WELDING INDUSTRIES Synchro-Pulse CDT 450 CP38-3 Owner's manual

l

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

(08)

8276 6494 Facsimile (08) 8276 6327

www.weldingindustries.com.au

[email protected]

l

~

i

OWNERS MANUAL

SYNCHRO-PULSE CDT

450

MODEL

NO. CP38-3,

REV.

G

1

/oo

QUALITY WELDING PRODUCTS, SYSTEMS

AND

SERVICE

8

5

?/I!:

f

.~

2

Page

2

SYNCHRO-PULSE

CDT

450

MANUAL

SAFETY

Before this equipment is put into operation. the

SAFE

PRACTICES section at the

back of the manual must be read completely

.

This will help to avoid possible injury

resulting from unsafe work habits

.

CONTENTS

Section Page

1

...............................

Introduction

.................................................................

3

2

...............................

Recelvmg

...................................................................

4

3

...............................

Specifications

.............................................................

4

...............................

Installation

..................................................................

5

...............................

Controls

......................................................................

10

6

...............................

Normal Weld Sequence

..............................................

14

7

...............................

Welding Performance

.................................................

15

8

...............................

Overview

....................................................................

17

10

.............................

Other Fault Conditions

................................................

26

11

.............................

Output Tests

...............................................................

27

12

.............................

Printed Circuit Boards

.................................................

28

13

.............................

Pads Lists

...................................................................

39

GENERAL

..

SERVICE INFORMATION

9

...............................

Fault Messages

..........................................................

19

APPENDICES

14

.............................

Weld Schedule List

.....................................................

49

15

.............................

Push-Pull Gun and Wirefeeder

...................................

54

16

.............................

Safe Practices

............................................................

61

Figure Page

1

...............................

Supply Voltage Selection

............................................

5

2

...............................

Cable and

Hose

Connections

......................................

7

3

...............................

Cable Connections MMAW

.........................................

8

4

...............................

Cable and Hose Connections GTAW

..........................

9

5

...............................

Typical Arc Current Waveform

...................................

17

6

...............................

Functional Block Diagram

...........................................

18

7

...............................

Transistor Driver Assembly CP38-31

..........................

22

8

...............................

Descriptive and Current Signal

...................................

29

9

...............................

Welding CPU Board CP38-10

.....................................

30

10

.............................

Display CPU Board CP38-11

......................................

32

11

.............................

Transistor Driver Board CP38-12

................................

33

12

.............................

Background Driver Board CP38-13

.............................

34

13

.............................

Wire/Gas Board CP38-16

...........................................

35

14

.............................

Control Fuse Assembly CP38-17

................................

36

15

.............................

CDT 450 Circuit Diagram

............................................

37

16 CDT 450 Assembly Diagram CP38-3 38

17

.............................

Main Switch Assembly CP38-21

.................................

40

18

.............................

Keypad-Display Assembly CP38-50

............................

42

.............................

..........................

19

.............................

Rectifier Assembly CP38-51

.......................................

43

20

.............................

Wirefeeder Assembly W35-0

......................................

44

21

.............................

W2-44 Two

Roll

Drive Assembly

...............................

45

24

.............................

AM223 Accessory Lead Kit

.........................................

48

26

.............................

Pull Gun Cable Assembly and Control Cable

..............

56

27

.............................

Hulftegger Gun Exploded View

...................................

57

29

.............................

Push Pull Wirefeeder Assembly W35-4

......................

60

22

.............................

Drive

Roll

and Wire Guide Table

................................

46

23

.............................

Gun Cable Assembly BE2-441 OA

...............................

47

25

.............................

Cable and

Hose

Connections, Push Pull

.....................

55

28

.............................

Torch Neck Assemblies

..............................................

59

~

SYNCHRO-PULSE

CDT

450

MANUAL

Paae

3

Y

The information contained in this manual is set out to enable you to properly

maintain your new equipment and ensure that you obtain maximum operating efficiency.

Please ensure that this information is kept in a safe place for ready reference when

required at any future time.

When requesting spare parts, please quote the model and serial no. of the

machine and part no. of the item required. All relevant part numbers are shown in lists

contained in this manual. Failure

to

supply this information may result in unnecessary

delays

in

supplying the correct parts.

1.

INTRODUCTION.

The WIA SYNCHRO-PULSE CDT

450

is a multi-purpose arc welding power source

providing for the following arc welding processes:

GAS METAL ARC WELDING (GMAW) is an arc welding process where an electrode

wire is fed by motor driven rollers to a welding gun, and where D.C. welding current is

supplied

from

the welding power source. The welding arc is struck between the work

piece and the end of the wire, which melts into the weld pool. The welding arc is

established in a gas shield of carbon dioxide or argon-rich mixed gases.

PULSED GMAW is an extension of the GMAW process offering improved arc transfer

control. In Pulsed GMAW, the arc is supplied with D.C. welding current which is

modulated between two distinct values. The lower level is referred to as the

'Background Current', and the higher level as the 'Pulse Current'. Under the influence

of this pulsed current, the transfer of metal within the arc is ideally in the form

of

a

single droplet, approximately the diameter of the electrode wire, which is transferred

during the low energy period following each pulse.

PULSED GMAW is a full spray transfer process which is almost spatter free,

producing weld deposits of smooth appearance with excellent penetration and

sidewall fusion. The positive nature of arc transfer provides ease of puddle control in

'out of position' joints. The process expands the useful welding current range of a

given diameter electrode wire. Only argon or argon-rich gases are used for pulsed

GMAW.

MANUAL METAL ARC WELDING (MMAW) is a welding process where an arc 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 arc is

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 metal is required, it is hand fed into the

welding arc. The DC current arc of the CDT

450

is suitable for welding most ferrous

and non-ferrous metals, but is not suitable for welding Aluminium for which an AC

machine is required.

Page

4

SYNCHRO-PULSE

CDT

450

MANUAL

2.

RECEIVING.

Check the equipment received against the shipping invoice

to

make sure the

shipment is complete and undamaged. If any damage has occurred in transit, 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) Owners Manual.

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 rear fan grilles.

INSULATION

......................................

Class F, 115°C Rise.

DIMENSIQNS

.....................................

720mm

H,

430rnrn

W,

780mm

L.

MASS

.................................................

~63 Kg

Note.

l

Duty cycle

is

defined

in

Australian Standard AS1966.A as the ratio

of

arcing

time to

5

minutes in any

5

minute period, expressed as a percentage.

SYNCHRO-PULSE

CDT

450

MANUAL

Page

5

4.

INSTALLATION.

A@€.

Al1,electiical work shall only be undertaken by a qualified electrician. Before

removieg

any

smachine,8covers,'

ENSURE

that the unit

,is

disconnected from the electrical

supbly.;

fl~n

the8~clnitl"is~energised

LETHAL

V,OLTAGES

are present 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

Duty PVC Supply Flexible cable. The supply cable must be correctly connected 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

current for

a

SYNCHRO-PULSE CDT 450 is

25

Amps. The minimum recommended

circuit breaker rating for a SYNCHRO-PULSE CDT

450

is

32

Amps.

The current rating of the mains cable depends on cable size and method of

installation. Refer to AS/NZS

3008.1,

Table

9.

If

it becomes necessary to replace the

mains flexible supply cable,

use

only cable with correct current rating.

Access to the machine supply terminals is gained by removing the power-source

side panel adjacent to the supply cable entry. Pass the replacement cable through the

bush fitted to the machine back panel. The Earth wire (green

/

yellow) must be securely

attached to the marked Earth stud. The three supply phases are terminated at the Main

Contactor. Remove the contactor dust cover to gain access to the connection points.

Ensure that the internal Brown and Blue loom wires remain connected to the 'live' side of

the contactor. Tighten the cable clamp leaving sufficient slack in the cable such that the

terminated wires are not in tension.

SUPPLY VOLTAGE SELECTION

The SYNCHRO-PULSE CDT 450 is factory adjusted for a nominal electrical supply

voltage of 41

5

volts,

3

phase,

50

Hz. The equipment is rated for variations of

k

IO%,

that

is voltages in the range

375

-

455V AC. If the voltage moves out of this range the

machine will cease to weld, and will display an appropriate fault message. The local

Supply Authority will usually make adjustments to correct for out of tolerance supply

voltage, however if necessary the machine can be set to accept nominal input voltages

of

380

or 440 Vac.

To change the supply voltage selection

two

separate transformers must be

adjusted, and it is necessary to first remove both side panels.

I

The Control Transformer terminal strip

is

located on the side

of

the machine

nearest the

Off

/

On switch. Move the Brown wire to the intended input voltage

tapping.

adjacent to the Supply Flexible cable. Move the wire link to 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

I

1

LINK

A-

BLt

CONTROL TRANSFORMER

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 shown in 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 used to

connect the output of the gas regulator to the gas nipple on the rear panel of the

CDT

450.

The gas connector for the regulator end is included with the regulator.

The second hose is used to make the gas connection from the CDT

450

front

pane! to the back panel of the W35 wirefeeder. Note that these connectors

incorporate an

'OB

ring seal and do not require excessive tightening.

CONTROL. Fit the Control Pendant and Wirefeeder cable male plugs into their

respectively marked sockets on the CDT

450

front panel. Fit the Wirefeeder cable

female plug into the 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 of the

two

roll drive. Fit

the cable clamp supplied. Attach the plug end to the Positive 'GMAW

/

PULSE'

welding output socket of the power source.

plug end to the Negative 'COMMON' welding output socket.

Connect the Work Clamp to the welding bench or work piece, and attach the

FITTING THE ELECTRODE WIRE

Place the spool

of

electrode wire onto the spool holder. The location pin should

mate with a hole in the wire

spool

body. Fit the spool retaining

'R'

clip supplied.

Check the adjustment of the spool brake, which should be 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 adjusted by rotating the Nyloc nut using

a

15/16"

AF or

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 requiring it to be replaced prematurely.

Check that the drive roller groove is correct for the electrode wire to be used. The

drive roller part number

is

marked on the visible side of the installed roller. Refer to the

drive roller selection chart in Figure

22.

Check also that the correct size contact tip is

fitted at the gun end. Refer to Section

13

for gun part numbers.

Open the two roll drive mechanism by rotating the compression spring assembly

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 roller to the closed position.

SYNCHRO-PULSE

CDT

450

MANUAL Page

7

GAS CYLINDER

&

REGULATOR

REMOTE CONTROL PENDANT

'WORK' CLAMP

CONTROL CABLE

W/F WELDING CABLE

GUN CABLE ADAPTOR

GREY VOLTAGE SENSE

WIRE

u%!i

!LmE

8

PIN PLUG

PLUG

€!Lx

&

SOCKET WIRE FEEDER

W35-0

EL

GUN PLUG WELDING

&

SOCKET

-

GUN

2

+

TWO

"3?

RED

"J

((

S$~&~

t

3

t

THREE

'47

BLACK

4

+

FOUR

-i$r-

BLACK

5

t

FIVE

\$

GREY

-

(VOLTAGE SENSE)

6

+

SIX//6

7

t

SEVEN

/,7

8

t

GREEN/YELLOW

d8

SPARE

I

t

ONE

-+

BLACK-

-

(W/F MOTOR)

3

CORE

PLUG

m

REMOTE CONTROL PENDANT

2

t

BROWN

-

CURRENT

1

t

BLUE

-

ARC LENGTH

3

t

GREEN

-

COMMON

1

-'CURRENT'

'ARC LENGTH

FIGURE

2.

CABLE

AND HOSE CONNECTIONS, GMAW AND PULSED GMAW.

e

Page

8

SYNCHRO-PULSE

CDT

450

MANUAL

CABLE CONNECTIONS

-

CONSTANT CURRENT MODES.

All welding current and control connections for Constant Current modes MMAW

and GTAW are shown in below. The SYNCHRO-PULSE CDT

450

in Constant Current

mode supplies DC (direct current) welding current to the arc.

MMAW.

It is important to select the electrode polarity in accordance with the manufacturers'

recommendations for that electrode. Both Positive electrode and Negative electrode

methods of connection are shown in 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 ease in all positions, vertical up

or

down. The smooth forceful arc makes it 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 mitre fillet welds. 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.

Unicord 31 2, Classification AS2576, 1330-A3

~

When Constant Current mode 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.

ELECTRODE POSITIVE

OUTPUT

ON

ELECTRODE NEGATIVE

1

l

no

~UUO

no

1:

0

unoo

OUTPUT

ON

\

Y

n

I

FIGURE

3.

CONNECTIONS FOR MMAW.

~

SYNCHRO-PULSE CDT

450

MANUAL Paae

9

~~

GTAW.

For

GTAW

the torch is connected electrode negative. Figure

4

illustrates the

correct connection of the welding torch and gas supply utilising 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

be set

in

the range

2-5

litredmin.

Tungsten electrodes

for

DC

GTAW should be

l

-

2%

Thoriated. This type will

provide the best arc initiation, arc stability and tip shape retention characteristics.

Thoriated electrodes can be recognised by a red coded end. The tungsten electrode is

ground to 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, the recommended angle

is

60".

When set in the torch, the tungsten

should protrude 12mm from the ceramic gas nozzle.

l7

l

GAS

CONNECTIQN

(WHERE

USED)

-0RCH

SW.

CONNECTION

(WHERE

USED)

TORCH SWITCH CONNECTION

1)

2)

TORCH SWITCH

3)

8

4

)

PLUG

5

)

6)

7)

8)

j

FIGURE

4.

CABLE AND HOSE CONNECTIONS

FOR

GTAW.

Paae

IO

SYNCHRO-PULSE

CDT

450

MANUAL

W

5.

CONTROLS.

The SYNCHRO-PULSE CDT

450

power source is equipped with an operator

keypad panel and a graphical display screen. All control facilities of the machine are

accessed by use of the keypad. The individual key names and functions are:

SCHEDULE used to select a Welding Schedule;

OPTION used to modify Weld and general purpose Options;

ARROW KEYS used to position the highlight bar over a menu item.

ENTER used to select the menu item;

HELP used to view 'Help' information for the current menu;

INCH used to Inch the electrode wire forward;

PURGE used to Purge the shielding gas hoses.

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.

When the machine

is

first energised, the screen briefly displays the WIA

logo

during which time the microprocessor circuits are performing self-test routines. When

these checks have been completed, and provided that no fault conditions exist, the

screen will display information simitar

to

that shown below. For assistance with fault

messages, refer to 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

The display indicates the presently selected Weld Schedule with its internal library

number, the recommended

gas

composition, the set wirefeed rate, the estimated

welding current and an Arc Length setting indicator. This

is

referred to

as

the 'Ready'

state, as the machine is ready to weld with the settings displayed.

SYNCHRO-PULSE CDT 450 MANUAL

Paae

l l

~~

v

TO

SELECT

A

WELD

SCHEDULE.

From the SCHEDULE menu, GMAW, Pulsed GMAW, MMAW and GTAW

schedules can be selected. The Pulsed GMAW Weld Schedules available have been

established for specific combinations of electrode wire type, wire diameter, and shielding

gas mixtures. More than

100

combinations are available in the CDT

450

library. It is

important that the correct Weld Schedule be selected for the consumables (wire and

gas) in use.

Press the SCHEDULE key. The screen will display a list of weld schedule groups

beginning with electrode types for Pulsed GMAW. Use the ARROW keys

to

position the

highlight bar over the required group, then press ENTER. When 'on-line' programming,

Weld Schedules sent to the machine from a separate programming device are

accessible through the DOWNLOAD group.

-

1

Choose

ELECTRODE

TYPE

required:

EPROM

:

COPPER

&

ALLOYS

#33

125

FLUX

CORED

WIRES

#3##07

l

I

Use the ARROW keys 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

Section

14

of this manual lists all of the Pulsed GMAW weld schedules currently

available in the

CDT

library, together with their individual schedule numbers.

In

addition

to the method described above, weld schedules may also be selected directly by

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

menu provides

two

groups of Options

as

shown below. The first

group of Weld Options are specific to the selected Weld Schedule, providing adjustment

of:

Pre-gas time;

w

Creep speed;

Crater-fill time;

Burn-back time;

Post-gas time.

The remaining options are not specific to the selected Weld Schedule, and provide

the following features:

Recall of the last weld Current and Voltage data;

Selection of standard

or

latching gun-switch modes;

Servicing tests;

Demonstration display.

l

Recall of the last Fault message;

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

Use the 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 positioned in the 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

Adjusted Weld Option values become part of the selected Weld Schedule. The

SYNCHRO-PULSE CDT

450

stores all Weld Option settings for the last

16

Weld

Schedules used, and automatically applies the adjusted values whenever one of these

schedules is selected.

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 any key to 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. This is 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. Each is described in the 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

key to exit from the demonstration.

SYNCHRO-PULSE

CDT

450

MANUAL

Page

13

REMOTE CONTROL PENDANT

welding process.

GMAW AND PULSED GMAW

The remote control pendant has differing functions depending on the selected

CURRENT. This potentiometer control sets the wirefeed rate, which in turn

fundamentally determines the welding current. The SYNCHRO-PULSE CDT

450

internally adjusts other welding parameters in accordance with the setting of this

control.

The dial is a ten-turn vernier device which is graduated from

0

to

10.00.

The

graduations do not directly relate to any welding parameter, however the setting

of this control is indicated by the wirefeed rate and estimated welding current

information displayed when the machine is

in

the 'Ready' condition.

ARC LENGTH. This potentiometer control allows 'fine tuning' of the arc length to

suit the welding requirement. The most ideal welding conditions are normally

achieved when the operating arc length is adjusted 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 control is indicated in five steps

of positive and five steps of negative adjustment by the display when the machine

is in the '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 current is

displayed when the machine

is

in the 'Ready' condition.

ARC LENGTH. Arc length control is not appropriate to MMAW and GTAW which

are both Constant Current welding processes. When these 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 switch may

be connected as shown in Figure

4.

INCH AND PURGE.

The INCH and PURGE keys may be used during the 'Ready' state. The selected

function is active while the key is pressed.

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 key is held down, the motor will accelerate to the welding wirefeed

speed as set by the CURRENT potentiometer.

For

maximum inching speed, press the

INCH and UP ARROW keys simultaneously. During inching, the intended speed of the

wirefeed motor is displayed

in

rpm.

PURGE energises the gas valve to fill 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 selected Weld Schedule.

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.

The SYNCHRO-PULSE CDT

450

incorporates a power-saving standby mode. If

the machine is left idle for more than

25

minutes, the welding transformer and cooling

fans are de-energised and a 'Standby' message is 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;

Wirefeed commences 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

actual arc voltage and current

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 Crater fill has been selected, the wirefeed motor slows over

the time period selected;

The wire drive motor is dynamically braked to a stop;

Welding voltage is held '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 key is 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 if all external components are

correctly installed, adjusted, maintained, and the correct consumables are being used.

In a situation of unsatisfactory welding results, the welding power source is often the first

item suspected, however the fau!t frequently lies in these more routine areas.

SHIELDING GAS

In GMAW, and especially Pulsed GMAW, the shielding gas composition plays a

most important part in 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 are all Argon rich, and in some cases are 100% Argon.

Carbon Dioxide gas alone is not suitable for pulse welding, but it is a component in

mixtures used

for

several applications, and can be used for non-pulsed

G.M.A.W.

One function of the shielding gas is to protect the molten weld pool from the effects

of oxygen in the atmosphere. Without this protection the weld deposit becomes

'honeycombed'

in

appearance, an effect which is described as weld porosity.

In draft-free conditions the gas flow rate required to give adequate protection is

typically 10 litres/min.

In

situations where drafts cannot be avoided, it may be necessary

to increase this rate and/or to provide screening of the work area. Holding down the

PURGE key will display a recommended minimum gas flow rate for the selected

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 seals in 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

discrepancy may indicate

a

previously undetected gas leak.

WIREFEED

In any GMAW process, the electrode wirefeed must be smooth and constant

in

order to obtain the most satisfactory welding results.

It

is important to observe the

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 in use. For drive

roll

data, refer to Figure

22

of this manual.

The gun cable liner must be correctly fitted

so

that the free end seats firmly into

the back of the welding gun head. In this way the electrode wire is supported and

guided directly into the welding tip. Refer to Section 13 for liner fitting instructions.

Replace the welding tip

as

it becomes worn.

Check that the electrode wire spool holder rotates smoothly and that the braking

action is not 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. Occasional arc short circuiting, associated with a crackling sound, is acceptable.

Changes

in

weld preparation and/or work piece temperature may require adjustment

of

the arc length to maintain these conditions.

If the arc length is too short, it will result in excessive crackle, shorting and spatter,

while if too long may result in weld undercut and lack of weld penetration.

SURFACE CONTAMINATION.

Surface contamination of the work piece with water,

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

requirement to clean the surface with a suitable solvent

or

by linishing

or

grinding.

ARC BLOW.

Arc blow occurs when a magnetic field distorts

or

extinguishes the welding arc. The

magnetic field is usually the result

of

welding current passing through the object being

welded

or

through adjacent steel clamp bars. This is 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 Transformer is 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.

When set for pulsed

GMAW,

the SYNCHRO-PULSE CDT

450

supplies to the

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,

/

CURRENT PULSE

BACKGROUND CURRENT

/-

'WINDOW' UPPER

1

'WINDOW' LOWER

/

CURRENT PULSE

I

\

BACKGROUND CURRENT

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

shielding gas combination. These parameters together are referred to as a 'Weld

Schedule'. The SYNCHRO-PULSE CDT

450

has an internal library of over

100

weld

schedules, allowing Pulsed

GMAW

using a wide range of electrode wire types, 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 switched On and

Off

in such a way that

the current is held within

a

specified 'window' range.

The SYNCHRO-PULSE CDT

450

has separate switches for pulse and background

current. The pulse current switch is a bank of three high current bipolar transistors

mounted on a fan cooled, monolithic heatsink. The background switch is a bank

of

three

Mosfet transistors. The basic D.C. welding current is the rectified and filtered output of

a

three phase welding transformer.

Central to the CDT

450

is a microprocessor based control circuit CP38-10. This

circuit takes input from the press button keypad and remote control pendant, 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 data to the graphical display.

The block diagram illustrates the connections between the control blocks of the

SYNCHRO-PULSE CDT

450.

DISPLAY

I

Y

REMOTE

CONTROL

I

DlSpBLoAAvR~PU

b

I

PRESS-BUTTON

CP38-11 KEYPAD

M

I

t

I

ARC

CURRENT

FEEDBACK

t

*

BACKGROUND

*

DRIVER BOARD

b

CP38-13

WELDING CPU BOARD

CP38- 10

ARC

VOLTAGE

k

FEEDBACK

TRANSISTOR

+

DRIVER BOARD

t

CP38-12

I

GUN SWITCH

WIREISAS

CONTROL BOARD

CP38-16

WIREFEED

MOTOR

FIGURE

6.

FUNCTIONAL

BLOCK

DIAGRAM.

i

SYNCHRO-PULSE

CDT

450

MANUAL

Paae

19

Y

9.

FAULT

MESSAGES

The SYNCHRO-PULSE CDT

450

has means to detect a variety of external and

internal fault conditions. If a fault is detected, the machine will cease welding and

display a fault message similar to that shown below. Each message includes a

description of the fault condition, a fault code number and suggested actions to assist

with fault correction.

*

Check

plug

P3

Q~I

Weld

CPU CP38-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

Fault messages are displayed in order

of

priority. If

two

or

more faults occur

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

intermittent faults. The Schedule and Option menus may still be accessed when a

fault exists, but the machine will not permit welding.

Diagrams for all circuits and printed circuit boards referred to may be found in the

next section of this manual.

Fault

No.

Fault Message Page

1

..............................

Display CPU Memory Problem'

..................

19

3

..............................

Output Terminals Live'

...............................

20

6

..............................

Supply Phase Failure'

................................

23

7/8

..........................

'Supply High

/

Supply Low'

.........................

23

2

..............................

Welding CPU

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'

This message results from

two

possible conditions relating to the Display CPU

Assembly CP38-11. The first is an incorrect checksum result obtained during the power-

up sequence which indicates corruption

of

the Eprom data. The second is failure of the

RAM read/write power-up test.

Fit a new Eprom to the CP38-1

l

board. Refer to Section 12 of 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-PULSE CDT

450

has two microprocessor based control circuits.

These are the Welding CPU 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 boards is

Confirm that the microprocessor

of

the Welding CPU board CP38-10 is

correctly fitted, and that the plugs and sockets are not damaged.

functioning correctly. This is indicated by regular flashing of the 'Beacon' LED

4.

If

it is not:

Check that the CP38-10 power supply indicators LEDI, 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 Section 12

of

this manual for fitting

Replace the complete Welding CPU board CP38-10. Refer to Section

12

of

Replace the Display CPU Board CP38-11.

'OUTPUT TERMINALS

LIVE'

If the CDT

450

detects voltage across the output terminals at a time when the

machine is not being instructed to weld, failure of internal components is presumed and

so

the machine defaults to a safe condition by de-energising the welding transformer

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.'

This fault message is displayed if a Welding CPU onboard power supply is

not

available. The supplies are each powered

from

electrically isolated control transformer

windings which are individually fused on the Control Fuse Assembly Board CP38-17.

The table below relates each power supply to its LED indicator number and fuse

number.

CP38-10 CP38-17

CPU

+5v

LED 3 Fuse F7

CPU -15V LED 2

Fuse F5

CPU +15V LED

l

Fuse

F6

SHUNT AMP +/-l

5V

No LED Fuse

F4

l

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