lincoln dc600 Service Manual

IDEALARC DC-600

World’s Leader in Welding and Cutting Products Premier Manufacturer of Industrial Motors

SERVICE MANUAL

Sales and Service through Subsidiaries and Distributors Worldwide

22801 St. Clair Ave. Cleveland, Ohio 44117-1199 U.S.A. Tel (216) 481-8100

For use with machines having Code Numbers:

9773MSP 9774 9776M 9778M 9779M 9780M 9793MSP 9910M

SVM108-A

August, 1998

Safety Depends on You

Lincoln arc welding and cutting equipment is designed and built with safety in mind. However, your overall safety can be increased by proper installation ... and thoughtful operation on your part. DO NOT

INSTALL, OPERATE OR REPAIR THIS EQUIPMENT WITHOUT READING THIS MANUAL AND THE SAFETY PRECAUTIONS CONTAINED THROUGHOUT.

And, most importantly, think before you act and be careful.

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SAFETY

i

WARNING

WELDING can be hazardous.

PROTECT YOURSELF AND OTHERS FROM POSSIBLE SERIOUS INJURY OR DEATH. KEEP CHILDREN AWAY. PACEMAKER WEARERS SHOULD CONSULT WITH THEIR DOCTOR BEFORE OPERATING.

Read and understand the following safety highlights. For additional safety information, it is strongly recommended that you purchase a copy of “Safety in Welding & Cutting - ANSI Standard Z49.1” from the American Welding Society, P.O. Box 351040, Miami, Florida 33135 or CSA Standard W117.2-1974. A Free copy of “Arc Welding Safety” booklet E205 is available from the Lincoln Electric Company, 22801 St. Clair Avenue, Cleveland, Ohio 44117-1199.

BE SURE THAT ALL INSTALLATION, OPERATION, MAINTENANCE AND REPAIR PROCEDURES ARE PERFORMED ONLY BY QUALIFIED INDIVIDUALS.

ELECTRIC SHOCK can kill.

1.a. The electrode and work (or ground) circuits are electrically “hot” when the welder or cutter is on. Do not touch these “hot” parts with your bare skin or wet clothing. Wear dry, hole-free gloves to insulate hands.

1.b. Insulate yourself from work and ground using dry insulation. Make certain the insulation is large enough to cover your full area of physical contact with work and ground.

In addition to the normal safety precautions, if welding or cutting must be performed under electrically hazardous conditions (in damp locations or while wearing wet clothing; on metal structures such as floors, gratings or scaffolds; when in cramped positions such as sitting, kneeling or lying, if there is a high risk of unavoidable or accidental contact with the workpiece or ground) use the following equipment:

• Semiautomatic DC Constant Voltage (Wire) Welder.

• DC Manual (Stick) Welder.

• AC Welder with Reduced Voltage Control.

1.c. In semiautomatic or automatic wire welding, the electrode, electrode reel, welding head, nozzle or semiautomatic welding gun are also electrically “hot”.

1.d. Always be sure the work cable makes a good electrical connection with the metal being welded. The connection should be as close as possible to the area being welded.

1.e. Ground the work or metal to be welded to a good electrical (earth) ground.

2.b. Use suitable clothing made from durable flame-resistant material to protect your skin and that of your helpers from the arc rays.

2.c. Protect other nearby personnel with suitable, non-flammable screening and/or warn them not to watch the arc nor expose themselves to the arc rays or to hot spatter or metal.

ting with electrodes which require special ventilation such as stainless or hard facing (see instructions on container or MSDS) or on lead or cadmium plated steel and other metals or coatings which produce highly toxic fumes, keep exposure as low as possible and below Threshold Limit Values (TLV) using local exhaust or mechanical ventilation. In confined spaces or in some circumstances, outdoors, a respirator may be required. Additional precautions are also required when welding on galvanized steel.

ARC RAYS can burn.

2.a. Use a shield with the proper filter and cover plates to protect your eyes from sparks and the rays of the arc when welding or cutting or observing open arc welding or cutting. Headshield and filter lens should conform to ANSI Z87. I standards.

FUMES AND GASES can be dangerous.

3.a.Welding or cutting may produce fumes and gases hazardous to health. Avoid breathing these fumes and gases.When welding, or cutting keep your head out of the fume. Use enough arc to keep breathing zone. When welding or cut-

ventilation and/or exhaust at the

fumes and gases away from the

1.f.

Maintain the electrode holder, work clamp, welding or cutting cable and condition. Replace

1.g. Never dip the electrode in water for cooling.

1.h. Never simultaneously touch electrically “hot” parts of electrode holders connected to two welders because voltage between the two can be the total of the open circuit voltage of both welders.

1.i. When working above floor level, use a safety belt to protect yourself from a fall should you get a shock.

1.j. Also see Items 4.c. and 6.

welding or cutting machine in good, safe operating

damaged insulation.

3.b.

Do not weld or cut in locations near chlorinated hydrocarbon vapors coming from degreasing, cleaning or spraying operations. The heat and rays of the arc can react with solvent vapors toform phosgene, a highly toxic gas, and other irritating products.

3.c. Shielding gases used for arc welding or cutting can displace air and cause injury or death. Always use enough ventilation, especially in confined areas, to insure breathing air is safe.

3.d. Read and understand the manufacturer’s instructions for this

equipment and the consumables to be used, including the material safety data sheet (MSDS) and follow your employer’s safety practices. MSDS forms are available from your welding distributor or from the manufacturer.

3.e. Also see item 7b.

IDEALARC DC-600

SAFETY ii

WELDING OR CUTTING SPARKS can cause fire or explosion.

4.a.

Remove fire hazards from the welding or cutting area. prevent the welding or cutting sparks from start-

ing a fire. Remember that welding or cutting sparks and hot materials from welding or cutting can easily go through small cracks and openings to adjacent areas. Avoid welding or cutting near hydraulic lines. Have a fire extinguisher readily available.

4.b. Where compressed gases are to be used at the job site, special precautions should be used to prevent hazardous situations. Refer to “Safety in Welding and Cutting” (ANSI Standard Z49.1) and the operating information for the equipment being used.

4.c. When not welding or cutting, make certain no part of the electrode circuit is touching the work or ground. Accidental contact can cause overheating and create a fire hazard.

4.d. Do not heat, cut or weld tanks, drums or containers until the proper steps have been taken to insure that such procedures will not cause flammable or toxic vapors from substances inside. They can cause an explosion even been “cleaned”. For information, purchase “Recommended Safe Practices for the Containers and Piping That Have Held Hazardous Substances”, AWS F4.1 from the American Welding Society

(see address above).

4.e. Vent hollow castings or containers before heating, cutting or welding. They may explode.

If this is not possible, cover them to

though

they have

Preparation

for Welding and Cutting of

CYLINDER may explode

if damaged.

5.a. Use only compressed gas cylinders containing the correct shielding gas for the process used and properly operating regulators designed for the gas and pressure used. All hoses, fittings, etc. should be suitable for the application and maintained in good condition.

5.b. Always keep cylinders in an upright position securely chained to an undercarriage or fixed support.

5.c. Cylinders should be located:

•Away from areas where they may be struck or subjected to

physical damage.

• A safe distance from arc welding or cutting operations and

any other source of heat, sparks, or flame.

5.d. Never allow the electrode, electrode holder or any other electrically “hot” parts to touch a cylinder.

5.e. Keep your head and face away from the cylinder valve outlet when opening the cylinder valve.

5.f. Valve protection caps should always be in place and hand tight except when the cylinder is in use or connected for use.

5.g. Read and follow the instructions on compressed gas cylinders, associated equipment, and CGA publication P-l, “Precautions for Safe Handling of Compressed Gases in Cylinders,” available from the Compressed Gas Association 1235 Jefferson Davis Highway, Arlington, VA 22202.

4.f.

Sparks and spatter are thrown from the welding and cutting arc. Wear oil heavy shirt, cuffless trousers, high shoes and a cap over your hair. Wear ear plugs when welding or cutting out of position or in confined places. Always wear safety glasses with side shields when in a welding or cutting area.

4.g. Connect the work cable to the work as close to the welding or cutting area as practical. Work cables connected to the building framework or other locations away from the welding area increase the possibility of the welding or cutting current passing through lifting chains, crane cables or other alternate circuits. This can create fire hazards or overheat lifting chains or cables until they fail.

4.h. Also see item 7c.

free protective garments such as leather gloves,

FOR ELECTRICALLY powered equipment.

6.a.Turn off input power using the disconnect switch at the fuse box before working on the equipment.

6.b. Install equipment in accordance with the U.S. National Electrical Code, all local codes and the manufacturer’s recommendations.

6.c. Ground the equipment in accordance with the U.S. National Electrical Code and the manufacturer’s recommendations.

IDEALARC DC-600

SAFETY iii

FOR ENGINE powered equipment.

7.a. Turn the engine off before troubleshooting and maintenance work unless the maintenance work requires it to be running.

____________________________________________________

7.b. Operate engines in open, well-ventilated areas or vent the engine exhaust fumes outdoors.

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7.c.Do not add the fuel near an open flame

welding or cutting arc or when the engine is running. Stop the engine and allow it to cool before refueling to prevent spilled fuel from vaporizing on contact with hot engine parts and igniting. Do not spill fuel when filling tank. If fuel is spilled, wipe it up and do not start engine until fumes have been eliminated.

____________________________________________________

7.d.Keep all equipment safety guards, covers

and devices in position and in good repair. Keep hands, hair, clothing and tools away from V-belts, gears, fans and all other moving parts when starting, operating or repairing equipment.

ELECTRIC AND MAGNETIC FIELDS may be dangerous

8.a. Electric current flowing through any conductor causes localized Electric and Magnetic Fields (EMF). Welding or cutting current creates EMF fields around welding or cutting cables and welding machines

8.b. EMF fields may interfere with some pacemakers, and welders or cutters having a pacemaker should consult their physician before welding or cutting.

8.c. Exposure to EMF fields in welding or cutting may have other health effects which are now not known.

8d. All welders or cutters should use the following procedures in

order to minimize exposure to EMF fields from the welding or cutting circuit:

8.d.1.

Route the electrode and work cables together - Secure them with tape when possible.

8.d.2. Never coil the electrode lead around your body.

8.d.3. Do not place your body between the electrode and

work cables. If the electrode cable is on your right side, the work cable should also be on your right side.

8.d.4. Connect the work cable to the workpiece as close as

possible to the area being welded.

8.d.5. Do not work next to welding or cutting power source.

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7.e. In some cases it may be necessary to remove safety guards to perform required maintenance. Remove guards only when necessary and replace them when the maintenance requiring their removal is complete. Always use the greatest care when working near moving parts.

7.f. Do not put your hands near the engine fan. Do not attempt to override the governor or idler by pushing on the throttle control rods while the engine is running.

7.g. To prevent accidentally starting gasoline engines while turning the engine or welding generator during maintenance work, disconnect the spark plug wires, distributor cap or magneto wire as appropriate.

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7.h. To avoid scalding, do not remove the radiator pressure cap when the engine is hot.

IDEALARC DC-600

SAFETY iv

PRÉCAUTIONS DE SÛRETÉ

Pour

votre propre protection lire et observer toutes les instructions et les précautions de sûreté specifiques qui parraissent dans ce manuel aussi bien que les précautions de sûreté générales suivantes:

Sûreté Pour Soudage A L’Arc

1. Protegez-vous contre la secousse électrique:

a. Les circuits à l’électrode et à la piéce sont sous tension

quand la machine à souder est en marche. Eviter toujours tout contact entre les parties sous tension et la peau nue ou les vétements mouillés. Porter des gants secs et sans trous pour isoler les mains.

b. Faire trés attention de bien s’isoler de la masse quand on

soude dans des endroits humides, ou sur un plancher metallique ou des grilles metalliques, principalement dans les positions assis ou couché pour lesquelles une grande partie du corps peut être en contact avec la masse.

c. Maintenir le porte-électrode, la pince de masse, le câble de

soudage et la machine à souder en bon et sûr état defonctionnement.

d.Ne jamais plonger le porte-électrode dans l’eau pour le

refroidir.

e. Ne jamais toucher simultanément les parties sous tension

des porte-électrodes connectés à deux machines à souder parce que la tension entre les deux pinces peut être le total de la tension à vide des deux machines.

f. Si on utilise la machine à souder comme une source de

courant pour soudage semi-automatique, ces precautions pour le porte-électrode s’applicuent aussi au pistolet de soudage.

zones où l’on pique le laitier.

6. Eloigner les matériaux inflammables ou les recouvrir afin de prévenir tout risque d’incendie dû aux étincelles.

7. Quand on ne soude pas, poser la pince à une endroit isolé de la masse. Un court-circuit accidental peut provoquer un échauffement et un risque d’incendie.

8. S’assurer que la masse est connectée le plus prés possible de la zone de travail qu’il est pratique de le faire. Si on place la masse sur la charpente de la construction ou d’autres endroits éloignés de la zone de travail, on augmente le risque de voir passer le courant de soudage par les chaines de levage, câbles de grue, ou autres circuits. Cela peut provoquer des risques d’incendie ou d’echauffement des chaines et des câbles jusqu’à ce qu’ils se rompent.

9. Assurer une ventilation suffisante dans la zone de soudage. Ceci est particuliérement important pour le soudage de tôles galvanisées plombées, ou cadmiées ou tout autre métal qui produit des fumeés toxiques.

10. Ne pas souder en présence de vapeurs de chlore provenant d’opérations de dégraissage, nettoyage ou pistolage. La chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs du solvant pour produire du phosgéne (gas fortement toxique) ou autres produits irritants.

11. Pour obtenir de plus amples renseignements sur la sûreté, voir le code “Code for safety in welding and cutting” CSAStandard W 117.2-1974.

2. Dans le cas de travail au dessus du niveau du sol, se protéger contre les chutes dans le cas ou on recoit un choc. Ne jamais enrouler le câble-électrode autour de n’importe quelle partie du corps.

3. Un coup d’arc peut être plus sévère qu’un coup de soliel, donc:

a. Utiliser un bon masque avec un verre filtrant approprié

ainsi qu’un verre blanc afin de se protéger les yeux du rayonnement de l’arc et des projections quand on soude ou quand on regarde l’arc.

b. Porter des vêtements convenables afin de protéger la

peau de soudeur et des aides contre le rayonnement de l‘arc.

c. Protéger l’autre personnel travaillant à proximité au

soudage à l’aide d’écrans appropriés et non-inflammables.

4. Des gouttes de laitier en fusion sont émises de l’arc de soudage. Se protéger avec des vêtements de protection libres de l’huile, tels que les gants en cuir, chemise épaisse, pantalons sans revers, et chaussures montantes.

5. Toujours porter des lunettes de sécurité dans la zone de soudage. Utiliser des lunettes avec écrans lateraux dans les

PRÉCAUTIONS DE SÛRETÉ POUR LES MACHINES À SOUDER À TRANSFORMATEUR ET À REDRESSEUR

1. Relier à la terre le chassis du poste conformement au code de l’électricité et aux recommendations du fabricant. Le dispositif de montage ou la piece à souder doit être branché à une bonne mise à la terre.

2. Autant que possible, I’installation et l’entretien du poste seront effectués par un électricien qualifié.

3. Avant de faires des travaux à l’interieur de poste, la debrancher à l’interrupteur à la boite de fusibles.

4. Garder tous les couvercles et dispositifs de sûreté à leur place.

IDEALARC DC-600

MASTER TABLE OF CONTENTS FOR ALL SECTIONS

Page

Safety .........................................................................................................................i-iv

Installation ..........................................................................................................Section A

Technical Specifications .......................................................................................... A-2

Safety Precautions .................................................................................................. A-3

Select Proper Location .............................................................................................A-3

Electrical Input Connections ................................................................................... A-4

Reconnect Procedure ............................................................................................. A-5

Output Connections ....................................................................................... A-8 - A-9

Operation ............................................................................................................Section B

Safety Precautions ................................................................................................. B-2

General Description ................................................................................................ B-3

Recommended Processes and Equipment..............................................................B-3

Operational Features and Controls .........................................................................B-3

Design Features and Advantages ...........................................................................B-3

Welding Capability .................................................................................................. B-4

Controls and Settings ..............................................................................................B-5

Operating Steps ...................................................................................................... B-6

Welding Procedure Recommendations .................................................................. B-6

v

Accessories........................................................................................................Section C

Accessories.....................................................................................................C-2 - C-8

Maintenance........................................................................................................Section D

Safety Precautions ...................................................................................................D-2

Routine and Periodic Maintenance ..........................................................................D-3

3-D Exploded View...................................................................................................D-4

Theory of Operation...........................................................................................Section E

Power Supply Operation ..................................................................................E-2 - E-4

SCR Operation .........................................................................................................E-5

Troubleshooting and Repair..............................................................................Section F

How To Use Troubleshooting Guide .........................................................................F-2

PC Board Troubleshooting Procedures....................................................................F-3

Troubleshooting Guide..................................................................................F-4 – F-52

Electrical Diagrams............................................................................................Section G

Parts Manual..............................................................................................................P-282

IDEALARC DC-600

TABLE OF CONTENTS

- INSTALLATION SECTION -

INSTALLATION ......................................................... Section A

Technical Specifications ................................................ A-2

Safety Precautions ........................................................ A-3

Select Proper Location....................................................A-3

Stacking ....................................................................A-3

Tilting.........................................................................A-3

Electrical Input Connections ......................................... A-4

Fuses and Wire Sizes ...............................................A-4

Ground Connection ................................................. A-4

Input Power Supply Connections..............................A-4

Reconnect Procedure ................................................... A-5

Output Connections ...................................................... A-8

Electrode and Work Leads........................................A-8

Connection for Wire Feeder Control .........................A-9

Connection for Stick Welding and Air Carbon Arc ....A-9

SECTION A-1

IDEALARC DC-600

A-2

INSTALLATION

TECHNICAL SPECIFICATIONS - IDEALARC DC-600

INPUT - THREE PHASE ONLY

Standard Voltage

208/230/416/460/575/3/60 125/113/63/57/45

Input Current at Rated Output

RATED OUTPUT

Duty Cycle

AMPS

V

olts at Rated Amps

100%

60% 50%

Mode

Constant Current Constant Voltage

Input Voltage /

Frequency

208/60 230/60 416/60 460/60 575/60

600 680 750

OUTPUT

Current

Range

90 to 850 Amps 70 to 850 Amps

Maximum Open

Circuit Voltage

72 VDC 55 VDC

115 VAC, 8 Amps

RECOMMENDED INPUT WIRE AND FUSE SIZES

Fuse

(Super Lag)

or Breaker Size

175 175 100

90 80

Input Ampere

Rating on

Nameplate

125 113

63 57 45

Type 75

Copper Wire in

Conduit AWG

(IEC) Sizes

2 (35mm 2 (35mm2) 6 (16mm2) 6 (16mm2) 6 (16mm2)

o

C

2

)

44 44 44

Auxiliary Power

Type 75 Copper Ground Wire in Conduit

AWG (IEC) Sizes

6 (16 mm2) 6 (16 mm2) 8 (10 mm2) 8 (10 mm2) 8 (10 mm2)

o

C

Height

30.75 in.

(781 mm.)

IDEALARC DC-600

PHYSICAL DIMENSIONS

Width

22.25 in.

(567 mm.)

Depth

39.0 in.

(988 mm.)

Weight

522 lbs.

(237 kg.)

INSTALLATION

A-3

Read entire Installation Section before installing the IDEALARC DC-600.

SAFETY PRECAUTIONS

WARNING

ELECTRIC SHOCK CAN KILL.

• Only qualified personnel should install

this machine.

• Turn the input power OFF at the disconnect switch or fuse box before working on the equipment.

• Do not touch electrically hot parts.

• Always connect the IDEALARC

DC-600 grounding terminal to a good electrical earth ground.

• Set the IDEALARC DC-600 Power ON/OFF PUSH BUTTON to OFF position when connecting power cord to input power.

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DO NOT stack the IDEALARC DC-600 on another type of machine.

Follow these guidelines when stacking:

1. Select a firm, level surface capable of supporting the total weight of up to three machines (1570 pounds/712 kilograms).

2. Set the bottom machine in place.

3. Stack the second machine on top of it by aligning the two holes in the base rails of the second machine with the two pins on top front of the bottom machine.

4. Repeat process for third machine.

NOTE: The machines must be stacked with the Case Front of each machine flush with each other. See Figure A.1.

SELECT PROPER LOCATION

Place the IDEALARC DC-600 where clean air can freely circulate in through the front intake and out through the rear louvers. Dirt, dust, or any foreign material that can be drawn into the machine should be kept at a minimum. Not following these precautions can result in the nuisance shutdown of the machine because of excessive operating temperatures.

STACKING

Three IDEALARC DC-600 machines can be stacked. DO NOT stack more than three machines in one

grouping.

STACKING HOLE

STACKING PINS

FIGURE A.1 - Stacking IDEALARC DC-600 machines

TILTING

The IDEALARC DC-600 must be placed on a stable, level surface so it will not topple over.

IDEALARC DC-600

A-4

Y

INSTALLATION

ELECTRICAL INPUT CONNECTIONS

Before installing the machine, check that the input supply voltage, phase, and frequency are the same as the machine’s voltage, phase, and frequency as specified on the machine’s rating plate on the Case Front Assembly Control Panel. Input power supply entry is through the hole in the Case Back Assembly. See Figure A.2 for the location of the machine’s input cable entry opening, Input Contactor (CR1), and reconnect panel assembly for dual voltage machines.

FIGURE A.2 - Rear Panel

INPUT SUPPLY CABLE ENTRY

OPENING

CONTACTOR (CR1)

INPUT

RECONNECT

PANEL ASSEMBLY

GROUND CONNECTION

Ground the frame of the machine. A ground terminal marked with the symbol ( ) is located inside the Case Back of the machine near the input contactor. Access to the Input Box Assembly is at the upper rear of the machine. See your local and national electrical codes for proper grounding methods.

INPUT POWER SUPPLYCONNECTIONS

A qualified electrician should connect the input power supply leads.

1. Follow all national and local electrical codes.

2. Follow Input Supply Connection Diagram located on the inside of the machine.

3. Use a three-phase line.

4. Remove Input Access Door at upper rear of machine.

FUSE AND WIRE SIZES

Protect the input circuit with the super lag fuses or delay type circuit breakers listed on the Technical Specifications page of this manual for the machine being used. They are also called inverse time or thermal/magnetic circuit breakers.

DO NOT use fuses or circuit breakers with a lower amp rating than recommended. This can result in “nuisance” tripping caused by inrush current even when machine is not being used for welding at high output currents.

Use input and grounding wire sizes that meet local electrical codes or see the Technical Specifications page in this manual.

5. Connect the three-phase AC power supply leads L1, L2, and L3 to the input contactor terminals in the Input Box Assembly. See Figure A.3.

INPUT

CONTACTOR (CR1)

INPUT POWER SUPPLY CABLE WITH BUSHING

OR BOX CONNECTOR

RECONNECT

PANEL ASSEMBL

FIGURE A.3 - Input Power Supply Connections

IDEALARC DC-600

RECONNECT PROCEDURE

Multiple voltage machines are shipped connected to the highest input voltage listed on the machine’s rating plate. Before installing the machine, check that the Reconnect Panel in the Input Box Assembly is connected for the proper voltage.

To reconnect a multiple voltage machine to a different voltage, remove input power and change the position of the reconnect board on the Reconnect Panel. Follow The Input Connection Diagram located on the inside of Case Back Input Access Door. These connection diagrams for the following codes are listed below.

1. For codes 9773MSP, 9910M, 9776M, 9780M, see Figure A.4.

CAUTION

Failure to follow these instructions can cause immediate failure of components within the machine.

__________________

CONNECTION FOR HIGHEST RATING PLATE VOLTAGE, 50 OR 60 HZ.

LINK

LINES INPUT

L3 L2 L1

GND

H3

W

V

CONTACTOR

U

H1

PILOT

TRANSF.

CRI

H2

1. TURN OFF THE INPUT POWER USING THE DISCONNECT SWITCH AT THE FUSE BOX DISCONNECT AND INSULATE THE H2 LEAD TERMINAL WITH TAPE TO PROVIDE AT

2.

LEAST 600 VOLT INSULATION.

CONNECT L1, L2 & L3 INPUT SUPPLY LINES H1 AND H3 TRANSFORMER LEADS TO THE INPUT SIDE OF

3.

THE CRI CONTACTOR AS SHOWN. 

CONNECT TERMINAL MARKED TO GROUND PER LOCAL AND NATIONAL ELECTRIC CODES.

4. MOUNT THE LINKS IN THE POSITIONS SHOWN WITH THE PROVIDED HEX NUTS,

5.

DOUBLE UP THE LINKS IN TWO OF THE POSITIONS TO SAVE THEM FOR FUTURE USE. SECURE THE REMAINING HEX NUTS IN PLACE.

2. For code 9778M, see Figure A.5.

3. For code 9779M, see Figure A.6.

4. For code 9774, see Figure A.7.

5. For code 9793MSP, see Figure A.8.

6. For codes not listed, see the Input Connection Diagram pasted on the inside of the Case Back Input Access Door.

CONNECTION FOR LOWEST RATING PLATE VOLTAGE, 50 OR 60 HZ.

LINK

LINES INPUT

L3 L2 L1

GND

H2

W

V

CTOR

U

H1

CRI

PILOT

TRANSF.

H3

1. TURN OFF THE INPUT POWER USING THE DISCONNECT SWITCH AT THE FUSE BOX DISCONNECT AND INSULATE THE H3 LEAD TERMINAL WITH TAPE TO PROVIDE AT

2.

LEAST 600 VOLT INSULATION.

CONNECT L1, L2 & L3 INPUT SUPPLY LINES H1 AND H2 TRANSFORMER LEADS TO THE INPUT SIDE OF

3.

THE CRI CONTACTOR AS SHOWN. 

CONNECT TERMINAL M A RKED TO GROUND PER LOCAL AND NATIONAL ELECTRIC CODES.



4. MOUNT THE LINKS IN THE POSITIONS SHOWN WITH THE PROVIDED HEX NUTS.

5.

FIGURE A.4-Reconnect Panel Board Positions for Dual Voltage Machines

A-6

LINES INPUT

LINKS

LINES INPUT

LINKS

L3 L2 L1

GND

L3 L2 L1

GND

H4

H3

INSTALLATION

CONNECTION FOR 440 VOLTS 50 OR 60 HZ. (460V 60HZ)

W

V

CONTACTOR

U

H1

W

V

CONTACTOR

U

H1

CRI

PILOT

TRANSF.

CRI

PILOT

TRANSF.

H3

H2

CONNECTION FOR 380 VOLTS, 50 OR 60 HZ.

H4

H2

CONNECTION FOR 220 VOLTS, 50 OR 60 HZ.

1. TURN OFF THE INPUT POWER USING THE DISCONNECT SWITCH AT THE FUSE BOX

2. DISCONNECT AND INSULATE THE H2 & H3 LEAD TERMINALS SEPARATELY WITH TAPE TO PROVIDE AT LEAST 600 VOLT INSULATION.

3. CONNECT L1, L2 & L3 INPUT SUPPLY LINES H1 AND H4 CONTROL TRANSFORMER LEADS TO THE INPUT SIDE OF THE CRI CONTRACTOR AS SHOWN.

4. CONNECT TERMINAL MARKED TO GROUND PER LOCAL AND NATIONAL ELECTRIC CODES.

5. MOUNT THE LINKS IN THE POSITIONS SHOWN: DOUBLE OR TRIPLE STACK THE LINKS IN THREE POSITIONS. CONNECT THE FLEX LEAD AS SHOWN: POSITIONING THE LUGS TO MAINTAIN MAXIMUM CLEARANCE TO THE LINKS. INSTA LL AND TIGHTEN ALL OF TH E HEX NUTS.

1. TURN OFF THE INPUT POWER USING THE DISCONNECT SWITCH AT THE FUSE BOX

2. DISCONNECT AND INSULATE THE H2 & H4 LEAD TERMINALS SEPARATELY WITH TAPE TO PROVIDE AT LEAST 600 VOLT INSULATION.

3. CONNECT L1, L2 & L3 INPUT SUPPLY LINES H1 AND H3 CONTROL TRANSFORMER LEADS TO THE INPUT SIDE OF THE CRI CONTACTOR AS SHOWN.

4. CONNECT TERMINAL M A RKED TO GROUND PER LOCAL AND NATIONAL ELECTRIC CODES.

5. MOUNT THE LINKS IN THE POSITIONS SHOWN: DOUBLE UP THE LINKS IN TWO OF THE POSITIONS, LOOP THE POSITIONS. INSTALL AND TIGHTEN ALL OF THE HEX NUTS.

LINES INPUT

LINKS

L3 L2 L1

GND

H2

W

V

CONTACTOR

U

H1

CRI

PILOT

TRANSF.

H4

H3

1. TURN OFF THE INPUT POWER USING THE DISCONNECT SWITCH AT THE FUSE BOX

2. DISCONNECT AND INSULATE THE H3 & H4 LEAD TERMINALS SEPARATELY WITH TAPE TO PROVIDE AT LEAST 600 VOLT INSULATION.

3. CONNECT L1, L2 & L3 INPUT SUPPLY LINES H1 AND H2 CONTROL TRANSFORMER LEADS TO THE INPUT SIDE OF THE CRI CONTACTOR AS SHOWN.

4. CONNECT TERMINAL M A RKED TO GROUND PER LOCAL AND NATIONAL ELECTRIC CODES.

5. MOUNT THE LINKS IN THE POSITIONS SHOWN. LOOP THE FLEX LEAD IN THE POSITION SHOWN. INSTALL AND TIGHTEN ALL OF THE HEX NUTS.

FIGURE A.5-Reconnect Panel Board Positions for 220/380/440 VAC Machines

CONNECTION FOR 380/460 VOLTAGES

H2

LINES INPUT

GND

1. DISCONNECT AND INSULATE THE H3 LEAD TERMINA WITH TAPE TO PROVIDE AT LEAST 600 VOLT INSULATION.

2. CONNECT H2 LEAD TO CONTACTOR.

3. CONNECT L1, L2 & L3 INPUT SUPPLY LINES TO THE INPUT SIDE OF THE CRI CONTACTOR AS SHOWN.

4. CONNECT TERMINAL MARKED TO GROUND PER NATIONAL ELECTRIC CODES.

5. REMOVE THE HEX NUTS AND POSITION LINKS AS SHOWN. REPLACE AND TIGHTEN ALL HEX NUTS

L3 L2 L1

H1

H3

W

V

CONTACTOR

U

CRI

TAPE

LINK

CONNECTION FOR 500/575 VOLTAGES

H3

GND

L3 L2 L1

H1

LINES INPUT

1. DISCONNECT AND INSULATE THE H2 LEAD TERMINAL WITH TAPE TO PROVIDE AT LEAST 600 VOLT INSULATION.

2. CONNECT H3 LEAD TO CONTACTOR..

3. CONNECT L1, L2 & L3 INPUT SUPPLY LINES TO THE INPUT SIDE OF THE CRI CONTACTOR AS SHOWN.

4. CONNECT TERMINAL MARKED TO GROUND PER NATIONAL ELECTRIC CODES.

5. REMOVE THE HEX NUTS AND POSITION LINKS AS SHOWN, REPLACE AND TIGHTEN ALL HEX NUTS

H2

CRI

W

V

CONTACTOR

U

TAPE

LINK

FIGURE A.6-Reconnect Panel Board Positions for 380/460, 500/575 VAC Machines

IDEALARC DC-600

SEE MACHINE RATING PLATE FOR REQUIRED INPUT SUPPLY VOLTAGE

1. TURN OFF THE INPUT POWER USING THE DISCONNECT SWITCH AT THE FUSE BOX

2. CONNECT TERMINAL MARKED TO GROUND PER NATIONAL ELECTRIC CODES.

3. CONNECT THE L1, L2, & L3 INPUT SUPPLY LINES TO INPUT SIDE OF THE CRI CONTACTOR AS SHOWN.

LINES INPUT

L3 L2 L1

GND

W V

CONTACTOR

U

CRI

FIGURE A.7-Reconnect Panel Board Positions for Single Voltage Machines

FIGURE A.8-Reconnect Panel Board Positions for 230/460/575 VAC Machines

A-8

INSTALLATION

OUTPUT CONNECTIONS

See Table A.1 for recommended IDEALARC DC-600 cable sizes for combined lengths of electrode and work cables.

TABLE A.1

IDEALARC DC-600 Cable Sizes for Combined Lengths of Electrode and Work Cable (Copper)

at 100% Duty Cycle

Cable SizeParallel CablesCable Length

Lengths up to 150 ft. (46m)

Connect Electrode and Work Leads to Output Terminals.

1. Set the ON/OFF PUSH BUTTON to OFF.

2. Locate the retractable strain relief loops directly below the output terminals in the lower right and lower left corners of the Case Front Assembly. See Figure A.9.

3. Pull out the retractable strain relief loops.

1/0 (53mm

2

2/0 (67mm

3/0 (85mm

2

)2

2

)150 ft.(46m) to 200 ft (61m)

2

)200 ft.(61m) to 250 ft.(76m)

4. Insert the electrode lead through the loop directly below the desired polarity (positive or negative). Pull through enough cable to reach the output terminals.

5. Connect electrode lead to the desired terminal (positive/negative).

6. Tighten the output terminal nut with a wrench.

7. Connect the work lead to the other output terminal following steps 4-6.

IDEALARC DC-600

FIGURE A.9 - Output Terminals.

Connection For Semi-Automatic or Automatic Wire Feeder Control

NOTE: See the ACCESSORIES Section of this manual for specific instructions on connecting the following semi-automatic and automatic wire feeders:

• LN-7

• LN-8

• LN-9

Semi-Automatic Wire Feeders

}

1. Set ON/OFF PUSH BUTTON to OFF.

2. Locate and open the hinged access door on the Front Case Assembly.

3. If necessary, disconnect all wire feeder control cable connections from the DC-600 terminal strip.

4. Remove the leads from the unit by pulling them through and out of the strain relief loops.

• NA-3

• NA-5

•LT-7

• LT-56

Connection for Stick Welding and Air/Carbon Arc Cutting Operation

Automatic Wire Feeders

}

Tractors

}

WARNING

THE OUTPUT TERMINALS ARE ENERGIZED AT ALL TIMES WHEN THE IDEALARC DC-600 IS CONNECTED FOR STICK WELDING AND AIR/CARBON ARC CUTTING.

__________________

5. Connect a jumper wire from terminal #2 to terminal #4 on the terminal strip.

6. Set the Welding Mode Switch to the VV position for both stick welding and air/carbon arc cutting.

NOTE: To use the IDEALARC DC-600 for both stick welding / air/carbon arc cutting, AND semi-automatic / automatic welding, the optional Multi-Process Switch (K804) must be used. See the ACCESSORIES Section of this manual for instructions on installing and using the Multi-Process Switch. When the MultiProcess Switch is not used, all control, work, and electrode leads from semi-automatic or automatic wire feeders must be disconnected from the IDEALARC DC-600 before connecting the machine for stick welding or air/carbon arc cutting.

TABLE OF CONTENTS

- OPERATION SECTION -

OPERATION ....................................................................... Section B

Safety Precautions ................................................................. B-2

General Description ............................................................... B-3

Recommended Processes and Equipment..............................B-3

Operational Features and Controls .........................................B-3

Design Features and Advantages ...........................................B-3

Welding Capacity ................................................................... B-4

Controls and Settings ..............................................................B-5

Operating Steps ..................................................................... B-6

Remote Control of Machine Operation.....................................B-6

Welding Procedure Recommendations ...................... B-6 Ñ B-9

Semi-Automatic and Automatic Wire Feeding

with a DC-600 and Wire Feeders.............................................B-7

NA-3 Automatic Wire Feeder.............................................B-7

NA-5 Automatic Wire Feeder.............................................B-9

LN-8 Semi-Automatic Wire Feeder....................................B-9

LN-7 & LN-9 Semi-Automatic Wire Feeders......................B-9

SECTION B-1

IDEALARC DC-600

OPERATING INSTRUCTIONS

Read and understand entire section before operating machine.

SAFETY PRECAUTIONS

WARNING

ELECTRIC SHOCK can kill.

• Do not touch electrically live parts or electrode with skin or wet clothing.

• Insulate yourself from work and ground.

• Always wear dry insulating gloves.

FUMES AND GASES can be dangerous.

• Keep your head out of fumes.

• Use ventilation or exhaust to remove fumes from breathing zone.

WELDING, CUTTING and GOUGING SPARKS can cause fire or explosion

• Keep flammable material away.

• Do not weld, cut or gouge on containers that have held combustibles.

ARC RAYS can burn.

• Wear eye, ear and body protection.

Observe additional Safety Guidelines detailed in the beginning of this manual.

GENERAL DESCRIPTION

The IDEALARC DC-600 is an SCR controlled three phase welding and cutting power source. It uses a single range potentiometer to control:

OPERATIONAL FEATURES AND CONTROLS

The IDEALARC DC-600 comes with the following standard controls:

• Submerged Arc Semi-Automatic or Automatic Welding

• Open Arc Semi-Automatic or Automatic Welding

• Stick Welding (Standard on All Machines)

• Air/Carbon Arc Cutting (Carbon Rod Sizes up to 3/8” Diameter)

The IDEALARC DC-600 has a three-position Welding Mode Switch to enable the user to operate in one of three modes:

• Constant Voltage (CV) Innershield

• Constant Voltage (CV) Submerged Arc

• Variable Voltage (VV - Constant Current) Submerged Arc

The IDEALARC DC-600 can be easily connected to wire feeding equipment, including:

• Semi-automatic wire feeders LN-7, LN-8, and LN-9

• Automatic wire feeders NA-3 and NA-5

• Tractors LT-56 and LT-7

The optional Multi-Process Switch allows the user to switch between semi-automatic or automatic welding and stick welding or air/carbon arc cutting without disconnecting the wire feeder equipment control, electrode, and work leads.

• ON/OFF PUSH BUTTON

• OUTPUT CONTROL POTENTIOMETER

• OUTPUT CONTROL SWITCH (Remote or Machine Control)

• WELDING MODE SWITCH

• CONTROL CIRCUIT POLARITY SWITCH

• POWER SOURCE PILOT LIGHT

• DC AMMETER (OPTIONAL)

• DC VOLTMETER (OPTIONAL)

DESIGN FEATURES AND ADVANTAGES

The following list of design features will help you understand the machine’s total capabilities and how you can take advantage of them to get maximum use of your machine.

• Excellent arc characteristics for optimum constant voltage submerged arc and Innershield welding performance.

• A control circuit designed to provide good starting for a large variety of processes and procedures.

• Output Control Potentiometer that provides easy single range continuous control.

• Output Control Switch that provides simple switching from local to remote control.

• Red neon pilot light to confirm that the Input Contactor is energized.

RECOMMENDED PROCESSES AND EQUIPMENT

The IDEALARC DC-600 is recommended for the following welding or cutting processes within its output capacity of 70 amps to 850 amps in the Constant Voltage mode and 90 amps to 850 amps in the Variable Voltage (Constant Current) mode:

• Submerged Arc Semi-Automatic or Automatic Welding

• Open Arc Semi-Automatic or Automatic Welding

• Stick Welding (Standard on All Machines)

• Air/Carbon Arc Cutting (Carbon Rod Sizes up to 3/8” Diameter)

• Auxiliary power source to provide 115-volt AC power (1000 VA) to wire feeding equipment.

• Multi-functional terminal strip for easy connection of wire feeding control cables and switching between CV Innershield and CV Submerged Arc welding when using the Dual Process or Dual Procedure Kits.

• Recessed output terminals to avoid any person or object from accidentally coming into contact with the output terminals and labeled positive and negative for easy identification.

• Thermostatically protected power source.

• Electronic protection circuit to protect power source against overloads.

• Input line voltage compensation to provide an essentially constant output.

• SCR electronically controlled welder output provides extra long life, especially for highly repetitive welding applications.

• Three circuit solid state control system provides maximum performance and circuit protection.

• Low profile case provides maximum use of space.

• Convenient access to all controls.

• Output lead strain relief loops to prevent terminal and cable damage.

• Easily removed case side, even when stacked.

• Outdoor operation because enclosure is designed with air intake louvers that keep dripping water from entering the unit. Transformer, SCR bridge, and choke have special corrosion resistant paint for added protection.

_____________________________________

WELDING CAPABILITY

The IDEALARC DC-600 has the following duty cycle ratings: If the duty cycle is exceeded, a thermal protector will shut off the output of the machine until it cools to the normal operating temperature.

Duty Cycle

50%

(Based on 10 min.)

60%

(Based on 10 min.)

100%

Amps Volts Hertz

750

680

600

44

50/60

_____________________________________

CONTROLS AND SETTINGS

All operator controls and adjustments are located on the Case Front Assembly of the IDEALARC DC-600. See Figure B.1 for the location of each control.

AMMETER (optional)

5.

CONTROL CIRCUIT

VOLTMETER

8. (optional)

5

4

3

2

1

2.

POLARITY SWITCH

FIGURE B.1 - CONTROL PANEL KEYS

1. ON/OFF PUSH BUTTON: This push button turns

the machine ON or OFF.

2. OUTPUT CONTROL POTENTIOMETER: This control provides tapered, continuous control of the machine output. The control can be rotated from minimum to maximum while machine is under load to adjust the machine output.

WELDING MODE

3. 4.7. SWITCH

6

7

8

9

10

OUTPUT CONTROL SWITCH

ON/OFF

1. PUSH BUTTON

POWER

6. SOURCE PILOT LIGHT

OUTPUT CONTROL POTENTIOMETER

5. CONTROL CIRCUIT POLARITY SWITCH: This toggle switch is used to set power source voltage sensing polarity to match the polarity to which the electrode is connected to the machine. This provides the correct polarity at the terminal strip for correct operation of the automatic wire feeding equipment powered by the auxiliary power from the power source.

3. WELDING MODE SWITCH: This toggle switch is used to select the proper welder performance characteristics for the process being used. There are three modes: CV (Constant Voltage) Innershield, CV (Constant Voltage) Submerged Arc, and VV (Variable Voltage) CC (Constant Current) Submerged Arc.

4. OUTPUT CONTROL SWITCH: This toggle switch is used to switch between "Output Control at DC600" for local control of machine output and "Output Control Remote" for remote control of machine output.

6. POWER SOURCE PILOT LIGHT: The red neon light glows when the power source input contactor is energized.

7. AMMETER: An optional ammeter is available.

8. VOLTMETER: An optional voltmeter is available.

OPERATING STEPS

The following procedures are for using the IDEALARC DC-600 in the local control mode of operation. For remote control of the machine, see the Remote Control of Machine Operation section.

Before operating the machine, make sure you have all materials needed to complete the job. Be sure you are familiar with and have taken all possible safety precautions before starting work. It is important that you follow these operating steps each time you use the machine.

REMOTE CONTROL OF MACHINE OPERATION

The toggle switch on the control panel labeled “Output Control at DC-600” — “Output Control Remote” gives the operator the option of controlling the machine output from a remote location. If in the Remote position a wire feeder with remote control capabilities or a remote control device such as a K775 must be connected to terminals 75, 76, and 77. Refer to Accessories Section for wire feeder remote information.

1. Turn on the main AC power supply to the machine.

2. Set the CONTROL CIRCUIT POLARITY SWITCH to the appropriate position.

- Set toggle to "Electrode Negative" position if the electrode is connected to the negative (-) output terminal.

- Set toggle to "Electrode Positive" position if the electrode is connected to the positive (+) output terminal.

3. Set the WELDING MODE SWITCH to welding process being used.

- CV Innershield

- CV Submerged Arc

- VV (CC)

4. Push the ON/OFF PUSH BUTTON to the ON position

- The red neon light glows.

- The fan starts.

5. Set Output Control Potentiometer to desired voltage or current.

6. Make the weld (NOTE: Terminal #2 and #4 must be connected together to energize the machine output).

WELDING PROCEDURE RECOMMENDATIONS

Select Welding Mode Switch position based on type of welding to be done.

1. Innershield Welding/Other Open Arc Processes: Use the CV Innershield mode.

2. Submerged Arc Welding: Use the CV Submerged Arc mode. If performing high speed welding, switch between the CV Submerged Arc and the CV Innershield mode and use the mode that produces the best welding results.

3. Air/Carbon Arc Cutting / Stick Welding / High Current, Large Puddle Submerged Arc Welding: Use the VV (CC) mode. When the IDEALARC DC600 is used for Air/Carbon Arc cutting, the OUTPUT CONTROL POTENTIOMETER should be set to "9" initially. Based on the size of the carbon being used or the process, turn the potentiometer to a lower setting as required by the process. You can use carbon rods up to 3/8" in diameter at currents as high as 750 amps with excellent arc control. The welder protection circuit protects the machine from extremely high short circuiting pulses.

OPERATION

B-7

SEMI-AUTOMATIC AND AUTOMATIC WIRE FEEDING WITH A IDEALARC DC-600 AND WIRE FEEDERS

When using the IDEALARC DC-600 with semi-automatic or automatic wire feeding equipment and for stick welding or air/carbon arc cutting, it is recommended that the optional MULTI-PROCESS SWITCH be used. This switch permits you to easily change the polarity of the connected wire feeding equipment or switch to stick welding or air/carbon arc cutting.

NA-3 AUTOMATIC WIRE FEEDER

1. Set the DC-600 Output Control Switch to Remote. NOTE: Later model NA-3 automatic wire feeders are capable of cold starts when the NA-3 Mode switch is in the CV or VV(CC) mode position. Some earlier models are capable of cold starting only in the VV(CC) mode position. Cold starting enables you to inch the wire down to the work, automatically stop, and automatically energize the flux hopper valve.

2. Set the DC-600 welding mode switch for the desired process: CV Submerged Arc, CV Innershield mode or VV(CC) mode.

3. Set the NA-3 mode Switch Position to either CV or VV(CC) to match the DC-600 mode selected in step 2.

4. Refer to the NA-3 operators manual for instructions on how to use the NA-3 in conjunction with the DC-600.

5. Follow the following guidelines for good arc striking detailed below for each welding mode.

GOOD ARC STRIKING GUIDELINES FOR THE NA-3 WITH THE IDEALARC DC-600 IN THE CV INNERSHIELD, CV SUBMERGED ARC OR VV(CC) WELDING MODES.

2. Set the NA-3 Open Circuit Voltage Control to the same dial setting as the Arc Voltage Control. If this is a new welding procedure, a good starting point is to set the Open Circuit Voltage Control to # 6.

NOTE: The open circuit voltage of the IDEALARC DC-600 varies from approximately 16 volts to 56 volts in the CV Innershield or CV Submerged Arc modes. The open circuit voltage is constant in the VV(CC) mode.

3. Run a test weld. Set proper current, voltage, and travel speed.

a. For the best starting performance, the NA-

3 Open Circuit Voltage Control and Voltage Control setting should be the same. Set the Inch Speed Control for the slowest inch speed possible.

b. To adjust the Open Circuit Voltage Control to

get the best starting performance, make repeated starts observing the NA-3 voltmeter.

When the voltmeter pointer swings smoothly up to the desired arc voltage, without undershooting or overshooting the desired arc voltage, the Open Circuit Voltage Control is set properly.

If the voltmeter pointer overshoots the desired voltage and then returns back to the desired voltage, the Open Circuit Voltage Control is set too high. This can result in a bad start where the wire tends to "Blast off."

If the voltmeter pointer hesitates before coming up to the desired voltage, the Open Circuit Voltage Control is set too low. This can cause the electrode to stub.

4. Start and make the weld. a. Cold starts. For cold starts, be sure the work

piece is clean and the electrode makes positive contact with the work piece.

Following are some basic arc striking techniques that apply to all wire feed processes. Using these procedures should provide trouble-free starting. These procedures apply to single, solid wires and Innershield wires.

1. Cut the electrode to a sharp point.

b. Hot "On the Fly" starts. For hot starts, travel

should begin before the wire contacts the work piece.

IDEALARC DC-600

B-8

OPERATION

ARC STRIKING WITH IDEALARC DC-600 AND THE NA-3 START BOARD

When electrical strikeouts exceed 1 3/4Ó (44.4mm) an NA-3 Start Board may be required to improve arc striking.

When the NA-3 Start Board is used to improve arc striking, use the following procedures:

1. Set start time at 0.

2. Set NA-3 start current and start voltage at midrange.

3. Set the NA-3 output current and voltage to the proper settings for the welding procedure to be used.

4. Turn the Start Board Timer to maximum.

5. Set Start Board current and voltage control.

a. Set the Start Board current control to 1 1/2 dial

numbers below that set on the NA-3 current control.

b. Set the Start Board voltage control equal with

the NA-3 voltage control setting.

NOTE: These Start Board current and voltage settings result in a start up current that is lower than the NA-3 current setting and approximately equal with the NA-3 voltage setting for the desired welding procedure.

6. Establish the correct arc striking procedure with the NA-3 Start Board timer set at maximum.

a. For the best starting performance, the NA-3

Open Circuit Voltage Control and V oltage Control setting should be the same. Set the Inch Speed Control for the slowest inch speed possible.

b. To adjust the Open Circuit V oltage Control to

get the best starting performance, make repeated starts observing the NA-3 voltmeter .

When the voltmeter pointer swings smoothly up to the desired arc voltage, without undershooting or overshooting the desired arc voltage, the Open Circuit Voltage Control is set properly .

If the voltmeter pointer overshoots the desired voltage and then returns back to the desired voltage, the Open Circuit V oltage Control is set too high. This can result in a bad start where the wire tends to "Blast of f."

If the voltmeter pointer hesitates before coming up to the desired voltage, the Open Circuit V oltage Control is set too low . This can cause the electrode to stub.

c. Set NA-3 Start Board current and voltage as

close to the welding procedure current and voltage as possible.

NOTE: The Start Board current and voltage should be as close as possible to the welding procedure current and voltage, while still getting satisfactory starts.

IDEALARC DC-600

d. Set the start time to as low a time as possible

while still getting satisfactory starts.

7. Start and make the weld.

OPERATION

B-9

IDEALARC DC-600 POWER SOURCE SETTING WHEN CONNECTED TO NA-5 WIRE FEEDER

When using the IDEALARC DC-600 with the NA-5 wire feeder, set the controls on the IDEALARC DC-600 as follows for the best performance:

1. Turn OFF main AC input power supply to the IDEALARC DC-600.

2. Connect the electrode cables to terminal polarity to be used.

3. Set the CONTROL CIRCUIT POLARITY SWITCH to the same polarity as the electrode cable connection.

4. Set the OUTPUT CONTROL SWITCH to REMOTE.

5. Set the IDEALARC DC-600 WELDING MODE SWITCH to the position that matches the welding process being used.

LN-8 SEMI-AUTOMATIC WIRE FEEDER

To use the LN-8 Semi-Automatic Wire Feeder with IDEALARC DC-600

1. Set the IDEALARC DC-600 WELDING MODE SWITCH to either CV Innershield mode or CV Submerged Arc mode depending on the welding process being used.

2. Set the IDEALARC DC-600 OUTPUT CONTROL SWITCH to the REMOTE position.

3. Set the LN-8 W elding Mode Switch to the CV position. The LN-8 Welding Mode Switch is located on the variable voltage (CC) board.

4. Refer to the LN-8 Operator Õs Manual for instructions on how to use the LN-8.

LN-7 AND LN-9 SEMI-AUTOMATIC WIRE FEEDERS OR OTHER CONSTANT WIRE FEEDERS

a. For submerged arc welding, set WELDING

MODE SWITCH TO CV SUBMERGED ARC position.

b. For all open arc welding processes set WELD-

ING MODE SWITCH TO CV INNERSHIELD position.

To use the LN-7, LN-9, or other constant wire feed speed semi-automatic wire feeders with IDEALARC DC-600

1. Set the IDEALARC DC-600 WELDING MODE SWITCH to either CV Innershield mode or CV Submerged Arc mode depending on the welding process being used.

NOTE: These semi-automatic wire feeders cannot be used in the VV(CC) mode.

2. Set the IDEALARC DC-600 OUTPUT CONTROL SWITCH.

a. LN-7: Use either an optional K775 Remote

Control Box Assembly or set the IDEALARC DC-600 OUTPUT CONTROL SWITCH in the Local position.

b. LN-9: Refer to the LN-9 Operator Õs Manual for

instructions of how to use the LN-9.

IDEALARC DC-600

TABLE OF CONTENTS

- ACCESSORIES SECTION -

ACCESSORIES .................................................................. Section C

Accessories.....................................................................C-2

Multi-Process Switch ......................................................C-2

Undercarriage .................................................................C-4

Meters .............................................................................C-4

Connections for Wire Feeder Control .............................C-5

NA-3..........................................................................C-5

NA-5..........................................................................C-6

LN-8 or LN-9 .............................................................C-7

LN-7 ..........................................................................C-8

Section C-1

IDEALARC DC-600

C-2

ACCESSORIES

OPTIONS/ACCESSORIES

¥ Multi-Process Switch (K804) ¥ Remote Control Box Assembly (K775) ¥ Undercarriages (K817, K817R, K842)

Semi-Automatic and Automatic Wire Feeders ¥ LN-7 ¥ LN-8 ¥ LN-9

¥ NA-3 ¥ NA-5

Semi-Automatic Wire Feeders

}

Automatic Wire Feeders

}

MULTI-PROCESS SWITCH

The MULTI-PROCESS SWITCH gives you the ability to: ¥ Switch between "stick welding or air/carbon arc

cutting" and using a semi-automatic or automatic

wire feeder .

¥ Change the polarity of a semi-automatic or auto-

matic wire feeder without changing any electrical

cable connections.

See Figure C.1

The MULTI-PROCESS SWITCH has two sets of output terminals. You connect the wire feeder unit cables to the set of terminals on the left side of the box and the stick or air/carbon arc cables to the set of terminals on the right side (facing the front of the machine) as shown in Figure C.1.

When the MULTI-PROCESS SWITCH is in the "Stick or Air/Carbon Arc" position, only those terminals are energized. The wire feeder nozzle or gun and electrode are not electrically "hot" when in this mode.

Follow these steps to install the MUL TI-PROCESS SWITCH:

1. Confirm that the IDEALARC DC-600 ON/OFF PUSH BUTTON is in the OFF position.

2. Disconnect main AC input power to the IDEALARC DC-600.

3. Open the terminal strip access door located on the Case Front Assembly.

4. Remove the two front, middle screws that secure the two side panels of the machine. See Figure C.2.

POSITIVE

NEGATIVE

Ð

WIRE

FEEDER

CABLES

STICK OR

AIR

CARBON

ARC

+

STICK OR

AIR/CARBON

ARC CABLES

FIGURE C.1 - MULTI-PROCESS SWITCH

REMOVE SCREWS TO MOUNT MULTI-PROCESS SWITCH

POSITIVE

NEGATIVE

Ð

STICK OR

AIR

CARBON

ARC

+

FIGURE C.2 - SIDE PANEL REMOVAL

IDEALARC DC-600

ACCESSORIES

C-3

5. Attach the MUL TI-PROCESS SWITCH bracket across the front of the machine with the flange down. Use the long, self-tapping screws and lock washers provided. The bracket should be on the outside of the side panel. See Figure C.3.

NOTE: If the machine does not have any holes in the front of the machine, use the switch template and drill two .153" diameter holes.

6. Position the MUL TI-PROCESS SWITCH at the front of the machine. See Figure C.3.

MULTI-

BRACKET

PROCESS SWITCH CONTROL LEADS

SELF TAPPING SCREWS (DRILL .153" HOLE IF NEEDED)

8. Connect the control leads from the MUL TIPROCESS SWITCH to terminals #2 and #4 on the IDEALARC DC-600's terminal strip.

9. Position the MUL TI-PROCESS SWITCH flush with the front of the machine about 2" lower than the bracket. Slide the switch straight up to the bracket.

10. Check that the bottom of the switch is hooked behind the top of the bottom louver .

11. Connect the right cable from the MUL TIPROCESS SWITCH (facing the front of the machine) to the IDEALARC DC-600 positive (+) output terminal. See Figure C.4.

TERMINAL

STRIP

21 4 2 31 32

75 76 77 80 81

CONTROL

LEADS

MULTIPROCESS SWITCH

WIRE FEED CONTROL CABLE

FIGURE C.3 - ATTACHING THE MULTIPROCESS SWITCH BRACKET.

7. Route the MUL TI-PROCESS SWITCH control leads through the strain-relief box connectors and into the terminal strip. The wire feeder control cable is routed through the strain-relief box connector also. See Figure C.3.

NEGATIVE (Ð)

OUTPUT

STUD

ELECTRODE

CABLE

WIRE FEEDER

WORK

CABLE

Ð

WORK

ELECTRODES

JUMPER (IF NEEDED SEE INSTRUCTIONS)

+

ELECTRODE

+

POSITIVE (+)

OUTPUT

STUD

CABLE

STICK AIR/CARBON ARC WELDING EQUIPMENT

WORK

CABLE

FIGURE C.4 - MULTI-PROCESS SWITCH CABLE CONNECTIONS.

12. Connect the left cable from the MUL TI-PROCESS SWITCH (facing the front of the machine) to the IDEALARC DC-600 negative (-) output terminal. See Figure C.4.

IDEALARC DC-600

C-4

ACCESSORIES

13. Connect the wire feeder electrode and work cables. See Figure C.4.

a. Insert the wire feeder electrode and work

cables through the strain relief loop on the left side of the IDEALARC DC-600 (facing the front of the machine).

b. Connect the wire feeder electrode and work

cables to the electrode and work terminals on the left side of the MUL TIPROCESS SWITCH.

NOTE: When using Dual Process Kits K317 or K318, connect the electrode and work cables to these terminals instead of the power source output terminals. See connection diagrams for details.

14. Connect wire feeder control cable to the terminal strip of the IDEALARC DC-600.

NOTE: Connect the control cable ground lead to the frame terminal marked ( ).

NOTE: See the connection diagram for the wire feeder being used for connection instructions.

15. Connect stick or air/carbon arc electrode and work cable. See Figure C.4.

NOTE: The instructions above are for connecting the stick polarity positive. To change the polarity , turn the IDEALARC DC-600 OFF, and reverse the cables.

NOTE: When it is not necessary to have separate ground cables for stick and semi-automatic or automatic welding, connect a jumper from the MULTI-PROCESS SWITCH "Work" terminal to the MULTI-PROCESS SWITCH "negative" terminal. See Figure C.4.

To operate the MUL TI-PROCESS SWITCH, refer to the operating instructions on the switch nameplate.

UNDERCARRIAGE (K817, K817R, K842)

The IDEALARC DC-600 is designed for use with the Lincoln K817, K817R, or K842 Undercarriage. Complete installation instructions are included with the undercarriage. When any of the undercarriages are installed, the IDEALARC DC-600 lift bail is no longer functional. Do not attempt to lift the machine with the undercarriage attached. The undercarriage is designed for moving the machine by hand only . Mechanized towing can lead to injury and/or damage to the IDEALARC DC-600.

a. Insert the electrode and work cables through

the strain relief loop on the right side (facing the front of the machine) of the IDEALARC DC-600.

b. Connect the electrode cable to the "Positive"

terminal on the right side of the MUL TIPROCESS SWITCH.

c. Connect the work cable to the "Negative" ter-

minal on the right side of the MUL TIPROCESS SWITCH.

METERS

Optional factory-installed voltmeter and ammeter are available.

IDEALARC DC-600

ACCESSORIES

C-5

CONNECTIONS FOR SEMI-AUTOMATIC OR AUTOMATIC WIRE FEEDER CONTROL

1. Set the ON/OFF PUSH BUTTON to OFF.

2. Locate and open the hinged access door on the Front Case Assembly.

3. Insert control cable through the strain relief box connector and pull enough cable through to reach the terminal strip.

4. Connect the automatic wire feeder control cable to the terminal strip. See corresponding connection diagram in this Section of the manual, or the instructions included with the wire feeder .

5. Connect the wire feeder grounding wire to the chassis ground screw marked with the symbol ( ).

NOTE: The IDEALARC DC-600 Auxiliary Power Circuit supplies 1 15-volt AC power to the wire feeding equipment. The circuit has a 1000 volt ampere rating. An 8-amp slow blow fuse on the machineÕ s control panel protects the auxiliary power supply from excessive overloads.

CONNECTING THE NA-3 IDEALARC DC-600

1. Disconnect main AC input power to the IDEALARC DC-600.

2. Set IDEALARC DC-600 ON/OFF PUSH BUTTON to OFF.

NA 3 WIRE FEEDER CONTROL CABLE

TO AUTOMATIC CONTROL BOX

77

76

75

21 4 2 31 32

Ð

NEGATIVE

TO WORK

75 76 77 80 81

+

POSITIVE

ELECTRODE CABLE TO AUTOMATIC EQUIPMENT

32

31

2

4

21

GND

FIGURE C.5 - NA-3 WIRE FEEDER CONNECTION TO THE IDEALARC DC-600

5. Extend wire feeder control cable lead # 21 so it can be connected directly to the work piece.

a. Make a bolted connection using AWG #14 or

larger insulated wire. Tape the bolted connection with insulating tape.

b. An S-16586- X remote voltage sensing work

lead is available for this purpose.

c. Keep the # 21 lead electrically separate from

the work cable circuit and connection.

d. Tape the # 21 lead to work cable for ease of

use.

NOTE: The connection diagram shown in Figure C.5 shows the electrode connected for positive polarity . To change polarity:

3. Connect the wire feeder control cable leads to the IDEALARC DC-600 terminal strip as shown in Figure C.5.

4. Connect the wire feeder control cable ground lead to the frame terminal marked ( ).

NOTE: The IDEALARC DC-600 must be properly grounded.

a. Set the IDEALARC DC-600 ON/OFF PUSH

BUTTON to OFF

b. Move the electrode cable to the Negative (-)

output terminal

c. Move the work cable to the Positive (+) output

terminal.

d. Set the IDEALARC DC-600 CONTROL CIR-

CUIT POLARITY SWITCH to NEGATIVE.

e. Reverse the leads at the back of the ammeter

and voltmeter on the wire feeder automatic control box.

IDEALARC DC-600

C-6

ACCESSORIES

CONNECTING THE NA-5 TO THE IDEALARC DC-600

NOTE: For optimum performance use the NA-5 with IDEALARC DC-600 codes 8288 and above.

1. Disconnect main AC input power to the IDEALARC DC-600.

2. Set the IDEALARC DC-600 ON/OFF PUSH BUTTON to OFF.

3. Connect the wire feeder control cable leads to the IDEALARC DC-600 terminal strip as shown in Figure C.6.

LN8 OR LN 9 WIRE FEEDER CONTROL CABLE

TO INPUT CABLE

C

B

A

21 4 2 31 32

Ð

NEGATIVE

TO WORK

75 76 77 80 81

+

POSITIVE

ELECTRODE CABLE TO WIRE FEEDER

32

31

GND

2

4

21

5. Extend wire feeder control cable lead # 21 so it can be connected directly to the work piece.

a. Make a bolted connection using AWG #14 or

larger insulated wire. Tape the bolted connection with insulating tape.

b. An S-16586- X remote voltage sensing work

lead is available for this purpose.

c. Keep the # 21 lead electrically separate from

the work cable circuit and connection.

d. Tape the # 21 lead to work cable for ease of

use.

6. Connect NA-5 wire feeder control jumpers on Voltage Control Board. See NA-5 Operator's Manual.

a. Connect red jumper on V oltage Control Board

to pin "S."

b. Connect white jumper on V oltage Control

Board to pin "B."

NOTE: The connection diagram shown in Figure C.6 shows the electrode connected for positive polarity . To change polarity:

a. Set the IDEALARC DC-600 ON/OFF PUSH

BUTTON to OFF.

FIGURE C.6 - NA-5 WIRE FEEDER CONNECTION TO THE IDEALARC DC-600

NOTE: If using a K215 control cable, connect control cable leads #75, #76, and #77 to the matching #75, #76, and #77 terminals on the terminal strip of the IDEALARC DC- 600.

4. Connect the wire feeder control cable ground lead to the frame terminal marked ( ). NOTE: The IDEALARC DC-600 must be properly grounded.

b. Move the electrode cable to the Negative (-)

output terminal.

c. Move the work cable to the Positive (+) output

terminal.

d. Set the IDEALARC DC-600 CONTROL

CIRCUIT POLARITY SWITCH to NEGATIVE.

NOTE: For proper NA-5 operation, the electrode cables must be secured under the clamp bar on the left side of the NA-5 Control Box.

IDEALARC DC-600

ACCESSORIES

C-7

CONNECTING THE LN-8 OR LN-9 TO THE IDEALARC DC-600

1. Disconnect AC input power to the IDEALARC DC-

600.

2. Set the IDEALARC DC-600 ON/OFF PUSH BUTTON to OFF.

3. Connect the wire feeder control cable leads to the IDEALARC DC-600 terminal strip as shown in Figure C.7.

4. Connect the wire feeder control cable ground lead to the frame terminal marked ( ). NOTE: The IDEALARC DC-600 must be properly grounded.

5. Extend wire feeder control cable lead #21 so it can be connected directly to the work piece.

a. Make a bolted connection using AWG #14 or

larger insulated wire. Tape the bolted connection with insulating tape.

b. An S-16586- X remote voltage sensing work

lead is available for this purpose.

c. Keep the #21 lead electrically separate from

the work cable circuit and connection.

d. Tape the #21 lead to work cable for ease of

use.

NOTE: Using the extended #21 lead eliminates the need to use the LN-9's remote work lead accessory which has a direct work lead jack.

6. Connect LN-9 wire feeder control jumpers on Voltage Control board. See LN-9 Operator's Manual.

LN8 OR LN 9 WIRE FEEDER CONTROL CABLE

TO INPUT CABLE

C

B

A

21 4 2 31 32

Ð

NEGATIVE

75 76 77 80 81

TO WORK

+

POSITIVE

ELECTRODE CABLE TO WIRE FEEDER

32

31

GND

2

4

21

FIGURE C.7 - LN-8 OR LN-9 WIRE FEEDER CONNECTION TO THE IDEALARC DC-600

NOTE: On earlier units, the blue jumper on V oltage Control Board is connected to Pin "B" on Start Board.

NOTE: The connection diagram shown in Figure C.7 shows the electrode connected for positive polarity . To change polarity:

a. Set the IDEALARC DC-600 ON/OFF PUSH

BUTTON to OFF

b. Move the electrode cable to the Negative (-)

output terminal

c. Move the work cable to the Positive (+) output

terminal.

d. Set the IDEALARC DC-600 CONTROL CIR-

CUIT POLARITY SWITCH to NEGATIVE.

a. White jumper on V oltage Control Board to pin

"S."

b. Blue jumper on V oltage Control Board to pin

"B."

IDEALARC DC-600

C-8

ACCESSORIES

LN-7 IDEALARC DC-600

1. Disconnect main AC input power to the IDEALARC DC-600.

2. Set the IDEALARC DC-600 ON/OFF PUSH BUTTON to OFF.

3. Connect the wire feeder control cable leads to the IDEALARC DC-600 terminal strip as shown in Figure C.8.

LN -7 WIRE FEEDER CONTROL CABLE

TO LN-7 INPUT CABLE

PLUG 77

76

75

21 4 2 31 32

Ð

NEGATIVE

75 76 77 80 81

TO WORK

+

POSITIVE

ELECTRODE CABLE TO LN CONDUCTOR BLOCK

32

31

21

GND

2

4

b. An S-16586- X remote voltage sensing work

lead is available for this purpose.

c. Keep the #21 lead electrically separate from

the work cable circuit and connection.

d. Tape the #21 lead to work cable for ease of

use.

NOTE: The connection diagram shown in Figure C.8 shows the electrode connected for positive polarity . To change polarity:

a. Set the IDEALARC DC-600 ON/OFF PUSH

BUTTON to OFF.

b. Move the electrode cable to the Negative (-)

output terminal.

c. Move the work cable to the Positive (+) output

terminal.

d. Set the IDEALARC DC-600 CONTROL

CIRCUIT POLARITY SWITCH to NEGATIVE.

FIGURE C.8 - LN-7 WIRE FEEDER CONNECTION TO THE IDEALARC DC-600

4. Connect the wire feeder control cable ground lead to the frame terminal marked ( ). NOTE: The IDEALARC DC-600 must be properly grounded.

5. PERFORM THIS STEP ONLY IF THE LN-7 IS EQUIPPED WITH A METER KIT.

Extend wire feeder control cable lead #21 so it can be connected directly to the work piece.

a. Make a bolted connection using AWG #14 or

larger insulated wire. Tape the bolted connection with insulating tape.

NOTE: If the work cable length is less than 25 feet and the connections to the work piece are secure, then wire feeder control cable lead #21 can be connected directly to the DC-600 terminal strip.

IDEALARC DC-600

TABLE OF CONTENTS

- MAINTENANCE SECTION -

MAINTENANCE .................................................................. Section D

Safety Precautions ...................................................................D-2

Routine and Periodic Maintenance ..........................................D-3

3-D Exploded V iew ...................................................................D-4

SectionD-1

IDEALARC DC-600

D-2

MAINTENANCE

SAFETY PRECAUTIONS

WARNING

ELECTRIC SHOCK CAN KILL.

Only qualified personnel should perform this maintenance.

Turn the input power OFF at the disconnect switch or fuse box before working on this equipment.

Do not touch electrically hot parts.

__________________

IDEALARC DC-600

MAINTENANCE

ROUTINE AND PERIODIC MAINTENANCE

1. Disconnect input AC power supply lines to the machine before performing periodic maintenance, tightening, cleaning, or replacing parts. See Figure D.1

Perform the following daily:

1. Check that no combustible materials are in the welding or cutting area or around the machine.

2. Remove any debris, dust, dirt, or materials that could block the air flow to the machine for cooling.

3. Inspect the electrode cables for any slits or punctures in the cable jacket, or any condition that would affect the proper operation of the machine.

D-3

Perform Periodically:

Clean the inside of the machine with low pressure air stream. Clean the following parts. Refer to Figure D.1.

• Main transformer and choke.

• Electrode and work cable connections.

• SCR rectifier bridge and heat sink fins.

• Control board.

• Firing board.

• Fan Assembly. NOTE: The fan motor has sealed bearings which require no maintenance.

IDEALARC DC-600

D-4

MAINTENANCE

FIGURE D.1 - General Assembly Exploded View

IDEALARC DC-600

TABLE OF CONTENTS

- THEORY OF OPERATION SECTION -

Section E-1

IDEALARC DC-600

THEORY OF OPERATION SECTION ................................ Section E

Power Supply Operation ..................................................E-2 - E-5

Input Line Voltage, Connector and Main Transformer.........E-2

Output, Rectification,Control and Feedback ........................E-3

Protection Devices and Circuits (Contactor Hold-In) ...........E-4

SCR Operation ..........................................................................E-5

FIGURE E.1 Block Logic Diagram

8/98

OUTPUT

CONTROL

TRANSFORMER

CONTACTOR

TO

CONTROL

BOARD

PROTECTION

DEVICES &

CIRCUTS

115 VAC

CONTACTOR

()

HOLD-IN

TRANSFORMER

R E C O N N E C T

TERMINAL

STRIP

REMOTE

CONTROL

MAIN

FAN

115 VAC

FAULT PROTECTION

MODE

FIRING BOARD

1 1 5 V A C

SCR BRIDGE

CHOKE

CONTROL

PILOT RELAY

BOARD

F E E D B A C K

SHUNT

SWITCH

POSITIVE

TERMINAL

F E E D B A C K

PILOT RELAY

LATCHING RESISTOR

NEGATIVE

TERMINAL

IDEALARC DC-600

E-2

THEORY OF OPERATION

INPUT LINE VOLTAGE, CONTACTOR AND MAIN TRANSFORMER

The desired three phase input power is connected to the DC-600 through an Input Contactor located in the input box at the rear of the machine. Two phases of the input line are also connected to the Control Transformer which supplies power to the Contactor Hold-In Circuit. The Contactor Hold-In Circuit will disable the Input Contactor if the DC-600 is overloaded or overheated.

A Reconnect Panel allows the user to configure the machine for the desired input voltage. This AC input voltage is applied to the primary of the Main

Transformer. The transformer changes the high voltage, low current input power to a low voltage, high current output. The finishes or "neutrals" of the main secondary coils are connected together and the six starts of the secondary windings are connected to the rectifier assembly . In addition the main transformer also has an isolated 115VAC auxiliary winding that supplies 115VAC to operate the cooling fan and offers 8 amps of auxiliary power to operate wire feeding equipment. The three 75VAC phase angle windings are also housed in the Main Transformer assembly. These windings provide power and "timing" to the firing board.

TERMINAL

STRIP

CONTACTOR

TO

CONTROL

BOARD

REMOTE

CONTROL

MAIN

TRANSFORMER

CONTROL

TRANSFORMER

115 VAC

FAULT PROTECTION

PROTECTION

DEVICES &

CIRCUTS

CONTACTOR

HOLD-IN

()

FIRING BOARD

CONTROL

BOARD

PILOT RELAY

F E

E D B A C K

F E E D B A C K

OUTPUT

CONTROL

MODE

SWITCH

POSITIVE

TERMINAL

NEGATIVE TERMINAL

LATCHING RESISTOR

PILOT RELAY

CHOKE

1 1 5 V A C

FAN

R E C O N N E C T

SCR BRIDGE

SHUNT

FIGURE E.2 Input Line Voltage, Contactor and Main Transformer

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

8/98

IDEALARC DC-600

E-3

THEORY OF OPERATION

FIGURE E.3 Output, Rectification, Control and Feedback

OUTPUT, RECTIFICATION, CONTROL AND FEEDBACK

The neutrals of the Main Transformer secondary windings are connected together and the six starts are connected to the six SCR assemblies to form a six phase output. This six phase AC output from the Main Transformer secondary is rectified and controlled through the SCR bridge. Output current and voltage is sensed at the shunt and output terminals. This feedback information is processed in the control board. The control board compares the commands of the Mode switch and the Output Control Potentiometer (or Remote Control) with the feedback information and sends the appropriate signal to the Firing Board.

The Firing Board is a three phase circuit. Each phase provides two firing pulses, one for each of the two Silicon Controlled Rectifiers (SCR) controlled by that phase. The firing circuit supplies the proper amount of

energy to the gates of the power SCRs. When this energy is applied, at the correct time, the SCR will turn "ON". The amount of "ON" time versus "OFF" time determines the output of the machine. See SCR Operation.

The Pilot Relay signals the Firing Board circuit to supply gate pulses to the SCR Bridge. Closing of the Pilot Relay ( a "dry" closure of leads #2 and #4) also brings the Latching Resistor into the machine output circuit. The Latching Resistor provides a pre-load for the SCR Bridge.

A Choke is connected between the neutral connection of the Main Transformer secondaries and the negative output terminal. This large inductor stores energy and provides filtering for the output of the DC-600.

TERMINAL

STRIP

CONTACTOR

TO

CONTROL

BOARD

REMOTE

CONTROL

MAIN

TRANSFORMER

CONTROL

TRANSFORMER

115 VAC

FAULT PROTECTION

PROTECTION

DEVICES &

CIRCUTS

CONTACTOR

HOLD-IN

()

FIRING BOARD

CONTROL

BOARD

PILOT RELAY

F E E D B A C K

OUTPUT

CONTROL

MODE

SWITCH

POSITIVE

TERMINAL

NEGATIVE

TERMINAL

LATCHING RESISTOR

PILOT RELAY

CHOKE

1 1 5 V A C

FAN

R E C O N N E C T

SCR BRIDGE

SHUNT

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

8/98

IDEALARC DC-600

E-4

THEORY OF OPERATION

FIGURE E.4 Protection Devices and Circuits (Contactor Hold-In)

PROTECTION DEVICES AND CIRCUITS (CONTACTOR HOLD-IN)

Two thermostats protect the DC-600 from excessive operating temperatures. Excessive operating temperatures may be caused by a lack of cooling air or operating the machine beyond the duty cycle and output rating. If excessive operating temperature should occur, the thermostat(s) will deactivate the input contactor, turning the machine off. The input contactor will remain open until the machine cools. The machine can then be restarted by operating the start push button. Upon restart if the fan does not turn or the air intake louvers are obstructed, then the input power must be removed and the fan problem or air obstruction be corrected.

The DC-600 is also protected against high current overloads. This electronic protection circuit senses an overload on the power source and opens the input contactor should the overload remain for a predetermined time. If the overload is great the machine will shut down immediately. The input contactor will remain open until the start push button is operated.

The Remote Control circuit is also protected from "grounds" or voltage intrusions. If the #75, #76 or #77 leads come in contact with either of the machine's output cables, the DC-600 will only operate at a minimum output or the input contactor will open.

TERMINAL

STRIP

CONTACTOR

TO

CONTROL

BOARD

REMOTE

CONTROL

MAIN

TRANSFORMER

CONTROL

TRANSFORMER

115 VAC

FAULT PROTECTION

PROTECTION

DEVICES &

CIRCUTS

CONTACTOR

HOLD-IN

()

FIRING BOARD

PILOT RELAY

F E E D B A C K

OUTPUT

CONTROL

MODE

SWITCH

POSITIVE

TERMINAL

NEGATIVE

LATCHING RESISTOR

PILOT RELAY

CHOKE

1 1 5 V A C

FAN

R E C O N N E C

T

CONTROL

BOARD

SCR BRIDGE

SHUNT

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

8/98

ANODE

INPUT

CATHODE

OUTPUT

GATE

THEORY OF OPERATION

FIGURE E.5 SCR Operation

E-5

NOTE: AS THE GATE PULSE IS APPLIED LATER IN THE C YCLE THE SCR OUTPUT IS DECREASED.

SCR OPERATION

A silicon controlled rectifier (SCR) is a three terminal device used to control rather large currents to a load. An SCR acts very much like a switch. When a gate signal is applied to the SCR it is turned ON and there is current flow from anode to cathode. In the ON state the SCR acts like a closed switch. When the SCR is turned OFF there is no current flow from anode to cathode thus the device acts like an open switch. As the name suggests, the SCR is a rectifier, so it passes current only during positive half cycles of the AC supply. The positive half cycle is the portion of the sine wave in which the anode of the SCR is more positive than the cathode.

When an AC supply voltage is applied to the SCR, the device spends a certain portion of the AC cycle time in the on state and the remainder of the time in the off state. The amount of time spent in the ON state is controlled by the Gate.

An SCR is fired by a short burst of current into the gate. This gate pulse must be more positive than the cathode voltage. Since there is a standard PN junction between gate and cathode, the voltage between these terminals must be slightly greater than 0.6V. Once the SCR has fired it is not necessary to continue the flow of gate current. As long as current continues to flow from anode to cathode the SCR will remain on. When the anode to cathode current drops below a minimum value, called holding current, the SCR will shut off. This normally occurs as the AC supply voltage passes through zero into the negative portion of the sine wave. If the SCR is turned on early in the positive half cycle, the conduction time is longer resulting in greater SCR output. If the gate firing occurs later in the cycle the conduction time is less resulting in lower SCR output.

IDEALARC DC-600

TABLE OF CONTENTS

- TROUBLESHOOTING & REPAIR SECTION -

Troubleshooting & Repair Section................................................................Section F

Safety Precautions .................................................................................................F-2

How to Use Troubleshooting Guide .......................................................................F-2

PC Board Troubleshooting Procedures .................................................................F-3

Troubleshooting Guide ................................................................................F-4 - F-12

Test Procedures

Control Transformer V oltage Test .......................................................F-13 - F-14

Main Transformer V oltage Test ...........................................................F-16 - F-20

Firing Board Test .................................................................................F-21 - F-27

Control Board Test ..............................................................................F-28 - F-32

Static SCR Test ...................................................................................F-33 - F-36

Active SCR Test ..................................................................................F-37 - F-40

Oscilloscope W aveforms

Normal Open Circuit V oltage W aveform Constant Current Mode .................F-41

Normal Maximum Open Circuit V oltage W aveform

Constant V oltage Innershield Mode .......................................................F-42

Normal Minimum Open Circuit V oltage W aveform

Constant V oltage Innershield Mode .......................................................F-43

Typical Output V oltage W aveform Machine Loaded

Constant V oltage Innershield Mode .......................................................F-44

Typical SCR Gate V oltage W aveform @ Maximum Output Setting .....................

Constant V oltage Innershield Mode .......................................................F-45

Abnormal Open Circuit V oltage W aveform

Constant V oltage Innershield Mode .......................................................F-46

Replacement Procedures

Input Contactor Cleaning and or Replacement ..................................F-47 - F-48

SCR Output Bridge Removal.........................................................................F-49

Removal of Individual SCR Heat Sinks ......................................F-50 - F-53

Removal of Lift Bail Assembly ............................................................F-54 - F-56

Removal of Transformer from Lift Bail Assembly ...............................F-57 - F-59

Transformer Disassembly and Coil Replacement .........................................F-60

Retest After Repair ..................................................................................F-61 - F-62

SECTION F-1

IDEALARC DC-600

F-2

TROUBLESHOOTING & REPAIR

HOW TO USE TROUBLESHOOTING GUIDE

Service and Repair should only be performed by Lincoln Electric Factory Trained Personnel. Unauthorized repairs performed on this equipment may result in danger to the technician and machine operator and will invalidate your factory warranty. For your safety and to avoid Electrical Shock, please observe all safety notes and precautions detailed throughout this manual.

______________________________

This Troubleshooting Guide is provided to help you locate and repair possible machine malfunctions. Simply follow the three-step procedure listed below.

Step 1. LOCATE PROBLEM (SYMPTOM).

Look under the column labeled “PROBLEM (SYMPTOMS)”. This column describes possible symptoms that the machine may exhibit. Find the listing that best describes the symptom that the machine is exhibiting. Symptoms are grouped into several main categories: output problems and welding problems.

Step 2. PERFORM EXTERNAL TESTS.

The second column labeled “POSSIBLE AREAS OF MISADJUSTMENT(S)” lists the obvious external possibilities that may contribute to the machine symptom. Perform these tests/checks in the order listed. In general, these tests can be conducted without removing the case wrap-around cover.

Step 3. PERFORM COMPONENT TESTS.

The last column labeled “Recommended Course of Action” lists the most likely components that may have failed in your machine. It also specifies the appropriate test procedure to verify that the subject component is either good or bad. If there are a number of possible components, check the components in the order listed to eliminate one possibility at a time until you locate the cause of your problem.

All of the referenced test procedures referred to in the Troubleshooting Guide are described in detail at the end of this chapter. Refer to the Troubleshooting and Repair Table of Contents to locate each specific Test Procedure. All of the specified test points, components, terminal strips, etc. can be found on the referenced electrical wiring diagrams and schematics. Refer to the Electrical Diagrams Section Table of Contents to locate the appropriate diagram.

IDEALARC DC-600

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

______________________________

TROUBLESHOOTING & REPAIR

PC BOARD TROUBLESHOOTING PROCEDURES

- Remove the P.C. Board from the static-shield-

WARNING

ELECTRIC SHOCK can kill.

Have an electrician install and service this equipment. Turn the input power OFF at the fuse box before working on equipment. Do not touch electrically hot parts.

ing bag and place it directly into the equipment. Don’t set the P.C. Board on or near paper, plastic or cloth which could have a static charge. If the P.C. Board can’t be installed immediately, put it back in the static-shielding bag.

- If the P.C. Board uses protective shorting jumpers, don’t remove them until installation is complete.

F-3

CAUTION: Sometimes machine failures

appear to be due to PC board failures. These problems can sometimes be traced to poor electrical connections. To avoid problems when troubleshooting and replacing PC boards, please use the following procedure:

1. Determine to the best of your technical ability that the PC board is the most likely component causing the failure symptom.

2. Check for loose connections at the PC board to assure that the PC board is properly connected.

3. If the problem persists, replace the suspect PC board using standard practices to avoid static electrical damage and electrical shock. Read the warning inside the static resistant bag and perform the following procedures:

P.C. Board can be damaged by static electricity.

- Remove your body’s static charge before opening

ATTENTION Static-Sensitive Devices Handle only at Static-Safe Workstations

the static-shielding bag. Wear an anti-static wrist strap. For safety, use a 1 Meg ohm resistive cord connected to a grounded part of the equipment frame.

- If you return a P.C. Board to The Lincoln Electric Company for credit, it must be in the static-shielding bag. This will prevent further damage and allow proper failure analysis.

4. Test the machine to determine if the failure symptom has been corrected by the replacement PC board.

NOTE: It is desirable to have a spare (known good) PC board available for PC board troubleshooting.

NOTE: Allow the machine to heat up so that all electrical components can reach their operating temperature.

5. Remove the replacement PC board and substitute it with the original PC board to recreate the original problem.

a. If the original problem does not reappear

by substituting the original board, then the PC board was not the problem. Continue to look for bad connections in the control wiring harness, junction blocks, and terminal strips.

b. If the original problem is recreated by the

substitution of the original board, then the PC board was the problem. Reinstall the replacement PC board and test the machine.

Reusable Container Do Not Destroy

equipment frame. Keep touching the frame to prevent static build-up. Be sure not to touch any electrically live parts at the same time.

- Tools which come in contact with the P.C. Board must be either conductive, anti-static or static-dissipative.

- If you don’t have a wrist strap, touch an unpainted, grounded, part of the

6. Always indicate that this procedure was followed when warranty reports are to be submitted.

NOTE: Following this procedure and writing on the warranty report, “INSTALLED AND SWITCHED PC BOARDS TO VERIFY PROBLEM,” will help avoid denial of legitimate PC board warranty claims.

IDEALARC DC-600

F-4

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines detailed in the beginning of this manual.

PROBLEMS (SYMPTOMS)

Major Physical or Electrical Damage is Evident

The Machine is dead- The Input contactor does not operate.

TROUBLESHOOTING GUIDE

POSSIBLE AREAS OF MISADJUSTMENT(S)

OUTPUT PROBLEMS

Contact the Lincoln Electric Service Dept. (216) 383-2531 or 1-800-8339353 (WELD)

1. Check for blown or missing fuses in input lines.

2. Check the three- phase input line voltage at the machine. The input voltage must match the rating plate and reconnect panel.

RECOMMENDED COURSE OF ACTION

1. The ON/OFF PUSHBUTTON (S1) may be faulty - Check for proper operation. See wiring diagram.

2. The Control Transformer (T2) may be faulty. Perform the Control Transformer Test.

3. The primary or secondary thermostats may be open. Check or replace. Also check the associated wiring. See wiring diagram.

4. The pilot relay (CR2) may be faulty. Check or replace. See wiring diagram.

5. The input contactor coil may be open. See wiring diagram.

6. The Control board may be faulty.- Replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-5

TROUBLESHOOTING GUIDE

PROBLEMS (SYMPTOMS)

Input contactor (CR1) chatters.

Input contactor pulls in when start button is pressed but immediately drops out when start button is released.

POSSIBLE AREAS OF MISADJUSTMENT(S)

1. The input line voltage may be

2. Make sure input line voltage

1. Make sure input line voltage

2. Remove all external wires

OUTPUT PROBLEMS

low. Check all three phases.

matches machine rating and the reconnect panel is connected correctly for the line voltage.

attached to terminal strip. ( 2, 4, 31, 32 75,76,77). If contactor (CR1) functions correctly there may be a "ground" or negative intrusion on the remote control leads (75, 76, or 77). There may also be a "short" at the welder output terminals.

Observe Safety Guidelines

detailed in the beginning of this manual.

RECOMMENDED COURSE OF ACTION

1. The pilot relay (CR2) may have bad contacts. Check or replace relay.

2. Check for loose or faulty wiring between pilot relay (CR2) and input contactor (CR1)coil connections.

3. The input contactor (CR1) may be faulty.-Replace.

1. The CR1 interlock may be faulty. Replace if necessary.

2. The ON/OFF PUSHBUTTON may be faulty. Check or replace.

3. Check internal remote control circuit ( leads 75, 76 and 77) and switch SW3 for grounds or shorts.

4. The control board may be faulty. Replace.

3. If the problem persists after performing steps #1 and #2 the problem is in the DC600.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

F-6

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines detailed in the beginning of this manual.

PROBLEMS (SYMPTOMS)

Machine input contactor operates but machine has no weld output.Fan runs and pilot light glows.

TROUBLESHOOTING GUIDE

POSSIBLE AREAS OF MISADJUSTMENT(S)

OUTPUT PROBLEMS

1. Install a jumper from #2 to #4 on machine terminal strip. If machine weld output is restored the problem is in the wire feeder or control cable.

2. If remote control is not being used make certain the OUTPUT CONTROL SWITCH (SW3) is in the "OUTPUT CONTROL AT DC 600" position.

3. Check 8AMP fuse in the front panel.Replace if blown.

4. Check for loose or faulty weld cable connections.

RECOMMENDED COURSE OF ACTION

1. Check operation of output pilot relay(CR4). There should be 115VAC present at leads #31 and #4 at (CR4) when #2 and #4 are jumpered together at the terminal strip. a. If the correct voltage is

present and the relay does not activate, the relay may be faulty.Replace.

b. If the 115VAC is missing,

check the associated wiring for loose or faulty connections. See wiring diagram.

2. Check the OUTPUT CONTROL POTENTIOMETER (R1) and associated circuitry for loose or faulty connections. See wiring diagram.

3. Perform Main Transformer test.

4. Perform Firing Board test.

5. Perform Control Board test.

6. Perform SCR Output Bridge test.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-7

TROUBLESHOOTING GUIDE

PROBLEMS (SYMPTOMS)

Machine has maximum weld output and no control.

POSSIBLE AREAS OF MISADJUSTMENT(S)

1. If remote control is being used

OUTPUT PROBLEMS

set OUTPUT CONTROL SWITCH (SW3) in "OUTPUT CONTROL AT DC600" position and control weld output with the OUTPUT CONTROL POTENTIOMETER (R1) at DC600. If the problem is solved check the remote control unit (or wire feeder) and associated control cable.

Observe Safety Guidelines

detailed in the beginning of this manual.

RECOMMENDED COURSE OF ACTION

1. Check OUTPUT CONTROL SWITCH (SW3) and associated wiring.

2. Check feedback leads #222 (negative output terminal), #215, and #210 (output shunt) for loose or faulty connections. See wiring diagram.

3. Check the #75 lead for continuity (zero ohms) from the OUTPUT CONTROL POTENTIOMETER (R1) to the control board plug 2J1. See wiring diagram.

4. Perform Firing Board test.

5. Perform Control Board test.

6. Perform SCR Output Bridge test.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

F-8

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines detailed in the beginning of this manual.

PROBLEMS (SYMPTOMS)

Machine has minimum output and no control.

TROUBLESHOOTING GUIDE

POSSIBLE AREAS OF MISADJUSTMENT(S)

OUTPUT PROBLEMS

1. If a remote control unit is NOT connected to the terminal strip #75, #76, and #77 terminals, the OUTPUT CONTROL SWITCH must be in the "OUTPUT CONTROL AT DC600" position.

2. If a remote control cable is connected to terminals #75, #76 and #77 the leads may be "shorted" to the positive weld output.

3. Make certain the Three Phase input voltage is correct and matches the machine rating and the reconnect panel.

RECOMMENDED COURSE OF ACTION

1. Check the OUTPUT CONTROL POTENTIOMETER (R1) and associated wiring.

2. Check the OUTPUT CONTROL SWITCH (SW3), the WELDING MODE SWITCH (SW4) and associated wiring.

3. Perform the Control Board test.

4. Perform the Firing Board test.

5. Perform the SCR Output Bridge test.

6. Perform the Main Transformer test.

The machine does not have maximum weld output.

1. Check all Three-Phase input lines at the DC600. Make sure input voltages match machine rating and reconnect panel.

2. Put OUTPUT CONTROL SWITCH (SW3) in "OUTPUT CONTROL AT DC600" position. If problem is solved then check remote control unit or wire feeder.

1. Check the OUTPUT CONTROL POTENTIOMETER (R1) and associated wiring for loose or faulty connections. See wiring diagram.

2. Perform Control Board test.

3. Perform Firing Board test.

4. Perform Main Transformer test.

5. Perform SCR Output Bridge test.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-9

TROUBLESHOOTING GUIDE

PROBLEMS (SYMPTOMS)

Machine shuts off (input contactor drops out) when the welder output terminals are made electrically "hot". (#2 to #4 closure at terminal strip.)

POSSIBLE AREAS OF MISADJUSTMENT(S)

1. Remove all welding cables and

2. If the machine still shuts off

OUTPUT PROBLEMS

control cables from the DC 600. Jumper #2 to #4 at the terminal strip. If the machine does NOT shut off and normal open circuit voltage is present at the welder output terminals the problem is external to the DC600. Either the remote leads #75, #76 or #77 are grounded to the negative output cable or there is a short on the welding output terminals.

when all control and welding cables are removed then the problem is internal to the DC600.

Observe Safety Guidelines

detailed in the beginning of this manual.

RECOMMENDED COURSE OF ACTION

1. Check for grounds and or shorts in the #75, #76, #77 circuit. See wiring diagram.

2. Check for grounds and shorts in the welder output terminals and associated leads. See wiring diagram.

3. Check the output shunt and associated leads. See wiring diagram.

4. Perform the Control Board test.

The DC600 will NOT shut off when the Stop button is pushed.

1. Contact your local Lincoln Authorized Field Service Facility.

1. The input contactor(CR1) contacts may be stuck closed. Check and replace if necessary.

2. The Interlock contacts (Part of CR1) may be faulty. Replace if necessary.

3. The ON/OFF PUSHBUTTON may be faulty. Check or replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

1/96

IDEALARC DC-600

F-10

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines detailed in the beginning of this manual.

PROBLEMS (SYMPTOMS)

The weld output terminals are always electrically "hot".

TROUBLESHOOTING GUIDE

POSSIBLE AREAS OF MISADJUSTMENT(S)

OUTPUT PROBLEMS

1. Remove any external leads hooked to #2 and #4 on the terminal strip. If the problem disappears the fault is in the control cable or wire feeder.

2. If some open circuit voltage is present (over 3VDC.) after performing Step #1. then the problem is within the DC600.

RECOMMENDED COURSE OF ACTION

1. Check for an internal short between leads #2 and #4. See wiring diagram.

2. The Pilot Relay (CR4)may be "stuck" closed. Check or replace.

3. Perform Firing Board test.

4. Perform Control Board test.

5. Perform the SCR Output Bridge test.

6. The SCR Snubber(s) may be "leaky". Check or replace. See wiring diagram.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

1/96

TROUBLESHOOTING & REPAIR

F-11

TROUBLESHOOTING GUIDE

PROBLEMS (SYMPTOMS)

Poor arc starting when the DC600 is in the CV Sub-Arc or CV Innershield Modes.

POSSIBLE AREAS OF MISADJUSTMENT(S)

1. Make sure the proper welding

2. Check weld cables for loose or

WELDING PROBLEMS

procedures are being used. (wire feed speed , arc voltage and wire size)

faulty connections.

Observe Safety Guidelines

detailed in the beginning of this manual.

RECOMMENDED COURSE OF ACTION

1. Check the CR3 reed switch. The voltage from lead #215 to lead #220 should be 8VDC when the DC600 is in an idle condition (on but not welding). When the machine is producing welding current the reed switch (CR3) should close and the voltage from #215 to #220 should drop to zero.

2. Perform the Firing Board test.

3. Perform the SCR Output Bridge test.

4. The control board may be faulty. - Replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

F-12

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines detailed in the beginning of this manual.

PROBLEMS (SYMPTOMS)

Poor arc characteristics in all processes.

TROUBLESHOOTING GUIDE

POSSIBLE AREAS OF MISADJUSTMENT(S)

WELDING PROBLEMS

1. Check for the correct input voltages on the three- phase input lines at the DC600.

2. Make sure the proper welding procedures are being used.(wire feed speed, arc voltage and wire size).

3. Check the welding cables for loose or faulty connections.

RECOMMENDED COURSE OF ACTION

1. Check the WELDING MODE SWITCH (SW4) and the associated wiring for loose or faulty connections. See wiring diagram.

2. Check the CR3 reed switch. The voltage from lead #215 to lead #220 should be 8VDC when the DC600 is in an idle condition. When the machine is producing welding current the reed switch (CR3) should close and the voltage from #215 to #220 should drop to zero.

3. Perform the Firing Board test.

4. Perform the SCR Output Bridge test.

5. The control board may be faulty - Replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-13

CONTROL TRANSFORMER (T2) VOLTAGE TEST

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

TEST DESCRIPTION

This test will determine if the correct voltage is being a. applied to the primary of the control transformer. b. induced on the secondary winding of the control transformer.

MATERIALS NEEDED

Volt/Ohm Meter (Multimeter) IDEALARC DC-600 wiring diagrams (See Electrical Diagram Section of Manual).

IDEALARC DC-600

F-14

TROUBLESHOOTING & REPAIR

CONTROL TRANSFORMER (T2) VOLTAGE TEST

FIGURE F.1 - Control Transformer and Lead Locations

TEST PROCEDURE

1. Disconnect main AC input power to the machine.

2. Remove the Top and Case Sides.

3. Locate the Control Transformer (T2) on the left side of the Input Box (facing the back the of the machine). See Figure F.1.

4. Locate the Control Transformer primary leads (H1, H2, H3, etc.). See wiring diagram. NOTE: Unused leads should be taped.

a. Inspect for broken or incorrect

connections.

5. Locate Control Transformer leads X1 and X2.

a. Lead X1 is connected to the

Input Contactor (CR1) interlock located underneath the Input Contactor. See Figure F.1.

b. Lead X2 is connected to the

secondary winding thermostat. See Figure F.1.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

CONTROL TRANSFORMER (T2) VOLTAGE TEST

F-15

6. Test for 115 VAC between leads X1 and X2.

NOTE: If the main AC input supply voltage varies, the Control Transformer voltage will vary by the same percentage.

a. Connect one end of an insulat-

ed alligator clip to the X1 connection at the Input Contactor (CR1) interlock. See Figure F.2.

CONTROL

TRANSFORMER

b. Connect the other end of the

alligator clip to one of the meter probes. Be sure that neither the alligator clip nor the meter probe touches any metal surfaces.

c. Connect the other meter probe

to the X2 connection at the secondary winding thermostat. See Figure F.2.

d. Apply current Input Power to

DC-600.

INPUT

CONTACTOR (CR1)

X1

METER

PROBE

ALLIGATOR CLIP CABLE

INSULATED

LEFT SIDE OF

LIFT BAIL ASSEMBLY CASE BACK

FIGURE F.2 - Control Transformer X1 and X2 Test Connections

7. Read meter for 115 VAC. a. If 115 VAC is present, the

Control Transformer is functioning properly.

b. If 115 VAC IS NOT present, go

to Step 8.

8. If 115 VAC is not present between leads X1 and X2, test for correct main AC input power to the Control Transformer primary windings (H1, H2, H3, etc.) See Wiring Diagram.

a. If the correct main AC input

power to the Control Trans-former primary windings is present AND the secondary voltage is not correct, the Control Transformer may be faulty. Replace.

IDEALARC DC-600

F-16

TROUBLESHOOTING & REPAIR

MAIN TRANSFORMER (T1) VOLTAGE TEST

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

TEST DESCRIPTION

This test will determine if the correct voltages are being a. applied to the primary windings of the Main Transformer (T1). b. induced on the secondary winding, auxiliary windings, and phase angle

windings.

MATERIALS NEEDED

Volt/Ohm Meter (Multimeter) IDEALARC DC-600 wiring diagram (See Electrical Diagram Section of Manual).

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

MAIN TRANSFORMER (T1) VOLTAGE TEST

L3

T3

L2

T2

L1

T1

F-17

FIGURE F.3 - Input Contactor, Reconnect Panel, and Primary Leads to

Main Transformer Locations

TEST PROCEDURE

1. Set ON/OFF PUSHBUTTON to OFF

2. Disconnect main AC input power from the machine.

3. Inspect the Input Contactor, Reconnect Panel, and primary leads to the Main Transformer for loose or faulty connections. See Figure F.3.

a. Confirm that the Reconnect

Panel is connected properly for the three-phase main AC input power supplied to the machine. See the Reconnect Panel Connection Diagram located on the inside of the Input Box Assembly Access Door.

4. Connect main AC input power to the machine.

5. Set the ON/OFF PUSHBUTTON to ON.

a. Make sure the Input Contact

(CR1) energizes. The fan runs.

6. Test with an AC voltmeter for proper main AC input voltage to the line side of the Input Contactor (CR1). See wiring diagram.

a. L1 to L2. b. L2 to L3. c. L1 to L3.

IDEALARC DC-600

F-18

TROUBLESHOOTING & REPAIR

MAIN TRANSFORMER (T1) VOLTAGE TEST

7. Read meter. a. If proper voltage is present for

all three phases, proper main AC input voltage is being supplied.

b. If proper voltage is not present

in any or all of the three phases, check input fuses and leads.

8. Test with an AC voltmeter for proper main AC input voltage from the output side of the Input Contactor (CR1). See wiring diagram. a. T1 to T2. b. T2 to T3. c. T1 to T3.

9. Read meter. a. If proper voltage is present for

all three phases, the Contactor is working properly.

b. If the proper voltage is not pre-

sent for any or all of the three phases, the contactor may be faulty. Replace.

10. Test with an AC voltmeter for 52 VAC from each of the six main transformer secondary leads to the common buss connected to the output choke. See Figure F.4.

a. If one or more of the above voltage

tests are incorrect, check for loose or faulty wiring.

b. If the wiring is good, then the Main

Transformer may be faulty. Replace.

IDEALARC DC-600

FIGURE F.4 - Main Secondary Lead Test Points.

TROUBLESHOOTING & REPAIR

MAIN TRANSFORMER (T1) VOLTAGE TEST

F-19

11. Test for 115 VAC between leads #31 and #32 on the terminal board.

a. Open the Front Panel

Assembly Door to gain access to the terminal board.

b. If the above voltage test is

incorrect, check for loose or faulty wiring.

c. If the wiring is good, then the

Main Transformer may be faulty. Replace.

12. Remove the six screws from the Control Box Cover with a 5/16" nut driver and flip the cover down. It does not have to be completely removed to perform the tests.

13. Test with an AC voltmeter for 75 VAC for each phase angle winding as shown in Figures F.5 and F.6.

NOTE: If the main AC input supply voltage varies, the Main Transformer voltages will vary proportionately.

a. If the Firing Board number is

G-1486-4 or lower, test for 75 VAC between the leads connected to the terminal strip located on the right side of the Control Box. See Figure F.5.

31 32A 203 204

205 206 207 208

From Lead # To Lead # Expected VAC

#203 #204 75 VAC

#205 #206 75 VAC

#207 #208 75 VAC

Figure F.5 - Phase Angle Windings Test Points and

Terminal Board location.

IDEALARC DC-600

F-20

TROUBLESHOOTING & REPAIR

MAIN TRANSFORMER (T1) VOLTAGE TEST

b. If the Firing Board number is

G-1486 - 5 or higher, test for 75 VAC between the leads connected to the firing board Molex plugs. See Figure F.6.

FIRING BOARD CONTROL BOARD

PIN 4

(LEAD #204)

(LEAD #206)

(LEAD #203)

c. If one or more of the above

voltage tests are incorrect, check for loose or faulty wiring.

d. If the wiring is good, then the

Main Transformer may be faulty. Replace.

TERMINAL STRIP

(LEAD #207)

PIN 3

PIN 2

J5

(LEAD #208)

(LEAD #205)

PIN 9

PIN 8

PIN 7

IDEALARC DC-600

From

Plug Pin Lead J5 2 #203 J5 4 #204

J5 7 #205 J5 3 #206

J5 9 #207 J5 8 #208

Plug Pin Lead

To

Expected VAC

75 VAC

FIGURE F.6 - Phase Angle Windings Test Points and Firing Board

Location.

TROUBLESHOOTING & REPAIR

FIRING BOARD TEST

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

F-21

TEST DESCRIPTION

This test determines whether or not the Firing Board is receiving the correct voltages and gate signals. The LEDs (Light Emitting Diodes) will help you determine if the Firing Board is generating gate signals to the main SCRs.

MATERIALS NEEDED

Volt/Ohm Meter (Multimeter) IDEALARC DC-600 wiring diagram and Firing Board schematic drawing (See Electrical Drawing Section of Manual).

IDEALARC DC-600

F-22

TROUBLESHOOTING & REPAIR

FIRING BOARD TEST

TEST PROCEDURE FOR NORMAL FIRING BOARD OPERATION

1. Disconnect main AC input power to the IDEALARC DC-600.

2. Locate the Firing Board on the left side of Control Box facing the machine.

3. Perform a visual inspection of the Firing Board to see if there are any loose or faulty connections.

4. Connect the correct main AC input power to the machine.

5. Set the ON/OFF PUSHBUTTON to ON.

6. Locate LEDs 7, 8, and 9 on the Firing Board. See Figure F.7. Each LED should be ON and be equally bright. Use Table F.1 to check the operation of each LED.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

FIRING BOARD TEST

F-23

FIGURE F.7 - Firing Board LED and Molex Plug Locations

IDEALARC DC-600

F-24

TROUBLESHOOTING & REPAIR

FIRING BOARD TEST

TABLE F.1 - LED 7, 8 and 9 Check List

IF

LED 7 is ON

LED 7 is OFF or is DIMMER than other LEDs

LED 8 is ON AC power is being supplied to the Firing Board from

LED 8 is OFF or is DIMMER than other LEDs

LED 9 is ON AC power is being supplied to the Firing Board from

LED 9 is OFF or is DIMMER than other LEDs

AC power is being supplied to the Firing Board from leads #203 and #204 connected to the phase angle winding in the Main Transformer.

The proper AC voltage may not be reaching Firing Board. Check for loose or faulty connections.

Perform Main Transformer Test.

leads #205 and #206 connected to the phase angle winding in the Main Transformer.

The proper AC voltage may not be reaching Firing Board. Check for loose or faulty connections.

Perform Main Transformer Test.

leads #207 and #208 connected to the phase angle winding in the Main Transformer.

The proper AC voltage may not be reaching Firing Board. Check for loose or faulty connections.

Perform Main Transformer Test.

THEN

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

FIRING BOARD TEST

F-25

7. Locate the terminal strip directly below the Control Box.

8. Connect a jumper wire from terminal #2 to terminal #4 on the terminal strip. See Figure F.8.

NOTE: This jumper connection initiates machine output.

FIGURE F.8 - Jumper Wire Connection Points

IDEALARC DC-600

F-26

TROUBLESHOOTING & REPAIR

FIRING BOARD TEST

9. Locate LEDs 1 to 6. Each LED should glow with equal brightness. NOTE: LEDs 1 to 6 indicate that the gate firing signals are being generated to send to each of the SCRs.

10. Set the OUTPUT CONTROL SWITCH (SW3) in the "Output Control at DC-600" position.

11. Set the WELDING CONTROL SWITCH in either of the "CV" positions.

12. Rotate the OUTPUT CONTROL POTENTIOMETER. As the pot is turned clockwise, the LEDs glow brighter. As the pot is turned counter-clockwise, the LEDs dim.

a. If the LEDs glow and change in

brightness equally as the pot is turned and the problem continues, then the SCR Bridge may be faulty. Perform SCR Bridge test.

b. If any or all of LEDs 1-6 do not

glow or do not change in brightness equally as the pot is turned, go to Step 13.

13. Test for 10 VDC to 13 VDC between leads #231 and #215 on the Firing Board in CV mode.

a. Locate on the Firing Board the

Molex Plug with leads #231 and #215 connected to it. See Figure F.7.

b. Set the ON/OFF PUSH

BUTTON to OFF.

c. Remove the Molex Plug from

the board.

d. Insert the meter probes into the

appropriate Plug lead cavities.

NOTE: OBSERVE POLARITY. DC VOLTAGES BEING TESTED.

e. Connect the Molex Plug into

the Firing Board.

f. Set the WELDING MODE

SWITCH in either of the "CV" positions.

g. Set the ON/OFF PUSHBUT-

TON to ON.

h. Rotate the OUTPUT CON-

TROL POTENTIOMETER clockwise and counter-clockwise. The DC voltage between leads #231 and #215 should vary from 10 VDC to 13 VDC as the pot is turned from minimum to maximum.

IDEALARC DC-600

i. If the voltage does NOT vary,

then the Control Board may be faulty. Replace.

TROUBLESHOOTING & REPAIR

FIRING BOARD TEST

F-27

14. Test for approximately 5.8 VDC between leads #231 and # 215 on the Firing Board in VV (CC) mode.

a. Keep the meter probes insert-

ed into the Plug lead cavities for leads #231 and #215.

b. Keep the jumper connected at

terminals #2 and #4 at the terminal strip.

c. Set the WELDING MODE

SWITCH (SW4) to the VV (CC) position.

d. Rotate the OUTPUT CON-

TROL POTENTIOMETER clockwise and counter-clockwise. The DC voltage between leads #231 and #215 should be constant at approximately 5.8 VDC. This voltage should not vary when the pot is turned.

15. Test Output Pilot Control Relay (CR4) for proper operation by removing and replacing repeatedly the jumper wire from terminal # 2. This should cause the relay contacts to open and close. The contacts can be seen closing and opening through the clear plastic relay case or can be heard opening and closing.

a. If the Output Control Relay

(CR4) does not close when energized, check for loose or faulty wiring.

16. Remove the jumper from terminals #2 and #4 on the terminal strip.

17. Replace the Firing Board if the above voltage and control relay tests were passed. It may be faulty.

e. Remove probes inserted into

the Molex Plug lead cavities of lead #231 and #215.

IDEALARC DC-600

F-28

TROUBLESHOOTING & REPAIR

CONTROL BOARD TEST

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

TEST DESCRIPTION

This test will determine if the Control Board is receiving the correct voltages and feedback signals.

MATERIALS NEEDED

Analog Volt/Ohm Meter (Multimeter) IDEALARC DC-600 wiring diagrams (See Electrical Diagrams Section of this Manual).

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

CONTROL BOARD TEST

See Table F .2 for LED function during normal operation. See Figure F.9 for LED location on Control Board.

F-29

LED #

1

2

4

5

FIGURE F.9 - Control Board LED Locations

FUNCTION DURING NORMAL OPERATION

(Machine is ON)

Glows to display that 115 VAC is present between leads #255 and #256 at Plug J2 on Control Board.

Glows to display that output voltage feedback is being supplied to the Control Board. Terminals #2 and #4 on the terminal strip must be jumped together.

Glows to display that power is applied to fault protection relay (CR2).3

DOES NOT GLOW. Glows only if there is a fault condition.

Glows to display a control signal (lead # 231) is being supplied to the Firing Circuit. When the OUTPUT CONTROL SWITCH (SW-3) is in the "Output Control at DC-600" position and the WELDING MODE SWITCH (SW-4) is in the "CV" position, the LED will glow brighter or dimmer as the OUTPUT CONTROL POTENTIOMETER is rotated. If the pot is rotated clockwise (open circuit voltage increased), the LED will glow dimmer. If the pot is rotated counter-clockwise (open circuit voltage decreased), the LED will glow brighter. When the WELDING MODE SWITCH (SW-4) is in the VV(CC) position for stick welding, the open circuit voltage is at maximum. LED 5 will be very dim or not lit.

TABLE F.2 - LED Function Description

IDEALARC DC-600

F-30

TROUBLESHOOTING & REPAIR

CONTROL BOARD TEST

TEST PROCEDURES

If LED 1 Does Not Glow When ON/OFF PUSH BUTTON is Set to ON

1. Test for 115 VAC between leads #255 and #256 at Plug J2 on the Control Board.

a. Disconnect main AC input sup-

ply power to the machine.

b. Locate the Control Board in the

Control Box. c Disconnect Molex Plug J2. d. Insert the probes into the Plug

lead cavities for leads

# 255 and # 256. e. Replace the Molex Plug J2. f. Connect main AC input power

to the machine. g. Set the ON/OFF PUSH BUT-

TON to ON. h. Read meter for 115 VAC.

If 1 15 VAC is present AND LED 1 does not glow, the Control Board may be faulty. Replace.

If 115 VAC is not present,

• Inspect leads #255 and #256 and associated wiring for loose or faulty connections. See wiring diagram.

• Test for continuity (zero ohms) between lead # 256 at Plug J2 on the Control Board and the ON/OFF PUSH BUTTON. See Figure F.10.

NOTE: Disconnect main AC input power to the machine

• Test for continuity (zero ohms) between lead #256 at Plug J2 on the Control Board and lead X2 at the secondary thermostat. See Figure F.10.

NOTE: Disconnect main AC input power to the machine.

IDEALARC DC-600

CONTROL BOARD

FIGURE F.10 - LED 1 Test Points

TROUBLESHOOTING & REPAIR

CONTROL BOARD TEST

If LED 2 Does Not Light When Machine is Operating Under Load (or terminals #2 and #4 are jumpered together on the terminal strip).

1. Test for the following open circuit voltages at the Weld Output Terminals

F-31

b. If the open circuit voltage is not

present at the Weld Output Terminals, then

• Check the Output Choke and associated heavy current carrying leads for loose or faulty connections.

• 15 - 58 VDC when the WELDING MODE SWITCH is in either of the CV positions

• 75 VDC when the WELDING MODE SWITCH is in the VV(CC) position.

NOTE: BE SURE TO OBSERVE POLARITY. DC VOLTAGES BEING TESTED.

2. Touch the negative (-) meter probe to the negative (-) Weld Output Terminal and positive (+) meter probe to the positive (+) Weld Output Terminal.

3. Read meter. a. If the open circuit voltage is

present at the Weld Output Terminals, then test for open circuit voltage the Control Board.

• Perform the Main Transformer Test

• Perform the Firing Board Test

• Perform the SCR Output Bridge Test

4. Test for open circuit voltage at the Control Board

a. Insert meter probes in to Plug

lead cavities to test for open circuit voltage from lead #222 at Plug J1 on the Control Board to lead #215 at Plug J3 on Control Board. See Figure F.11.

FIGURE F.11 - LED 2 Open Circuit Voltage Test Points

IDEALARC DC-600

F-32

TROUBLESHOOTING & REPAIR

CONTROL BOARD TEST

b. If the open circuit voltage is not

present at the Control Board, then check leads #222 and #215 for loose or faulty wiring connections. See wiring diagram.

5. Test for continuity (zero ohms) between the negative output terminal and lead #222 at Plug J1 on the Control Board.

a. If more than zero ohms is mea-

sured, the lead may be faulty.

6. Test for continuity (zero ohms) between the positive output terminal and lead #215 at Plug J3 on the Control Board.

a. If more than zero ohms is mea-

sured, the lead may be faulty.

NOTE: If previous tests do not reveal the problem then the Control Board may be faulty. Replace.

a. If LED 4 glows or flickers,

• Check the Weld Output Terminals and associated wiring for a "short" condition. See wiring diagram.

• Check the Remote Control Circuit (leads #75, #76, #77). They may be shorted to the negative welding voltage. See wiring diagram.

b. If the above procedures do not

uncover the problem, the Control Board may be faulty. Replace.

If LED 5 Does Not Glow and Vary in Brightness Under the Following Conditions

Machine is operating under load (or terminals #2 and #4 are jumpered together on the terminal strip).

If LED 3 Does Not Glow But LED 1 Does Glow When ON PUSH BUTTON Is Pushed

NOTE: When this condition occurs, the Fault Protection Relay (CR2) is not receiving the 24 VDC supply voltage. Therefore, the Input Contactor (CR1) cannot close. Perform the following:

1. Set and hold in the ON position the ON/OFF PUSH BUTTON.

The OUTPUT CONTROL POTENTIOMETER is rotated.

The WELD MODE SWITCH is in either CV position.

The OUTPUT CONTROL SWITCH is in the "Output Control at DC-600" position.

1. Check the OUTPUT CONTROL POTENTIOMETER and associated wiring for loose or faulty connections.

a. If all the above conditions are

met, the Control Board may be faulty. Replace.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-33

STATIC SCR TEST

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

TEST DESCRIPTION

The Static SCR Test is used to quickly determine if an SCR is shorted or "leaky." See the Waveform Section in this manual for normal and abnormal SCR waveforms.

MATERIALS NEEDED

Analog Ohmmeter (Multimeter) IDEALARC DC-600 wiring diagrams (See Electrical Diagrams Section of this Manual).

IDEALARC DC-600

F-34

TROUBLESHOOTING & REPAIR

STATIC SCR TEST

TEST PROCEDURE

1. Disconnect main AC input power to the machine.

2. Disconnect all Molex Plugs from the Firing Board and Control Board. See Figure F.12.

IDEALARC DC-600

FIGURE F.12 - Firing Board and Control Board Molex Plug Locations.

TROUBLESHOOTING & REPAIR

STATIC SCR TEST

F-35

FIGURE F.13 - Heat Sink Test Points.

3. Remove the red insulating paint from the heat sink test points. See FIGURE F.13. NOTE: DO NOT DISASSEMBLE THE HEAT SINKS.

4. Test for high or infinite resistance from the anode to the cathode of SCR 1. See Figure F.14. Use an analog ohmmeter (Multimeter).

IDEALARC DC-600

F-36

TROUBLESHOOTING & REPAIR

STATIC SCR TEST

5. Test for high or infinite resistance from the cathode to the anode of SCR 1 by reversing the leads. See Figure F.14.

a. If a high or infinite resistance is

indicated for both tests 4 and 5, the SCR 1 is not shorted.

b. If a low resistance is indicated

in either strips 4 or 5, go to Step 6.

6. Disconnect the snubber circuit. See wiring diagram.

7. Retest SCR 1 with the snubber circuit disconnected.

a. If a low resistance is still indi-

cated, SCR 1 is faulty. Replace. If one SCR is shorted they may all appear shorted. The SCRs will have to be tested separately by disconnecting the secondary leads from the bridge assembly.

b. If a very high or infinite resis-

tance is indicated with the snubber circuit disconnected, replace the snubber circuit.

8. Repeat Steps 3 to 7 for SCRs 2 - 6.

9. Replace all Molex Plugs on the Firing Board and Control Board.

NOTE: To further check the SCR’s

Function, use an SCR tester and proceed to active SCR Test.

FIGURE F.14 - SCR 1 Test Points.

8/98

TROUBLESHOOTING & REPAIR

F-37

ACTIVE SCR TEST

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

TEST DESCRIPTION

The Active SCR Test will determine if the device is able to be gated ON and conduct current from anode to cathode.

MATERIALS NEEDED

An SCR Tester as specified in this procedure. IDEALARC DC-600 wiring diagrams (See Electrical Diagrams Section of this Manual).

IDEALARC DC-600

F-38

TROUBLESHOOTING & REPAIR

ACTIVE SCR TEST

TEST PROCEDURE

1. Disconnect main AC input power to the machine.

2. Disconnect all Molex Plugs from the Firing Board and Control Board. See Figure F.15.

IDEALARC DC-600

FIGURE F.15 - Firing Board and Control Board Molex Plug Locations.

TROUBLESHOOTING & REPAIR

ACTIVE SCR TEST

FIGURE F.16 - Heat Sink Test Points.

F-39

3. Remove the red insulating paint from the heat sink test points. See FIGURE F.16.

NOTE: DO NOT DISASSEMBLE THE HEAT SINKS.

FIGURE F.17 - SCR Tester Circuit and SCR connections.

4. Construct the circuit shown in Figure F.17. One 6-volt lantern battery can be used. Set voltmeter scale low, at approximately 0-5 volts or 0-10 volts.

a. Test the voltage level of the

battery. Short leads (A) and (C). Close switch SW-1. Battery voltage should be 4.5 volts or higher. If lower, replace the battery.

IDEALARC DC-600

F-40

TROUBLESHOOTING & REPAIR

ACTIVE SCR TEST

5. Connect the Tester to the SCR 1 as shown in Figure F.17.

a. Connect Tester lead (A) to the

anode.

b. Connect Tester lead (C) to the

cathode.

c. Connect Tester lead (G) to the

gate.

6. Close switch SW-1. NOTE: Switch SW-2 should be open.

7. Read meter for zero voltage. a. If the voltage reading is higher

than zero, the SCR is shorted.

8. Close or keep closed switch SW-1

9. Close switch SW-2 for 2 seconds and release and read meter.

10. Open switch SW-1.

11. Reconnect the Tester leads. See Figure F.17.

a. Connect Tester lead (A) to the

cathode.

b. Connect Tester lead (C) to the

anode.

c. Disconnect Test lead (G) from

the gate.

12. Close switch SW-1.

13. Read meter for zero voltage. a. If the voltage is zero, the SCR

is functioning.

b. If the voltage is higher than

zero, the SCR is shorted.

14. Perform the Active Test Procedure outlined in Steps 5-13 for SCRs 2-6.

a. If the voltage is 3 - 6 volts while

the switch is closed and after the switch is open, the SCR is functioning.

b. If the voltages is 3-6 volts only

when the switch is closed or there is no voltage when the switch is closed, the SCR is defective.

NOTE: Be sure battery is functioning properly. A low battery can affect the results of the test. Repeat Battery Test Procedure in Step 4 if needed.

15. Replace all SCR assemblies that do not pass the above tests.

16. Replace all Molex Plugs onto the Firing Board and Control Board.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM

CONSTANT CURRENT MODE - NO LOAD

CH1

F-41

50 volts 2ms

This is the typical DC open circuit voltage waveform generated from a properly operating machine. Note that each vertical division represents 50 volts and that each horizontal division represents 2 milliseconds in time.

Note: Scope probes connected at machine ouput terminals: (+) probe to positive terminal, (-) probe to negative terminal.

0 volts

SCOPE SETTINGS

Volts/Div . . . . . . . . . . . . . .50 V/Div.

Horizontal Sweep . . . . . . .2 ms/Div.

Coupling . . . . . . . . . . . . . . . . . . .DC

Trigger . . . . . . . . . . . . . . . . .Internal

IDEALARC DC-600

F-42

TROUBLESHOOTING & REPAIR

NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM

CONSTANT VOLTAGE INNERSHIELD

MAXIMUM OUTPUT SETTING - NO LOAD

CH1

50 volts 2ms

This is the typical DC open circuit voltage waveform generated from a properly operating machine. Note that each vertical division represents 50 volts and that each horizontal division represents 2 milliseconds in time.

Note: Scope probes connected at machine ouput terminals: (+) probe to positive terminal, (-) probe to negative terminal.

0 volts

SCOPE SETTINGS

Volts/Div . . . . . . . . . . . . . .50 V/Div.

Horizontal Sweep . . . . . . .2 ms/Div.

Coupling . . . . . . . . . . . . . . . . . . .DC

Trigger . . . . . . . . . . . . . . . . .Internal

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

NORMAL OPEN CIRCUIT VOLTAGE WAVEFORM

CONSTANT VOLTAGE INNERSHIELD

MINIMUM OUTPUT SETTING - NO LOAD

LINE

F-43

20 volts 2ms

This is the typical DC open circuit voltage waveform generated from a properly operating machine. Note that each vertical division represents 20 volts and that each horizontal division represents 2 milliseconds in time.

Note: Scope probes connected at machine ouput terminals: (+) probe to positive terminal, (-) probe to negative terminal.

0 volts

SCOPE SETTINGS

Volts/Div . . . . . . . . . . . . . .20 V/Div.

Horizontal Sweep . . . . . . .2 ms/Div.

Coupling . . . . . . . . . . . . . . . . . . .DC

Trigger . . . . . . . . . . . . . . . . .Internal

IDEALARC DC-600

F-44

TROUBLESHOOTING & REPAIR

TYPICAL OUTPUT VOLTAGE WAVEFORM - MACHINE LOADED

CONSTANT VOLTAGE INNERSHIELD MODE

CH 1

20 volts 2ms

This is the typical DC open circuit voltage waveform generated from a properly operating machine. Note that each vertical division represents 20 volts and that each horizontal division represents 2 milliseconds in time. The machine was loaded with a resistance grid bank. The grid bank meters read 200 amps at 28VDC.

0 volts

SCOPE SETTINGS

Volts/Div . . . . . . . . . . . . . .20 V/Div.

Horizontal Sweep . . . . . . .2 ms/Div.

Coupling . . . . . . . . . . . . . . . . . . .DC

Trigger . . . . . . . . . . . . . . . . .Internal

Note: Scope probes connected at machine ouput terminals: (+) probe to positive terminal, (-) probe to negative terminal.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

TYPICAL SCR GATE VOLTAGE WAVEFORM

CONSTANT VOLTAGE INNERSHIELD

MAXIMUM OUTPUT SETTING - NO LOAD

CH1

F-45

2 volts 5ms

This is the typical SCR gate pulse voltage waveform. The machine was in an open circuit condition (no load) and operating properly. Note that each vertical division represents 2 volts and that each horizontal division represents 5 milliseconds in time.

Note: Scope probes connected at SCR gate and cathode: (+) probe to gate, (-) probe to cathode.

0 volts

SCOPE SETTINGS

Volts/Div . . . . . . . . . . . . . . .2 V/Div.

Horizontal Sweep . . . . . . .5 ms/Div.

Coupling . . . . . . . . . . . . . . . . . . .DC

Trigger . . . . . . . . . . . . . . . . .Internal

IDEALARC DC-600

F-46

TROUBLESHOOTING & REPAIR

ABNORMAL OPEN CIRCUIT VOLTAGE WAVEFORM

CONSTANT VOLTAGE INNERSHIELD

ONE OUTPUT SCR NOT FUNCTIONING

CH 1

20 volts 2ms

This is NOT the typical DC output voltage waveform. One output SCR is not functioning. Note the “gap” in the waveform. One SCR gate is disconnected to simulate an open or non-functioning output SCR. Each vertical division represents 20 volts and each horizontal division represents 2 milliseconds in time.

Note: Scope probes connected at machine ouput terminals: (+) probe to positive terminal, (-) probe to negative terminal.

0 volts

SCOPE SETTINGS

Volts/Div . . . . . . . . . . . . . .20 V/Div.

Horizontal Sweep . . . . . . .2 ms/Div.

Coupling . . . . . . . . . . . . . . . . . . .DC

Trigger . . . . . . . . . . . . . . . . .Internal

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-47

INPUT CONTACTOR (CR1) CLEANING/REPLACEMENT

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

MATERIALS NEEDED

Phillips head screwdriver 5/16" socket wrench Flat head screw driver Low pressure air source

IDEALARC DC-600

F-48

TROUBLESHOOTING & REPAIR

INPUT CONTACTOR (CR1) CLEANING/REPLACEMENT

CLEANING PROCEDURE

1. Disconnect main AC input power supply to the machine.

2. Locate and get access to the Input Contactor (CR1) in the Input Box. See Figure F.18.

3. Remove the Input Contractor cover plate using a Phillips head screwdriver.

DO NOT APPLY INPUT POWER TO THE MACHINE WITH THE INPUT CONTACTOR COVER PLATE REMOVED.

4. Blow out any dirt or dust in or around the contacts with a low pressure air stream.

CONTACTOR REPLACEMENT PROCEDURE

1. Disconnect main AC input power supply to the machine.

2. Locate and get access to the Input Contactor (CR1) in the Input Box. See Figure F.18.

3. Disconnect the main AC input power supply leads L1, L2, and L3 to the Input Contactor.

4. Disconnect the output leads T1, T2, and T3 from the Input Contactor.

5. Identify and label the leads connected to the Input Contactor coil and interlock. See wiring diagram.

6. Disconnect the leads from the Input Contactor coil (leads #271 & #272). See wiring diagram.

5. Inspect the contacts for signs of excessive wear, pitting, or contacts fused (stuck) to together.

a. If any of these conditions are

present, replace the Input Contactor Assembly .

6. Replace the Input Contactor cover plate.

CONTROL

TRANSFORMER

INPUT

CONTACTOR (CR1)

X1

7. Disconnect the leads from the Input Contactor interlock (leads #211 & #212). See wiring diagram.

8. Remove the three self-tapping mounting screws using a 5/16" socket wrench. See Figure F.18.

9. Remove the Input Contactor.

10. Insert the replacement Input Contactor and install it following the procedures in reverse order.

NOTE: Be sure to reconnect all leads correctly.

IDEALARC DC-600

CASE BACK

FIGURE F.18 - Input Contactor

Cleaning and Removal

TROUBLESHOOTING & REPAIR

F-49

SCR / SCR OUTPUT BRIDGE REMOVAL

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

MATERIALS NEEDED

9/16" socket wrench 1/2" socket wrench 1/2" open end wrench

IDEALARC DC-600

F-50

TROUBLESHOOTING & REPAIR

SCR / SCR OUTPUT BRIDGE REMOVAL

A. REMOVAL OF INDIVIDUAL SCR HEAT SINK

FIGURE F.19 - Individual Heat Sink Removal

NOTE: If it is necessary to remove and replace only one or two individual SCRs and they are easy to work on, use these procedures.

1. Disconnect main AC input power supply to the machine.

2. Identify and label the following : a. The transformer secondary

lead (heavy aluminum conductor) connected to the anode of the SCR heat sink for each assembly to be removed. See Figure F.19.

b. The snubber leads for each

SCR heat sink to be removed. See Figure F.19.

3. Disconnect the transformer secondary lead to the anode of the heat sink assembly using 1/2" socket wrench and 1/2" open end wrench.

4. Disconnect the gate lead to the SCR.

a. If the gate lead is cut, it will

have to be re-soldered when the replacement SCR is installed.

b. If a new snubber board is used,

install properly.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-51

5. Remove the four thru bolts and associated nuts and washers hold. ing the SCR heat sink to the bridge tie bars.

a. The main mounting bolts that

mount the SCR bridge assembly to the frame rail may have to be loosened to slide the SCR Heat Sink out from under the buss jumper strap.

b. When all four thru-bolts are

removed, the SCR Heat Sink directly above or below will be detached also. Support the SCR Heat Sink above or below. To hold the Heat Sink in place temporarily, insert one of the thru-bolts and replace the nut hand tight.

6. Install the replacement SCR Heat Sink in reverse order of removal.

a. Apply a thin layer of Lincoln

E1868 (Dow Corning 340) heat sink compound to all bolted electrical connections on the aluminum heat sinks.

IDEALARC DC-600

F-52

TROUBLESHOOTING & REPAIR

SCR / SCR OUTPUT BRIDGE REMOVAL

B. REMOVAL OF COMPLETE BRIDGE ASSEMBLY

FIGURE F.20 - SCR Output Bridge Removal

NOTE: If it is necessary to remove and replace the entire SCR Output Bridge Assembly, use these procedures.

1. Disconnect the Gate Lead Molex Plug J4 from the Firing Board (later models).

a. If working on an earlier model

and there is no Gate Lead Molex Board, identify and label the six Gate leads and cut or unsolder the leads from their respective snubber boards.

2. Remove the four self-tapping bolts that mount the SCR Bridge Assembly to the horizontal rails using a 9/16" socket wrench. See Figure F.20.

a. Note placement of insulting

washers, tubes, and pads so they can be replaced correctly.

3. Identify and label the six transformer secondary (heavy aluminum) leads that connect to the anodes of the SCR Head Sink Assemblies. See Figure F.20.

4. Remove the transformer secondary leads using a 1/2" socket wrench.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

SCR / SCR OUTPUT BRIDGE REMOVAL

F-53

5. Remove the bolt that connects the Shunt Assembly (heavy copper) lead to the SCR Bridge Assembly. The Shunt Assembly connects the positive Weld Output Terminal to the SCR Bridge Assembly.

6. Remove the small snubber lead from the left hand (facing the front of the machine) rear heat sink mounting bolt using a 1/2" socket wrench.

7. Clear all leads from any obstructions.

8. Lift the SCR Bridge Assembly straight up and out of the machine being sure that no leads become tangled or hooked on the other machine parts.

a. Be sure to locate the SCR

Bridge Assembly on a stable work surface capable of holding the weight of the assembly.

9. Remove individual SCR Heat Sinks following the procedure described in A above.

10. Replace all insulating materials, including the insulators on the frame rail and all insulating tubes, when installing the SCR Output Bridge Assembly .

11. The Output Bridge assembly should be electrically isolated from ground. Check with an analog ohm meter. Minimum resistance is 500,000 ohms to ground.

IDEALARC DC-600

F-54

TROUBLESHOOTING & REPAIR

LIFT BAIL REMOVAL (INCLUDING MAIN TRANSFORMER,

CHOKE, AND OUTPUT BRIDGE ASSEMBLY)

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

LIFT BAIL REMOVAL (INCLUDING MAIN TRANSFORMER,

CHOKE, AND OUTPUT BRIDGE ASSEMBLY)

REMOVAL PROCEDURE

F-55

FIGURE F.21 - Lift Bail Removal

1. Disconnect gate leads. a. On later models, remove gate

lead Molex Plug J5 from the Firing Board.

b. On earlier models, identify and

label the six gate leads and cut or unsolder the leads from their respective Snubber Board.

2. Disconnect the Shunt lead from the SCR Bridge Assembly. See Figure F.21.

3. Disconnect the leads from the secondary thermostat. See wiring diagram.

4. Disconnect auxuliary winding leads.

a. On later models, remove Molex

Plug J5 from the Firing Board.

b. On earlier models, disconnect

the following leads from the terminal strip in the Control Box: 31, 32A, 203, 204, 205, 206, 207, and 208.

IDEALARC DC-600

F-56

TROUBLESHOOTING & REPAIR

LIFT BAIL REMOVAL (INCLUDING MAIN TRANSFORMER,

CHOKE, AND OUTPUT BRIDGE ASSEMBLY)

5. Disconnect leads #215 and #216 from Relay CR4 and lead #231 from the splice connector.

6. Disconnect leads #211 and #212 from the ON/OFF PUSH BUTTON.

7. Disconnect lead #256 from the PILOT LIGHT.

8. Disconnect lead #271 from relay CR2 located in the Control Box.

9. Remove resistor R2 from the horizontal rail. See Figure F.21.

10. Cut and remove all cable ties and unbundle all wires.

11. Label and cut fan motor leads.

12. Separate leads #271, #211, and X2 from the harness.

13. Disconnect lead #272 from Input Contactor (CR1) coil.

14. Disconnect the heavy copper lead from the negative Weld Output Terminal.

15. Identify, label, and disconnect the Main Transformer leads from the Reconnect Panel and the three leads that go to the Input Contactor.

16. Remove the four mounting nuts that hold the Lift Bail Assembly to the Base.

17. Lift the Bail Assembly carefully straight up and out of the machine using a hoist. Be sure all leads are free to move with the assembly.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

F-57

TRANSFORMER REMOVAL FROM LIFT BAIL ASSEMBLY

WARNING

Service and repair should be performed only by Lincoln Electric factory trained personnel. Unauthorized repairs performed on this equipment could result in danger to the technician or the machine operator and will invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety notes and precautions detailed throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln Electric service department for technical troubleshooting assistance before you proceed. Call (216) 383-2531 or (800) 833-9353 (WELD).

______________________________

MATERIALS NEEDED

9/16" socket wrench 9/16" open end wrench 1/2" socket wrench 1/2" open end wrench 3/8" socket wrench

IDEALARC DC-600

F-58

TROUBLESHOOTING & REPAIR

TRANSFORMER REMOVAL FROM LIFT BAIL ASSEMBLY

TRANSFORMER REMOVAL PROCEDURE

FIGURE F.22 Transformer Bail Assembly Removal

1. Remove the four screws that connect the top and side baffles around the Output Choke using a 3/8" socket wrench.

2. Remove the two bolts and nuts connecting the Output Choke leads to the copper strap and the main secondary common buss lead using a 9/16" socket wrench and a 9/16" open end wrench.

a. Identify and label the small

snubber leads.

3. Remove the four nuts mounting the Output Choke to the transformer through bolts using a 9/16" socket wrench.

4. Lift the Output Choke straight up until the through bolts are cleared and then move it out toward the rear of the transformer.

5. Remove the six transformer secondary leads from the SCR Output Bridge Assembly using a 1/2" socket wrench and a 1/2" open end wrench.

a. Identify and label all leads,

including the small snubber leads.

b. Clear the secondary leads so

they are free to move when the transformer is removed.

IDEALARC DC-600

TROUBLESHOOTING & REPAIR

TRANSFORMER REMOVAL FROM LIFT BAIL ASSEMBLY

F-59

6. Remove the four self-tapping bolts that hold the Lift Bail to the transformer base using a 9/16" socket wrench. See Figure F.22.

NOTE: There is one bolt on each side of the transformer that must be removed by inserting the wrench through the hole in Lift Bail.

7. Remove the Lift Bail and Output Bridge Assembly from the transformer by lifting the Lift Bail up slightly and sliding the Lift Bail towards the SCR Bridge.

TRANSFORMER DISASSEMBLY

1. Identify and label all leads to the transformer.

2. Cut or unsolder all leads. a. Cut the secondary leads.

These must be re-TIG welded to the new transformer coils.

3. Remove the four nuts from the through bolts that hold the transformer together.

4. Attach a hoist to the top of the E Iron and lift from assembly.

IDEALARC DC-600

lincoln dc600 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

SAFETY

Major Physical or Electrical Damage is Evident

The Machine is dead- The Input contactor does not operate.

Input contactor (CR1) chatters.

Input contactor pulls in when start button is pressed but immediately drops out when start button is released.

Machine input contactor operates but machine has no weld output.Fan runs and pilot light glows.

Machine has minimum output and no control.

The DC600 will NOT shut off when the Stop button is pushed.

The weld output terminals are always electrically "hot".

Poor arc starting when the DC600 is in the CV Sub-Arc or CV Innershield Modes.

Poor arc characteristics in all processes.