Telwin Superior Plasma 90 HF, Руководство по устранению неисправностей и ремонту

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transformer (E ALTO and C BASSO);
the connections of the auxiliary transformer and to the
auxiliary board;
the connections of the armoured resistors R1 and R2 to JP3A
and JP3B.
In particular it is necessary to make the following checks on the
:
connections between the power transformer and the 2 bushes
on the secondary board;
correct connection of the output levelling inductance (between
secondary board bush and HF transformer bush);
the connections of Hall-1 and Hall-2 sensors to connector
(JP1) on the control board;
wiring of the secondary dissipator thermostatic capsules and
power transformer (in series with one another).
correct connection of the HF transformer (between end of the
inductance and OUT- dinse socket on the machine);
correct connection of the HF transformer (J3-A, J8-B) to the
HF board;
correct connections of the auxiliary board to the solenoid
valves and from the control board to the pressure switch.
A) With the digital multimeter set on check the
following components (joint voltages not less than 0.2V):
rectifier bridges D1, D2, D3 ( );
IGBT's 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 (no short circuits between
collector - gate and collector - emitter
);
diodes D1, D2, D3, D4, D5 on secondary board between
anode and cathode (
).
B) With the digital multimeter set on ohms check the following
components:
resistors R1, R2: 100ohm 12W 5% (preload );
resistors R17, R18, R24, R25: 1ohm 4W 10% (primary
snubber );
resistor R1: 22ohm 13W 5% (secondary snubber );
thermostatic capsule continuity test on power transformer and
secondary dissipator: disconnect the fastons (so that the
thermostatic capsules are connected in series) and measure
the resistance over their ends, it should be approx 0 ohm.
Before proceeding with troubleshooting, we should
remind you that during these tests the power source is powered
and therefore the operator is exposed to the danger of electric
shock. The tests described below can be used to check operation
of the power and control parts of the machine.
A) From the primary board disconnect the E ALTO and C BASSO
eyelets of the power transformer (
).
B) Set up the oscilloscope with the voltage probe x10 connected
between the collector of Q6 (probe) and the rheofore towards the
outside of resistor R38 (earth) on the primary board (
).
C) From the auxiliary control board disconnect fastons JP3A and
JP3B and from the primary board disconnect faston TF1. Connect
the wiring shown in
.
D) Disconnect connector JP5 from the primary board and join the
wiring shown in fig. B between the wiring and the board.
E) Connect the torch button simulator to the machine.
F) Connect the power supply cable of the machine to a 3-phase
variac with variable output 0-500Vac.
during testing prevent body contact with the metal
part of the torch because of the presence of high voltages that are
hazardous to the operator.
A) Switch on switch SW1 of the wiring in (auxiliary power
supply) and verify that:
-
with a slight delay, preload relays K1, K2 and K3 on the primary
board close (
);
- the power supply green LED D5 (control board) lights up;
- the red machine alarm LED D2 (control board) lights up;
- the yellow air alarm LED D3 (control board) lights up after
about 5 seconds;
If the power source remains
permanently in alarm status this could be due to a control
board failure (in any case proceed to make further tests).
B) Open switch SW1 (OFF).
C) Set the machine in
by first pressing the air button
on the front panel and then closing switch SW1 (ON) of the wiring
in
Keep the air button pressed for more than 6 sec, after
which diode D3 will start to flash (this status will remain until the
machine is switched off).
In this mode we disable HF (which is
lethal to any instrument connected to the machine) and air input.
Before continuing with testing make sure the machine is in test
mode.
D) Use the oscilloscope to make sure the waveform between the
collector of Q6 (probe) and the rheophore towards the outside of
resistance R38 (earth), resembles the one shown in
E) On the auxiliary power supply board (fig. 3) verify the
following power supply voltage values:
between the anode of D2 and case of U2 equal to +12Vdc
5%;
between the anode of D3 and case of U3 equal to +5Vdc 5%;
between the cathode of D7 and pin 1 of U4 equal to -12Vdc
5%;
between the cathode of D8 and pin 1 of U5 equal to -5V 5%.
F) Set up the single trace oscilloscope (CH1 x10), press the
torch button simulator and verify that:
between the anode of D22 and cathode of D20 the voltage is
equal to +25Vdc 5%;
- between the anode of D25 and cathode of D24 the voltage is
equal to +25Vdc 5%.
G) Set up the oscilloscope with the probe x10 connected between
resistor R15 (rheofore towards D8, probe) and the cathode of
diode D7 (earth) on the primary board (
). Press the torch
button simulator (button in fig. A) and verify that:
-
the yellow voltage over torch LED, D4, goes off after about 2
seconds;
- the waveform on the display resembles that in ;
- the operating frequency is equal to 25KHz 5%;
- if the frequency reading on the oscilloscope is not 25KHz 5%,
adjust the frequency using the trimmer R55 on the control
board (
).
To obtain the waveform it is necessary to press the torch
button simulator several times, because the machine remains
switched on for a maximum of about 2 seconds.
-
-
secondary board (fig. 5)
-
-
-
-
Other checks:
-
-
-
diode testing
- fig. 6
-
fig. 6
-
fig. 5
- fig. 6
-
fig. 6
- fig. 5
-
WARNING!
fig. 3
fig. 6
fig. A
WARNING!
fig.A
fig. 6
N.B.
“test mode”,
fig. A.
N.B.
fig. C.
-
-
-
-
-
fig. 5
fig. D
fig. 7
N.B.
5.0 Electrical measurements with the machine
switched off
6.0 Electrical measurements with the machine in
operation
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6.1 Preparation for testing
6.2 Scheduled tests
15
SUPERIOR PLASMA 90 HF
FIGURA C
SETTINGS
PROBE CH1 x10;
10 V/Div;
2.5 sec/Div.
VERIFY THAT:
THE FREQUENCY IS
90KHz 10%;
THE AMPLITUDE ON CH1
IS 25V 10%;.
µ
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