) OUTPUT VOLTAGE TEST.
HF board (22), terminals FISS1 and J5 (gnd) = fig. 5.2.1, with start button pressed (open
q
circuit nozzle voltage, interrupted after approximately 300 msec., for missing pilot arc
current).
♦ On HF board (22), check the connection of the secondary circuit of the HF
transformer (T2) between terminals J5 and TP5. If you detect cold welds or
interruptions in the printed circuit, reset the original connections, and make sure
that the torch cable conductors are properly insulated.
♦ With the power source off, check the resistance between the terminals FISS1 and
J6-E on the HF board (22). Correct value = approximately 0 ohm (NC contact of
relay RL2 closed). If incorrect, make sure that there are no interruptions in the
printed circuit, make sure that the torch cable conductors are properly insulated,
and replace RL2 if necessary.
♦ Replace the HF board (22).
♦ Check the wiring between terminals FISS1 and J5 on HF board (22) with terminals P5 and P6
on power board (35).
♦ Check the wiring between connectors J1 panel board (31) and J1 power board (35).
♦ Replace the panel (31) and/or power (35) boards.
3.302.089
NOTE
button, due to failure by the pilot arc to strike.
WARNING
Correct?
NO
Correct?
NO
YES
YES
16
31/05/02