F-15-098-AFebruary, 1995

Be sure this information reaches the operator.You can get extra copies through your supplier.

These INSTRUCTIONS are for experienced operators. If you are not fully familiar with the principles of operation andsafe practices for electric welding equipment, we urge you to read our booklet, "Precautions and Safe Practices forArc Welding, Cutting, and Gouging," Form 52-529. Do NOT permit untrained persons to install, operate, or maintainthis equipment. Do NOT attempt to install or operate this equipment until you have read and fully understand theseinstructions. If you do not fully understand these instructions, contact your supplier for further information. Be sureto read the Safety Precautions before installing or operating this equipment.

ESAB Welding &Cutting Products

INSTRUCTION MANUAL

VI 450WELDING POWER SOURCE

This manual provides installation and operation instructions for the following VI 450 power sources:

P/N 33322 - 230/460/575 V ac, 60 HzP/N 33323 - 220/380/415 V ac, 50 Hz

300A MAX

INDUCTANCE

SLOPE

4

INDUCTANCE

9

7

8MIN

1

26

3

ON

OFF

MAX

5

A

1

43

7

65

VOLTAGE

2(CONTACTOR ON)

VOLTAGEPRESET

MIN9

MAX

8

LOCALREMOTE

VI-450

V

NOTE: This manual is also suitable for use with the L-TEC VI-450. It is also suitable for use with the ESAB Phase Arc II 450made prior to April 1, 1995.

USER RESPONSIBILITYThis equipment will perform in conformity with the description thereof contained in this manual and accompanyinglabels and/or inserts when installed, operated, maintained and repaired in accordance with the instructions pro-vided. This equipment must be checked periodically. Defective equipment should not be used. Parts that arebroken, missing, worn, distorted or contaminated should be replaced immediately. Should such repair or replace-ment become necessary, the manufacturer recommends that a telephone or written request for service advice bemade to the Authorized Distributor from whom purchased.

This equipment or any of its parts should not be altered without the prior written approval of the manufacturer. Theuser of this equipment shall have the sole responsibility for any malfunction which results from improper use, faultymaintenance, damage, improper repair or alteration by anyone other than the manufacturer or a service facilitydesignated by the manufacturer.

TABLE OF CONTENTSSECTION TITLE PAGE

PARAGRAPH

SECTION 1 DESCRIPTION ................................................................................................................................... 51.1 General ............................................................................................................................................... 51.2 Receiving-Handling ............................................................................................................................ 51.3 Description ......................................................................................................................................... 51.3.1 Available Models ................................................................................................................................ 51.3.2 Power Source ..................................................................................................................................... 61.3.3 Volt-Ampere Characteristics .............................................................................................................. 61.4 Optional Accessories ......................................................................................................................... 61.4.1 HC-3B Remote Voltage and Contactor Hand Pendant Control ........................................................ 61.4.2 TR-22 Truck Kit .................................................................................................................................. 61.5 Safety ................................................................................................................................................. 6

SECTION 2 INSTALLATION ................................................................................................................................. 72.1 Location .............................................................................................................................................. 72.2 Receiving, Unpacking and Placement ............................................................................................... 72.3 Primary (Input) Electrical Connection ................................................................................................ 72.4 Secondary (Output) Welding Connections ........................................................................................ 82.5 Power Source/Wire Feeder/Control Interconnections ....................................................................... 92.5.1 Wire Feeder Control ........................................................................................................................... 92.5.2 Remote Voltage and Contactor Control ............................................................................................. 92.5.3 Auxiliary 115 V ac Receptacle ........................................................................................................... 9

SECTION 3 OPERATION ...................................................................................................................................... 113.1 Controls .............................................................................................................................................. 113.1.1 Power Switch (ON-OFF) .................................................................................................................... 113.1.2 Voltage Preset/Contactor Control Switch .......................................................................................... 113.1.3 Local/Remote Switch ......................................................................................................................... 113.1.4 Voltage Control ................................................................................................................................... 113.1.5 Inductance Control ............................................................................................................................. 123.1.6 Over Temperature Indicator ............................................................................................................... 123.1.7 Voltmeter and Ammeter ..................................................................................................................... 123.2 Sequence of Operation ...................................................................................................................... 123.2.1 General Procedures for Mig and Sub Arc .......................................................................................... 123.2.2 Specific Procedures for Mig and Sub Arc .......................................................................................... 12

SECTION 4 MAINTENANCE ................................................................................................................................. 134.1 General ............................................................................................................................................... 134.2 Cleaning ............................................................................................................................................. 134.3 Inspection and Service ....................................................................................................................... 134.3.1 Fan Motor ........................................................................................................................................... 134.3.2 Transformer ........................................................................................................................................ 134.3.3 Wire Feeder and Control Circuits ...................................................................................................... 134.3.4 Over Temperature Protection ............................................................................................................ 13

SECTION 5 TROUBLESHOOTING ....................................................................................................................... 145.1 General ............................................................................................................................................... 145.2 Testing and Replacing Bridge Assembly Components ..................................................................... 14

SECTION 6 PARTS ................................................................................................................................................ 296.1 General ............................................................................................................................................... 296.2 Ordering .............................................................................................................................................. 29

10/98

WARNING: These Safety Precautions are foryour protection. They summarize precaution-ary information from the references listed inAdditional Safety Information section. Before

performing any installation or operating procedures, besure to read and follow the safety precautions listed belowas well as all other manuals, material safety data sheets,labels, etc. Failure to observe Safety Precautions can resultin injury or death.

PROTECT YOURSELF AND OTHERS --Some welding, cutting, and gougingprocesses are noisy and require earprotection. The arc, like the sun, emitsultraviolet (UV) and other radiation and

can injure skin and eyes. Hot metal can cause burns.Training in the proper use of the processes and equip-ment is essential to prevent accidents. Therefore:

1. Always wear safety glasses with side shields in any workarea, even if welding helmets, face shields, and gogglesare also required.

2. Use a face shield fitted with the correct filter and coverplates to protect your eyes, face, neck, and ears fromsparks and rays of the arc when operating or observingoperations. Warn bystanders not to watch the arc andnot to expose themselves to the rays of the electric-arcor hot metal.

3. Wear flameproof gauntlet type gloves, heavy long-sleeveshirt, cuffless trousers, high-topped shoes, and a weld-ing helmet or cap for hair protection, to protect againstarc rays and hot sparks or hot metal. A flameproof apronmay also be desirable as protection against radiatedheat and sparks.

4. Hot sparks or metal can lodge in rolled up sleeves,trouser cuffs, or pockets. Sleeves and collars should bekept buttoned, and open pockets eliminated from thefront of clothing

5. Protect other personnel from arc rays and hot sparkswith a suitable non-flammable partition or curtains.

6. Use goggles over safety glasses when chipping slag orgrinding. Chipped slag may be hot and can fly far.Bystanders should also wear goggles over safety glasses.

FIRES AND EXPLOSIONS -- Heat fromflames and arcs can start fires. Hot slagor sparks can also cause fires and ex-plosions. Therefore:

1. Remove all combustible materials well away from thework area or cover the materials with a protective non-flammable covering. Combustible materials include wood,cloth, sawdust, liquid and gas fuels, solvents, paints andcoatings, paper, etc.

2. Hot sparks or hot metal can fall through cracks orcrevices in floors or wall openings and cause a hiddensmoldering fire or fires on the floor below. Make certainthat such openings are protected from hot sparks andmetal.“

3. Do not weld, cut or perform other hot work until theworkpiece has been completely cleaned so that thereare no substances on the workpiece which might pro-duce flammable or toxic vapors. Do not do hot work onclosed containers. They may explode.

4. Have fire extinguishing equipment handy for instant use,such as a garden hose, water pail, sand bucket, orportable fire extinguisher. Be sure you are trained in itsuse.

SAFETY PRECAUTIONS

5. Do not use equipment beyond its ratings. For example,overloaded welding cable can overheat and create a firehazard.

6. After completing operations, inspect the work area tomake certain there are no hot sparks or hot metal whichcould cause a later fire. Use fire watchers when neces-sary.

7. For additional information, refer to NFPA Standard 51B,"Fire Prevention in Use of Cutting and Welding Pro-cesses", available from the National Fire Protection Asso-ciation, Batterymarch Park, Quincy, MA 02269.

ELECTRICAL SHOCK -- Contact with liveelectrical parts and ground can causesevere injury or death. DO NOT use ACwelding current in damp areas, if move-ment is confined, or if there is danger offalling.

1. Be sure the power source frame (chassis) is connectedto the ground system of the input power.

2. Connect the workpiece to a good electrical ground.3. Connect the work cable to the workpiece. A poor or

missing connection can expose you or others to a fatalshock.

4. Use well-maintained equipment. Replace worn or dam-aged cables.

5. Keep everything dry, including clothing, work area, cables,torch/electrode holder, and power source.

6. Make sure that all parts of your body are insulated fromwork and from ground.

7. Do not stand directly on metal or the earth while workingin tight quarters or a damp area; stand on dry boards oran insulating platform and wear rubber-soled shoes.

8. Put on dry, hole-free gloves before turning on the power.9. Turn off the power before removing your gloves.

10. Refer to ANSI/ASC Standard Z49.1 (listed on next page)for specific grounding recommendations. Do not mistakethe work lead for a ground cable.

ELECTRIC AND MAGNETIC FIELDS —May be dangerous. Electric current flow-ing through any conductor causes lo-calized Electric and Magnetic Fields(EMF). Welding and cutting current cre-ates EMF around welding cables andwelding machines. Therefore:

1. Welders having pacemakers should consult their physi-cian before welding. EMF may interfere with some pace-makers.

2. Exposure to EMF may have other health effects which areunknown.

3. Welders should use the following procedures to minimizeexposure to EMF:A. Route the electrode and work cables together. Secure

them with tape when possible.B. Never coil the torch or work cable around your body.C. Do not place your body between the torch and work

cables. Route cables on the same side of your body.D. Connect the work cable to the workpiece as close as

possible to the area being welded.E. Keep welding power source and cables as far away

from your body as possible.

3

4

FUMES AND GASES -- Fumes andgases, can cause discomfort or harm,particularly in confined spaces. Donot breathe fumes and gases. Shield-ing gases can cause asphyxiation.Therefore:

1. Always provide adequate ventilation in the work area bynatural or mechanical means. Do not weld, cut, or gougeon materials such as galvanized steel, stainless steel,copper, zinc, lead, beryllium, or cadmium unless positivemechanical ventilation is provided. Do not breathe fumesfrom these materials.

2. Do not operate near degreasing and spraying opera-tions. The heat or arc rays can react with chlorinatedhydrocarbon vapors to form phosgene, a highly toxicgas, and other irritant gases.

3. If you develop momentary eye, nose, or throat irritationwhile operating, this is an indication that ventilation is notadequate. Stop work and take necessary steps to im-prove ventilation in the work area. Do not continue tooperate if physical discomfort persists.

4. Refer to ANSI/ASC Standard Z49.1 (see listing below)for specific ventilation recommendations.

5. WARNING: This product, when used for welding orcutting, produces fumes or gases whichcontain chemicals known to the State ofCalifornia to cause birth defects and, insome cases, cancer. (California Health &Safety Code §25249.5 et seq.)

CYLINDER HANDLING -- Cylinders, ifmishandled, can rupture and violentlyrelease gas. Sudden rupture of cylin-der, valve, or relief device can injure orkill. Therefore:

1. Use the proper gas for the process and use the properpressure reducing regulator designed to operate fromthe compressed gas cylinder. Do not use adaptors.Maintain hoses and fittings in good condition. Followmanufacturer's operating instructions for mounting regu-lator to a compressed gas cylinder.

2. Always secure cylinders in an upright position by chainor strap to suitable hand trucks, undercarriages, benches,walls, post, or racks. Never secure cylinders to worktables or fixtures where they may become part of anelectrical circuit.

3. When not in use, keep cylinder valves closed. Havevalve protection cap in place if regulator is not con-nected. Secure and move cylinders by using suitablehand trucks. Avoid rough handling of cylinders.

4. Locate cylinders away from heat, sparks, and flames.Never strike an arc on a cylinder.

5. For additional information, refer to CGA Standard P-1,"Precautions for Safe Handling of Compressed Gases inCylinders", which is available from Compressed GasAssociation, 1235 Jefferson Davis Highway, Arlington,VA 22202.

EQUIPMENT MAINTENANCE -- Faulty orimproperly maintained equipment cancause injury or death. Therefore:

1. Always have qualified personnel perform the installa-tion, troubleshooting, and maintenance work. Do notperform any electrical work unless you are qualified toperform such work.

2. Before performing any maintenance work inside a powersource, disconnect the power source from the incomingelectrical power.

3. Maintain cables, grounding wire, connections, powercord, and power supply in safe working order. Do notoperate any equipment in faulty condition.

4. Do not abuse any equipment or accessories. Keepequipment away from heat sources such as furnaces,wet conditions such as water puddles, oil or grease,corrosive atmospheres and inclement weather.

5. Keep all safety devices and cabinet covers in positionand in good repair.

6. Use equipment only for its intended purpose. Do notmodify it in any manner.

ADDITIONAL SAFETY INFORMATION -- Formore information on safe practices for elec-tric arc welding and cutting equipment, askyour supplier for a copy of "Precautions andSafe Practices for Arc Welding, Cutting andGouging", Form 52-529.

The following publications, which are available from theAmerican Welding Society, 550 N.W. LeJuene Road, Mi-ami, FL 33126, are recommended to you:1. ANSI/ASC Z49.1 - "Safety in Welding and Cutting"2. AWS C5.1 - "Recommended Practices for Plasma Arc

Welding"3. AWS C5.2 - "Recommended Practices for Plasma Arc

Cutting"4. AWS C5.3 - "Recommended Practices for Air Carbon

Arc Gouging and Cutting"5. AWS C5.5 - "Recommended Practices for Gas Tungsten

Arc Welding“6. AWS C5.6 - "Recommended Practices for Gas Metal Arc

Welding"“7. AWS SP - "Safe Practices" - Reprint, Welding Hand-

book.8. ANSI/AWS F4.1, "Recommended Safe Practices for

Welding and Cutting of Containers That Have HeldHazardous Substances."

MEANING OF SYMBOLS - As used through-out this manual: Means Attention! Be Alert!Your safety is involved.

Means immediate hazards which, ifnot avoided, will result in immediate,serious personal injury or loss of life.

Means potential hazards which couldresult in personal injury or loss of life.

Means hazards which could result inminor personal injury.

SP98-10

5

SECTION 1 DESCRIPTION

VI 450 Power Source

1.1 GENERAL

This manual has been prepared for use by an experi-enced operator. It provides information to familiarizethe operator with the design, installation and operationof this equipment. DO NOT attempt to install or operatethis equipment until you have read and fully understoodthese instructions. The information presented hereshould be given careful consideration to ensure opti-mum performance of this equipment.

1.2 RECEIVING-HANDLING

Upon receipt, remove all packing material and carefullyinspect for any damage that may have occurred duringshipment. Any claims for loss or damage that may haveoccurred in transit must be filed by the purchaser withthe carrier. A copy of the bill of lading and freight bill willbe furnished by the carrier on request.

When requesting information concerning this equip-ment, it is essential that Stock, Serial and Model num-bers of the equipment be supplied.

1.3 DESCRIPTION

The VI 450 is designed for Mig short arc, spray arc andflux core welding, as well as submerged arc applica-tions.

1.3.1 AVAILABLE MODELS

VI 450 230/460/575, 60 Hz, 3 phase, P/N 33322VI 450 220/380/415, 50 Hz, 3 phase, P/N 33323

Table 2-1. SpecificationsOPEN CIRCUIT VOLTAGE (Uo) 13-52 V

OUTPUT

DUTY CYCLE 65% 100%

FlatCurrent (I2) 500 A 450 A

Voltage (U2) 40 V 38 V

SteepCurrent (I2) 350 A 300 A

Voltage (U2) 34 V 32 V

INPUT 3 Phase

60 Hz

Volts (U1) Current (I1) Flat Current (I1) Flat

230 V 73 A 66 A

460 V 36 A 33 A

575 V 29 A 26 A

50 Hz

220 V 77 A 69 A

380 V 44 A 40 A

415 V 41 A 37 A

Power Factor at Rated Output 83%

Maximum Welding Range 500 A/40 V - 50 A/14 V

Maximum Auxiliary Power 115 V ac @ 10 A, 60 Hz

PHYSICAL SPECIFICATIONS

Height 31.0" (79.0 cm)

Width 21.6" (55.0 cm)

Depth 33.0" (83.9 cm)

Net Weight 465 lbs (211 kg)

Shipping Weight 487 lbs (221 kg)

SECTION 1 DESCRIPTION

VI 450 Power Source6

range remote output control and provides a contactorclosure switch to close the contactor making the outputterminal "hot" at all times for arc gouging. The local/remote switch on the front panel must be placed in theremote position when using this accessory.

Figure 1-1. Volt-Ampere Curves

1.4.2 TR-22 TRUCK KIT, P/N 33650

This accessory provides for complete mobility of thepower source. The kit consists of front castors, rear twocylinder rack and wheels, gas cylinder bracket, andhandle.

1.5 SAFETY

Before the equipment is put into operation, the safetysection at the front of this manual should be readcompletely. This will help avoid possible injury due tomisuse or improper welding applications. The defini-tions relating to the DANGER, WARNING, and CAU-TION safety notations are described at the end of theSafety Section in the front of this manual — read themand their specific text references carefully.

1.3.2 POWER SOURCE

The power source is a constant potential, Silicon Con-trolled Rectifier (SCR), three phase, star-connectedtransformer/rectifier type dc unit with solid state contactorand control circuitry. It provides the volt-ampere curvecharacteristics desired for Mig and submerged arcwelding.

The power source is equipped with a thermally con-trolled fan. It helps to minimize the amount of dirt,spatter and dust deposited in the power source as aresult of a continuously running cooling fan. It consistsof two relays and a thermal switch which allow the fanto run only when welding and when necessary toprovide cooling to the internal magnetics and compo-nents.

NOTE: As shipped, this feature is disabled. To activatethe thermal fan control circuit, remove the left sidepanel. Locate relay K4 on the rear left transformermounting support. Move the white wire from terminal 1to terminal 5. When activated, it is normal for thecabinet sheet metal to be hot to the touch when in theidle mode (fan not running). When required, the fan willautomatically energize and cool the internal compo-nents as well as the cabinet sheet metal.

1.3.3 VOLT-AMPERE CHARACTERISTICS

The curves shown in Figure 1-1 represent the volt-ampere static characteristics for the power source.The slant of these curves is referred to as the 'slope' andis generally defined as the 'voltage drop per 100 am-peres of current use.' These curves show the outputvoltage available at any given output current for theminimum and maximum settings of the voltage control.Values for other settings will fall between the minimumand maximum curves. Because the volt-ampere slopeis fixed, it is possible to select welding conditions byestimating the open-circuit voltage required for the loadcurrent. The static voltage-ampere slope is not affectedby the inductor rheostat setting.

1.4 OPTIONAL ACCESSORIES

1.4.1 HC-3B REMOTE VOLTAGE ANDCONTACTOR HAND PENDANTCONTROL (P/N 33838)

This accessory operates in parallel with the powersource's voltage control potentiometer to provide full

50

40

30

20

10

0

60

100 200 300 400 500

STEEPFLAT

SECTION 2 INSTALLATION

7VI 450 Power Source

2.1 LOCATION

A proper installation site is necessary for the unit toprovide dependable service. This means the powersource should be placed in a way that provides freedomof air movement through the unit while minimizingexposure to dust, dirt, moisture, and corrosive vapors.A minimum of 18 inches (46 cm) is required betweenthe side and rear panels of the power source and thenearest obstruction.

The selected site should also allow easy removal of thepower source outer enclosure for maintenance. SeeFigure 2-1 for overall dimensions of the unit.

Figure 2-1. Dimensions

2.2 RECEIVING, UNPACKING AND PLACEMENT

A. Immediately upon receipt of the power source,inspect for damage which may have occurredin transit. Notify the carrier of any defects ordamage.

B. Remove the power source from the container.Remove all packing materials. Check thecontainer for any loose parts.

C. Check air passages at front and rear of cabi-net, making sure that no packing materials thatmay obstruct air flow through the power source.

D. After selecting an installation site (see para-graph 2.1), place the power source in thedesired location. The unit may be lifted eitherby using the lifting ring or by forklift truck. If aforklift is used for lifting the unit, be sure that thelift forks are long enough to extend completelyunder the base.

Do not use filters on this unit as they would restrictthe volume of intake air. Output ratings on this unitare based on an unobstructed supply of cooling airdrawn over its internal components. Warranty isvoid if any type of filtering device is used.

2.3 PRIMARY (INPUT) ELECTRICAL CONNECTION

This power source is a three-phase unit and must beconnected to a three-phase power supply. It is recom-mended that the unit be operated on a dedicated circuitto prevent impairment of performance due to an over-loaded circuit.

ELECTRIC SHOCK CAN KILL! Before making elec-trical input connections to the power source, "Ma-chinery Lockout Procedures" should be employed.If the connections are to be made from a linedisconnect switch, place the switch in the off posi-tion and padlock it to prevent inadvertent tripping. If the connection is made from a fusebox, removethe corresponding fuses and padlock the box cover.If it is not possible to use padlocks, attach a red tagto the line disconnect switch (or fuse box) warningothers that the circuit is being worked on.

A. The primary power leads should be insulatedcopper conductors. Three power leads andone ground wire are required. Either rubbercovered cable or conduit (flexible or solid) may

300A MAX

INDUCTANCE

SLOPE

4

INDUCTANCE

9

7

8MIN

1

26

3

ON

OFF

MAX

5

A

1

43

7

65

VOLTAGE

2(CONTACTOR ON)

VOLTAGEPRESET

MIN9

MAX

8

LOCALREMOTE

VI-450

V

2.88"

LIFT EYE

21.63"33.0"

33.82"

SECTION 2 INSTALLATION

8

VI 450 Power Source

be used. Table 2-1 provides recommendedinput conductors and line fuse sizes.

B. Open the access door on the right side of themachine. Identify primary power input connec-tions on the input terminal board, customerground connection to chassis ground lug, andprimary voltage-changeover terminal board.Refer to Figures 2-2 and 2-3.

Table 2-1. Recommended Sizes for InputConductors and Line Fuses

Rated Input Input &GND

ConductorCU/AWG

Fuse SizeAmpsVolts Amps

230460575

663326

No. 4No. 8No. 10

1005050

*Sized per National Code for 80 °C rated copper conductors @ 30°C ambient. Not more than three conductors in raceway or cable.Local codes should be followed if they specify sizes other than thoselisted above.

C. Thread the input and ground cable(s) throughthe large strain-relief hole in the rear panel ofthe power source. Connect the primary powerleads to terminals L1, L2, and L3 on the inputterminal board. Secure the strain relief on theinput cable. Connect the ground wire to theterminal lug, which is located directly below theinput terminal board on the chassis base insidethe cabinet.

The chassis must be connected to an approvedelectrical ground. Failure to do so may result insevere electrical shock, causing severe burns ordeath.

D. Recheck all connections for proper tightness.Ensure all connections are correct and well-insulated.

E. The primary voltage-changeover input termi-

nal board (Figure 2-2) illustrates the primaryvoltage link connections. The voltage links onthis board are factory set for highest voltageoperation and must be reset for the requiredservice voltage. Figure 2-2 shows the requiredconnections to reestablish the desired servicevoltage. The voltage links are set up byreconfiguring the copper link bars to the silk-screened voltage designations for the desiredvoltage.

2.4 SECONDARY (OUTPUT) WELDING CONNECTIONS

Before making any connections to the power sourceoutput terminals, make sure that all primary inputpower to the machine is off.

Figure 2-2. Voltage Changeover Input TerminalBoard (230/460/575 V illustrated)

The output terminals are located on the front panel(Figure 2-3). Four output terminals are provided. Thetwo NEGATIVE (-) (high inductance and low induc-tance) terminals are located at the bottom right-handcorner and the two POSITIVE (+) (steep slope and flatslope) terminals are located at the bottom left corner.The output cable connections will depend on the mate-rials to be welded and on the welding process desired.Table 2-2 provides the recommended cable outputsizes.2.5 POWER SOURCE/WIRE FEEDER/

575460

575460

230

230

230

230

230

230

230

460230

230460

L1

L2

L3460230

575

460

460230

575460

575

230

575

575

575

SECTION 2 INSTALLATION

9VI 450 Power Source

CONTROL INTERCONNECTIONS

Refer to Figure 2-3.

2.5.1 WIRE FEEDER CONTROL

Wire feeder control connections are provided by a 19-pin amphenol connector (J1) located on the rear panelof the power source in the upper right-hand corner.

2.5.2 REMOTE VOLTAGE ANDCONTACTOR CONTROL

This function is provided by a 14-pin amphenol connec-tor (J2) located on the rear panel directly below connec-tor J1. It receives a mating plug from a Hand ControlAssembly (optional). This receptacle is operative onlyif the Local/Remote switch on the power source frontpanel is in the "Remote" position.

2.5.3 AUXILIARY 115 V AC RECEPTACLE

Ten amperes of 115 V ac power can be supplied toexternal accessories by connecting them to receptacleJ3 on the rear panel directly above the fuses.

Table 2-2. Secondary Cable Sizes

WeldinCurrent

Total Length (Feet) ofCable in Weld Circuit*

50 100 150 200 250

100 6 4 3 2 1/0

150 4 3 1 1/0 2/0

200 3 1 1/0 2/0 3/0

250 2 1/0 2/0 3/0 4/0

300 1 2/0 3/0 4/0 4/0

400 2/0 3/0 4/0 4/0 2-2/0

500 3/0 3/0 4/0 2-2/0 2-3/0

*Total cable length includes work and electrode cables. Cable sizeis based on direct current, insulated copper conductors, 100-percent duty cycle and a voltage drop of 4 or less volts. The weldingcable insulator must have a voltage rating that is high enough towithstand the open circuit voltage of the machine.

SECTION 2 INSTALLATION

10

VI 450 Power Source

Figure 2-3. Interconnection Diagram

SECTION 3 OPERATION

11VI 450 Power Source

Never, under any circumstances, operate the powersource with the cover removed. In addition to thesafety hazards, which are considerable, impropercooling may cause damage to the components.Keep side panels closed when unit is energized.Welding helmet, gloves, and other personal pro-tection should always be worn when welding.

3.1 CONTROLS (See Figure 3-1)

3.1.1 POWER SWITCH (ON-OFF)

The power switch is located on the front panel of thepower source. In the "off" position, the unit is essen-tially shut down. With the switch in the "off" position,power is still present at the main contactor and at theswitch itself. To fully shut down the power source,power must be disconnected at the line disconnectswitch or the fuse box, depending upon the installation.

With the switch in the "on" position, 115 V ac power isprovided to energize the main contactor coil, closingthe main contactor which provides input power to themain transformer and the low voltage control circuitry.

3.1.2 VOLTAGE PRESET/CONTACTORCONTROL SWITCH

The Voltage Preset switch is located on the front panelof the power source. In the Preset (on) position, thesolid state contactor is energized from the powersource. In the Remote (maintained) position, the solidstate contactor is energized from a remote location,such as a wire feeder. The "on" position thus allowspresetting an approximate welding condition withoutactually striking an arc. The "maintained" positionallows the solid state contactor and the constant volt-age output to be controlled from a remote Mig wirefeeder or mechanized sub arc control.

3.1.3 LOCAL/REMOTE SWITCH

With this switch in the Local position, output is con-trolled by setting the voltage potentiometer on the frontpanel to the output desired. In the Remote position,output is controlled using the optional Remote VoltageControl Assembly via connector J2.

3.1.4 VOLTAGE CONTROL

This control allows the operator to regulate the requiredamount of welding voltage. Placing the Local/Remoteswitch in the Remote position disables the voltagecontrol.

Figure 3-1. Control Locations

300A MAX

INDUCTANCE

SLOPE

4

INDUCTANCE

9

7

8MIN

1

26

3

ON

OFF

MAX

5

A

1

43

7

65

VOLTAGE

2(CONTACTOR ON)

VOLTAGEPRESET

MIN9

MAX

8

LOCALREMOTE

VI-450

V

3.1.3

3.1.1

3.1.6

3.1.2

3.1.7

3.1.4

3.1.5

SECTION 3 OPERATION

12

VI 450 Power Source

3.1.5 INDUCTANCE CONTROL

This control allows the desired amount of inductance tobe set and regulated during short arc welding opera-tions. Variable control allows the operator to fine tunethe inductance needed to make the weld puddle morefluid and to minimize weld spatter.

3.1.6 OVER TEMPERATURE INDICATOR

This indicator will light when an internal overheatingcondition has occurred and one of the thermal switcheshas opened, causing the power source to shut down toprotect critical components.

3.1.7 VOLTMETER AND AMMETER

A voltmeter (0-60V) and ammeter (0-800A) provide anaccurate indication of dc open circuit and weldingvoltage, and welding current.

3.2 SEQUENCE OF OPERATION

Prior to performing the steps below, open the walldisconnect switch or remove fuse from fuse box toelectrically isolate the power source.

3.2.1 GENERAL PROCEDURES FORMIG AND SUB ARC

A. Make the secondary output connections to thepositive and negative output terminals.

B. Make the control connections. Refer to theappropriate wire feeder, mechanized control,and/or torch instruction booklets for additionalprocess requirements or control connections.

C. If primary power connections have been madeto the main contactor, and the voltagechangeover terminal board and control trans-former jumpers properly match the incomingvoltage, close the main wall disconnect switchor reinstall fuses in the fuse box.

3.2.2 SPECIFIC PROCEDURES FORMIG AND SUB ARC

A. Set the local/remote switch to the desiredsetting.

B. Set the on-off switch to the "on" position.

C. To preset the approximate welding voltage,place the contactor switch to the "closed" (on)position. This action will energize the powersource on output terminals, allowing the de-sired voltage condition to be preset using theVoltage Control potentiometer and observingthe voltmeter.

D. After setting the desired voltage condition,release the Voltage Preset switch. This moderequires a remote start control activation inorder to start the welding sequence.

E. Set the variable inductance control to thedesired amount of inductance. Lower induc-tance settings may be required in order toobtain better arc starts. The established arcand puddle characteristics can then be finetuned under load.

F. Commence welding. Observe the voltmeter,ammeter, and the weld. Readjust the voltage,inductance, and wire feed speed settings asnecessary to obtain a satisfactory weld.

G. When welding is completed, release torchswitch at the remote location. (This action willdeenergize the power source solid statecontactor and remove dc power from the out-put terminals.)

If the welding operation terminates prematurely, checkthe front panel overheat light. If the light is on, internalovertemperature conditions have caused the thermalswitches to open, deenergizing the solid state contactor.When the unit has sufficiently cooled, these switcheswill reset, the overheat light will go out, and weldingmay resume.

SECTION 4 MAINTENANCE

VI 450 Power Source

13

4.1 GENERAL

If this Power Source does not operate properly, stopwork immediately and investigate the cause of themalfunction. Maintenance work must be performed byan experienced person, and electrical work by a trainedelectrician. Do not permit untrained persons to inspect,clean, or repair this Power Source. Use only recom-mended replacement parts.

BE SURE THAT THE BRANCH CIRCUIT OR MAINDISCONNECT SWITCH IS OFF, OR ELECTRICALINPUT FUSES ARE REMOVED, BEFORE ATTEMPT-ING ANY INSPECTION OR WORK INSIDE THEPOWER SOURCE. PLACING THE POWER SWITCHIN THE OFF POSITION DOES NOT REMOVE ALLPOWER FROM INSIDE THE POWER SOURCE.

4.2 CLEANING

Periodically, remove the cover from the Power Sourceand blow accumulated dust and dirt from the air pas-sages and interior components by using clean lowpressure air. The frequency of cleaning required de-pends upon the environment in which the Power Sourceis used.

It is imperative that all air passages be kept as clean aspossible in order to allow adequate air flow to provideproper cooling.

After cleaning with low pressure air, check for andtighten any loose hardware, including all electricalconnections. Check for frayed and/or cracked insula-tion on all power cables and replace if necessary.

FAILURE TO REPLACE WORN OR DAMAGEDCABLES MAY RESULT IN A BARE CABLE TOUCH-ING A GROUND SURFACE. THE RESULTING ELEC-TRICAL ARC MAY DAMAGE UNPROTECTED EYESAND WILL PRESENT A SERIOUS FIRE HAZARD.BODY CONTACT WITH A BARE CABLE, CONNEC-TOR, OR CONDUCTOR MAY RESULT IN SEVEREELECTRICAL SHOCK, CAUSING SERIOUS BURNSOR DEATH.

4.3 INSPECTION AND SERVICE

Regularly, check cylinder valves, regulators, hoses,and gas connections for leaks using a soap solution ora leak test solution.

Keep the Power Source dry, free of oil and grease, andprotected at all times from damage by hot metal andsparks.

4.3.1 FAN MOTOR

Keep the fan motor free of accumulated dust and lint byusing low pressure air. Lubricate the motor every 3months with a few drops of SAE-20 non-detergent oil.

4.3.2 TRANSFORMER

Other than periodically cleaning the dust and dirt fromthe transformer as described above, no maintenance isrequired. Ensure that only clean, dry, low pressure airis used.

4.3.3 WIRE FEEDER AND CONTROL CIRCUITS

These circuits are protected by two 10 amp fusesmounted in the rear panel fuse holder (CB1, 2). If thesefuses fail, the contactor, shielding gas, and wire feederwill not operate.

When replacing a fuse in the welding Power Source,ensure that the proper size fuse is used as areplacement.

4.3.4 OVER TEMPERATURE PROTECTION

If the Power Source reaches an abnormally high inter-nal temperature, the Thermal Fan Kit relay willdeenergize, shutting down the Power Source but leav-ing the cooling fan on. After the Power Source hascooled to a safe level, this relay will be energized andnormal operation will be restored. While deenerigized,the contactor, shielding gas, and wire feeder cannot beoperated.

SECTION 5 TROUBLESHOOTING

14

VI 450 Power Source

5.1 GENERAL

DISCONNECT PRIMARY POWER AT WALLSWITCH, OR CIRCUIT BREAKER, BEFORE AT-TEMPTING INSPECTION OR WORK INSIDE THEPOWER SOURCE.

If the Power Source is operating improperly, the follow-ing troubleshooting information may be used to locatethe source of the trouble.

Check the problem against the symptoms in the follow-ing troubleshooting guide (Table 5-2.) The remedy forthe problem may be quite simple. If the cause cannotbe quickly located, open up the unit and perform asimple visual inspection of all the components andwiring. Check for proper terminal connections, loose orburned wiring or components, blown fuses, bulged orleaking capacitors, or any other sign of damage ordiscoloration.

5.2 TESTING AND REPLACING BRIDGE ASSEMBLY COMPONENTS

The silicon diodes and SCRs used in the Power Sourceare devices which allow current to flow in only onedirection. The diodes and SCRs are designed toprovide long trouble-free operation; however, should afailure occur, they may require replacement.

A. Testing SCRs.

1. Locate the main rectifier assembly containingthe silicon diodes and SCRs.

2. Remove top and right side panel from thePower Source.

3. Electrically isolate main bridge assembly bydisconnecting the capacitor bank and resistorR5.

4. With the ohmmeter on RX1 scale, place thepositive lead on the anode (end of SCR withscrew threads) and the negative lead on thecathode (positive output terminal on the frontpanel). The meter should read 30-50 ohms(high resistance).

5. Reverse leads and check each SCR. Allreadings should again show high resistance.The SCRs are bad if they show low resistancein either direction.

6. Check the gate circuit on the SCRs by jumperingthe gate lead to the anode of the SCR. Themeter should read less than 5 ohms. Removethe jumper from the gate. The meter readingshould increase (30-50 ohms).

When replacing diodes on SCRs, make sure mount-ing surfaces are clean. Coat mounting surfaceswith Alcoa No. 2 EJC Electrical Joint Compound.Use a torque wrench to tighten diodes and SCRs.Recommended torques are 20-30 in-lbs for diodes;125-150 in-lbs for SCRs.

SECTION 5 TROUBLESHOOTING

VI 450 Power Source

15

Table 5-1. PCB Voltage Tests*

NOTE

All voltage readings are taken with the front accesspanel open.

ELECTRICAL SERVICE AND REPAIR SHOULD BEATTEMPTED ONLY BY A TRAINED ELECTRICIAN.

SCR VOLTAGES (INPUT)

FROM TO READING

P1-8 P1-9 115 V ac

P2-8 (SCR1)P2-7 (SCR2)P2-3 (SCR3)P2-6 (SCR4)P2-1 (SCR5)P2-4 (SCR6)

OTB+ (Flat) 14 V ac

SCR VOLTAGES (OUTPUT)

FROM TO READING

P1-11 OTB+ (Flat) +10 V dc

P1-4 OTB+ (Flat) 0-10 V dc**

P2-5 (SCR1)P2-2 (SCR2)P2-12 (SCR3)P2-9 (SCR4)P2-10 (SCR5)P2-11 (SCR6)

OTB+ (Flat) .3 V dc withcontactor on

*Refer to Schematic Diagram**Varies with VCP (R1)

SECTION 5 TROUBLESHOOTING

16

VI 450 Power Source

Table 5-2. Troubleshooting Guide

CONDITION ACTION

Unit inoperative A.B.C.D.

E.

F.

No input power. Check main line (user's) switch fuses -- replace if needed.Poor or improper input (terminal board) connections.Defective ROS switch on front panel -- replace.Main transformer overheating. Also check for proper cooling, proper primaryhookup, or shorted turn on secondary.Fan motor not operating -- check motor and leads. Remember, this is normal whenThermal Fan Kit is used.Main contactor defective -- check for proper operation.

No Output -- FanRunning

A.B.C.

D.E.

Poor or improper electrical input -- check input connections on TB.Poor connections at output terminals/work station -- check, tighten or replace.Main transformer overheating -- thermal switches tripped due to restricted coolingair. Let unit cool down.Solid-state breaker tripped due to current overload.PC board defective or loose PC board connector(s) -- if loose, reinsert; if defective,replace.

Limited Output or LowOpen-Circuit Voltage

A.

B.C.D.

Input voltage jumper links on terminal board improperly set -- check for propervoltage.Poor output connections. Take apart, clean, and reassemble.Unit may be single-phasing -- check incoming power for three phases.Panel-Remote switch in Remote position and remote voltage pot disabled.

Erratic Weld Current A.B.C.D.E.F.

Welding cable size too small -- use correct cables.Loose welding cable connection (will usually get hot) -- tighten all connections.Improper wire feeder setup.Defective SCR in bridge rectifier.PC board defective -- replace.Unit may be single phasing -- check the incoming power for three phases.

High Output, NoVoltage Control

PC board defective or loose -- reset and/or replace board.

No 115 Volt ac Output A.B.

Check secondary of control winding on main transformer for 115 V ac.Circuit breaker tripped -- reset.

Line Fuse Blows WhenPower Source is FirstTurned On

A.B.

Shorted SCR in Main Bridge -- replace.Shorted capacitor in Capacitor Bank.

Wire Sparks andSticks to Workpiece atEnd of Weld

A.

B.

Allow 2 to 4 seconds for capacitor banks to discharge after completing the weld andbefore touching wire to workpiece.If doubling the discharge rate is desired (twice as fast) and you are not using theThermal Fan Kit (generate excessive heat), change R1 (16 ohm, 300 watt) resistorto 8 ohm, 300 watt resistor (P/N 17300008). To quadruple the discharge rate (fourtimes as fast), two 8 ohm resistors may be connected in parallel in place of R1.

SECTION 5 TROUBLESHOOTING

VI 450 Power Source

17

Figure 5-1. VI 450 Power Source Schematic Diagram - 60 Hz (Sheet 1 of 2)

SECTION 5 TROUBLESHOOTING

18

VI 450 Power Source

Figure 5-1. VI 450 Power Source Schematic Diagram - 60 Hz (Sheet 2 of 2)

SECTION 5 TROUBLESHOOTING

VI 450 Power Source

19

Figure 5-2. VI 450 Power Source Wiring Diagram - 60 Hz (Sheet 1 of 4)

SECTION 5 TROUBLESHOOTING

20

VI 450 Power Source

Figure 5-2. VI 450 Power Source Wiring Diagram - 60 Hz (Sheet 2 of 4)

SECTION 5 TROUBLESHOOTING

VI 450 Power Source

21

Figure 5-2. VI 450 Power Source Wiring Diagram - 60 Hz (Sheet 3 of 4)

SECTION 5 TROUBLESHOOTING

22

VI 450 Power Source

Figure 5-2. VI 450 Power Source Wiring Diagram - 60 Hz (Sheet 4 of 4)

SECTION 5 TROUBLESHOOTING

VI 450 Power Source

23

Figure 5-3. VI 450 Power Source Schematic Diagram - 50 Hz (Sheet 1 of 2)

SECTION 5 TROUBLESHOOTING

24

VI 450 Power Source

Figure 5-3. VI 450 Power Source Schematic Diagram - 50 Hz (Sheet 2 of 2)

SECTION 5 TROUBLESHOOTING

VI 450 Power Source

25

Figure 5-4. VI 450 Power Source Wiring Diagram - 50 Hz (Sheet 1 of 4)

SECTION 5 TROUBLESHOOTING

26

VI 450 Power Source

Figure 5-4. VI 450 Power Source Wiring Diagram - 50 Hz (Sheet 2 of 4)

SECTION 5 TROUBLESHOOTING

VI 450 Power Source

27

Figure 5-4. VI 450 Power Source Wiring Diagram - 50 Hz (Sheet 3 of 4)

SECTION 5 TROUBLESHOOTING

28

VI 450 Power Source

Figure 5-4. VI 450 Power Source Wiring Diagram - 50 Hz (Sheet 4 of 4)

SECTION 6

VI 450 Power Source

29

REPLACEMENT PARTS6.1 GENERAL

Replacement Parts are illustrated on the following fig-ures. When ordering replacement parts, order by partnumber and part name, as illustrated on the figure. DONOT ORDER BY PART NUMBER ALONE.

Always provide the series or serial number of the unit onwhich the parts will be used. The serial number isstamped on the unit nameplate.

6.2 ORDERING

To assure proper operation, it is recommended thatonly genuine ESAB parts and products be used with thisequipment. The use of non-ESAB parts may void yourwarranty.

Replacement parts may be ordered from your ESABdistributor or from:

ESAB Welding & Cutting ProductsAttn: Customer Service Dept.PO Box 100545, Ebenezer RoadFlorence, SC, 29501-0545

Be sure to indicate any special shipping instructionswhen ordering replacement parts.

To order parts by phone, contact ESAB at 1-803-664-5540 or 4460. Orders may also be faxed to 1-800-634-7548. Be sure to indicate any special shipping instruc-tions when ordering replacement parts.

Refer to the Communication Guide located on the lastpage of this manual for a list of customer service phonenumbers.

SECTION 6

VI 450 Power Source

30

REPLACEMENT PARTS

300A MAX

INDUCTANCE

SLOPE

4

INDUCTANCE

9

7

8MIN

1

26

3

ON

OFF

MAX

5

A

1

43

7

65

VOLTAGE

2(CONTACTOR ON)

VOLTAGEPRESET

MIN9

MAX

8

LOCALREMOTE

VI-450

V

9,13

Figure 6-1. VI 450 (Front View)

1

2

3

7

10,11

4

5

6

8,12

ITEMNO.

QTYREQ.

PARTNO. DESCRIPTION

CIRCUITDESIG.

123456789

10111213

1111111114211

13735182672508634515

2134926634516951278951280639541672507

137339351379251320622012062171

LIGHT, INDICATORSWITCH, 3-POS.SWITCH, TOGGLE, SPDTLIGHT, INDICATORSWITCH, TOGGLE, SPDTVOLTMETER, DC, 60 VAMMETER, DC, 600 APOTENTIOMETER, 15 KRHEOSTAT, 300 W, 12 OHMRECEPTACLE, CABLECONNECTOR, QUICK (SUPPLIED)KNOBKNOB

PL1S1S3

PL2S2VMAMR1R2

SECTION 6

VI 450 Power Source

31

REPLACEMENT PARTS

Figure 6-2. VI 450 Control Access Panel (Open)

3

1

2

4

ITEMNO.

QTYREQ.

PARTNO. DESCRIPTION

CIRCUITDESIG.

1234

1111

13735102635686675312950417

RELAY, 3PDT, 42 VBLOCK, TERMINAL, 8-POINTPC BOARD ASSYRELAY, DPDT, 24 V

K2TB5

PCB1K3*

* K3 relay was added starting with Ser. No. D94E48975 (5/94) for improved main transformer protection.

SECTION 6

VI 450 Power Source

32

REPLACEMENT PARTS

Figure 6-3. VI 450 (Left Side View)

1,2

3

4567

8

9

10

11

ITEMNO.

QTYREQ.

PARTNO. DESCRIPTION

CIRCUITDESIG.

1

23456

789

1011

1

11111

11112

3333233217

6735023376933216

635686334863314133162

672330673676

206233413735308

TRANSFORMER, CONTROL (60 HZ)TRANSFORMER, CONTROL (50 HZ)CONTACTOR, 75 ASHUNTINDUCTOR ASSYBLOCK, TERMINAL, 8-POINTTRANSFORMER ASSY, MAIN (60 HZ)TRANSFORMER ASSY, MAIN (50 HZ)RESISTOR ASSY, SLOPESPIDER, FANBLADE, FANMOTOR, FANRELAY, DPDT, 120 V AC

T2

K1SHL1

TB4T1

R4

M1K4,5

SECTION 6

VI 450 Power Source

33

REPLACEMENT PARTS

Figure 6-4. VI 450 (Right Side View)

1

2

34

5

BRIDGE ASSY (REFERTO FIGURE 6-6)

6

ITEMNO.

QTYREQ.

PARTNO. DESCRIPTION

CIRCUITDESIG.

12

3456

11

1113

9515413332833171

95120117300016

673459672348

BLOCK, TERMINAL, 20-POINTBOARD, TERMINAL (60 HZ)BOARD, TERMINAL (50 HZ)FUSE, 10 A, 600 VRESISTOR, 16 OHM, 300 WCAPACITOR, 9800 uF, 50 V DCCAPACITOR, .01 uF, 1.0 KV

TB2TB1

F1,2R5

C13-22C10-12

SECTION 6

VI 450 Power Source

34

REPLACEMENT PARTS

Figure 6-5. VI 450 (Rear View)

1

2

3

4

5

ITEMNO.

QTYREQ.

PARTNO. DESCRIPTION

CIRCUITDESIG.

12345

11111

951539951540951540647298950122

RECEPTACLE, 19-PINRECEPTACLE, 14-PINPANEL, REAR, SILKSCREENEDRECEPTACLE, 115 V, DUPLEXCIRCUIT BREAKER, 10 AMP

J1J2

J3CB1,2

SECTION 6

VI 450 Power Source

35

REPLACEMENT PARTS

Figure 6-6. Bridge Assembly

1

2

34

ITEMNO.

QTYREQ.

PARTNO. DESCRIPTION

CIRCUITDESIG.

1234

6663

67234813735018

950841950711

CAPACITOR, .01 uF, 1.0 KVCORE, TOROIDTHYRISTOR, SCRSWITCH, THERMAL

C1-6L2-7

SCR1-6TS1-3

F-15-098-A 2/95 1.5M Printed in U.S.A.

ESAB Welding & Cutting ProductsPO Box 100545 Florence SC 29501-0545

COMMUNICATIONS GUIDE

A. CUSTOMER SERVICE QUESTIONS: Telephone: (803) 664-5540 / FAX: (800) 634-7548Order Entry Product Availability Pricing Order Changes Hours: 8:30 AM to 5:00 PM EST

B. ENGINEERING SERVICE: Telephone: (803) 664-4416 or -5550 / FAX: (800) 446-5693Welding Equipment Troubleshooting Warranty Returns Hours: 7:30 AM to 5:00 PM EST

C. TECHNICAL SERVICE: Telephone: (803) 664-5547 / FAX: (803) 664-5575Part Numbers Technical Applications Hours: 7:30 AM to 5:00 PM ESTPerformance Features Technical Specifications

D. LITERATURE REQUESTS: Telephone: (803) 664-5501 / FAX: (803) 664-5575Hours: 7:30 AM to 4:00 PM EST

E. WELDING EQUIPMENT REPAIRS: Telephone: (803) 664-4487 / FAX: (803) 664-5557Repair Estimates Repair Status Hours: 7:30 AM to 3:30 PM EST

F. WELDING EQUIPMENT TRAINING: Telephone: (803) 664-5524 / FAX: (803) 664-5575Training School Information and Registrations Hours: 7:30 AM to 4:00 PM EST

G. WELDING PROCESS ASSISTANCE: Telephone: (803) 664-4248 / FAX: (803) 664-4454Hours: 7:30 AM to 4:00 PM EST

H. TECHNICAL ASST. CONSUMABLES: Telephone: (800) 934-9353Hours: 7:30 AM to 5:00 PM EST

IF YOU DO NOT KNOW WHOM TO CALL

Telephone: (803) 664-5540 and (803) 664-4460

Hours: 7:30 AM to 5:00 PM EST