In Open Circuit Operation, The Output Voltage Is Not Regular - Cebora PLASMA PROF 164 HQC Service Manual

CEBORA S.p.A.
♦ Check the wiring between the terminal of the HF transformer (7) secondary circuit, TP3 on
control box board (5), and the torch electrode terminal. If you find loose connections, tighten
and replace any damaged components.
♦ Make sure that there is no short-circuit between connectors CN1 and CN4 on HF board (2) or
in the wiring of the HF transformer (7) primary circuit.
♦ Check the distance between the tips of the scintillator SCI1 (correct distance = 0.95 mm).
♦ Check torch cable. If aged and cracked or leaking isolation, replace.
♦ Check electrode and torch nozzle. Replace if worn or damaged.
♦ Make sure that the gas pressure in the torch plasma chamber is not too high (see Instruction
Manual).
♦ Replace the HF (2) and/or control box (5) boards in the module HV18.
♦ Replace HF transformer (7).

3.3.8 - In open circuit operation, the output voltage is not regular.

POWER SOURCE OUTPUT VOLTAGE TEST.
Pilot arc board (58), terminals TP3(+) – TP7(-) = approximately +280 Vdc (if pilot arc off) or
+150 Vdc (with pilot arc lit), for a duration of 1 second (maximum pilot arc time) after
pressing the start command.
♦ Power source output voltage correct.
SETTINGS BOARD (54) ENABLE TEST.
Settings board (54), connector J3, terminals 4(+) – 7(-) = +5 Vdc, for a duration of 1 second
(maximum pilot arc time) after pressing the start command.
♦ Check the wiring between J3 settings board (54) and J7 of control board (38).
♦ With Power Source off, temporarily disconnect J7 from control board (38) and
check the resistance on terminals 4 and 7 of settings board (54). Correct value =
approximately 10 Kohm. If incorrect, replace control board (54).
♦ Check supply voltages of the settings (54) and control (38) boards, performing if
necessary the SETTINGS BOARD (54) POWER SUPPLY TEST and CONTROL
BOARD (38) POWER SUPPLY TEST in par. 3.3.1..
♦ Replace the control board (38).
PILOT ARC CURRENT REFERENCE TEST.
Settings board (54), connector J3, terminals 3(+) – 7(-) = fig. 5.2.1 = +4 Vdc (pilot arc current
reference signal) for a duration of 1 second (maximum pilot arc time), after pressing the start
command; (+5 Vdc with the Start command resting).
3.302.218
Correct?
NO
Correct?
YES
YES
NO
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9/8/2006