Cebora 961 - Page 13

CEBORA S.p.A. 13
♦ Check the condition of the torch cable and torch, especially making sure there are
no short-circuits or isolation leaks between the conductors, and that electrode,
nozzle, nozzle holder and diffuser are not to be replaced.
PILOT ARC FIRING SOLENOID VALVE ELT (6) TEST.
NOTE
All auxiliary services, contactors, solenoid valves, fan, are supplied directly at mains
potential, so that detecting the following waveform use a battery scope or a scope with insulating
probe.
Correct?
 Solenoid valve ELT (6) terminals = fig. 5.2.2, 230 Vac approximately, with torch button
pressed. Solenoid valve ELT (6) voltage supply, interrupted after 400 msec. approximately for
missing pilot arc light on.
YES
NO
♦ Check the wiring between solenoid valve ELT (6) and terminals 4 and 10 of J4 on
control board (4).
♦ With power source off, check the resistance between terminals of solenoid valve
ELT (6) = approximately 2 Kohm. If 0 ohm (short-circuit), replace solenoid valve
ELT (6) and control board (4).
♦ Check the wired bridge between terminals 1 and 2 of J3 on control board (4). All
auxiliary services, contactors and solenoid valves, are connected under such wired
bridge and fuse F1.
♦ Perform the CONTROL BOARD (4) POWER SUPPLY TEST, par. 3.3.1.
♦ Replace control board (4).
♦ With power source off, check the resistance between the terminals of solenoid valve ELT (6)
= approximately 2 Kohm. If >Mohm (winding broken) replace solenoid valve ELT (6).
♦ Make sure there are no occlusions in the gas hoses of the power source, especially in the
conduit between ELT (6) and the pilot arc firing ram inside the torch.
♦ 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.
♦ Make sure that the pressure in the torch plasma chamber is not excessive, and regulator (E)
and pressure gauge (F) are working properly.
♦ Check the condition of the torch cable and torch, especially making sure there are no short-
circuits or isolation leaks between the conductors and that electrode, nozzle, nozzle holder and
diffuser are not to be replaced (see Instruction Manual).
♦ Replace solenoid valve ELT (6).
♦ Replace the complete torch.
♦ Replace control board (4).
3.302.170 06/07/04