Cebora PLASMA PROF 164 HQC Service Manual page 20

CEBORA S.p.A.
♦ Shut off the Power Source, wait for the capacitors to discharge (1 minute),
temporarily disconnect connector J4 from pre-charge board (45) and check the
resistance between terminals 1 and 2 of J1 of pilot arc board (58). Correct value =
diode junction in one direction and >Mohm with the instrument probes reversed.
If >Mohm in both directions, replace pilot arc board (58). If 0 ohm (short-circuit),
replace pilot arc board (58) and pre-charge board (45).
♦ Check on J3 of pre-charge board (45), terminals 5 and 6 voltage = 25 Vac with
switch (39) closed. If incorrect, with Power Source off, temporarily disconnect
connector J3 from pre-charge board (45) and check the resistance between
terminals 5 and 6 of J3 of pre-charge board (45). Correct value = approximately
300 ohm. If >Mohm replace pre-charge board (45). If 0 ohm (short-circuit),
replace pre-charge board (45) and control board (38). If correct, check the power
supply of the control board (38) by performing the CONTROL BOARD (38)
POWER SUPPLY TEST in par. 3.3.1.
♦ Check on J3 of pre-charge board (45) terminals 3 and 4 voltage = approximately
25 Vac, for a duration of 1 sec., starting 1 sec. after closing switch (39). If
incorrect, with Power Source off, temporarily disconnect connector J3 from pre-
charge board (45) and check the resistance between terminals 3 and 4 of J3 of pre-
charge board (45). Correct value = approximately 60 ohm. If >Mohm replace pre-
charge board (45). If 0 ohm (short-circuit), replace pre-charge board (45) and
control board (38). If correct, check the power supply of the control board (38) by
performing the CONTROL BOARD (38) POWER SUPPLY TEST in par. 3.3.1.
♦ On the coil terminals of the contactor (44), make sure voltage = 25 Vac with
switch (39) closed, after the pre-charging the DC-capacitors and pre-magnetizing
the transformer (27). If incorrect, with Power Source off, temporarily disconnect
connector J13 from control board (38) and check resistance between the terminals
of the contactor (44) coil. Correct value = approximately 3.7 ohm. If >Mohm
replace contactor (44). If 0 ohm (short-circuit), replace contactor (44) and control
board (38). If correct, check the power supply of the control board (38) by
performing the CONTROL BOARD (38) POWER SUPPLY TEST in par. 3.3.1.
♦ Replace contactor (44) and/or pre-charge (45) and/or control (38) boards.
♦ Check the wiring between fan (20), starting capacitor (18) and power voltage change.
♦ Make sure the power voltage change is correctly positioned.
♦ Check for the presence of the three power supply phases on the transformer (27) primary
circuit.
3.302.218
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9/8/2006