Telwin Superior Plasma 90 HF Operating instructions

inverter
SUPERIOR PLASMA 90 HF
Cod.988343
“reparation no-problem”
TROUBLESHOOTING
AND REPAIR MANUAL
TROUBLESHOOTING
AND REPAIR MANUAL
TROUBLESHOOTING
AND REPAIR MANUAL
TROUBLESHOOTING
AND REPAIR MANUAL
CONTENTS PAGE
OPERATION AND WIRING DIAGRAMS.........................2
REPAIR GUIDE..............................................................12
SPARE PARTS LIST...................................................... 24
REPAIRING CARD........................................................ 27
Block diagram 2
Analysis of block diagram 3
Illustrations 5
Wiring diagrams 7
Equipment required 12
General repair instructions 13
Troubleshooting and remedies 13
Testing the machine 17
Illustrations 20

SUPERIOR PLASMA 90 HF
BLOCK DIAGRAM
OPERATION AND WIRING DIAGRAMSOPERATION AND WIRING DIAGRAMS
OPERATION AND WIRING DIAGRAMSOPERATION AND WIRING DIAGRAMS
OUTPUT
26 27 28 29 30
36 32
35 39
27
15
21
33
12345678
34
911
AIR BUTTON
ELECTROVALVE
E- E-
REGULATOR
CURRENT MAX
HF FILTER
+
-
20
16 17
MICROCONTROLLER
22 23
43
13 14
33 24 25 19
CURRENTPOTENT.
12
40
HF GENERETOR
37
AP
31
41 42
18
MAINS INPUT EMC FILTER VARISTOR RECTIFIER
BRIDGE
PRE-CHARGE FILTER CHOPPER PR.CURRENT
CONTROL TRANSFORMER TRANSFORMER
SEC. DIODES SEC.EMC FILTER
FAN
UNDERVOLTAGE
SAFEGUARD
OVERVOLTAGE
SAFEGUARD FLYBACK POWER
SUPPLY
CURRENT READER
AND LIMITER PR.
DRIVER
MAKER
DUTY CICLE
ALARM BLOCK
ADDER
SHUNT AMPLIFIER PILOT ARC
ACTIVATION.
POWER SUPPLY
LED
VOLTAGE OVER
TORCH LED
HF PROTECTION
AUXILIARY
TRANSFORMER
DIODE
THERMOSTAT SEC.
INDUCTANCE
THERMOSTAT
PROTECTION HF
FASE FAILURE
AIR FAILURE
LED
ELECTROVALVE
TORCH BUTTON
FASE FAILURE
LED
GENERAL ALARM
LED
2
10
INDUCTANCE
HALL SENSOR

3
ANALYSIS OFTHE BLOCK DIAGRAM
NOTE:Unless indicated otherwise, it should be assumed that
the components are assembled on the primary board or
machine.
:C1,C2,C3,C4,C5,C6,C7,L1(inputfilterboard)
Preventsnoisefromthe machine from beingtransmittedalong
themainpowerlineandviceversa.
Consistingof:RV1,RV2,RV3(inputfilterboard)
Prevents spike noise from the mains, with amplitude greater
than400V,fromenteringthemachine.
Consistingof:D1,D2,D3
Converts the mains alternating voltage into continuous pulsed
voltage.
Consistingof:K1,K2,K3,R1,R2
Prevents the formation of high transitory currents that could
damage the main power switch, the rectifier bridge and the
electrolytic capacitors.When the power source is switched on
relaysK1,K2andK3arede-energised,capacitorsC1,C2,C3,
C4,C1A, C2A, C3A C4A and C39 arethen chargedbyR1 and
R2. When the capacitors are charged the relays will be
energised.
Consistingof:C1,C2,C3,C4,C1A,C2A,C3AC4A,C39
Converts the pulsed voltage from the rectifier bridge into
continuousvoltage.
Consistingof:IGBT1,2,3,4,5,6,7,8,9,10
Converts the continuous voltage from the filter into a high
frequency square wav capable of piloting the power
transformer. Regulates the power according to the required
weldingcurrent/voltage.
Consistingof:TA
TheC.T.isusedtomeasurethecurrentcirculatinginthepower
transformer primary and transmit the information to block 14
(primarycurrentreaderandlimiter).
Consistingof:T1
Adapts the voltage and current to the values required for the
welding procedure. Also forms galvanic separation of the
primary from the secondary (welding circuit from the power
supplyline).
Consistingof:D1,D2,D3,D4,D5(secondaryboard)
D1 and D2 convert the current circulating in the transformer to
asingledirection,preventingsaturationofthecore.
D3,D4andD5recirculatetheinductanceoutputcurrent(block
9) while the IGBT's are not conducting, bypassing the power
transformer(block8).
Consistingof:L1,Hall1andHall2
The inductance levels the output current from the secondary
board diodes making it practically direct. Hall1 sensor reads
the current of the pilot arc, Hall2 sensor reads the current
circulating in the inductance and sends it to block 20 (Hall
sensoramplifiers)whichwillprocesstheinformation.
Consistingof:C4,C5(HFfilterboard)
Prevents noise from the power source from being transmitted
throughtheweldingcablesandviceversa.
Consistingof:T2
The HF transformer boosts the signal from block 40 (hf power
source), raising the voltage impulse in the secondary at the
instantwhenarcstrikeisgenerated.
Italsoisolatestheweldingcircuitfromtheprimarycircuit
Consistingof:U4,Q6,T3,U1,U2,U3
Uses switching methods to transform and stabilise the voltage
obtained from block 5 (filter) and supply 2 voltage values of
27V that enable block 14 (driver) to be powered correctly.The
auxiliary power supply board, on the other hand, generates
four further stabilised voltages (U2, U3, U4, U5) equal to a
+12V, +5V, -12V and 5V which are mainly used to power the
controlboard.
Consisting of: U1 (opto-insulators board), Q7, Q8 and U2
(opto-insulatorsboard),Q9,Q10.
Takes the signal from block 13 (flyback power supply) and,
controlled by block 16 (duty cycle maker), makes the signal
suitableforpilotingblock6(chopper).
Consistingof:D3,R1,R2,R3andR9andR16(controlboard)
Detectsandlimits the signalfrom block7 (currenttransformer)
and sets the maximum allowed primary current.This signal is
alsoscaled downso that it can beprocessed and comparedin
block16(dutycyclemaker).
Consistingof:U1(controlboard)
Processes the information from block 18 (adder) and block 15
(primary current reader and limiter) and produces a square
wave with variable duty cycle limiting the primary current to a
maximumpre-setvalueunderallcircumstances.
Consistingof:U4A,U4B(controlboard)
Collects all the information arriving from block 21 (maximum
currentcontrol)andfromblock19(microcontroller),andsends
ittoblock16(dutycyclemaker).
Block 1
Block 2
Block 3
Block 4
Block 5
Block 6
Block 7
Block 8
Block 9
Block 10
Block 11
Block 12
Block 13
Block 14
Block 15
Block 16
Block 17
EMC Filter
Consistingof
Varistor
Rectifier bridge
Pre-charge
Filter
Chopper
Current transformer
Power transformer
Secondary diodes
Inductance and Hall sensors
Secondary EMC Filter
HFTransformer
Flyback power supply
Driver
Primary current reader and limiter
Duty cycle maker
Adder
SUPERIOR PLASMA 90 HF

4
Block 18
Block 19
Block 20
Block 21
Block 22
Block 23
Block 24
Block 25
Block 26
Block 27
Block 28
Block 29
Block 30
Block 31
Block 32
Block 33
Alarm block
Microcontroller
Hall sensor amplifiers
Maximum current control
Overvoltage safeguard
Undervoltage safeguard
Secondary diodes thermostat
Power transformer thermostat
Red LED for general alarm
Yellow LED for air failure
Yellow LED for torch voltage
Green LED for power supply
Yellow LED for phase failure
Current Potentiometer
Air button
Phase failure
Auxiliary transformer
Consistingof:Q3,D12,D15(controlboard)
Whenanalarmisdetected,theblockdrasticallylimitsmachine
outputcurrentbyactingdirectlyonandchangingthereference
signal obtained from block 16 (duty cycle maker), in the event
of:
1)Triggering of thermostatic capsule on secondary board
dissipatordiodes.
2)Triggeringofthermostaticcapsuleonpowertransformer.
3)Triggeringduetoundervoltage.
4)Triggeringduetoovervoltage.
5)Phasefailureatinput.
6) Short circuit at output (electrode holder clamp and earth
cable connected to each other or electrode stuck to piece
beingwelded).
Consistingof:U7(controlboard).
Control logic, which manages typical timing for the plasma
cutting cycle. It also drastically limits power source output
currentwhenitdetectsan alarm.In the eventof an alarm ithas
a direct effect on block 18 (alarm block), directly changing the
reference signal obtained from block 31 (current
potentiomenter).
Consistingof:U3A,U3C,U4C,U4DandU5(controlboard)
They amplify the signals arriving from block 10 (Hall sensors
inductance) and the Hall sensors (Hall1 and Hall2) supplying
twotypesofoutputsignal:
- analogue signal: used to obtain a current-controlled cutting
arcandpilotarc(signalarrivingfrom theHall1sensor);
- digital signal: by means of two comparators placed
downstream of the shunt amplifiers, it is used to obtain two
signals (pilot arc presence and cutting arc presence) which
aresent tothe microcontroller(signal arriving fromthe Hall2
sensor).
Consistingof:R55(controlboard)
Processes the information arriving from block 20 (shunt
amplifiers) and uses R55 to adjust the maximum welding
current thatcanbesuppliedbythepowersource.
Consistingof:U5A,R38,R40
If the main supply voltage exceeds the maximum value this
safeguard triggers (a tolerance of approx.±15% of the power
supply voltage is allowed: outside this range the safeguard
triggers).
Consistingof:U5B,R30,R32
If the main supply voltage falls below the minimum allowed
value this safeguard triggers (a tolerance of approx.±15% of
the power supply voltage is allowed: outside this range the
safeguardtriggers).
Consisting of: thermostatic capsule ST1 When the
temperature of the secondary board dissipator reaches 70°C
(approx.) this safeguard triggers.Reset is automatic when the
causeforalarmisremoved.
Consistingof:thermostaticcapsuleST2
Whenthe temperaturein thepowertransformer is too high this
safeguard triggers. It is reset automatically when the alarm
conditionisnolongerpresent.
Consisting of: D2 (panel board)
Lights up following triggering of main supply overvoltage or
under voltage or of thermostatic capsules.
Consistingof:D7(panelboard)
LightsupsimultaneouslywithredLEDD37iftheairpressureis
insufficientorlacking.
Consistingof:D4(panelboard)
Lights up when the torch button is pressed, and shows the
cuttingcircuitisactivated.
Consistingof:D5(panelboard)
Lights up when the machine is powered and shows the
machineisreadyforoperation.
Consistingof:D1(panelboard)
Lights up simultaneously with red LED D37 if there is a power
supplyphasefailure.
Consistingof:R1(panelboard)
Used to create the reference voltage needed to adjust the
output current: varies the current from the minimum to the
maximumvalue.
Consistingof:S1(panelboard)
When this button is pressed, air will continue to flow from the
torch for approx.45 sec.It is usually used to cool the torch and
toadjustthepressureonthepressuregauge.
Consisting of: ISO2,ISO3 (opto-isolators board), UT (control
board).
If one of the 3 phases of the main supply fails this safeguard
triggers.
Consistingof:T3
Its purpose is to supply the machine with two alternating
voltageswithdifferentvalues:
- 230Vactopowerblock43(fan);
- 18Vac-0-18Vac to power the auxiliary power supply board;
- 9Vac to power block 35 (HF safeguard).
Block 34
SUPERIOR PLASMA 90 HF

Block 35
Block 36
Block 37
Block 38
Block 39
Block 40
Block 41
HF safeguard
Torch button
Pilot arc activation
HF filter
Solenoid valve 1,Solenoid valve 2 and hf activation.
HF Generator
Solenoid valve 1
Consistingof:D3,K4,C9,C8(hffilterboard)
The HF safeguard is powered by block 34 (auxiliary
transformer), at the instant when block 36 (torch button) is
pressed relay K4 sends the signal to block 19
(microcontroller), which will process this information. The hf
safeguard also separates the control board from the high
frequency so as to prevent the residual signal from the torch
buttoncablesfromenteringtheboard.
Consistingof:plasmatorch
Activatingtheplasmatorchbuttonwillstrikethepilotarc.
This signal is scaled down so that it can be processed and
comparedinblock17(adder).
Consistingof:Q8,K1(controlboard)andK3(hffilterboard).
When the torch button is pressed block 19 (microcontroller)
sends a signal to block 37 which, with the aid of block 38 (hf
filter),generatesthepilotarc.
Consistingof:R1,R2,C2,C2A,C3,C4andC5(hffilterboard).
The signal arriving from block 10 (inductance shunt) is filtered
andconveyedtoblock37(pilotarcactivation).
Consisting of: Q8, Q7, Q6 (control board) and K1, K2, K3
(auxiliarycontrolboard)
When the torch button is pressed block 19 (microcontroller)
sends 3 signals to block 39 which will adjust them for piloting
blocks40 (hfgenerator),41(solenoidvalve1)and42(solenoid
valve2).
Consistingof:hfboard
By means of a signal from block 39 (hf solenoid valve
activation) this block produces a high frequency signal that is
thensenttoblock12(hftransformer).
Consistingof:Y1
When the torch button is pressed solenoid valve Y1 is
energised, causing air outfeed which will allow the pilot arc to
5
SUPERIOR PLASMA 90 HF
(6) CHOPPER
(6)
CHOPPER
(13)
DRIVER
IGBT THERMOSTAT
Input filter board
Primary board
ILLUSTRATIONS
(1) EMC FILTER
(2)
VARISTOR
(1) EMC FILTER
(5)
FILTER
OPTO
ISOLATOR
(U1,U2, ISO2, ISO3)
(4) PRECHARGE
(3) RECTIFIER
BRIDGE

6
SUPERIOR PLASMA 90 HF
(18)
ALARM BLOCK
(20)
HALL SENSOR AMPLIFIERS
Control board
(9) DIODESECONDARY
Secondary board
(24) SECONDARY
DIODE THERMOSTAT
(17)
ADDER (19)
MICROCONTROLLER
(21)
MAXIMUM
CURRENT
CONTROL . (16) DUTY CYCLE MAKER

SUPERIOR PLASMA 90 HF
7
General wiring diagram
WIRING DIAGRAMS
Wiring diagram input filter board

SUPERIOR PLASMA 90 HF
8
Wiring diagram primary board - power
Wiring diagram primary board - driver

SUPERIOR PLASMA 90 HF
Wiring diagram control board - B
Wiring diagram control board - A
9

SUPERIOR PLASMA 90 HF
Wiring diagram control board - D
Wiring diagram control board - C
10

SUPERIOR PLASMA 90 HF
11
Wiring diagram auxiliary control
Wiring diagram HF filter board
Wiring diagram HF filter board
Wiring diagram secondary board

ESSENTIAL INSTRUMENTS
USEFUL INSTRUMENTS
MISCELLANEOUS
1 Dual trace oscilloscope 802401 (*)
2 Static load generator 802111 (*)
3 Variac 0 - 500V 4500VA 802440 (*)
4 Digital multimeter
5 Hall probe 802406 (*)
6 Unsoldering station
7 Flat jaw pincers
8 Cutting nippers
12
SUPERIOR PLASMA 90 HF
4
2
6
1
3
8 7
5
EQUIPMENT REQUIRED
REPAIR GUIDEREPAIR GUIDE
REPAIR GUIDEREPAIR GUIDE
(*) The instruments with codes can be supplied by Telwin. The sale price is available on request!

WARNING:
WARNING
BEFORE PROCEEDING WITH REPAIRS TO THE
MACHINE READ THE INSTRUCTION MANUAL
CAREFULLY.
EXTRAORDINARY MAINTENANCE OPERATIONS
SHOULD BE CARRIED OUT ONLY AND EXCLUSIVELY
BY EXPERT OR SKILLED ELECTRICAL-MECHANICAL
PERSONNEL.
IFCHECKSAREMADEINSIDETHEMACHINEWHILE IT
ISLIVE,THIS MAY CAUSESERIOUSELECTRICSHOCK
DUETO DIRECT CONTACTWITH LIVE PARTS AND/OR
INJURY DUE TO DIRECT CONTACT WITH MOVING
PARTS.
WARNING:
WIRING NEEDED FORTESTING
GENERAL REPAIR INSTRUCTIONS
TROUBLESHOOTING AND REMEDIES
Tocarryoutthelowvoltagetestsonthemachine,itisnecessaryto
use two special sets of test wiring that allow a 230Vac supply to
power the auxiliary transformer and by force some alarm signals
betweentheprimaryboardandcontrolboard.
Follow the two electrical diagrams below to make the two sets of
wiringinfigures AandB:
Every operation should be carried out in complete safety with the
powersupplycabledisconnectedfromthemainsoutlet.
- undothe12screwsfasteningthe2plasticshells(6each)tothe
frontand back( ). toextract the frontplastic shell
it is necessary to disconnect all connectors on the control
board assembly. Fasten the control board assembly to the
metal front piece using its 4 screws and reconnect all the
connectors;
- undothe2screwsonthehandlefastenedtothetopcover
(;
- undothe14screwsfasteningthetopcovertothestructure
();
- pullgentlyoutwardsandslideoutthetopcover( );
- undothe4screwsfasteningthebasetothestructure( );
- separate the top metal structure from the base and place it on
the work bench. the base should be removed if it is
necessarytoreachtheinternalboards.
After completing the repairs, proceed in the reverse order to re-
assemblethemachineandfastenthetopcoverandshells.
Using compressed air, carefully clean the power source
components since dirt is a danger to parts subjected to high
voltages and adversely affects the galvanic separation between
the primary and secondary boards.
It is important to be particularly
carefulwhencleaningthefollowingparts:
Wiring for Aux Transf/Power supply/Aux Board
The following is a list of practical rules which must be strictly
adheredtoifrepairsaretobecarriedoutcorrectly.
A) When handling the active electronic components, in particular
IGBT's and power DIODES, take elementary precautions for
electrostatic protection (such as wearing antistatic wristbands
orfootwear,usingantistaticworkingsurfacesetc.).
B) To ensure the heat flow between the electronic components
and the dissipator, always place a thin layer of thermo-
conductive grease (e.g. COMPOUND GREASIL MS12)
betweenthecontactzones.
C) The power resistors (should they require replacement) should
alwaysbesolderedatleast3mmabovetheboard.
D) Ifsiliconeis removedfrom some points on the boardsitshould
bere-applied.
N.B. Use only non-conducting neutral or oximic reticulating
silicones(e.g.DOWCORNING 7093).Otherwise,siliconethat
isplaced incontactwith pointsatdifferentpotential(rheofores,
IGBT's etc.) should be left to reticulate before the machine is
tested.
E) Thesemiconductordevicesshouldbesolderedkeepingbelow
the maximum temperature limits (usually 300°C for no more
than10seconds).
F) It is essential to take the greatest care at each disassembly
andassemblystageofthevariousmachineparts.
G) Keepthesmallpartsandotherpiecesthataredismantledfrom
the machine so as to be able to replace them in the reverse
order when re-assembling (damaged parts should never be
omittedbutshould be replaced, referring to thespare partslist
givenattheendofthismanual).
H) The boards (repaired when necessary) and the machine
wiring should never be modified without prior authorisation
fromTelwin.
I) For further information on machine specifications and
operationseetheInstructionManual.
1.0 Disassembling the machine
fig.1A NOTE:
fig.1A)
fig.1B fig.1B
fig.1B
NOTE:
2.0 Cleaning inside the machine
To clean the electronic
boards we advise reducing the air pressure to prevent
damage to the components.
13
SUPERIOR PLASMA 90 HF
Figure B
JP5A
280373-1
1
2
3
4
5
6
7
8
JP5
280373-1
1
2
3
4
5
6
7
8
Figure A
230Vac
Alim.Aux 400V
Faston-M 6,3x0,8
SW1
Switch
0V
Faston-M 6,3x0,8
JP3B
Faston-M 6,3x0,8
L1
L2
230V
Faston-M 6,3x0,8
JP3A
Faston-M 6,3x0,8
Auxiliary transformer T3
Auxiliary power supply board
Auxiliary control wiring
Wiring auxiliary board side
Wiring control side

14
Air inlet fan fastened to the back (fig.2B)
Primary board (fig. 6):
Auxiliary power supply board (fig. 3)
Auxiliary transformer (fig. 3)
Secondary board (fig. 5):
Power transformer and inductance assembly (fig. 3)
HF transformer (fig. 5)
Parts fastened to the base (fig. 4)
Main power supply switch (fig.2B)
Current potentiometer control board R1 fig. 2A
Post-air button (fig. 2A)
Relays K1,K2 on primary board (fig.6)
Electrolytic capacitors C1, C2, C1A, C2A, C4, C5, C4A, C5A on
primary board (fig. 6)
IGBT's 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 (fig. 6)
Primary diodes D6, D8, D9, D10 (fig. 6)
Secondary diodes D1, D2, D3, D4, D5 (fig. 5)
Hall-1 and Hall-2 sensors (fig.5)
Power transformer and filter inductance (fig. 3)
Input filter board varistors RV1, RV2, RV3 (fig. 4)
Relays K1,K2 and K3 on auxiliary control board (fig. 3)
elays K3 and K4 on HF filter board (fig.4)
HF transformer (fig. 5)
Air unit assembly (fig. 4)
Torch (fig. 1A)
Check whether dirt is adversely affecting correct rotation of the
blades;ifthereisstilldamageaftercleaningreplacethefan.
- rheoforesofIGBT's1,2,3,4,5,6,7,8,9,10;
- rheoforesofrecirculatingdiodesD8,D10;
- rheoforesofsnubbernetworkdiodesD6,D9;
- zone for connection with the black box (contains the board to
whichtheopto-isolatorsofthedrivercircuitareattached).
To get at the inside of the metal structure undo the 4 screws (2 on
eachside)thatfastenthepresspaninsulatortothestructure.
- powerdiodesD1,D2,D3,D4,D5;
- thermostaticcapsuleondissipator;
- HALL-1andHALL-2sensors.
Inthiscaseitisnecessarytoremovetheprimaryboard,orelseitis
possible to clean the part superficially from the sides of the metal
structure.
If the base is removed, carefully clean all the components
attachedtothestructure:
- airunitassembly;
- inputfilterboard;
- HFboard;
- HFfilterboard;
- auxiliarycontrolboard.
Make sure there is no mechanical deformation, dent, or damaged
and/or disconnected connector.Make sure that the power supply
cable has not been damaged or disconnected internally and that
the fan operates when the machine is switched on. Inspect the
componentsandcableslistedbelowforsignsofburning orbreaks
thatmayadverselyaffectoperationofthepowersource.Checkthe
followingparts:
Use the multimeter to check whether the contacts are stuck
togetheroropen.Probablecause:
- mechanical or electrical shock (e.g. rectifier bridge or IGBT's
shorted,handlingunderload).
Probablecause:
- mechanicalshock.
Probablecause:
- mechanicalshock.
Probablecause:
- see the power supply switch; If the relay contacts are
stuck together or dirty, do not attempt to separate or clean
them,justreplacetherelay.
Probablecause:
- mechanicalshock;
- machineconnectedtoamuchhighervoltagethan400Vac;
- rheofore of one or more capacitor broken:any that remain will
be subjected to excessive stress and will be damaged by
overheating;
- ageingafterasubstantialnumberofworkinghours;
- overheating due to failed operation of the thermostatic
capsules.
Probablecause:
- breakinsnubbernetwork;
- controlcircuitfailure(driver);
- poor thermal contact between IGBT's and dissipator (e.g.
loosenedfasteningscrews:check);
- excessiveoverheatingrelatedtofaultyoperation.
Probablecause:
- excessiveoverheatingrelatedtofaultyoperation.
Probablecause:
- breakinsnubbernetwork;
- poor dissipator-diodes thermal contact (e.g. loosened
fasteningscrews:check);
- faultyconditionsatmachineoutput.
Checkthemforcolourchanges.Probablecause:
- overheating due to loosening of the screws connecting the
shuntstothesecondarycircuits.
Probablecause:
- powersupplyvoltagemuchgreaterthan400Vac.
Probablecause:
- see the main power supply switch ; If the contacts are
stuck together or dirty, do not attempt to separate or clean
them,justreplacetherelay.
Probablecause:
- seethemainpowersupplyswitch. Iftherelaycontactsare
stuck together or dirty, do not attempt to separate or clean
them,justreplacetherelay.
Probablecause:
- seethepowertransformer;
Inspecttheoperationofthefollowingcomponents:
- pressuregauge;
- pressureswitch;
- solenoidvalves;
- torchconnector;
- miscellaneousconnectingpipesandhookups.
Maintenance status, referring to the instructions given in the
instruction manual. Condition of parts not subject to wear of the
connectingcablebetweentorchandmachine(insulation).
It is important to make sure that all the connections are in good
condition and that the connectors are inserted and/or attached
correctly.To dothis,takethe cablesbetween 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. If the power cables are not tight enough this
couldcausedangerousoverheating.Inparticularitisnecessaryto
makethefollowingchecksonthe :
wiring (JP3) towards primary board (JP5), auxiliary control
board(JP10andJP5)andammetershunt(TA);
wiring(CN2X)towardsauxiliarycontrolboard(CN2);
wiring (JP2) towards the thermostatic capsules, pressure
switchandHFfilterboard(J5).
In particular, it is necessary to make the following checks on the
:
connections RF, SF,TF of the 3 phases to the main switch and
downstream of the switch itself: input filter board and power
supplycable;
the 2 connections between primary board and power
N.B.
N.B.
R
N.B.
N.B.
controlboard(fig.7)
-
-
-
primaryboard(fig.3)
-
-
3.0 Visual inspection of the machine
4.0 Checking the power and signal wiring
()
control board assembly S1
Inspectthewindingsforcolourchanges.
- ageingafterasubstantialnumberofworkinghours;
- excessiveoverheatingrelatedtofaultyoperation.
SUPERIOR PLASMA 90 HF

transformer(EALTOandCBASSO);
the connections of the auxiliary transformer and to the
auxiliaryboard;
the connections of the armoured resistors R1 and R2 to JP3A
andJP3B.
In particular it is necessary to make the following checks on the
:
connectionsbetween the powertransformer and the 2bushes
onthesecondaryboard;
correctconnection of the output levellinginductance(between
secondaryboardbushandHFtransformerbush);
the connections of Hall-1 and Hall-2 sensors to connector
(JP1)onthecontrolboard;
wiring of the secondary dissipator thermostatic capsules and
powertransformer(inserieswithoneanother).
correct connection of the HF transformer (between end of the
inductanceandOUT-dinsesocketonthemachine);
correct connection of the HF transformer (J3-A, J8-B) to the
HFboard;
correct connections of the auxiliary board to the solenoid
valvesandfromthecontrolboardtothepressureswitch.
A) With the digital multimeter set on check the
followingcomponents(jointvoltagesnotlessthan0.2V):
rectifierbridgesD1,D2,D3( );
IGBT's 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 (no short circuits between
collector-gateandcollector-emitter );
diodes D1, D2, D3, D4, D5 on secondary board between
anodeandcathode( ).
B) With the digital multimeter set on ohms check the following
components:
resistorsR1,R2:100ohm12W 5%(preload );
resistors R17, R18, R24, R25: 1ohm 4W 10% (primary
snubber );
resistorR1:22ohm13W 5%(secondarysnubber );
thermostatic capsule continuity test on power transformer and
secondary dissipator: disconnect the fastons (so that the
thermostatic capsules are connected in series) and measure
theresistanceovertheirends,itshouldbeapprox0ohm.
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
ofthepowerandcontrolpartsofthemachine.
A) Fromthe primary board disconnect the EALTOandCBASSO
eyeletsofthepowertransformer( ).
B) Setuptheoscilloscopewiththevoltageprobex10connected
betweenthecollectorofQ6(probe)andtherheoforetowardsthe
outsideofresistorR38(earth)ontheprimaryboard( ).
C) FromtheauxiliarycontrolboarddisconnectfastonsJP3Aand
JP3BandfromtheprimaryboarddisconnectfastonTF1.Connect
thewiringshownin .
D) DisconnectconnectorJP5fromtheprimaryboardandjointhe
wiringshowninfig.Bbetweenthewiringandtheboard.
E) Connectthetorchbuttonsimulatortothemachine.
F) Connectthepowersupplycableofthemachinetoa3-phase
variacwithvariableoutput0-500Vac.
during testing prevent body contact with the metal
part of the torch becauseof the presence of highvoltagesthat are
hazardoustotheoperator.
A) Switch on switch SW1 of the wiring in (auxiliary power
supply)andverifythat:
- withaslightdelay,preloadrelaysK1,K2andK3ontheprimary
boardclose( );
- thepowersupplygreenLEDD5(controlboard)lightsup;
- theredmachinealarmLEDD2(controlboard)lightsup;
- 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
boardfailure(inanycaseproceedtomakefurthertests).
B) OpenswitchSW1(OFF).
C) Setthemachinein byfirstpressingtheairbutton
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
machineisswitchedoff). InthismodewedisableHF(whichis
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
resistanceR38(earth),resemblestheoneshownin
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%;
betweentheanodeofD3andcaseofU3equalto+5Vdc 5%;
between the cathode of D7 and pin 1 of U4 equal to -12Vdc
5%;
betweenthecathodeofD8andpin1ofU5equalto-5V 5%.
F) Setupthesingletraceoscilloscope(CH1x10),pressthe
torchbuttonsimulatorandverifythat:
between the anode of D22 and cathode of D20 the voltage is
equalto+25Vdc 5%;
- between the anode of D25 and cathode of D24 the voltage is
equalto+25Vdc 5%.
G) Setuptheoscilloscopewiththeprobex10connectedbetween
resistor R15 (rheofore towards D8, probe) and the cathode of
diode D7 (earth) on the primary board ( ). Press the torch
buttonsimulator(buttoninfig.A)andverifythat:
- the yellow voltage over torch LED, D4, goes off after about 2
seconds;
- thewaveformonthedisplayresemblesthatin ;
- theoperatingfrequencyisequalto25KHz 5%;
- ifthefrequencyreadingontheoscilloscopeisnot25KHz 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
switchedonforamaximumofabout2seconds.
-
-
secondaryboard(fig.5)
-
-
-
-
Otherchecks:
-
-
-
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.
“testmode”,
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
±±
±
±±
±±
±
±
±±
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
·
·
·
·
±
·
±

- repeat this test with the differential probe connected between
resistor R20 (rheofore towards D10) and the earth on the cathode
ofdiodeD11(checkbottombranch).
If the signal is not present and/or the machine is in alarm
status (yellow LED on) the fault could be in the control board (in
which case we recommend replacing it) or in the IGBT driver
circuit( ).
H) Setupthe oscilloscopewith theprobex10connectedbetween
the collector (probe) and emitter (earth) of IGBT 6 on the primary
board( ).
I) On the primary board reconnect the E ALTO and C BASSO
eyeletsofthepowertransformer( ).
J) Keeping the machine in “test mode” switch on the variac
(initially set to 0V), close the main power supply switch on the
machine and gradually increase the voltage generated by the
variacuntilitreaches24Vac.Pressthetorchbuttonandmakesure
that:
- the yellow voltage over torch LED, D38, goes off after about 2
seconds;
- thewaveformonthedisplayresemblesthatin ;
- repeatthistestonIGBT1oftheprimaryboard.
J) Take the variac back down to 0V and also:
- openthemainpowersupplyswitchonthemachine(OFF);
- openswitchSW1(OFF)onthewiringshownin .
- disconnecttheoscilloscope.
If it is very complicated or impossible to repair the boards, replace
them completely. Each board is distinguished by a 6-digit code
(printed in white on the component side after the initialsTW).This
code should be used for reference when ordering replacements:
Telwin reserves the right to supply boards that are compatible but
with different codes.Warning:before inserting a new board check
it carefully for damage that may have occurred in transit. We
supply boards that have already been tested and so if the fault is
still present after correct replacement check the other machine
parts Unless the instructions explicitly require it, never adjust the
trimmersontheboards.
- disconnect all the wiring connected to the board and the
cables from the board to the fans and the power transformer.
Never under any circumstances invert the connections
between the primary board and the power transformer when
assemblingthenewboard;
- undo the 4 screws fastening the primary board to the metal
structure;
- undo the 6 screws fastening the dissipator to the metal
structure;
- extract the board upwards from the front panel side (this
movementissimplified bypullingslightlyoutwardsonthefront
panelplate).
Forassemblyproceedinthereverseorder.
EvenifonlyoneIGBTisdamaged,all10shouldbereplaced.
- after removing the board from the machine undo the 4 nuts
fasteningthedissipators(fig.6);
- unsoldertheparts,cleanthetin fromthebumpcontactsonthe
PCBandseparatethedissipatorfromtheboard;
- before making the replacement make sure that the parts
pilotingtheIGBT'sarenotdamagedaswell:
- with the multimeter on ohms check the PCB to make sure
there is no short circuit between the 1 and 3 bump
contacts (between gate and emitter) corresponding to
eachcomponent;
- alternatively resistors R33, R35, R41, R42, R43,
R44, R45, R46, R47, R48 could have burst and/or diodes
D26, D27, D28 and D29 could be unable to operate at a
correct Zener voltage (this should have shown up in the
preliminarytests).
- remove the components (IGBT's, diode bridges or both) by
looseningthescrewsfasteningthemtothedissipators;
- cleananyirregularitiesordirtfromthedissipators.IftheIGBT's
have burst the dissipators may have been irreversibly
damaged:insuchacasetheyshouldbereplaced;
- apply thermoconductive grease following the general
instructions;
- prepare the components to be replaced. For the IGBT's it is
necessaryto bendtherheoforesthrough90° (nevereverbend
ortensionthepartsoftheIGBT'snearthecase);
- position the component fastening screws, but do not tighten
themupcompletely;
- join the dissipator/component assembly with the PCB,
inserting all the rheofores in the bump contacts and the
threadedspacersintothe4fasteningholes;
- fasten down the dissipators with the nuts and then tighten up
thecomponentscompletelyinthefollowingorder:
- nutsfasteningdissipatortoPCBwithtorquewrenchsetting
2Nm 20%;
- screws fastening rectifiers to dissipators with torque
wrenchsetting2Nm 20%;
- screws fastening IGBT's to dissipators with torque wrench
setting1Nm 20%;
- solder the terminals taking care not to let the tin run along
them;
- on the components side cut the protruding part of the
rheofores and make sure they have not shorted (gate and
emitterinparticular).
The 10 IGBT's should belong to the same selection Kit
suppliedbyTelwin.
N.B.
fig.6
fig.6
fig.3
fig.E
fig.A
N.B.
N.B.
A) Take special note of the procedure for replacing the
IGBT'sand/orrectifierbridges:
N.B.
7.0 Repairs, replacing the boards
.
7.1 Removing the primary board (fig. 6)
st rd
±
±
±
16
SUPERIOR PLASMA 90 HF
FIGURE D
SETTINGS
PROBE CH1 x10;
5 V/Div;
10 sec/Div.
VERIFY THAT:
THE FREQUENCY IS
25KHz 5%;
THE AMPLITUDE ON CH1
IS 10V 10%.
µ
·
·
·
·
±
·
±
FIGURE E
SETTINGS
PROBE CH1 x10;
10 V/Div;
VERIFY THAT:
THE FREQUENCY IS
25KHz 5%;
THE AMPLITUDE ON CH1
IS 35V 10%;.
µ
·
·
· 10 sec/Div.
·
±
·
±

B) Removing the secondary board (fig. 5)
C) Replacing the control board (fig. 2A)
1.1 Preparation for testing
1.2 Scheduled tests
Unless the dissipator has been damaged by a destructive
explosionofthe diodes,the secondary boardshouldnotgenerally
beremovedandthediodescanbereplaceddirectlywiththeboard
mountedonthemachine.Inanycase,itshouldbespecifiedthatto
removeitisnecessaryto :
- removethebasebyundoingthe4screws;
- turn the machine upside down and undo the 6 screws
fasteningthebaseassemblytothemetalstructure;
- disconnect all wiring that hampers removal of the base
assembly;
- after separating the base assembly disconnect the fastons
fromthethermostaticcapsuleandmakethereplacement.
Forassemblyproceedinthereverseorder.
- operatingontheupturnedmachine,undothescrewsfastening
the damaged components to the dissipator and unsolder the
metaltab;
- after removing the components clean the dissipator, removing
dirtandirregularities;
- apply thermoconductive grease following the general
instructions;
- placethe components on the dissipator to correspondwiththe
solderingzonesandfastenthemdownwiththescrews(torque
wrenchsetting1.4Nm 20%);
- solder the rheofores taking care not to let the tin form short
circuits.
makesurethat R1 and C1(secondarysnubber)arecorrectly
solderedtothePCB.
If the fault is in the control board we strongly advise replacing it
withoutfurtherintervention.
- undothe4screwsonthefrontpanel;
- disconnectalltheconnectors.
Forassemblyproceedinthereverseorder.
Testing should be carried out on the assembled machine before
closing the top cover. During tests never ever commute the
selectors or operate the ohmic load contactor with the machine in
operation.
A) Using cables with suitable dinse connectors, connect the
machine to the ohmic load (two ohmic loads connected in parallel
shouldbeavailable).
To connect the negative of the ohmic loads to the torch
connector it is necessary to use the adapter with torch button
simulator.If no adapter is available, it can always be ordered from
Telwin.
B) Connect a voltage probe x100 between the collector (probe)
andemitter(earth)of IGBT6.
C) Pass the current probe of the Hall effect transducer along the
cable connecting the power transformer at eyelet C BASSO with
thereferencearrowpointingintoCBASSO.
D) Lastly, connect the Hall Probe and the current probe to the
oscilloscope.
E) Keep the auxiliary cables ( and ) connected to the
machineaspreviously.
F) On the control board position the current potentiometer to
minimum.
G) Connect the power supply cable of the machine to a 3-phase
variacwithvariableoutput0-500Vac.
To obtain the waveform it is necessary to press the torch
button simulator several times, because the machine remains
switchedonforamaximumofabout2seconds.
- with the loads switched off, set the machine in“ ”, by
first pressing the air button on the front panel and then closing
switch SW1 (ON) of the wiring in fig. A. 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
continuingtestingmakesurethemachineisintestmode.
- switch onthemachineandthevariacand takethelatterto400
Vac.
- press the torch button simulator and make sure the voltage
and current waveforms displayed on the oscilloscope
resemblethosein
- switch off the auxiliary power supply, the machine and the
variac;
- disconnect the wiring shown in fig. A from the machine and
restore the original wiring on the auxiliary transformer and on
thepowersupplyboard;
- disconnect the wiring shown in fig. B from the machine and
restore the original wiring between the control board and the
primaryboard;
- connectthemachinetothe3-phase400Vacpowerline.
- switch on the machine and set it to “ ”, by first
pressing the air button on the front panel and then closing the
main switch (ON).Keep the air button pressed for more than 6
sec, after which diode D3 will start to flash (this status will
remainuntilthemachineisswitchedoff).
In this mode we disable HF (which is lethal to any
instrumentconnectedtothemachine)andairinput.
Beforecontinuingwith testingmakesurethemachineis in test
mode.
setuptheohmicloadswiththeswitchsettingsasinthetablein
- on the front panel position the current potentiometer to
minimum;
- start up the ohmic load, press the torch button simulator and
verifythat:
- the waveforms displayed on the oscilloscope resemble
thosein ;
- the output current is equal to +20Adc 10% and the output
voltageisequalto+88Vdc 10%;
(fig.4)
N.B.
B) Take special note of the procedure for replacing the
secondarydiodes:
N.B.
N.B.
N.B.
fig. A fig. B
N.B.
A) Loadlesstest: test mode
N.B.
fig.F.
B) Minimumloadtest: test mode
N.B.
fig.G;
fig.G
±
Before proceeding with testing, 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 the power
sourceunderload.
±
±
TESTINGTHE MACHINE
WARNING!
-
17
SUPERIOR PLASMA 90 HF
FIGURE F
SETTINGS
PROBE CH1 x10;
5V/Div;
PROBE CH4 = 5A/Divv;
10mV/Div;
10 sec/Div.
VERIFY THAT:
THE FREQUENCY IS
25KHz 5%;
THE AMPLITUDE CH1 IS
560V 10%.
·
·
·
·
·±
·
±
·
±

- if the output current on the load is not 90A, adjust it using
R55onthecontrolboard( )
- disabletheohmic loads andswitchoffthe machineatthemain
switch.
- setupthe ohmicloads withtheswitchsettingsasinthetablein
- on the front panel position the current potentiometer on
maximum (turn clockwise as far as it will go) and switch on the
machinein“ ”;
- start up the ohmic load, press the torch button simulator and
verifythat:
- the waveforms displayed on the oscilloscope resemble
thosein ;
- the output current is equal to +90Adc 5% and the output
voltageisequalto+116Vdc 10%;
- if the output current on the load is not 90A, adjust it using
R55onthecontrolboard( );
- disabletheohmic loads andswitchoffthe machineatthemain
switch.
Topreventtheohmicloadsfrombeingsubjectedtoexcessive
overheating, do not leave the machine in operation under these
conditionsforlongperiods.
- set up the dual trace oscilloscope by connecting probes CH1
and CH2 x100 to the secondary outputs of the power
transformer. The earth terminals should be connected
together to the shunt towards the secondary dissipator;
remove the multimeter from the OUT+ and OUT- bump
contacts;
- set up the ohmic load with the switch settings as in the table in
;
- on the front panel position the current potentiometer on
maximum(turnclockwiseasfarasitwillgo);
- start up the ohmic load, press the torch button simulator and
make sure the waveforms displayed on the oscilloscope
resemblethosein .
- disable the ohmic load and switch off the machine at the main
switch.
- to carry out the endurance test it is absolutely necessary to
procure 4 static load generators (make a series with 2 pairs in
parallel) to prevent the load generators themselves from
breakingdown.
- under the load conditions shown in the table in and with
the cutting current potentiometer on maximum, switch on the
machine in “ ” and keep the torch button pressed
until the thermostatic capsules trigger (machine in alarm
status).
switch on the machine in “test mode”, press the air button on
thepanelboardandmakesurethatthesolenoidvalveremains
energised for a period of approx. 45 seconds (duration of
coolingcycleorpost-air).
After making sure the wiring and boards are positioned
correctly, disconnect the oscilloscope and ohmic loads.
HFpresentintorch.
- Switch on the machine normally (not in test mode) and check
thefrontpaneltomakesurethefollowingLED'slightup( ):
greenLEDD5(powersupply);
yellowLEDD3(airpressuretoolow);
redLEDD2(generalalarm);
switchoffthemainswitchonthemachine.
fig.7
C) Ratedloadtest:
fig.H;
testmode
fig.H
fig.7
N.B.
D) Checkingthesecondaryboarddiodevoltages:
fig.H
fig.I
E) Endurancetest
fig. J
test mode
F) Operationalchecks:
-
-
Warning!
fig.7
-
-
-
-
±
±
18
SUPERIOR PLASMA 90 HF
Switch number
Switch position
Switch position
6
3
2
145
000111
00
0000
LOAD 1
LOAD 2
FIGURE G
SETTINGS
PROBE CH1 x100;
200V/Div;
PROBE CH4 = 10A/Divv;
10mV/Div;
10 sec/Div.
VERIFY THAT:
THE FREQUENCY IS
25KHz 5%;
THE AMPLITUDE ON
CH1 IS 560V 10%;
THE AMPLITUDE ON
CH2 IS 26A 10%.
µ
·
·
·
·
·
·
±
·
±
·
±
Switch number
Switch position
Switch position
111111
6
3
2
145
11
1110
LOAD 1
LOAD 2
FIGURE H
SETTINGS
PROBE CH1 x100;
200V/Div;
PROBE CH4 = 50A/Divv;
10mV/Div;
10 sec/Div.
VERIFY THAT:
THE FREQUENCY IS
25KHz 5%;
THE AMPLITUDE ON
CH1 IS 560V 10%;
THE AMPLITUDE ON
CH2 IS 100A 10%.
µ
·
·
·
·
·
·
±
·
±
·
±
FIGURE I
SETTINGS
PROBE CH1 x100;
200V/Div;
PROBE CH2 x100;
200V/Div;
10 sec/Div.
VERIFY THAT:
THE REVERSE
VOLTAGE ON CH1
DOES NOT EXCEED
900v;
THE REVERSE
VOLTAGE ON CH2
DOES NOT EXCEED
900V;
µ
·
·
·
·
·
·
·
FIGURE J
222222
6
3
2
145
22
2222
LOAD 1
LOAD 2
222222
222222
LOAD 3
LOAD 4
Switch number
Switch position
Switch position
Switch position
Switch position

G) Checkingtorchoperation(fig.K)
a)
b)
H) CheckingHFoperation
(fig.4)
I) Cuttingtest
If the load test was positive but arc strike is difficult or even
impossible, the fault could be located in the torch. With the
machine disconnected from the main supply check electrical
continuityinthetorchwiththetorchmountedonthemachine:
OUT-:
between the central part of the torch (the nozzle-holder should
be unscrewed to allow access to the inside) and the HF
transformeroutput(OUT-);
OUTAP:
betweentheouterthreadedpartofthetorch(thenozzle-holder
should be unscrewed to allow access to the inside) and the
outputfastonOUTAPconnectedtoJ4ontheHFfilterboard.
For the following test, disconnect all the instruments, disconnect
fastonsJ2andJ5ontheHFboard ;
Beforecontinuingcheckcarefullyto makesurealltheinstruments
have been disconnected. Prevent body contact with the OUT
terminals and with parts inside the power source. Switch on the
machine and with a digital multimeter set on volts make sure that
when the torch button is pressed the voltage over fastons J2 and
J5(disconnected)isequalto230Vac 20%;
If the result of the previous test was positive the fault could be in
the HF board or in the HF filter board (torch button). In this case
make sure the wiring is correctly assembled on the boards, if the
problem persists we advise replacing the board concerned.
Switchoffthemachineandassemblethemachinedefinitively.
With the machine set up as described in the instruction manual,
make a test cut on a piece of iron plate (less than 30 mm thick).
To make the test it is necessary to connect the compressed air
(pressure 5.5 bar). Monitor the dynamic behaviour of the
machine.
±
19
SUPERIOR PLASMA 90 HF
FIGURE K
Electrode
Nozzle
Insulating diffusorors
Nozzle holder
Spacers

ILLUSTRATIONS
SCREWS
SCREW
SCREWS
TOP COVER
SCREWS BOTTOM
SCREWS
20
SUPERIOR PLASMA 90 HF
SCREW
SCREWS
SCREWS