Cebora PLASMA PROF 162 Service Manual page 19

CEBORA S.p.A.
VOLTAGE TEST AT IGBT INPUT.
Terminals 2 - 3 of IGBT (72) = 260 VDC, with rated mains voltage, stable even with pilot
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arc lit (- 10% max.).
♦ Check 3 x 180 VAC, with rated mains voltage, on input terminals of rectifier
bridge (78); if not correct check transformer connections (79), main voltage
change, remote switch (5) and mains voltage.
♦ Check rectifier bridge (78); replace if defective.
♦ Replace board (62).
PILOT ARC REFERENCE TEST.
Driver board (9), connector J3, terminals 1 – 2 = fig. 5.2.1. (pilot arc current set-point).
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♦ Check the wiring between connectors J3 on board (9) and J2 on board (62).
♦ Make sure that terminals 1 - 2 of J3 on board (9) are not short-circuited. If so,
replace board (9).
♦ Replace board (62).
PILOT ARC CURRENT REACTION TEST.
Control board (9), connector J4 terminals 2 – 3 = +15 VDC and 2 - 1 = -15 VDC (power
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supplies); terminals 2 - 4 = fig. 5.2.2. (pilot arc current feed-back).
♦ Check the wiring between current transducer (71) and connector J4 on board (9).
♦ Replace current transducer (71).
♦ Check IGBT (72). Replace if defective. According to the type of defect, it may
also be necessary to replace the board (9).
♦ Replace board (9).
♦ Check the adapter and torch cable; replace if aged or cracked.
♦ Check electrode and torch nozzle; replace if worn or damaged.
♦ Make sure the internal parts of the torch are properly insulated, including cables; if in doubt,
replace the entire torch.
3.302.002
Correct?
YES
NO
Correct?
YES
NO
Correct?
YES
NO
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03/08/00