Transfer Arc Does Not Take Place Or Is Too Weak For Cutting - Cebora PLASMA PROF 164 HQC Service Manual

CEBORA S.p.A.
♦ With Power Source off, temporarily disconnect the cables of the extension art. 1179 from the
Power Source terminals (53) and J5 of torch board (42), and check the isolation between the
disconnected cables and towards earth. This makes it possible to test the isolation of extension
art. 1197, module HV18 and the torch. If you find a short-circuit or low resistance, locate and
replace the defective component.
♦ Carry out the test in par. 3.3.8.

3.3.10 - Transfer arc does not take place or is too weak for cutting.

NOZZLE CURRENT TRANSDUCER POWER SUPPLY TEST.
Pilot arc board (58), connector J2 terminals 2(+) – 3(-) = +15 Vdc; terminals 4(+) - 3(-) = -15
Vdc.
♦ Check the wiring between J2 pilot arc board (58) and J1 settings board (54).
♦ With Power Source off, temporarily disconnect the connector J1 from settings
board (54) and check the resistance between the terminals 2-3 and 4-3 of the patch
connector disconnected from J1. Correct value = approximately 22 Kohm, for
each measurement point. If incorrect, replace pilot arc board (58).
♦ Power up the Power Source again, keeping J1 disconnected from settings board
(54), and check voltages on J1 of settings board (54), terminals 2(+) and 3(-) =
+15 Vdc; terminals 4(+) and 3(-) = -15 Vdc. If incorrect, replace settings board
(54).
♦ Check supply voltages of the settings board (54), performing if necessary the
SETTINGS BOARD (54) POWER SUPPLY TEST in par. 3.3.1..
♦ Replace settings (54) and/or pilot arc (58) boards.
NOZZLE CURRENT SIGNAL TEST.
Settings board (54), connector J1, terminals 1(+) – 3(-) = fig. 5.2.3 = +5 Vdc approximately
(nozzle current feedback signal with pilot arc lit), for a duration of 1 second (maximum pilot
arc time) with start command activated.
♦ Check the wiring between J2 pilot arc board (58) and J1 settings board (54).
♦ With Power Source off, temporarily disconnect the connector J1 from settings
board (54) and check the resistance between terminals 1 and 3 of J1 on settings
board (54). Correct value = approximately 22 Kohm. If incorrect, replace settings
board (54).
♦ With the Power Source off, on pilot arc board (58) check terminals TP3 and J5
resistance = approximately >Mohm for each measurement point. If incorrect,
perform the PILOT ARC BOARD (58) POWER SUPPLY TEST and NOZZLE
IGBT COMMAND TEST in par. 3.3.6, and replace pilot arc board (58) if
necessary.
♦ Replace the pilot arc board (58).
3.302.218
Correct?
YES
Correct?
YES
NO
NO
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9/8/2006