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

CEBORA S.p.A.

3.3.6 - Gas flows from the torch, pilot arc does not start (no nozzle voltage).

POWER SOURCE OUTPUT VOLTAGE TEST.
Power board (56), terminals TP1(+) – TP6(or terminal 1 of igbt module)(gnd) = fig. 5.2.1a
(+280 Vdc approximately) Power Source output voltage with pilot arc off, for 2.5 seconds
(pilot arc maximum time), with start button pressed.
♦ Go to par. 3.3.8.
POWER BOARD (56) OUTPUT VOLTAGE TEST.
Power board (56), terminals J1(+) – TP6(or terminal 1 of igbt module)(gnd) = fig. 5.2.1a
(+280 Vdc approximately) output voltage for nozzle, with pilot arc off, for 2.5 seconds (pilot
arc maximum time), with start button pressed.
♦ Make sure that terminals TP1 and J1 on power board (56) are connected between
them, through the LEM Hall effect current transducer. If interrupted restore the
connection. If not possible replace power board (56).
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. 3.3.7.
♦ Check the wiring between terminal J1 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 resistor (33). Correct value = 1.5 ohm. If incorrect, replace it.
♦ Check the wiring contactor (55) coil terminals and J10, terminals 4 and 11 on control board
(47) (CONTACTOR (55) COMMAND LINE).
♦ Check on contactor (55) coil terminals, voltage = 25 Vac with start button pressed. If correct,
make sure that contactor (55) has not contacts blocked in open position. If required, replace
contactor (55). If incorrect, check the supply voltage of the control board (47) taking special
care for 27 Vac voltage carrying out the CONTROL BOARD (47) POWER SUPPLY TEST
of par. 3.3.1.
♦ With Power Source off, temporarily disconnect J10 from control board (47) and check the
resistance between contactor (55) coil terminals. Correct value = approximately 7 Kohm. If
>Mohm, replace contactor (55). If 0 ohm (short-circuit), replace contactor (55) and control
board (47).
♦ Replace control board (47) and/or contactor (55).
3.302.269
Correct?
YES
Correct?
YES
Correct?
NO
NO
NO
YES
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12/04/2012