-
-
N.B.
-
fig.3
fig.3
WARNING!
fig.3
fig.3
fig.3
WARNING!
WARNING!
fig.3
rheofores ofopto-couplers ISO1 and ISO2;
rheofores ofconnectors J4 and J6;
Do this if it is necessary to remove the primary board, otherwise it
is possible to clean the part superficially from the side of the
secondaryboard.
If the primary and secondary boards are removed (with the
diaphragm), carefully clean all the parts fastened to the base, or
cleanthe base partially fromthe sides ofthe machine.
Make sure there is no mechanical deformation, dent, or damaged
and/ordisconnected connector.
Make sure the power supply cable has not been damaged or
disconnected internally and that the fan works with the machine
switched on. Inspect the components and cables for signs of
burning or breaks that may endanger operation of the power
source.Checkthe following elements:
Probablecause:
- see main power supply switch. If the relay contacts are
stuck together or dirty, do not attempt to separate them and
cleanthem, just replacethe relay.
Probablecause:
- mechanical shock;
- machine connected to power supply voltage much higher than
therated value;
- broken rheophore on one or more capacitor:the remainder will
beoverstressedandbecome damaged byoverheating;
- ageing aftera considerablenumberof working hours;
- overheating causedbythermostatic capsulefailure.
Probablecause:
- discontinuationin snubbernetwork,
- fault indrivercircuit
- poorly functioning thermal contact between IGBT and
dissipator(e.g.loosenedattachment screws:check),
- excessiveoverheating relatedto faultyoperation
Probablecause:
- excessiveoverheating relatedto faultyoperation.
Probablecause:
-mechanical shock.
Probablecause:
- discontinuationin snubbernetwork;
- poorly functioning thermal contact between IGBT and
dissipator(e.g.loosenedattachment screws:check);
- faulty outputconnection.
Checkitforcolour changes.
Probablecause:
overheating due to loosening of the screws connecting the shunt
tothe PCB.
Inspectthe windings forcolour changes.
Probablecauses:
- aging aftera substantial numberof working hours;
- excessive overheating related to faultyoperation.
It is important to check that all the connections are in good
condition and the connectors are inserted and/or attached
correctly.To do this, take the cables between finger and thumb (as
close as possible to the fastons or connectors) and pull outwards
gently: the cables should not come away from the fastons or
connectors.N.B.If the power cablesare not tight enough this could
causedangerous overheating.
A) With the multimeter set on diode testing check the following
components(joint voltagesnot lessthan 0.2V):
- rectifierbridgesD3, D5 ( );
- IGBT's Q1, Q2, Q3, Q4, (no short circuits between collector-
gateand collector-emitter ( );
Before proceeding with faultfinding,we should remind
you that during these tests the power source is powered and
therefore theoperator is exposedto the dangerof electric shock.
The tests described below can be used to check the operation of
thepowerand control partsof the powersource.
A) From the primary board, disconnect fastons CN3 (XF+) and
CN10(XF-) forthepowertransformer ( ).
B) Onthe primary board disconnect the jumper onJP1.
C) Connect the HV power supply OUT (code 802403) on the
primary boardas follows ( ):
- (+) Positive (clamp) to rheofore of resistor R35 towards JP1
(afterremoving jumper JP1);
- (-)Negative(faston)to negativefastonof diode bridge D3.
D) Set up the oscilloscope with the voltage probe x100 connected
between the rheofore of R40B (collector Q10) towards JP1
(probe) and the negative of diode bridge D3 (earth) to the primary
board( ).
the high frequency voltage will permanently damage
any instrument connected to the generator. Before proceeding
makevery sure that the fastons listed aboveare disconnected and
completelyisolated from oneanother.
F) Connect the power supply cable to a single phase variac with
variable output0-300Vac.
during testing prevent contact with the metal part of
the torch because of the presence of high voltages that are
hazardousto the operator.
A) Switch on the HV power supply (HV OUT) and make sure that
():
- pre-chargerelaysK1 and K2 close;
- thefan starts to turn forthe powertransformer;
Power transformer and inductance assembly
Parts fastened to the base
Relays K1, K2 primary board fig. 3
Electrolytic capacitors C2,C4,C6,C7 primary board (fig. 3
IGBT's Q1, Q2, Q3, Q4 primary board (fig. 3)
Primary diodes D1, D4, D6, D8 primary board (fig. 3)
Mode selector switches SW1 and SW3 primaryboard
(fig. 3)
Secondary diodes D1, D2, D3, D5 secondary board (fig. 4)
Shunt R1 secondary board (fig. 6)
Power transformer and filter inductance
3.0 Visual inspection of the machine
4.0 Checking the power and signal wiring
5.0 Electrical measurements with the machine
switched off
6.0 Electrical measurements with the machine in
operation
()
)
.
6.1 Preparation for testing
6.2 Scheduled tests
Secondary board (fig. 4):)
-
-
-
fig. 4
fig.3
fig.3
fig.4
fig.4
rheofores of secondary power diodes D1, D2, D3, D5 (N.B.not
presentonTechnology 150);
thermostat ST1 on secondary diode dissipator;
shuntR1.
- secondary diodes D1, D2, D3, D5 between anode and
cathode ( ).The secondary diodes can be tested without
removing the primary board, placing a prod on the secondary
diode dissipator and the other in sequence on the 2 power
transformer output terminals.
B) With the multimeter in ohm mode check the following
components:
- resistorR1:47 ohm (precharge ).
- resistorsR2,R6:10 ohm (primary snubber ).
- resistorR1:10ohm (secondary snubber ).
- thermostat continuity test on inductance and secondary
dissipator: disconnect connector J2 from the primary board
and makesure the resistance between pins 4 and 5 is approx.
0ohm( ).
E) Position the current potentiometer R16 on maximum (turn
clockwiseas far as it will go) and switchSW1 to SOFT (as fardown
asit will go);
Current potentiometer R16 (fig. 3)
Probablecause:
- mechanicalshock.
-12-
TECHNOLOGY 150-170-200-186CE/GE
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