40 - Dangerous Voltage - Cebora PLASMA PROF 123 ACC Service Manual

CEBORA S.p.A.
♦ With Power Source off, temporarily disconnect J4 from control board (47) and
check resistance between terminals 1 and 3 of J4 on control board (47). Correct
value = approximately 21 Kohm. If incorrect, replace control board (47).
♦ Check the presence of supply voltage at the nozzle current transducer on power
board (56), performing the NOZZLE CURRENT TRANSDUCER POWER
SUPPLY TEST of par. 3.3.10.
♦ Replace power board (56).

3.4.5 - 40 - Dangerous voltage.

DANGEROUS VOLTAGE TEST.
Sensor board (52), connector J5, terminals 4(+) - 1(-) = approximately 0 Vdc, with Power
Source powered and without start command; +280 Vdc approximately, with pilot arc off;
+160 Vdc approximately, with start command and pilot arc lit.
♦ Check wiring between terminal 1 of J5 on sensor board (52), TP4 terminal on
HF-filter board (32), TP2 terminal on HF-filter board (32) and common terminal
between choke (35) and HF transformer (50).
♦ Check wiring between terminal 4 of J5 on sensor board (52), TP3 terminal on HF-
filter board (32), TP1 terminal on HF-filter board (32) with output terminal (+)
(ground potential) of Power Source.
♦ Check the continuity between terminals TP4 and TP2 on HF-filter board (32) and
between terminal TP3 and TP1 on HF-filter board (32). If broken reset the
connection.
♦ Check delivery of output voltage, performing, if necessary, the tests in par. 3.3.6..
SENSOR BOARD (52) POWER SUPPLY TEST.
Sensor board (52), connector J7, terminals 1 and 2 = approximately 20 Vac.
♦ Check the wiring between J7 sensor board (52) and J1, terminals 4 and 5 on fuse
board (53).
♦ Check fuse F3 on fuse board (53). Replace if broken after having checked, with
Power Source off and J7 disconnected from sensor board (52), the resistance
between terminals 1 and 2 of J7 on sensor board (52). Correct value = >Mohm in
both directions. If incorrect replace the sensor board (52).
♦ Check 20 Vac voltage on terminals 0V-20V on fuse board (53); if correct check
the wiring between services transformer (53) and fuse board (53) and replace
services transformer (53), if necessary.
♦ With Power Source off, temporarily disconnect J5 from sensor board (52) and check the
resistance on terminals 1 and 4 of J5 on sensor board (52). Correct value = approximately 9.5
Kohm. If incorrect replace the sensor board (52).
3.302.269
Correct?
YES
Correct?
YES
NO
NO
27
12/04/2012