Cebora 961 - Transfer Arc Does Not Take Place or Is too Weak for Cutting

CEBORA S.p.A. 15
3.3.6 - Transfer arc does not take place or is too weak for cutting.
CONTACTOR TLM (32) COMMAND TEST.
Correct?
 Contactor TLM (32) = closed (230 Vac on coil terminals), with start button pressed and pilot
arc lit, for the pressure over start button lasting time.
YES
NO
♦ Check the wiring between contactor TLM (32) coil and terminals 1 and 7 of J4 on
control board (4).
♦ With power source off, check the resistance between terminals of contactor TLM
(32) coil. Corrected value = approximately 500 ohm. If 0 ohm (short-circuit),
replace contactor TLM (32) and control board (4).
♦ Replace control board (4).
♦ With power source off, check the resistance between terminals of contactor TLM (32) coil.
Corrected value = approximately 500 ohm. If >Mohm (coil interrupted), replace contactor
TLM (32).
POWER SOURCE OUTPUT VOLTAGE WITH PILOT ARC LIT TEST.
Correct?
 Electrode terminal on terminal board (31) (-) and power source output terminal (H)(51) (+) =
approximately +100 - +180 Vdc, with start button pressed and pilot arc lit, for the pressure
over start button lasting time.
YES
NO
♦ Check connections between positive terminal of rectifier (33), contactor TLM
(32) and output terminal (H)(51) of the power source. If any defective connections
are found, restore them and replace any components with damaged terminals.
♦ With the power source off, check the efficiency of the contacts of contactor TLM
(32), by manually activating it, and make sure that the resistance on each contact
is approximately 0 ohm. If you find burnt contacts or interference in moving the
parts, replace the TLM (32) contactor.
♦ Check connections between torch cable and negative terminal of the rectifier (33), and
between work cable, contactor TLM (32) and positive terminal of the rectifier (33). If you
find any deteriorated connections, reset them and replace any damaged components.
♦ Check connections between work cable and workpiece.
♦ Make sure that the gas lines in the power source are not partially clocked, so that the gas
throughput is enough for the pilot arc but not for the transfer arc.
♦ 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 malfunction of the regulator (E).
♦ Check the condition of electrode, nozzle, nozzle holder and diffuser of the torch.
♦ Check the wiring between J7 of control board (4) and electrode and nozzle torch cable
terminals on terminal board (31).
♦ Replace control board (4).
3.302.170 06/07/04