Cebora 965, Руководство по обслуживанию, Страница: 5 / 24

CEBORA S.p.A.
5
When the start button is pressed, the control board (6) strikes the pilot arc by activating the
solenoid valve EL1 (34) (the one with the flow reducer), the input contactor TLP (30) and high
frequency generation.
When solenoid valve EL1 (34) is opened, the gas starts to flow out from the torch for the
pressure on the start button lasting time plus the post-gas time (90 seconds).
With the contactor TLP (30) closed, the voltage rectified by the bridge (32) is applied to the
torch nozzle through the resistors (37).
High frequency generation lasts approximately 300 msec., during which the pilot arc must
light on. If pilot arc doesn’t start, you need to release and press again the start button, to perform
a new tentative.
When the pilot arc is lit, you have approximately 2 seconds to begin cutting, after which timer
the pilot arc shuts off until the start button is pressed again.
When the torch with lit pilot arc is placed near the workpiece, the arc current begins
circulating on the earth conductor due to the potential difference caused by the resistors (37).
The solenoid with reed bulb (42) detects this arc current and provides information about it to
the control board (6), which begins operation in transfer arc, thus it opens solenoid valve EL2
(34) (the one without flow reducer).
When cutting ends, input contactor TLP (30) and solenoid valve EL2 (34) are deactivated,
while solenoid valve EL1 (34) remains powered for the post-gas time (approximately 90
seconds).
The signals processed by the electronic boards and present at their connectors are listed in the
tables in chapter five of this manual.
3.302.173 28/07/04