WELDING INDUSTRIES Synchro-Pulse CDT 450 CP38-3 User manual

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WELDING INDUSTRIES OF AUSTRALIA
A DIVISION OF WELDING INDUSTRIES LTD
ABN 18 004547 111
Head Office and international Sales
5 Allan Street, Melrose Park
South Australia, 5039
Telephone
[phone]Facsimile(08)82766327
www.weldingindustries.com.au
[email protected]
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i
OWNERS MANUAL
SYNCHRO-PULSE CDT 450
MODEL NO. CP38-3, REV. G
1 1 /oo
QUALITY WELDINGPRODUCTS, SYSTEMS AND SERVICE 8 5 ?/I!: f
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Page 2 SYNCHRO-PULSE CDT 450 MANUAL
SAFETY
Before this equipment is put into operation. the SAFE PRACTICES section at the
backof themanualmustbereadcompletely
. Thiswillhelptoavoidpossibleinjury
resulting from unsafe work habits
.
CONTENTS
Section Page
1 ............................... Introduction ................................................................. 3
2
............................... Recelvmg ................................................................... 4
3
............................... Specifications ............................................................. 4
4
............................... Installation .................................................................. 5
5 ............................... Controls ...................................................................... 10
6
............................... NormalWeld Sequence .............................................. 14
7 ............................... Welding Performance ................................................. 15
8
............................... Overview .................................................................... 17
10
............................. Other Fault Conditions ................................................ 26
11 ............................. OutputTests ............................................................... 27
12
............................. PrintedCircuitBoards ................................................. 28
13
............................. Pads Lists ................................................................... 39
GENERAL
..
SERVICE INFORMATION
9 ............................... FaultMessages .......................................................... 19
APPENDICES
14 ............................. Weld Schedule List ..................................................... 49
15 ............................. Push-PullGun andWirefeeder ................................... 54
16
............................. Safe Practices ............................................................ 61
Figure Page
1 ............................... SupplyVoltage Selection ............................................ 5
2 ............................... Cable and Hose Connections ...................................... 7
3
............................... CableConnections MMAW ......................................... 8
4
............................... Cable and Hose ConnectionsGTAW .......................... 9
5 ............................... TypicalArc CurrentWaveform ................................... 17
6 ............................... FunctionalBlockDiagram ........................................... 18
7
............................... TransistorDriverAssembly CP38-31 .......................... 22
8 ............................... Descriptiveand CurrentSignal ................................... 29
9 ............................... Welding CPU Board CP38-10 ..................................... 30
10
............................. DisplayCPU Board CP38-11 ...................................... 32
11
............................. TransistorDriverBoard CP38-12 ................................ 33
12 ............................. BackgroundDriverBoard CP38-13 ............................. 34
13
............................. Wire/Gas BoardCP38-16 ........................................... 35
14
............................. Control FuseAssembly CP38-17 ................................ 36
15 ............................. CDT 450Circuit Diagram ............................................ 37
16 CDT450AssemblyDiagramCP38-3 38
17
............................. Main SwitchAssembly CP38-21 ................................. 40
18
............................. Keypad-Display Assembly CP38-50 ............................ 42
............................. ..........................
19 ............................. Rectifier Assembly CP38-51 ....................................... 43
20
............................. WirefeederAssembly W35-0 ...................................... 44
21
............................. W2-44 Two Roll DriveAssembly ............................... 45
24
............................. AM223 Accessory LeadKit ......................................... 48
26
............................. PullGun Cable Assembly andControlCable .............. 56
27 ............................. HulfteggerGun Exploded View ................................... 57
29
............................. PushPullWirefeederAssembly W35-4 ...................... 60
22 ............................. Drive Roll andWire Guide Table ................................ 46
23
............................. Gun Cable Assembly BE2-441OA ............................... 47
25 ............................. Cable and Hose Connections, PushPull ..................... 55
28 ............................. Torch NeckAssemblies .............................................. 59
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SYNCHRO-PULSE CDT 450 MANUAL Paae 3
Y
Theinformationcontained in thismanualissetouttoenableyoutoproperly
maintain your new equipment and ensure that you obtain maximum operating efficiency.
Pleaseensurethatthisinformationiskept in asafeplaceforreadyreferencewhen
required at any future time.
Whenrequestingspareparts,pleasequotethemodelandserialno.ofthe
machine and part no. of the item required. All relevant part numbers are shown in lists
contained in thismanual.Failure
to supplythisinformationmayresult in unnecessary
delays
in supplying the correct parts.
1. INTRODUCTION.
The WIA SYNCHRO-PULSE CDT 450 isa multi-purpose arc welding power source
providing for the following arc welding processes:
GAS METAL ARC WELDING (GMAW)isan arc welding process whereanelectrode
wire isfed by motor driven rollers to a welding gun, and where D.C. welding currentis
supplied
from the welding power source. The welding arcisstruck between the work
piece and the endof the wire, which melts into the weld pool. The welding arcis
established ina gas shield of carbon dioxide or argon-rich mixed gases.
PULSED GMAW isan extensionof the GMAW process offering improved arc transfer
control. InPulsed GMAW, the arcissupplied with D.C. welding current which is
modulated between two distinct values. The lower levelis referred to asthe
'Background Current', and the higher level as the 'Pulse Current'. Under the influence
of this pulsed current, the transfer of metal within the arcis ideally inthe form
of a
single droplet, approximately the diameter of the electrode wire, whichistransferred
during the low energy period following each pulse.
PULSED GMAW is a full spray transfer process which is almost spatter free,
producingwelddepositsofsmoothappearancewithexcellentpenetrationand
sidewall fusion. The positive nature of arc transfer provides ease of puddle control in
'outofposition'joints. The processexpandstheusefulweldingcurrentrangeofa
givendiameterelectrodewire.Onlyargonorargon-richgasesare used forpulsed
GMAW.
MANUAL METAL ARC WELDING (MMAW)is a welding process whereanarc is
struck between a flux-coated consumable electrode and the work piece. The arc and
the weld
pool are both shielded by gases generated by the flux coating of the
electrode.
GAS TUNGSTEN ARC WELDING (GTAW) is a welding process where the arcis
struck between a non-consumable tungsten electrode and the work piece.
A ceramic
nozzle surrounds the tungsten electrode and directs a flow of inert gas, usually Argon,
over the electrode and the weld zone. If filler metalisrequired, it ishand fed into the
weldingarc. The DC current arc of the CDT
450 is suitable for welding most ferrous
and non-ferrous metals, butisnot suitable for welding Aluminium for whichanAC
machineisrequired.

Page 4 SYNCHRO-PULSE CDT 450 MANUAL
2. RECEIVING.
Check theequipmentreceivedagainsttheshippinginvoice to makesure the
shipment is completeandundamaged.Ifanydamagehasoccurredintransit,please
immediately notify your supplier.
The SYNCHRO-PULSE CDT 450 package contains:
CP38-3 Power Source.
W35-0 Wirefeeder.
CP34-36 Remote Control pendant.
AM223-0/3 Inter-connecting Accessory lead kit, 3 metre.
w BE2-441OWlA BERNARD Gun cable, 3 metre.
Regulator and Flowmeter. (Argon)
(This)OwnersManual.
3. SPECIFICATIONS.
PRIMARY VOLTAGE ......................... 380, 415, 440 Volts A.C.,
EFFECTIVE PRIMARY CURRENT
.... 25 Amps (at 415 Volts)
MAXUMUM PRIMARY CURRENT
..... 36 Amps (at 415 Volts)
Three Phase,
50 Hz.
OPEN CIRCUIT VOLTAGE ................ 70 Volts.
WELDING CURRENT RANGE
...........
35 -450Amps.
RATED OUTPUT (Note. 1)
.................
350 Amps, 100% Duty cycle
CIRCUIT BREAKER RATING
.............
32 Amps
FITTED SUPPLY CABLE
...................
56/0.30 Four Core, Heavy Duty PVC
450 Amps, 60% Duty cycle
WIRE
SIZE RANGE ............................ 0.6mm - 2.4mm diameter.
WIRE SPEED
RANGE ........................ A to q 6 Metredmin.
COOLING
.............................................. cooled, air drawn in
through rearfan grilles.
INSULATION
...................................... Class F, 115°C Rise.
DIMENSIQNS
..................................... 720mm H, 430rnrn W, 780mm L.
MASS ................................................. ~63Kg
Note.
l Duty cycle is defined in Australian StandardAS1966.A asthe ratio of arcing
timeto
5 minutesinany 5 minute period, expressed as a percentage.

SYNCHRO-PULSE CDT 450 MANUAL Page 5
4. INSTALLATION.
A@€. Al1,electiicalwork shall only be undertakenby a qualifiedelectrician. Before
removieg any smachine,8covers,' ENSURE that the unit ,is disconnected fromthe electrical
supbly.; fl~n the8~clnitl"is~energised LETHAL V,OLTAGES arepresent on these/ectricall
cbrnponeots~~~encIoseti. 8'
-
-
CONNECTION TO ELECTRICAL SUPPLY
The SYNCHRO-PULSE CDT 450 is supplied with a 3 metre, 4 core 56/0.30 Heavy
DutyPVCSupplyFlexiblecable.Thesupplycablemustbecorrectlyconnected to
a
suitable 3 Phase plug top or fixed connection point.
The minimum capacity of the mains wiring and power outlet supplying a welder
is
selected according to the effective primary current of the machine. The effective primary
currentfor
a SYNCHRO-PULSECDT450is 25 Amps.Theminimumrecommended
circuit breaker rating for a SYNCHRO-PULSE CDT
450 is 32 Amps.
Thecurrentratingofthemainscabledependsoncablesizeandmethodof
installation.Refer to AS/NZS
3008.1, Table 9. If itbecomesnecessary to replacethe
mains flexible supply cable,
use only cable with correct current rating.
Access to themachinesupplyterminalsisgainedbyremoving the power-source
side panel adjacent to the supply cable entry. Pass the replacement cable through the
bush fittedto the machine back panel. The Earth wire (green
/ yellow) must be securely
attachedto the marked Earth stud. The three supply phases are terminated at the Main
Contactor.Removethecontactordustcovertogainaccess to the connectionpoints.
Ensure thatthe internal Brown and Blue loom wires remain connectedtothe 'live' side of
the contactor. Tighten the cable clamp leaving sufficient slackin the cable such thatthe
terminated wires are not in tension.
SUPPLY VOLTAGE SELECTION
The SYNCHRO-PULSE CDT 450 is factory adjustedfor a nominal electrical supply
voltage of 41
5 volts, 3 phase, 50 Hz. The equipment is rated for variations of k IO%, that
isvoltages in therange
375 - 455VAC.Ifthevoltagemovesoutofthisrangethe
machinewillcease to weld,andwilldisplayanappropriatefaultmessage.Thelocal
SupplyAuthoritywillusuallymakeadjustmentstocorrectforoutoftolerancesupply
voltage, however if necessary the machine canbe set to accept nominal input voltages
of
380 or 440 Vac.
Tochangethesupplyvoltageselection
two separatetransformersmustbe
adjusted, andit is necessaryto first remove both side panels.
I TheControlTransformerterminalstrip is locatedontheside of themachine
nearest the
Off / On switch. Move the Brown wireto the intended input voltage
tapping.
adjacenttothe Supply Flexible cable. Move the wire linkto the intended input
The Welding Transformer terminals are located on the side of the machine
voltage tappings.
MAIN TRANSFORMER
1380 c L2 I '115 L': 440 l
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LINK A-
BLt
CONTROLTRANSFORMER
J
FIGURE l. SUPPLY VOLTAGE SELECTION.

Page 6 SYNCHRO-PULSE CDT 450 MANUAL
CABLE AND HOSE CONNECTIONS - @MAW AND PULSED GMAW.
All Welding Current, Control and Shielding gas connections are shownin Figure 2.
The cables and hoses are contained in the accessory kit AM223.
9 GAS. The accessory kit contains two gas hoses. The shorter length is usedto
connectthe output of the gas regulatortothe gas nipple onthe rear panel ofthe
CDT
450. The gas connector for the regulator end is included with the regulator.
The second hose is used to make the gas connection fromthe CDT
450 front
pane! to the backpanel of the W35wirefeeder.Notethattheseconnectors
incorporate an
'OB ring seal and do not require excessive tightening.
CONTROL. Fitthe Control Pendant and Wirefeeder cable male plugs into their
respectively marked sockets onthe CDT
450 front panel. Fit the Wirefeeder cable
female plug intothe socket at the rear of the wirefeeder.
WELDING CABLES. Bolt the lugged end of the wirefeeder welding cable plus the
grey Arc Voltage Sensing wire to the brass gun adaptor ofthe
two roll drive. Fit
the cable clamp supplied. Attach the plug endto the Positive 'GMAW
/ PULSE'
welding output socket of the power source.
plug endto the Negative 'COMMON' welding output socket.
Connect the Work Clamp to the welding bench or work piece, and attachthe
FITTING THE ELECTRODE WIRE
Place the spool of electrodewireontothespoolholder.Thelocationpinshould
mate with a holeinthewire
spool body. Fit the spool retaining 'R' clip supplied.
Check the adjustment of the spool brake, which shouldbe set to prevent over run
of the wire
spool at the end of a weld, without unduly loading the wirefeed motor. The
braking
can be adjustedbyrotating the Nylocnutusing a 15/16" AFor 24mm socket
wrench.
Do not use dirty, rusty or kinked wire as it will not feed smoothly through the gun
cable and will cause erratic welding. Deposits from contaminated wire will clog the gun
cable liner requiringitto be replaced prematurely.
Check that the drive roller groove is correct for the electrode wireto be used. The
drive roller part number
is marked on the visible side of the installed roller. Referto the
driverollerselectionchartinFigure
22. Checkalso thatthecorrectsizecontacttipis
fitted atthegun end. Referto Section
13 for gun part numbers.
Open the tworolldrivemechanismbyrotatingthecompressionspringassembly
towards the front of the wirefeeder, allowing the upper roller housing to be lifted away
from the driven roller. Straighten the end of the welding wire and pass it through the inlet
guide, over the bottom driven roller and into the gun cable adaptor guide tube. Return
the top rollerto the closed position.

SYNCHRO-PULSE CDT 450 MANUALPage 7
GASCYLINDER
& REGULATOR
REMOTECONTROLPENDANT
'WORK'CLAMP
CONTROLCABLE
W/FWELDINGCABLE
GUNCABLEADAPTOR
GREYVOLTAGESENSE
WIRE
u%!i !LmE
8 PINPLUG
PLUG €!Lx
& SOCKETWIREFEEDER
W35-0 EL GUNPLUGWELDING
& SOCKET - GUN
2 + TWO "3? RED "J (( S$~&~ t
3 t THREE '47 BLACK
4 + FOUR -i$r- BLACK
5 t FIVE \$ GREY - (VOLTAGESENSE)
6 + SIX//6
7 t SEVEN /,7
8 t GREEN/YELLOW d8 SPARE
I t ONE -+ BLACK-
-
(W/FMOTOR)
3 PIN 3 CORE
PLUG
m REMOTECONTROLPENDANT
2 t BROWN - CURRENT
1 t BLUE - ARCLENGTH
3 t GREEN - COMMON
1
-'CURRENT'
'ARC LENGTH
FIGURE 2. CABLE AND HOSE CONNECTIONS, GMAW AND PULSED GMAW.

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Page 8 SYNCHRO-PULSE CDT 450 MANUAL
CABLE CONNECTIONS - CONSTANT CURRENT MODES.
AllweldingcurrentandcontrolconnectionsforConstantCurrentmodesMMAW
and GTAW are shown in below. The SYNCHRO-PULSE CDT
450 in Constant Current
mode suppliesDC (direct current) welding current to the arc.
MMAW.
It is important to select the electrode polarityin accordance with the manufacturers'
recommendationsforthatelectrode.BothPositiveelectrodeandNegativeelectrode
methods of connection are shownin Figure 3. Some popular WIA AUSTARC electrodes
are listed below with their recommended operating polarity.
Austarc 12P, Classification AS1
553, E41 12.
A popular general purpose electrode used with easeinall positions, vertical up
or
down. The smooth forceful arc makesit an ideal electrode for all general mild steel
applications. Preferred polarity electrode positive.
A smooth running electrode with
a soft arc, particularly suited to light sheetmetal
and smooth mitrefilletwelds. Preferred polarity electrode positive.
A low hydrogen electrode with good arc stability and out-of-position welding
characteristics. This electrode
is ideal for medium carbon steels, or steels of
unknown analysis. Operate electrode positive.
A high tensile (770 MPa), high chromium nickel electrode specially formulated for
joining all alloy steels and irons, and for tool and die maintenance. Operate
electrode positive.
Austarc 13S, Classification AS1 553,
E41 13.
Austarc 16TC, Classification AS1 553, E481 6.
Unicord31 2, Classification AS2576, 1330-A3
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WhenConstantCurrentmodeschedulesareselected,theArcLengthcontrol is
reconfigured as an output Off-On control switch. Rotate the potentiometer clockwise to
energise the welding output, and anti-clockwise to de-energise the welding output.
ELECTRODEPOSITIVE
OUTPUT ON
ELECTRODENEGATIVE
1 l
no
~UUO
no
1: 0 unoo
OUTPUT ON
\
Y n
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FIGURE 3. CONNECTIONS FOR MMAW.

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SYNCHRO-PULSE CDT 450 MANUAL Paae 9
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GTAW.
For GTAW thetorch is connectedelectrodenegative.Figure 4 illustratesthe
correctconnectionof theweldingtorchandgassupplyutilising the
CDT 450 internal
gas valve.
Before initial use
of the welding torch, allow gas to purge the torch and hoses for 5
minutes at approximately IO litreslmin. For welding purposes, the gas flow rate should
beset
in the range 2-5 litredmin.
Tungstenelectrodes
for DC GTAWshouldbe l - 2% Thoriated.Thistypewill
providethebestarcinitiation,arcstabilityand tip shaperetentioncharacteristics.
Thoriated electrodes can be recognised by a red coded end. The tungsten electrodeis
groundto a point, with the grinding marks pointing towards the tip.
For welding currents
less than
20 amps, the included angle of the point should be 30°, for currents greater
than
20 amps,therecommendedangle is 60". Whenset in thetorch,thetungsten
should protrude 12mm from the ceramic gas nozzle.
l7
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GAS CONNECTIQN
(WHERE
USED)
-0RCH SW. CONNECTION
(WHERE
USED)
TORCHSWITCHCONNECTION
1)
2) TORCHSWITCH
3)
8 PIN
4 )
PLUG
5 )
6)
7)
8)
j FIGURE 4. CABLEANDHOSECONNECTIONS FOR GTAW.

Paae IO SYNCHRO-PULSE CDT 450 MANUAL
W
5. CONTROLS.
TheSYNCHRO-PULSECDT 450 powersource is equippedwithanoperator
keypadpaneland a graphicaldisplayscreen.Allcontrolfacilitiesofthemachineare
accessed by use of the keypad.The individual key names and functions are:
SCHEDULEusedtoselect a WeldingSchedule;
OPTIONusedtomodifyWeldandgeneralpurposeOptions;
ARROWKEYSusedtopositionthehighlightbaroveramenuitem.
ENTERusedtoselectthemenuitem;
HELPused to view'Help'informationforthecurrentmenu;
INCHusedtoInchtheelectrodewireforward;
PURGEusedtoPurgetheshieldinggashoses.
The display screen provides information such
as:
The selected Weld Schedule or Process;
The selected wirefeed rate;
The estimated welding current;
Actual weld current and voltage during welding;
Average weld current and voltage during the last weld;
Advice of any detected fault condition.
Whenthemachine
is firstenergised,thescreenbrieflydisplaysthe WIA logo
duringwhichtimethemicroprocessorcircuitsareperformingself-testroutines.When
thesecheckshavebeencompleted,andprovidedthatnofaultconditionsexist,the
screenwilldisplayinformationsimitar
to thatshownbelow.Forassistancewithfault
messages, referto Section
9 of this manual.
#l97 85.9 ER316L
8.8 STAINLESS 316L
GAS: ARGON +5#t HE +2 C&
'IRE 5.2 mlmin CURRENT:
APPROX.
FEED : 75 ips
I I
The display indicates the presently selectedWeld Schedule with its internal library
number,therecommended
gas composition,thesetwirefeedrate,theestimated
welding current and an Arc Length setting indicator. This
is referred to as the 'Ready'
state, as the machineis ready to weld with the settings displayed.

SYNCHRO-PULSE CDT 450 MANUAL Paae ll
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v
TO SELECT A WELD SCHEDULE.
FromtheSCHEDULEmenu,GMAW, Pulsed GMAW,MMAW andGTAW
schedulescanbeselected.ThePulsedGMAWWeldSchedulesavailablehavebeen
established for specific combinationsof electrode wire type, wire diameter, and shielding
gasmixtures.Morethan
100 combinationsareavailableintheCDT 450 library.It is
importantthatthecorrect Weld Schedulebeselectedfortheconsumables(wireand
gas) in use.
Press the SCHEDULE key. The screen will display a list of weld schedule groups
beginning with electrode types for PulsedGMAW. Use the ARROW keys
to position the
highlight bar over the required group, then press ENTER. When 'on-line' programming,
Weld Schedulessenttothemachinefromaseparateprogrammingdeviceare
accessible through the DOWNLOAD group.
-
1 Choose ELECTRODE TYPE required:
EPROM :
COPPER & ALLOYS #33 125
FLUX CORED WIRES #3##07
l I
Use the ARROWkeys to highlight the required schedule, then press ENTER.
1.2rnrn
STRINLESS
318 A5.9 ER318
8.9mrn
STAINLESS 312
A5.9 ER312
0.9mrn STAINLESS 316LSi BHP 3CR12 plutle
I I
Section 14 of this manual lists all of the Pulsed GMAW weld schedules currently
available inthe
CDT library, together with their individual schedule numbers. In addition
tothemethoddescribedabove,weldschedules mayalsobeselecteddirectlyby
number. This feature is available
as the last item in the SCHEDULE menu. When this
mode is in use, the screen will initially display the number
of the currently selected weld
schedule. Using the ARROW and ENTER keys, index each digit to show the number
of
the new schedule required, then press ENTER.
OPTIONS
The OPTION menuprovides two groupsofOptions as shownbelow.Thefirst
group ofWeld Options are specific to the selected Weld Schedule, providing adjustment
of:
Pre-gastime;
w Creepspeed;
Crater-filltime;
Burn-backtime;
Post-gastime.
The remaining options are not specific to the selectedWeld Schedule, and provide
the following features:
Recallof the last weld Current and Voltage data;
Selection of standard or latching gun-switch modes;
Servicingtests;
Demonstrationdisplay.
l Recallof thelastFaultmessage;

Page 12 SYNCHRO-PULSE CDT 450 MANUAL
TO ADJUST AN OPTION.
Press the OPTION key. The screen shows a menu of available options.
Chum OPTION TYPE to. be chunged:
POST-GAS - gus flow time ufter welding
I I
Usethe ARROW keys to highlight the desired Option, then press ENTER.
For Weld Options, the screen now shows a list of time periods appropriate to the
Option, with the default,
or the last value selected already positionedinthe highlight bar.
Use the ARROW keys
to highlight the required new value, then press ENTER.
"
[how vulue far CRATER-FILL durutiw: I
nil seconds
1.2
seconds
1.5 slecclnds
I I
Adjusted Weld Optionvaluesbecomepartoftheselected Weld Schedule.The
SYNCHRO-PULSECDT
450 stores all Weld Optionsettingsforthelast 16 Weld
Schedules used, and automatically applies the adjusted values whenever one of these
schedulesisselected.
The remaining Options provide the following facilities:
INFORMATION. Display of Current and Voltage data relating to the last weld
performed. The figures are averages taken over the last one second of the
weld,
excluding Crater-fill and Burn-back periods. Press anykeyto exit from this
display.
FAULT. To assist with fault finding, selection of this option will re-display the last
fault message. Press any key
or the gun switch to exit from this option.
GUN SWITCH. This option provides a choice between 'Normal' and 'Latching'
modes of gun-switch operation. When Latching
is selected, the gun switch must
be closed then released to start the weld, then closed and released
to end the
weld. Thisis intended to reduce operator fatigue during long welding periods.
SERVICE. Selection of this option will display a menu of special facilities
available to assist a Service person. Eachisdescribedinthe relevant sections of
this manual.
DEMONSTRATION. Selection of this option will initiate a graphical, non welding
demonstration of the features of the SYNCHRO-PULSE
CDT 450. Hold down any
keyto exit from the demonstration.

SYNCHRO-PULSE CDT 450 MANUAL Page 13
REMOTE CONTROL PENDANT
welding process.
GMAW AND PULSED GMAW
Theremotecontrolpendanthasdifferingfunctionsdependingontheselected
CURRENT. This potentiometer control sets the wirefeed rate, whichinturn
fundamentally determines the welding current. The SYNCHRO-PULSE CDT
450
internally adjusts other welding parametersinaccordance with the setting of this
control.
The dial is a ten-turn vernier device whichis graduated from
0 to 10.00. The
graduations do not directly relate to any welding parameter, however the setting
ofthiscontrol is indicatedbythewirefeedrateandestimatedweldingcurrent
information displayed when the machineis
in the 'Ready' condition.
ARC LENGTH.This potentiometer control allows'fine tuning' of the arc length to
suit the welding requirement. Themost ideal welding conditions are normally
achievedwhen the operating arc lengthisadjusted to be as short as practicable,
while maintaining a stable welding arc. An occasional short circuit associated with
a crackle sound
is acceptable. The setting of this controlis indicated infive steps
of positive and five steps of negative adjustment by the display when the machine
is inthe 'Ready' condition.
Changes to the weld preparation and/or work piece temperature may require
adjustment of the arc length
in order to maintain these conditions.
CONSTANT CURRENT MODES - MMAW AND GTAW
CURRENT.This control sets the output welding current directly within the range
of the selected Constant Current schedule. The estimated welding currentis
displayed when the machine
is in the 'Ready' condition.
ARC LENGTH. Arc length controlisnot appropriate to MMAW and GTAW which
are both Constant Current welding processes.Whenthese schedules are
selected, the Arc Length control is reconfigured as an output
Off-On control
switch. Rotate the potentiometer clockwise to energise the welding output, and
anti-clockwise to de-energise the welding output. Alternatively,
a torch switchmay
be connected as shownin Figure
4.
INCH ANDPURGE.
TheINCHandPURGEkeysmay be used during the 'Ready' state. The selected
function isactive while the keyispressed.
INCH runs the wirefeed motor to feed electrode wire through the gun cable without
applying welding potential to the wire. If INCH
is pressed momentarily, small increments
of wire are fed. If the keyisheld down, the motorwill accelerate to the welding wirefeed
speedassetbytheCURRENTpotentiometer.
For maximuminchingspeed,pressthe
INCH and UP ARROW keys simultaneously. During inching, the intended speed of the
wirefeed motorisdisplayed
in rpm.
PURGE energises the gas valve tofill the gas hoses with shielding gas,
or to allow
adjustment of the gas flow rate. During PURGE, the display indicates a recommended
range of gas flow rate, plus some commercial names for the gas mixture required for the
currently selectedWeldSchedule.

Page 14 SYNCHRO-PULSE CDT 450 MANUAL
HELP KEY.
At any stage of operation of the CDT 450 (except during welding), the HELP key
may be pressed to display additional information relating to the present operating mode
of the machine. To exit from each message, press the HELP button a second time.
STANDBY MODE.
TheSYNCHRO-PULSECDT 450 incorporatesapower-savingstandbymode.If
the machine is left idle for more than
25 minutes, the welding transformer and cooling
fans are de-energised and a 'Standby' messageis displayed. Use of the keypad
or gun
switch will return the machine to normal operation.
6. NORMAL WELD SEQUENCE.
GMAW AND PULSED GMAW
WELD START.
The gas valve opens allowing shielding gas to flow for the selected Pre-gas time;
Welding voltage is applied between the electrode wire and the work piece;
Wirefeedcommences at creep speed;
The wire contacts the work piece, and the arc is established. Wirefeed steps to
run speed as determined by the setting of the remote Current control.
During welding, the screen displays information similar to that shown below. The
actualarcvoltage andcurrent
is displayed both as a digital number, and in bar-graph
form.
L
8.9 AUSTMIG 316LSi 135.9 ER316LSi
24 V 0
lI1S1111111
10 20 30 40 50
75 fi B188 288 3aa 488 588
I nl111111s1
l I
WELD END.
If a non-zero value of Craterfill has been selected, the wirefeed motor slows over
the time period selected;
The wire drive motorisdynamically braked to a stop;
Welding voltageisheld 'On' for the selected 'Burnback' time. Burnback ensures
that the electrode wire does not freeze in the solidifying weld pool.
The gas valve is held 'On' for the selected Post-gas time. Post-gas allows the
After welding, the screen displays information relating to the last weld. The
molten weld pool to solidify before exposure to atmospheric gases.
Current and Voltage figures shown are averages taken over the last one second
of the last weld excluding crater-fill and burnback periods. The information
is
displayed for IO seconds, or until a keyis pressed. The same information can be
recalled
by selecting OPTION > INFORMATION.

SYNCHRO-PULSE CDT 450 MANUAL Page l5
7. WELDiNG PERFORMANCE.
GMAW AND PULSED GMAW.
GMAW equipment can only provide optimum results ifall external components are
correctlyinstalled,adjusted, maintained,andthecorrectconsumablesarebeing used.
Ina situation of unsatisfactory welding results, the welding power sourceisoften the first
item suspected, however the fau!t frequently liesinthese more routine areas.
SHIELDING GAS
InGMAW,andespeciallyPulsedGMAW,theshieldinggascompositionplaysa
most important partin establishing correct arc behaviour.
Each SYNCHRO-PULSE CDT 450 pulsed weld schedule has been established for
use with a specific gas mixture. It is important that the gas mixtures recommended be
adhered to. The gases specified areallArgon rich, andin some cases are 100% Argon.
CarbonDioxidegasalone is notsuitableforpulsewelding,but it isacomponent in
mixtures used
for several applications, and canbeused for non-pulsed G.M.A.W.
One function of the shielding gas isto protect the molten weld pool from the effects
ofoxygen in theatmosphere.Withoutthisprotectionthewelddepositbecomes
'honeycombed'
in appearance,an effect whichis described as weld porosity.
In draft-freeconditionsthegasflowraterequired to giveadequateprotectionis
typically 10 litres/min.
In situations where drafts cannot be avoided,it may be necessary
toincreasethisrateand/ortoprovidescreeningoftheworkarea.Holdingdownthe
PURGEkey willdisplayarecommendedminimumgasflowratefortheselected
schedule.
If weld porosity occurs:
Remove spatter build-up from inside the gun nozzle. Check for fraying of the
internal nozzle insulator,and replace the nozzle if necessary.
w Check that the gas hoses have not become cracked or frayed, and that the
rubber sealsin each gas connection point are not broken
or perished.
Check the gas flow rate at the nozzle, and compare this reading with the flow rate
at the regulator.
A discrepancymay indicate a previously undetected gas leak.
WIREFEED
In anyGMAWprocess,theelectrodewirefeedmustbesmoothandconstant in
ordertoobtainthemostsatisfactoryweldingresults. It is important to observethe
following points:
Minimise the build up of dirt, dust and swarf in the gun cable liner by the use of
clean electrode wire. Ensure that the compression force of the drive rollers
is not
excessive, and that the rollers have been correctly selected for the welding
electrode inuse. For drive
roll data, referto Figure 22 of this manual.
The gun cable liner mustbecorrectly fitted so that the free end seats firmly into
the back of the welding gun head.Inthis way the electrode wireissupported and
guided directly into the welding tip. Referto Section 13 for liner fitting instructions.
Replace the weldingtip as it becomes worn.
Check that the electrode wire spool holder rotates smoothly and that the braking
action isnot excessive.

l
Page l6 SYNCHRO-PULSE CDT 450 MANUAL
ARC LENGTH.
The most ideal pulsed GMAW welding conditions are achieved when the arc length
is adjusted to be as short as possible while maintaining a stable spray mode of welding
arc.Occasionalarcshortcircuiting,associatedwithacracklingsound,isacceptable.
Changes
in weld preparation and/or work piece temperaturemay require adjustment of
the arc length to maintain these conditions.
If the arc lengthistoo short, itwill result in excessive crackle, shorting and spatter,
while if too longmay result in weld undercut and lack of weld penetration.
SURFACE CONTAMINATION.
Surfacecontaminationoftheworkpiecewithwater, oil, grease,galvanising, or
paint can often cause severe disruption to the arc. Gases generated can contaminate
the shielding gas, and may affect the chemical composition of the weld. It is normally a
requirementto clean the surface with a suitable solvent
or by linishing or grinding.
ARC BLOW.
Arc blow occurswhen a magneticfield distorts or extinguishes the welding arc. The
magneticfield is usually the result
of welding current passing through the object being
welded
or through adjacent steel clamp bars. Thisis most often seen when welding steel
sections, and particularly where there is a root gap or at the extreme end of a section.
Arc blow
can also result from the use of magnetic clamps.
Arc blow can be difficult to overcome, however the following steps have been found
useful:
Re-position the Work clamp on the work piece. It is usually best to weld towards
the clamp;
If possible, bridge the end of a gap with a heavy tack weld or backing bar.Weld
towards the bridge;
m Isolate clamp bars from the welding current path;
Remove magnetic clamps;
Use non-magnetic materials for welding fixtures.

SYNCHRO-PULSE CDT 450 MANUAL Paae 17
~ -~~ - . ~
~~- -
SERVICE INFORMATION.
CONTROL CIRCUIT MAINS FUSES
The supply circuit to the Control Transformeris protected by two H.R.C. fuse links.
These fuses are located inside the power source and are only accessible by removing
the right hand side panel.
8. OVERVIEW OF PULSED GMAW.
Whensetforpulsed GMAW, theSYNCHRO-PULSECDT 450 suppliestothe
l. Current pulses of controlled amplitude, time duration and frequency.
2. Controlled amplitude background current.
Typical value ranges for these parameters are:
welding arc a
DC current comprising two distinct elements. These are:
Pulse current peak: 200 - 600 amps;
w Pulse width: 2 - 5 mS;
Pulse frequency: 30 - 400 Hz;
Background current: 12 - 75 amps average.
/-
'WINDOW'UPPER
11
I
'WINDOW'LOWER
I,
/ CURRENTPULSE
BACKGROUNDCURRENT
/-
'WINDOW'UPPER
1
'WINDOW'LOWER
/ CURRENTPULSE
I \ BACKGROUNDCURRENT
Ih a
J
4-w
11
I
I,
I
Y
FIGURE 5. TYPICAL ARC CURRENT WAVEFORM.

~
Paae 18 SYNCHRO-PULSE CDT 450 MANUAL
Y
The individual pulse and background parameters, plus pulse frequency, wirefeed,
arc voltage and other data have been predetermined to suit the welding electrode and
shieldinggascombination.Theseparameterstogetherarereferredtoasa 'Weld
Schedule'.TheSYNCHRO-PULSECDT
450 hasaninternallibraryofover 100 weld
schedules,allowingPulsed
GMAW usingawiderangeofelectrodewiretypes,wire
diameters and shielding gas combinations.
The pulse and background currents are both derived
by 'switch-mode' control. In
this technique, the welding current is repeatedly switchedOn and Off in such a way that
the currentisheld within
a specified 'window' range.
The SYNCHRO-PULSE CDT
450 has separate switches for pulse and background
current.Thepulsecurrentswitch is abankofthreehighcurrentbipolartransistors
mountedon a fan cooled, monolithic heatsink. The background switch is a bank
of three
Mosfet transistors. The basic D.C. welding currentisthe rectified and filtered output of
a
three phase welding transformer.
Centraltothe CDT
450 is amicroprocessorbasedcontrolcircuitCP38-10.This
circuittakesinputfromthepressbuttonkeypadandremotecontrolpendant,plus
current and voltage feedback
from the arc, and in turn controls the drivers for each of
the current switches. The circuit also manages the flow of shielding gas, wire feed and
feed rate and sends datato the graphical display.
Theblockdiagramillustratestheconnectionsbetweenthecontrolblocksofthe
SYNCHRO-PULSE CDT
450.
DISPLAY I
Y
REMOTE
CONTROL
I DlSpBLoAAvR~PU b I PRESS-BUTTON
CP38-11KEYPAD
M I I
t I I
ARC
CURRENT
FEEDBACK
t *
BACKGROUND
*
DRIVERBOARD
b
CP38-13
WELDINGCPUBOARD
CP38- 10
ARC
VOLTAGE
k
FEEDBACK TRANSISTOR
+
DRIVERBOARD
t
CP38-12
I
GUNSWITCH
WIREISAS
CONTROLBOARD
CP38-16
WIREFEED
MOTOR
FIGURE 6. FUNCTIONAL BLOCK DIAGRAM.

i
i
SYNCHRO-PULSE CDT 450 MANUAL Paae 19
Y
9. FAULT MESSAGES
The SYNCHRO-PULSECDT 450 hasmeanstodetectavarietyofexternaland
internalfaultconditions.Ifafault is detected,themachinewillceaseweldingand
displayafaultmessagesimilartothatshownbelow.Eachmessageincludesa
description of the fault condition, a fault code number and suggested actions to assist
with fault correction.
* Check plug P3 Q~I Weld CPUCP38-l#. I
FAULT - R&e Pendud DiSCDnnECtEd I
# Check that the control pendant plug
is correctly inserted) and that
the cuble is not damaged.
$ Tt-y another control pendant.
l I
Faultmessagesaredisplayedinorder of priority.If two or morefaultsoccur
simultaneously, the fault of highest priority will be displayed first. Following correction of
that fault, the next highest priority fault will be displayed. In the following list, the faults
are given
in descending order of priority.
Fault messages are displayed when
a fault condition exists, or if the 'Display last
fault message' Option has been selected. This feature may be used to assist detection
of intermittentfaults.TheScheduleandOptionmenusmay still beaccessedwhena
fault exists, but the machinewill not permit welding.
Diagrams forall circuits and printed circuit boards referred to maybe found in the
next section of this manual.
Fault
No. FaultMessagePage
1
.............................. Display CPU Memory Problem' .................. 19
3
.............................. Output Terminals Live' ............................... 20
6
.............................. Supply Phase Failure' ................................ 23
7/8 .......................... 'Supply High / Supply Low' ......................... 23
2 .............................. WeldingCPU Not Responding' .................. 20
4 ............................. .CPU Board Power Supply' ......................... 20
5 .............................. Transistor Driver Power' ............................. 21
9 ............................ .'Background Driver Power' .......................... 24
10
........................... 'Overcurrent Detected' ................................ 24
11 ............................ Thermostat Overheated' ............................. 24
12 ........................ ...' Arc Voltage Sensing Problem'.. .................. 25
13 ........................... 'Wirefeed Control Problem' ......................... 25
14.. .......................... Remote Pendant Disconnected' ................. 26
15 ...................... .....' External Detection Input' ............................ 26
'DISPLAY CPU MEMORY PROBLEM'
Thismessageresultsfrom two possibleconditionsrelatingtotheDisplayCPU
Assembly CP38-11. The firstisan incorrect checksum result obtained during the power-
up sequence which indicates corruption
of the Eprom data. The second isfailure of the
RAM read/write power-up test.
Fit anew Eprom tothe CP38-1 l board. Refer to Section 12of this manual for
fitting instructions.
Replace the complete printed circuit assembly CP38-11.
I

Paae 20 SYNCHRO-PULSE CDT 450 MANUAL
Y
'WELDING CPU NOT RESPONDING'
The SYNCHRO-PULSECDT 450 hastwomicroprocessorbasedcontrolcircuits.
These are theWeldingCPU Board CP38-IO, and the Display CPU Board CP38-11. The
two circuits communicate via a serial data link. This fault message indicates a failure of
the
two boards to establish correct communications.
w Check that the connecting cable between the CP38-11 and CP38-10 boardsis
Confirm that the microprocessor of the WeldingCPU board CP38-10is
correctly fitted, and that the plugs and sockets are not damaged.
functioning correctly. Thisis indicated by regular flashing of the 'Beacon' LED
4. If
it isnot:
Check that the CP38-10 power supply indicatorsLEDI, LED2, and LED3
are each lit. If any are not, refer to the information below for the fault
message 'Circuit Board Power Supply'.
the numbers '380', and that it is correctly fitted.
instructions.
this manual for fitting instructions.
w Confirm that the CP38-10 has an Eprom with a code number beginning with
Fit another known good Eprom. Refer to Section12 of this manual forfitting
Replace the complete Welding CPU board CP38-10. Refer to Section 12 of
Replace the Display CPU Board CP38-11.
'OUTPUT TERMINALS LIVE'
IftheCDT 450 detectsvoltageacrosstheoutputterminalsatatimewhenthe
machine is not being instructed to weld, failure of internal componentsis presumed and
so themachinedefaults toasafeconditionbyde-energisingthe weldingtransformer
supply contactor. This fault message can only be reset by switching the power source
Off.
Inspect the output transistors of the Transistor Switch Assembly for damage.
Using an ohmmeter, ensure that the transistor collector
/ emitter junctions are not
short circuited. If any components have failed, the complete Transistor Switch
Assembly CP38-21 must be replaced. Refer to Figure 17.
'CPU BOARD POWER SUPPLY.'
Thisfaultmessageisdisplayed if aWelding CPUonboardpowersupply is not
available. The supplies are each powered from electrically isolated control transformer
windingswhichareindividuallyfused on theControlFuseAssemblyBoardCP38-17.
ThetablebelowrelateseachpowersupplytoitsLEDindicatornumberandfuse
number. CP38-10CP38-17
CPU
+5v LED 3 Fuse F7
CPU-15VLED 2 FuseF5
CPU+15VLED
l
Fuse F6
SHUNTAMP +/-l 5V NoLED Fuse F4
l
l