Transfer Arc Does Not Take Place Or Is Too Weak For Cutting - Cebora PLASMA PROF 80 Service Manual

CEBORA S.p.A.

3.3.9 - Transfer arc does not take place or is too weak for cutting.

OPERATING TEST IN PILOT ARC.
Pilot arc lights normally, pilot arc stable.
Go to par. 3.3.8.
TRANSFER ARC SWITCHING TEST.
Control board (9), connector J2, terminals 1 and 2 = 0 Vdc, with transfer arc, thus while
cutting (27 Vac with pilot arc on). This situation remains constant for as long as cutting
continues.
♦ Make sure the reed bulb (26) is properly mounted in the corresponding solenoid,
and the solenoid on the power board (20).
♦ With the power source off, make sure that the switch in the reed bulb (26) is
working properly: move a magnet near the bulb and check the resistance between
the terminals 1 and 2 of J2 on control board (9) = 0 ohm (reed contact closed).
Move the magnet away from the bulb; resistance = approximately 7 Kohm (reed
contact open). If incorrect replace reed bulb (26) or the complete power board
(20).
♦ Check the earth cable connection to the workpiece.
♦ Replace control board (9).
TRANSFER ARC SOLENOID VALVE EL2 (37) TEST.
Solenoid valve EL2 (37) terminals = 26 Vac with transfer arc, for the entire cutting time.
♦ Check the wiring between solenoid valve EL2 (37) and terminals 4 and 10 of J5
on control board (9).
♦ With power source off, check the resistance between the terminals of solenoid
valve EL2 (37) = approximately 25 ohm. If 0 ohm (short-circuit), replace solenoid
valve EL2 (37) and control board (9).
♦ Replace control board (9).
♦ With power source off, check the resistance between the terminals of solenoid valve EL2 (37)
= approximately 25 ohm. If >Mohm (winding broken) replace solenoid valve EL2 (37).
♦ Check connections between central terminal of central adapter (12), HF transformer (23)
secondary circuit, choke (44) and terminal TP5 of power board (20), and between earth cable,
output terminal (H) of the power source and terminal TP4 power board (20). If you find any
deteriorated connections, reset them and replace any damaged components.
♦ Check the condition of the central adapter, the torch cable and torch; especially make sure
there are no short-circuits or insulation leaks between the conductors or between the contacts
of the central adapter. Replace any worn or damaged components.
3.302.167
Correct?
YES
Correct?
YES
Correct?
YES
NO
NO
NO
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25/06/04