Cebora 965, Service Manual, Page: 17 / 24

CEBORA S.p.A.
17
3.4 - Alarm signals.
3.4.1 - Lamp (G) (45) lit, with fix light = transformer (44) temperature above the limit.
Power source remains in block with contactor TLP (30) opened.
We recommend not to shut off the power source, to keep the fan (39) running and thus allow
rapid cooling.
This is reset automatically when the temperature returns within the allowed limits.
Thermostat in reality is made by two thermostatic switches connected in series between them,
located on two columns of the transformer (44).
THERMOSTAT ON THE TRANSFORMER (44) TEST.
Correct?
‰
Control board (6), connector J3, terminals 6 and 7 = 0 Vac, contact closed, with transformer
(44) at ambient temperature; 24 Vac, contact open, with temperature beyond limits.
YES
NO
♦
Check the wiring between thermostats on transformer (44) and terminals 6 and 7
of J3 on control board (6), considering that in reality thermostatic switches are
two, series connected between them.
♦
Make sure that the two thermostatic switches are intact and properly positioned on
the windings of the transformer (44).
♦
If the alarm occurs while cutting, and the transformer (44) is evenly heated, make
sure that the duty-cycle is not greater than indicated in the power source
specifications.
♦
If the alarm occurs while cutting, and only some of the windings of the
transformer (44) are heated, one may infer that the transformer (44) is partially
short-circuited, and must therefore be replaced.
♦
Replace thermostat on transformer (44).
♦
Replace control board (6).
3.4.2 - Lamp (G) (45) flashing (two flashes with one second pause) = start button pressed
during power source start-up.
If at the start up the start button on the torch is detected closed, the power source remains in
block with contactor TLP (30) opened, without output voltage and with lamp (G) (45) flashing.
The reset is automatic when the start button is released.
For the problem analysis perform the START COMMAND TEST, par. 3.3.3.
3.4.3 - Lamp (G) (45) flashing (three flashes with one second pause) = reed contact (42)
closed at power source start-up.
If the reed contact (42) is found closed upon start-up, the power source remains blocked, with
contactor TLP (30) opened, without delivering current and with lamp (G) (45) flashing.
To restore proper operation, shut off and restart the power source after first removing the
cause that closed the reed contact (42).
To analyze the problem, carry out the TRANSFER ARC SWITCHING TEST, par. 3.3.9.
3.302.173 28/07/04