Cebora SOUND MIG 3840/T Pulse Service Manual page 34

CEBORA S.p.A.
♦ Check the wiring between the terminals 2 and 4 on pre-charge board (562), fuse
(BN) on rear panel and fast-on connector (inserted in the wiring between cooling
unit and power source).
♦ Check fuse (BN) on power source rear panel. If tripped, replace and make sure
resistance on fast-on connector terminals (inserted in the wiring between cooling
unit and power source). Correct value = approximately 19 ohm. If incorrect open
cooling unit and make sure resistance of pump (125) = 21 ohm, approximately,
and fan (131) = 500 ohm approximately, each fan. If incorrect replace the
defective device.
PRESSURE SWITCH (127) TEST.
Interface board (543), connector J5, terminals 3(+) and 2(-) = 0 Vdc, with pump (125) and
fans (131) running (pressure switch contact closed = suitable pressure); +24 Vdc, with pump
(125) and fans (131) stopped (pressure switch contact open = pressure low).
♦ Check the wiring between pressure switch (127) and connector J1 pre-charge
board (562), and between J2 pre-charge board (562) and J5 interface board (543).
♦ With power source off, temporarily disconnect J1 from pre-charge board (562).
Power up the power source and check the voltage on terminals 1(+) and 2(-) of J1,
pre-charge board (562) = +24 Vdc. If correct, check the integrity of pressure
switch (127). If incorrect, make sure on J5 interface board (543), terminals 5(+)
and 2(-) voltage = +24 Vdc. If correct replace control board (543). If not correct
make sure on J2 pre-charge board (562), terminals 1(+) and 4(-) voltage = +24
Vdc. If correct replace pre-charge board (562). If not correct check wiring
between J2 pre-charge board (562) and J6 flyback board (539), and if necessary
replace flyback board (539).
♦ Make sure that the lines of the cooling circuit are not clogged, especially in the
part where it is connected the pressure switch (127).
♦ Check rotation direction of the pump (125).
♦ Replace pressure switch (127) and/or pump (125).
♦ Open cooling unit and check wiring between fast-on connector (inserted in the wiring
between cooling unit and power source), pump (125) and fans (131).
♦ With power source off, temporarily disconnect connections between cooling unit devices
(pump (125) and fans (131)) and make sure resistance on each single device terminals.
Correct values: pump (125) = 21 ohm, approximately, and fan (131) = 500 ohm
approximately, each fan.
♦ Check the integrity and connection of the starting capacitor of the pump (125). Replace if
necessary.
♦ Check rotation direction of the pump (125).
♦ Make sure that there are no mechanical impediments jamming the pump (125) and/or fans
(131).
♦ Make sure coolant liquid level.
♦ Replace pump (125) and/or fans (131) and/or control board (543).
3.302.191
Correct?
YES
Correct?
YES
NO
NO
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15/02/05