Thermal Comfort 3000 User Manual
MERLIN 3000
Plasma Cutting Power Supply
October 6, 1999
A-00907
Service Manual
Manual No. 0-2533
WARNING
Read and understand this entire Service Manual and your
employer’s safety practices before installing, operating, or
servicing the equipment.
WARNING
While the information contained in this Service Manual represents our best judgement, Thermal Dynamics Corporation
assumes no liability for its use.
MERLIN 3000 Plasma Cutting Power Supply
Service Manual Number 0-2533
Published by:
Thermal Dynamics Corporation
Industrial Park No. 2
West Lebanon, New Hampshire, USA 03784
(603) 298-5711
Copyright 1996 by
Thermal Dynamics Corporation
All rights reserved.
Reproduction of this work, in whole or in part, without written
permission of the publisher is prohibited.
The publisher does not assume and hereby disclaims any liability
to any party for any loss or damage caused by any error or
omission in the MERLIN 3000 Plasma Cutting Power Supply
Service Manual, whether such error results from negligence,
accident, or any other cause.
Printed in the United States of America
October 6, 1999
TABLE OF CONTENTS
SECTION 1:
GENERAL INFORMATION .................................................................................................. 1
1.01 Notes, Cautions and Warnings ...................................................................... 1
1.02 Important Safety Precautions ........................................................................ 1
1.03 Publications ................................................................................................... 2
1.04 Note, Attention et A v ertissement ................................................................... 3
1.05 Precautions De Securite Importantes ............................................................ 3
1.06 Documents De Reference ............................................................................. 5
1.07 Declaration of Conformity .............................................................................. 7
1.08 Statement of W arr anty................................................................................... 8
SECTION 2:
INTRODUCTION ................................................................................................................. 9
2.01 Scope Of Manual........................................................................................... 9
2.02 General Service Philosophy .......................................................................... 9
2.03 Service Responsibilities................................................................................. 9
SECTION 3:
INTRODUCTION & DESCRIPTION................................................................................... 11
3.01 Scope of Manual.......................................................................................... 11
3.02 General Description..................................................................................... 11
3.03 Specifications & Design Features ................................................................ 11
3.04 Theory Of Operation.................................................................................... 12
3.05 Options And Accessories ............................................................................ 13
SECTION 4:
SERVICE TR OUBLESHOOTING DIAGNOSTICS ............................................................. 15
4.01 Introduction.................................................................................................. 15
4.02 Periodic Inspection & Procedures................................................................ 15
4.03 System Theory ............................................................................................ 16
4.04 Troub leshooting Guide................................................................................. 18
4.05 T est Procedures............................................................................................ 23
SECTION 5:
REPAIRS & REPLACEMENT PROCEDURES................................................................... 33
5.01 Introduction.................................................................................................. 33
5.02 Anti-Static Handling Procedures .................................................................. 33
5.03 Parts Replacement - General Information.................................................... 33
5.04 External Parts Replacement ........................................................................ 34
5.05 Access Panel P arts Replacement................................................................ 35
5.06 Front P anel/Chassis Parts Replacement ..................................................... 35
5.07 Rear Panel P arts Replacement ................................................................... 36
5.08 Base Assembly P arts Replacement............................................................. 39
5.09 Upper Chassis Parts Replacement.............................................................. 40
5.10 Main Heatsink Assembly Parts Replacement .............................................. 45
5.11 Hose Assembly Replacements.................................................................... 47
TABLE OF CONTENTS (continued)
SECTION 6:
PARTS LISTS.....................................................................................................................51
6.01 Introduction.................................................................................................. 51
6.02 Ordering Information.................................................................................... 51
6.03 External Power Supply Replacement Parts List ........................................... 52
6.04 Access Panel Replacement P arts................................................................ 53
6.05 Front P anel/Chassis Replacement Parts ..................................................... 54
6.06 Rear Panel Replacement P arts ................................................................... 56
6.07 Base Assembly Replacement P arts............................................................. 58
6.08 Upper Chassis Replacement Parts.............................................................. 60
6.09 Main Heatsink Assembly Replacement Parts .............................................. 62
6.10 Pow er Supply Options And Accessories...................................................... 64
APPENDIX I: INPUT WIRING REQ UIREMENTS ...................................................................... 67
APPENDIX II: SEQUENCE OF OPERATION BLOCK DIAGRAM.............................................. 68
APPENDIX III: TYPICAL MECHANIZED SYSTEM CABLE CONNECTIONS ............................ 69
APPENDIX IV: INTERFACE CABLES FOR REMOTE CONTROL (RC6010) AND
STANDOFF CONTROL (SC11) ......................................................................................... 70
APPENDIX V: CNC INTERFACE ............................................................................................... 71
APPENDIX VI: 120 VAC CIRCUIT DIA GRAM............................................................................ 72
APPENDIX VII: LADDER DIAGRAM - 15 V DC .......................................................................... 73
APPENDIX VIII: SIGNAL FLOW BLOCK DIAGRAM.................................................................. 74
APPENDIX IX: START CIRCUIT DIARGRAM............................................................................ 75
APPENDIX X: CURRENT CONTR OL / DISPLAY CIRCUIT DIAGRAM ..................................... 76
APPENDIX XI: CSD (CORNER SLO WDOWN) CIRCUIT DIAGRAM......................................... 77
APPENDIX XII: OK-TO-MOVE CIRCUIT DIAGRAM.................................................................. 78
APPENDIX XIII: HOSE BLOCK DIA GRAM................................................................................ 79
APPENDIX XIV: SYSTEM SCHEMATIC .................................................................................... 80
APPENDIX XV: RECOMMENDED R OUTINE MAINTENANCE SCHEDULE FOR
LIQUID COOLED PLASMA CUTTING SYSTEMS............................................................. 82
SECTION 1:
GENERAL INFORMATION
1.01 Notes, Cautions and Warnings
Throughout this manual, notes, cautions, and warnings
are used to highlight important information. These highlights are categorized as follows:
NOTE
An operation, procedure, or backgr ound information which requires additional emphasis or is helpful in efficient operation of the system.
CAUTION
A procedure which, if not properly followed, may
cause damage to the equipment.
W ARNING
A procedure which, if not properly followed, may
cause injury to the operator or others in the operating area.
1.02 Important Safety Precautions
WARNINGS
OPERATION AND MAINTENANCE OF
PLASMA ARC EQUIPMENT CAN BE DANGEROUS AND HAZARDOUS TO YOUR
HEALTH.
GASES AND FUMES
Gases and fumes produced during the plasma cutting
process can be dangerous and hazardous to your health.
• Keep all fumes and gases from the breathing area.
Keep your head out of the welding fume plume.
• Use an air-supplied respirator if ventilation is not
adequate to remove all fumes and gases.
• The kinds of fumes and gases from the plasma arc
depend on the kind of metal being used, coatings
on the metal, and the different processes. Y ou must
be very careful when cutting or welding any metals which may contain one or more of the following:
Antimony Chromium Mercury
Arsenic Cobalt Nickel
Barium Copper Selenium
Beryllium Lead Silver
Cadmium Manganese Vanadium
• Always read the Material Safety Data Sheets (MSDS)
that should be supplied with the material you are
using. These MSDSs will give you the information
regarding the kind and amount of fumes and gases
that may be dangerous to your health.
• For information on how to test for fumes and gases
in your workplace, refer to item 1 in Subsection
1.03, Publications in this manual.
• Use special equipment, such as water or down draft
cutting tables, to capture fumes and gases.
• Do not use the plasma torch in an area where combustible or explosive gases or materials are located.
• Phosgene, a toxic gas, is generated from the vapors
of chlorinated solvents and cleansers. Remove all
sources of these vapors.
Plasma arc cutting produces intense electric and
magnetic emissions that may interfere with the
proper function of cardiac pacemakers, hearing
aids, or other electronic health equipment. Persons who work near plasma arc cutting applications should consult their medical health professional and the manufacturer of the health
equipment to determine whether a hazard exists.
To prevent possible injury, read, understand and
follow all warnings, safety precautions and instructions before using the equipment. Call 1-603298-5711 or your local distributor if you have any
questions.
Date: 6/22/99 1 GENERAL INFORMA TION
Electric Shock can injure or kill. The plasma arc process
uses and produces high voltage electrical energy. This
electric energy can cause severe or fatal shock to the operator or others in the workplace.
ELECTRIC SHOCK
• Never touch any parts that are electrically “live” or
“hot.”
• W ear dry gloves and clothing. Insulate yourself from
the work piece or other parts of the welding circuit.
• Repair or replace all worn or damaged parts.
• Extra care must be taken when the workplace is
moist or damp.
• Install and maintain equipment according to NEC
code, refer to item 9 in Subsection 1.03, Publications.
• Disconnect power source before performing any service or repairs.
• Read and follow all the instructions in the Operating Manual.
FIRE AND EXPLOSION
Fire and explosion can be caused by hot slag, sparks, or
the plasma arc.
• Be sure there is no combustible or flammable material in the workplace. Any material that cannot be
removed must be protected.
• Ventilate all flammable or explosive vapors from
the workplace.
• Do not cut or weld on containers that may have held
combustibles.
• Provide a fire watch when working in an area wher e
fire hazards may exist.
• Hydrogen gas may be formed and trapped under
aluminum workpieces when they are cut underwater or while using a water table. DO NOT cut
aluminum alloys underwater or on a water table
unless the hydrogen gas can be eliminated or dissipated. T rapped hydr ogen gas that is ignited will
cause an explosion.
NOISE
Noise can cause permanent hearing loss. Plasma arc processes can cause noise levels to exceed safe limits. You
must protect your ears from loud noise to prevent permanent loss of hearing.
• T o pr otect your hearing fr om loud noise, wear protective ear plugs and/or ear muffs. Protect others
in the workplace.
• Noise levels should be measured to be sure the decibels (sound) do not exceed safe levels.
• For information on how to test for noise, see item 1
in Subsection 1.03, Publications, in this manual.
PLASMA ARC RAYS
Plasma Arc Rays can injure your eyes and burn your skin.
The plasma arc process produces very bright ultra violet
and infra red light. These arc rays will damage your
eyes and burn your skin if you are not properly pr otected.
• To protect your eyes, always wear a welding helmet or shield. Also always wear safety glasses with
side shields, goggles or other protective eye wear.
• Wear welding gloves and suitable clothing to protect your skin from the arc rays and sparks.
• Keep helmet and safety glasses in good condition.
Replace lenses when cracked, chipped or dirty.
• Protect others in the work area from the arc rays.
Use protective booths, screens or shields.
• Use the shade of lens as suggested in the following
per ANSI/ASC Z49.1:
Minimum Protective Suggested
Arc Current Shade No. Shade No.
Less Than 300* 8 9
300 - 400* 9 12
400 - 800* 10 14
* These values apply where the actual arc is clearly
seen. Experience has shown that lighter filters
may be used when the arc is hidden by the workpiece.
1.03 Publications
Refer to the following standards or their latest revisions
for more information:
1. OSHA, SAFETY AND HEALTH STANDARDS,
29CFR 1910, obtainable from the Superintendent of
Documents, U.S. Government Printing Office, W ashington, D.C. 20402
2. ANSI Standard Z49.1, SAFETY IN WELDING AND
CUTTING, obtainable from the American Welding
Society, 550 N.W. LeJeune Rd, Miami, FL 33126
3. NIOSH, SAFETY AND HEALTH IN ARC WELDING AND GAS WELDING AND CUTTING, obtainable from the Superintendent of Documents, U.S.
Government Printing Office, W ashington, D.C. 20402
4. ANSI Standard Z87.1, SAFE PRACTICES FOR OCCUP ATION AND EDUCA TIONAL EYE AND F ACE
PROTECTION, obtainable from American National
Standards Institute, 1430 Broadway, New York, NY
10018
5. ANSI Standard Z41.1, STANDARD FOR MEN’S
SAFETY-TOE FOOTWEAR, obtainable from the
American National Standards Institute, 1430 Broadway, New York, NY 10018
6. ANSI Standard Z49.2, FIRE PREVENTION IN THE
USE OF CUTTING AND WELDING PROCESSES,
obtainable from American National Standar ds Institute, 1430 Broadway, New York, NY 10018
7. AWS Standard A6.0, WELDING AND CUTTING
CONTAINERS WHICH HAVE HELD COMBUSTIBLES, obtainable from American Welding Society,
550 N.W. LeJeune Rd, Miami, FL 33126
GENERAL INFORMATION 2 Date 6/22/99
8. NFPA Standard 51, OXYGEN-FUEL GAS SYSTEMS
FOR WELDING, CUTTING AND ALLIED PROCESSES, obtainable from the National Fire Protection
Association, Batterymarch Park, Quincy, MA 02269
9. NFP A Standar d 70, NA TIONAL ELECTRICAL CODE,
obtainable from the National Fire Protection Association, Batterymarch Park, Quincy, MA 02269
10. NFPA Standard 51B, CUTTING AND WELDING
PROCESSES, obtainable from the National Fire Protection Association, Batterymarch Park, Quincy, MA
02269
11. CGA Pamphlet P-1, SAFE HANDLING OF COMPRESSED GASES IN CYLINDERS, obtainable from
the Compressed Gas Association, 1235 Jefferson
Davis Highway, Suite 501, Arlington, VA 22202
12. CSA Standard W117.2, CODE FOR SAFETY IN
WELDING AND CUTTING, obtainable from the Canadian Standards Association, Standards Sales, 178
Rexdale Boulevard, Rexdale, Ontario, Canada M9W
1R3
13. NWSA booklet, WELDING SAFETY BIBLIOGRAPHY obtainable from the National Welding Supply
Association, 1900 Arch Street, Philadelphia, PA 19103
14. American W elding Society Standard A WSF4.1, RECOMMENDED SAFE PRACTICES FOR THE PREP ARA TION FOR WELDING AND CUTTING OF CONTAINERS AND PIPING THAT HAVE HELD
HAZARDOUS SUBSTANCES, obtainable from the
American Welding Society, 550 N.W. LeJeune Rd,
Miami, FL 33126
15. ANSI Standard Z88.2, PRACTICE FOR RESPIRATORY PROTECTION, obtainable from American
National Standards Institute, 1430 Broadway, New
York, NY 10018
1.04 Note, Attention et Avertissement
Dans ce manuel, les mots “note,” “attention,” et
“avertissement” sont utilisés pour mettre en relief des
informations à caractère important. Ces mises en relief
sont classifiées comme suit :
A VERTISSEMENT
Toute procédure pouvant provoquer des blessures
de l’opérateur ou des autres personnes se trouvant
dans la zone de travail en cas de non-respect de la
procédure en question.
1.05 Precautions De Securite Importantes
AVERTISSEMENTS
L’OPÉRATION ET LA MAINTENANCE DU
MATÉRIEL DE SOUDAGE À L’ARC AU JET
DE PLASMA PEUVENT PRÉSENTER DES
RISQUES ET DES DANGERS DE SANTÉ.
Coupant à l’arc au jet de plasma produit de l’énergie
électrique haute tension et des émissions
magnétique qui peuvent interférer la fonction
propre d’un “pacemaker” cardiaque, les appareils
auditif, ou autre matériel de santé electronique.
Ceux qui travail près d’une application à l’arc au
jet de plasma devrait consulter leur membre
professionel de médication et le manufacturier de
matériel de santé pour déterminer s’il existe des
risques de santé.
Il faut communiquer aux opérateurs et au personnel TOUS les dangers possibles. Afin d’éviter les
blessures possibles, lisez, comprenez et suivez tous
les avertissements, toutes les précautions de sécurité
et toutes les consignes avant d’utiliser le matériel.
Composez le + 603-298-5711 ou votr e distributeur
local si vous avez des questions.
FUMÉE et GAZ
NOTE
Toute opération, procédure ou renseignement
général sur lequel il importe d’insister davantage
ou qui contribue à l’efficacité de fonctionnement
du système.
ATTENTION
Toute procédure pouvant r ésulter
l’endommagement du matériel en cas de nonrespect de la procédur e en question.
Date: 6/22/99 3 GENERAL INFORMA TION
La fumée et les gaz produits par le procédé de jet de
plasma peuvent présenter des risques et des dangers de
santé.
• Eloignez toute fumée et gaz de votre zone de respiration. Gardez votre tête hors de la plume de fumée
provenant du chalumeau.
• Utilisez un appareil respiratoire à alimentation en
air si l’aération fournie ne permet pas d’éliminer la
fumée et les gaz.
• Les sortes de gaz et de fumée provenant de l’arc de
plasma dépendent du genre de métal utilisé, des
revêtements se trouvant sur le métal et des différ ents
procédés. Vous devez prendre soin lorsque vous
coupez ou soudez tout métal pouvant contenir un
ou plusieurs des éléments suivants:
antimoine cadmium mercure
argent chrome nickel
arsenic cobalt plomb
baryum cuivre sélénium
béryllium manganèse vanadium
• Lisez toujours les fiches de données sur la sécurité
des matières (sigle américain “MSDS”); celles-ci
devraient être fournies avec le matériel que vous
utilisez. Les MSDS contiennent des renseignements
quant à la quantité et la nature de la fumée et des
gaz pouvant poser des dangers de santé.
• Pour des informations sur la manière de tester la
fumée et les gaz de votre lieu de travail, consultez
l’article 1 et les documents cités à la page 5.
• Utilisez un équipement spécial tel que des tables de
coupe à débit d’eau ou à courant descendant pour
capter la fumée et les gaz.
• N’utilisez pas le chalumeau au jet de plasma dans
une zone où se trouvent des matières ou des gaz
combustibles ou explosifs.
• Le phosgène, un gaz toxique, est généré par la fumée
provenant des solvants et des produits de nettoyage
chlorés. Eliminez toute source de telle fumée.
INCENDIE ET EXPLOSION
Les incendies et les explosions peuvent résulter des scories
chaudes, des étincelles ou de l’arc de plasma. Le procédé
à l’arc de plasma produit du métal, des étincelles, des
scories chaudes pouvant mettre le feu aux matières combustibles ou provoquer l’explosion de fumées
inflammables.
• Soyez certain qu’aucune matière combustible ou inflammable ne se trouve sur le lieu de travail.
Protégez toute telle matière qu’il est impossible de
retirer de la zone de travail.
• Procurez une bonne aération de toutes les fumées
inflammables ou explosives.
• Ne coupez pas et ne soudez pas les conteneurs ayant
pu renfermer des matières combustibles.
• Prévoyez une veille d’incendie lors de tout travail
dans une zone présentant des dangers d’incendie.
• Le gas hydrogène peut se former ou s’accumuler
sous les pièces de travail en aluminium lorsqu’elles
sont coupées sous l’eau ou sur une table d’eau. NE
P AS couper les alliages en aluminium sous l’eau ou
sur une table d’eau à moins que le gas hydrogène
peut s’échapper ou se dissiper. Le gas hydrogène
accumulé explosera si enflammé.
RAYONS D’ARC DE PLASMA
CHOC ELECTRIQUE
Les chocs électriques peuvent blesser ou même tuer. Le
procédé au jet de plasma requiert et produit de l’éner gie
électrique haute tension. Cette énergie électrique peut
produire des chocs graves, voire mortels, pour l’opérateur
et les autres personnes sur le lieu de travail.
• Ne touchez jamais une pièce “sous tension” ou
“vive”; portez des gants et des vêtements secs.
Isolez-vous de la pièce de travail ou des autres parties du circuit de soudage.
• Réparez ou remplacez toute pièce usée ou
endommagée.
• Prenez des soins particuliers lorsque la zone de travail est humide ou moite.
• Montez et maintenez le matériel conformément au
Code électrique national des Etats-Unis. (Voir la
page 5, article 9.)
• Débranchez l’alimentation électrique avant tout travail d’entretien ou de réparation.
• Lisez et respectez toutes les consignes du Manuel
de consignes.
Les rayons provenant de l’arc de plasma peuvent blesser
vos yeux et brûler votre peau. Le procédé à l’arc de plasma
produit une lumière infra-rouge et des rayons ultra-violets très forts. Ces rayons d’arc nuiront à vos yeux et
brûleront votre peau si vous ne vous protégez pas
correctement.
• Pour protéger vos yeux, portez toujours un casque
ou un écran de soudeur. Portez toujours des lunettes
de sécurité munies de parois latérales ou des lunettes de protection ou une autre sorte de protection oculaire.
• Portez des gants de soudeur et un vêtement
protecteur approprié pour protéger votre peau
contre les étincelles et les rayons de l’arc.
• Maintenez votre casque et vos lunettes de protection en bon état. Remplacez toute lentille sale ou
comportant fissure ou rognure.
• Protégez les autres personnes se trouvant sur la zone
de travail contre les rayons de l’arc en fournissant
des cabines ou des écrans de protection.
GENERAL INFORMATION 4 Date 6/22/99
• Utilisez la nuance de lentille qui est suggèrée dans
le recommendation qui suivent ANSI/ASC Z49.1:
Nuance Minimum Nuance Suggerée
Courant Arc Protective Numéro Numéro
Moins de 300* 8 9
300 - 400* 9 12
400 - 800* 10 14
* Ces valeurs s’appliquent ou l’arc actuel est observé
clairement. L ’experience a démontrer que les filtres
moins foncés peuvent être utilisés quand l’arc est
caché par moiceau de travail.
BRUIT
Le bruit peut provoquer une perte permanente de l’ouïe.
Les procédés de soudage à l’arc de plasma peuvent
provoquer des niveaux sonores supérieurs aux limites
normalement acceptables. Vous dú4ez vous protéger les
oreilles contre les bruits forts afin d’éviter une perte
permanente de l’ouïe.
• Pour protéger votre ouïe contre les bruits forts, portez
des tampons protecteurs et/ou des protections
auriculaires. Protégez également les autres
personnes se trouvant sur le lieu de travail.
• Il faut mesurer les niveaux sonores afin d’assurer
que les décibels (le bruit) ne dépassent pas les
niveaux sûrs.
• Pour des renseignements sur la manière de tester le
bruit, consultez l’article 1, page 5.
1.06 Documents De Reference
Consultez les normes suivantes ou les révisions les plus
récentes ayant été faites à celles-ci pour de plus amples
renseignements :
1. OSHA, NORMES DE SÉCURITÉ DU TRAVAIL ET
DE PROTECTION DE LA SANTÉ, 29CFR 1910,
disponible auprès du Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402
2. Norme ANSI Z49.1, LA SÉCURITÉ DES
OPÉRATIONS DE COUPE ET DE SOUDAGE,
disponible auprès de la Société Américaine de
Soudage (American Welding Society), 550 N.W.
LeJeune Rd., Miami, FL 33126
3. NIOSH, LA SÉCURITÉ ET LA SANTÉ LORS DES
OPÉRATIONS DE COUPE ET DE SOUDAGE À
L ’ARC ET AU GAZ, disponible aupr ès du Superintendent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402
4. Norme ANSI Z87.1, PRA TIQUES SURES POUR LA
PROTECTION DES YEUX ET DU VISAGE AU
TRAVAIL ET DANS LES ECOLES, disponible de
l’Institut Américain des Normes Nationales (American National Standards Institute), 1430 Broadway,
New York, NY 10018
5. Norme ANSI Z41.1, NORMES POUR LES
CHAUSSURES PROTECTRICES, disponible auprès
de l’American National Standards Institute, 1430
Broadway, New York, NY 10018
6. Norme ANSI Z49.2, PRÉVENTION DES
INCENDIES LORS DE L ’EMPLOI DE PROCÉDÉS
DE COUPE ET DE SOUDAGE, disponible auprès
de l’American National Standards Institute, 1430
Broadway, New York, NY 10018
7. Norme A6.0 de l’Association Américaine du
Soudage (A WS), LE SOUDAGE ET LA COUPE DE
CONTENEURS AYANT RENFERMÉ DES
PRODUITS COMBUSTIBLES, disponible auprès de
la American W elding Society, 550 N.W. LeJeune Rd.,
Miami, FL 33126
8. Norme 51 de l’Association Américaine pour la Protection contre les Incendies (NFP A), LES SYSTEMES
À GAZ AVEC ALIMENTATION EN OXYGENE
POUR LE SOUDAGE, LA COUPE ET LES
PROCÉDÉS ASSOCIÉS, disponible auprès de la
National Fire Protection Association, Batterymarch
Park, Quincy, MA 02269
9. Norme 70 de la NFPA, CODE ELECTRIQUE NATIONAL, disponible auprès de la National Fire Protection Association, Batterymarch Park, Quincy, MA
02269
10. Norme 51B de la NFPA, LES PROCÉDÉS DE
COUPE ET DE SOUDAGE, disponible auprès de
la National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269
11. Brochure GCA P-1, LA MANIPULATION SANS
RISQUE DES GAZ COMPRIMÉS EN CYLINDRES,
disponible auprès de l’Association des Gaz
Comprimés (Compressed Gas Association), 1235
Jefferson Davis Highway, Suite 501, Arlington, VA
22202
12. Norme CSA W1 17.2, CODE DE SÉCURITÉ POUR
LE SOUDAGE ET LA COUPE, disponible auprès
de l’Association des Normes Canadiennes, Standards Sales, 178 Rexdale Boulevard, Rexdale,
Ontario, Canada, M9W 1R3
13. ivret NWSA, BIBLIOGRAPHIE SUR LA SÉCURITÉ
DU SOUDAGE, disponible auprès de l’Association
Nationale de Fournitures de Soudage (National
Welding Supply Association), 1900 Arch Street,
Philadelphia, PA 19103
Date: 6/22/99 5 GENERAL INFORMA TION
14. Norme A WSF4.1 de l’Association Américaine de
Soudage, RECOMMANDATIONS DE PRATIQUES SURES POUR LA PRÉPARATION À LA
COUPE ET AU SOUDAGE DE CONTENEURS
ET TUYAUX AYANT RENFERMÉ DES
PRODUITS DANGEREUX , disponible auprès de
la American Welding Society, 550 N.W. LeJeune
Rd., Miami, FL 33126
15. Norme ANSI Z88.2, PRATIQUES DE PROTECTION RESPIRATOIRE, disponible auprès de
l’American National Standards Institute, 1430
Broadway, New York, NY 10018
GENERAL INFORMATION 6 Date 6/22/99
1.07 Declaration of Conformity
Manufacturer: Thermal Dynamics Corporation
Address: Industrial Park #2
W est Lebanon, New Hampshire 03784
USA
The equipment described in this manual conforms to all applicable aspects and regulations of the ‘Low Voltage Directive’ (European Council Directive 73/23/EEC as amended by Council Directive 93/68/EEC) and to the National
legislation for the enforcement of this Directive.
Serial numbers are unique with each individual piece of equipment and details description, parts used to manufacture
a unit and date of manufacture.
National Standard and Technical Specifications
The product is designed and manufactured to a number of standards and technical requir ements among them are:
* CSA (Canadian Standards Association) standard C22.2 number 60 for Arc welding equipment.
* UL (Underwriters Laboratory) rating 94VO flammability testing for all printed-circuit boar ds used.
* ISO/IEC 60974-1 (BS 638-PT10) (EN 60 974-1) (EN50192) (EN50078) applicable to plasma cutting equipment and associ-
ated accessories.
* Extensive product design verification is conducted at the manufacturing facility as part of the routine design and
manufacturing process. This is to ensure the product is safe, when used accor ding to instructions in this manual and
related industry standards, and performs as specified. Rigorous testing is incorporated into the manufacturing
process to ensure the manufactured pr oduct meets or exceeds all design specifications.
Thermal Dynamics has been manufacturing products for more than 30 years, and will continue to achieve excellence in our
area of manufacture.
Manufacturers responsible repr esentative: Steve W ard
Director of Operations
Thermadyne UK
Chorley England
Date: 6/22/99 7 GENERAL INFORMA TION
1.08 Statement of Warranty
LIMITED WARRANTY: Thermal Dynamics® Corporation (hereinafter “Thermal”) warrants that its products will be free of defects in
workmanship or material. Should any failure to conform to this warranty appear within the time period applicable to the Thermal
products as stated below , Thermal shall, upon notification thereof and substantiation that the product has been stor ed, installed, operated,
and maintained in accordance with Thermal’s specifications, instructions, recommendations and recognized standard industry prac tice,
and not subject to misuse, repair , neglect, alteration, or accident, corr ect such defects by suitable r epair or replacement, at Thermal’s sole
option, of any components or parts of the product determined by Thermal to be defective.
THIS WARRANTY IS EXCLUSIVE AND IS IN LIEU OF ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PA R TICULAR PURPOSE.
LIMITATION OF LIABILITY: Thermal shall not under any circumstances be liable for special or consequential damages, such as, but
not limited to, damage or loss of purchased or replacement goods, or claims of customers of distributor (hereinafter “Purchaser”) for
service interruption. The remedies of the Purchaser set forth herein are exclusive and the liability of Thermal with respect to any
contract, or anything done in connection therewith such as the performance or breach thereof, or from the manufacture, sale, delivery,
resale, or use of any goods covered by or furnished by Thermal whether arising out of contract, negligence, strict tort, or under any
warranty, or otherwise, shall not, except as expressly provided herein, exceed the price of the goods upon which such liability is based.
THIS WARRANTY BECOMES INVALID IF REPLACEMENT PARTS OR ACCESSORIES ARE USED WHICH MAY IMPAIR THE
SAFETY OR PERFORMANCE OF ANY THERMAL PRODUCT.
THIS WARRANTY IS INVALID IF THE PRODUCT IS SOLD BY NON-AUTHORIZED PERSONS.
The limited warranty periods for Thermal products shall be as follows (with the exception of XL Plus Series, CutMaster 80XL , Cougar
and DRAG-GUN): A maximum of three (3) years from date of sale to an authorized distributor and a maximum of two (2) years from
date of sale by such distributor to the Purchaser, and with the further limitations on such two (2) year period (see chart below).
The limited warranty period for XL Plus Series and CutMaster 80XL shall be as follows: A maximum of four (4) years from date
of sale to an authorized distributor and a maximum of three (3) years from date of sale by such distributor to the Purchaser, and
with the further limitations on such three (3) year period (see chart below).
The limited warranty period for Cougar and DRAG-GUN shall be as follows: A maximum of two (2) years from date of sale to an
authorized distributor and a maximum of one (1) year from date of sale by such distributor to the Purchaser, and with the further
limitations on such two (2) year period (see chart below).
Parts
XL Plus Series & Parts Parts
PAK Units, Power Supplies CutMaster 80XL Cougar/Drag-Gun All Others Labor
Main Power Magnetics 3 Years 1 Year 2 Years 1 Year
Original Main Power Rectifier 3 Years 1 Year 2 Years 1 Year
Control PC Board 3 Years 1 Year 2 Years 1 Year
All Other Circuits And Components Including, 1 Year 1 Year 1 Year 1 Year
But Not Limited To, Starting Circuit,
Contactors, Relays, Solenoids, Pumps,
Power Switching Semi-Conductors
Consoles, Control Equipment, Heat 1 Year 1 Year 1 Year
Exchanges, And Accessory Equipment
Torch And Leads
Maximizer 300 Torch 1 Year 1 Year
All Other Torches 180 Days 180 Days 180 Days 180 Days
Repair/Replacement Parts 90 Days 90 Days 90 Days None
Warranty repairs or replacement claims under this limited warranty must be submitted by an authorized Thermal Dynamics® repair
facility within thirty (30) days of the repair. No transportation costs of any kind will be paid under this warranty. Transportation
charges to send products to an authorized warranty repair facility shall be the responsibility of the customer. All returned goods shall
be at the customer’s risk and expense. This warranty supersedes all previous Thermal warranties.
Effective May 6, 1999
GENERAL INFORMATION 8 Date 6/22/99
SECTION 2:
INTRODUCTION
2.01 Scope Of Manual
This Manual provides Service Instructions for Thermal
Dynamics Merlin 3000 Power Supply.
Refer to Operating Manual (0-2532) for individual operating procedures. Information in this edition is ther efore
particularly applicable to the T roubleshooting and Repair
of the equipment, and is intended for use by properlytrained Service T echnicians familiar with this equipment.
Read this Manual and the Operating Manual, 0-2532,
thoroughly. A complete understanding of the capabilities and functions of the equipment will assure obtaining
the performance for which it was designed.
2.02 General Service Philosophy
Several key points are essential to properly support the
application and operation of this equipment.
2.03 Service Responsibilities
The Service T echnician should be familiar with the equipment and its capabilities. He should be prepared to r ecommend arrangements of components which will provide the most efficient layout, utilizing the equipment to
its best possible advantage.
Maintenance work should be accomplished in a timely
manner . If problems are encountered, or the equipment
does not function as specified, contact T echnical Services
Department at West Lebanon for assistance.
A. Application
The equipment should satisfy the customer ’s requirements as supplied and as described in Section 3 of this
manual. Be sure to confirm that the equipment is capable
of the application desired.
B. Modifications
No physical or electrical modifications other than selection of standard options, Accessories, or Factory appr oved
updates are to be made to this equipment.
C. Customer/Operator Responsibilities
It is the customer/operators’ responsibility to maintain
the equipment and peripheral Accessories provided by
Thermal Dynamics in good operating order in accordance
with the procedures outlined in the Operating Manual,
and to protect the equipment from accidental or malicious damage.
D. Repair Restrictions
The electronics consists of Printed Circuit Board Assemblies which must be carefully handled, and must be replaced as units. No replacement of printed circuit solder-mounted components is allowed except as noted in
this manual.
If to be returned, the replaced Printed Circuit Board Assemblies must be properly packaged in protective material and returned intact per normal procedures.
Manual 0-2533 9 INTRODUCTION
INTRODUCTION 10 Manual 0-2533
SECTION 3:
INTRODUCTION &
DESCRIPTION
3.01 Scope of Manual
The information in this Section is the same information
contained in Section 2 of the Operating Manual. It is supplied here to familiarize the Service Technician with the
capabilities and limitations of the equipment. This information will also provide the Service Technician with an
overall understanding of the equipment which will, in
turn, allow proper training of the customer’s operating
personnel.
3.02 General Description
The Power Supply contains all operator controls, electrical and gas inputs and outputs, and the torch leads receptacle. Many options and accessories can be added to
further improve the versatility of the system.
• Power Supply with Running Gear and Handles
• Arc Starter Box
• Maximizer 300 Machine Torch with Mounting Assembly and Leads
• Torch Leads Extension
• Maximizer 300 Spare Parts Kit
• 25 ft (7.6 m) Work Cable and Clamp
• Air Line Filter Assembly (or) High Pressure Regulators
NOTE
Refer to Section 3.05 for complete list of Power Supply Options and Accessories.
3.03 Specifications & Design Features
The following apply to the Power Supply only:
1. Controls
ON/OFF Switch, Output Current Control, RUN/
SET/PURGE Switch, Secondary Gas Regulator,
Plasma Gas Regulator, Secondary Mode Switch
A-00907
Figure 3-1 Power Supply
The Standard Coolant supplied with the Power Supply
can be used in ambient temperatures down to 10° F
(-12° C). If the ambient temperature will be below 10° F
(-12° C) then Super Coolant should be used. This coolant
can be used in areas where the ambient temperature dr ops
to -34° F (-36° C).
A typical system configuration will contain the following:
2. Control Indicators
LED Indicators:
AC , TEMP, GAS, DC, PILOT, COOLANT PRES, and
COOLANT COND
Gauges:
Secondary, Plasma, and Coolant Pressure Gauges
3. Input Power
Voltage Frequency Phase Amperage
200/220/230 50 or 60 Hz 3 98/89/85
380/415/460 50 or 60 Hz 3 51/47/42
500/575 50 or 60 Hz 3 40/34
NOTE
Refer to Appendix I for recommended input wiring size, current ratings, and circuit pr otection requirements.
Amps depends on input voltage (Refer to Appendix
I).
4. Output Power
Continuously adjustable by potentiometer from 50 to
150 amps
Manual 0-2533 11 INTRODUCTION & DESCRIPTION
5. Duty Cycle
100%
6. Pilot Modes
Auto-Restart, Pre-Flow Delay, Recycle
7. CNC Signals
Enable Start/Stop, OK-to-Move, Pilot Sensing Relay
(PSR), Full CNC Available with Remote
8. Coolant Pressure
3.04 Theor y Of Operation
A. Plasma Arc Cutting and Gouging
Plasma is a gas which is heated to an extremely high temperature and ionized so that it becomes electrically conductive. The plasma arc cutting process uses this plasma
gas to transfer an electric arc to a workpiece. The metal
to be cut is melted by the intense heat of the arc and then
blown away by the flow of gas. Plasma arc gouging uses
the same process to remove material to a controlled depth
and width.
Internal Service-adjustable
130 psi (8.8 BAR) at zero flow
120 - 125 psi (8.2 - 8.5 BAR) at 0.6 gpm (2.6 lpm)
9. Coolant Flow Rate
0.5 gpm (2.2 lpm) with 150 feet (45.7m) of total torch
and torch leads at 70°F (21°C)
NOTE
The flow rate varies with lead length, torch configuration, ambient temperature, amperage level,
etc.
10. Cooling Capacity
4,000 to 10,000 BTU
NOTE
Maximum value based on “free flow” condition.
11. Coolant Reservoir Capacity
2 gallons (8.8 liters)
Capable of handling a total of 150 feet (45.7m) of torch
lead length
12. Power Supply Dimensions
Enclosure Only -
Width: 24.12 in (0.61 m)
Height: 38.38 in (0.98 m)
Depth: 34.25 in (0.87 m)
Fully Assembled -
Width: 28.50 in (0.72 m)
Height: 43.38 in (1.10 m)
Depth: 43.75 in (1.11 m)
With a simple change of torch parts, the system can also
be used for plasma arc gouging. Plasma arc gouging is
used to remove material to a controlled depth and width.
B. Input and Output Power
The Power Supply accepts input voltages from 200 to
575V, 50 or 60 Hz, three-phase. Input voltages are set by
an internal changeover in the unit. The unit converts AC
input power to DC power for the main cutting arc. The
negative output is connected to the torch electrode
through the negative torch lead, and the positive output
connects to the workpiece through the work cable.
C. Pilot Arc
When the torch is activated there is a selectable (2, 4, 7, or
10 second) gas pre-flow , followed by a uninterrupted DC
pilot arc established between the electrode and tip. The
pilot arc is initiated by a momentary high frequency pulse
from the Ar c Starter Box. The pilot creates a path for the
main arc to transfer to the work. When the main arc is
established, the pilot arc shuts off. The pilot can automatically restart (factory set for No Auto-Restart) when
the main arc stops, as long as the torch remains activated.
NOTE
For the arc to restart automatically, AUTO RESTART must be enabled at switch settings inside
the Power Supply.
D. Main Cutting Arc
The Power Supply accepts 50 or 60 Hz three-phase line
input. An internal changeover switches input line voltages in three ranges, for 200/220/230V, 380/415/460V,
or 500/575V operation. The power supply converts AC
input power to DC power for the main cutting arc. The
negative output is connected to the torch electrode
through the negative torch lead. The positive output is
connected to the workpiece via the work cable and clamp
connection.
13. Weight of Power Supply Only
678 lbs (308 kg)
INTRODUCTION & DESCRIPTION 12 Manual 0-2533
E. RF Shielding
All machine torch systems are shielded to minimize radio frequency (RF) interference which results from the
high frequency arc initiation. These shielded systems are
designed with features such as a wire for establishing an
earth ground and shielded torch and control leads.
ply lead. At the torch, the coolant is circulated around
the torch tip and electrode, where the extra cooling helps
to prolong parts life. Coolant then circles back to the
power supply through the return lead. The Maximizer
300 also can use secondary gases such as compressed air ,
nitrogen (N2), water, and carbon dioxide (CO2).
F. Interlocks
The system has several built-in interlocks to provide safe
and efficient operation. When an interlock shuts down
the system, the torch switch (or control device) must be
used to restart the system.
1. Parts-In-Place (PIP) Interlock
The Power Supply has a built-in parts-in-place interlock that prevents accidental torch starting when tor ch
parts are not properly installed. A flow switch on the
coolant return lead detects reduced coolant flow
caused by improper torch assembly. If not satisfied,
the switch interrupts power to the tip and electrode.
2. Gas Pressure Interlock
Pressure switches act as an interlock for the gas supplies. If supply pressure falls below minimum requir ements the pressure switches will open, shutting off
the power to the contactors, and the GAS indicator
will go out. When adequate supply pressure is available the pressure switches close, allowing power to
be resumed for cutting.
3. Thermal Interlock
Thermal overload sensors are located in the Main
Transformer, Main Heatsink Assembly, and Pilot Resistor in the power supply. If one of these components is overheated the appropriate switch will open
up, causing the temperature light to turn from green
to red and shutting off power to the main contactor.
When the overheated component cools down the
switch will close again and allow operation of the system.
3.05 Options And Accessories
These items can be used to customize a standard system
for a particular application or to further enhance performance. T or ch accessories are listed in the separate Torch
Instruction Manual.
NOTE
Refer to Section 6, Parts Lists, for ordering information.
A. RC6010 Remote Control
For mechanized systems, this low profile unit provides
full CNC capability and allows the operator to control most system functions from a remote location.
B. Computer Control Cable Kits
For interfacing the power supply with a computer or
auxiliary control device. Available in various cable
lengths.
C. SC-10 or SC11 Standoff Control
NOTE
Standoff Control SC10 requires installation of Remote Control RC6010.
For machine torch systems, the SC-10 automatically
finds height and maintains torch standoff with a high
speed torch lifter motor.
D. High Pressure Regulators
Available for air, oxygen, argon/hydrogen, nitrogen,
CO2 and water.
G. Plasma Torches
Plasma torches are similar in design to the common automotive spark plug. They consist of negative and positive sections which are separated by a center insulator.
Inside the torch, the pilot arc is initiated in the gap between the negatively charged electrode and the positively
charged tip. Once the pilot arc has ionized the plasma
gas, the superheated column of gas flows through the
small orifice in the torch tip, which is focused on the metal
to be cut.
The Maximizer 300 Torch uses an internal closed-loop
cooling system. Deionized coolant is distributed from a
reservoir in the Power Supply through the coolant sup-
Manual 0-2533 13 INTRODUCTION & DESCRIPTION
E. High Flow Water Shield (HFWS) Assembly
Reduces arc glare, noise, and fumes during the cutting process.
F. Two Stage Air Line Filter
Removes damaging contaminants as small as 5 microns from the plasma stream when using compr essed
air .
G. Hour/Counter Meters
Meter assembly containing two meters. One meter
indicates the total number of hours that the main cutting arc has been on. The second meter counts the
number of times that the cutting arc has been started.
Both meters display a maximum of 999999 hours or
starts and cannot be reset.
H. Plasma/Secondary Gas Control
A r emote control to select one of various plasma and
secondary gases, including secondary water , that can
be connected to the Power Supply.
INTRODUCTION & DESCRIPTION 14 Manual 0-2533
SECTION 4:
SERVICE
TROUBLESHOOTING
DIAGNOSTICS
4.01 Introduction
This Section provides service diagnostics for the Merlin
3000 Power Supply, allowing the Technician to islolate
any faulty Subassemblies. Refer to Section 5, Repairs &
Replacement Procedures, for parts replacement instructions.
Under no circumstances are field repairs to be attempted
on Printed Circuit Boards or other Subassemblies of this
unit. Evidence of unauthorized repairs will void the factory warranty.
NOTE
To clean the unit, first make sure that the power is
disconnected. Remove the side panels and blow out
any accumulated dirt and dust with compressed air
especially from the radiator. The unit should also be
wiped clean. If necessary, solvents that are recommended for cleaning electrical apparatus may be used.
While the side panels are off, inspect the wiring in the
unit. Look for any frayed wires or loose connections
that should be corrected.
C. Coolant Filter Assembly (Rear Panel)
The rear panel filter screen should be cleaned periodically. Remove the filter screen by unscrewing the
filter holder from the Coolant Filter Assembly. Clean
the filter screen by rinsing with hot soapy water. Remove soap residue by rinsing with clean hot water.
Be sure that all the soap has been removed and the
screen is dry of water before re-installing in the Coolant Filter Assembly.
The troubleshooting contained in this manual is
for the Merlin 3000 Power Supply only. Troubleshooting other parts of the system is covered in the
separate manuals for that product.
4.02 Periodic Inspection &
Procedures
NOTE
Refer to Appendix XV for a recommended maintenance schedule for water cooled plasma cutting
systems.
This subsection describes inspection procedures which
should be performed at periodic intervals as required.
A. Fan Motor and Pump Lubrication
The fan motor and pump in the power supply should
be oiled twice per year or once for each 100 hours of
operation. To oil the motor, remove one side panel
and add two or three drops of 20 SAE oil to the front
and rear oil holes on the motor.
NOTE
Some units may utilize a sealed motor design which
does not require lubrication.
B. Routine Maintenance
The only other routine maintenance required for the
power supply is a thorough cleaning and inspection,
with the frequency depending on the usage and the
operating environment.
Coolant Filter Assembly
Filter Screen
A-01018
Figure 4-1 Coolant Filter Assembly (Rear Panel)
Filter Holder
D. Internal Filter Assembly
The internal filter screen should be cleaned periodically. To gain access to the Internal Filter Assembly
remove the Left Side Panel (viewed from the fr ont of
unit) of the Power Supply. Remove the filter screen
by unscrewing the filter holder from the Internal Filter Assembly. Clean the filter screen by rinsing with
Manual 0-2533 15 SER VICE TROUBLESHOO TING
hot soapy water . Remove soap residue by rinsing with
clean hot water. Be sure that all the soap has been
removed and the screen is dry of water before re-installing in the Internal Filter Assembly.
4. Reconnect the hose to the filter assembly.
5. Install new coolant and deionizer bag.
6. Reinstall the top and right side panels.
E. Coolant Level and Conductivity
1. Coolant Level
The coolant level should be checked every day at
the rear panel coolant gauge. If the coolant in the
reservoir is more than 2 inches (50mm) from the
top of the reservoir then add Torch Coolant.
2. Coolant Conductivity
The coolant conductivity LED on the front panel
must be ON for normal operation. If the LED is
OFF then drain the old coolant from the Power
Supply and torch leads and replace with new coolant. Check the condition of the deionizer bag in
the reservoir basket, if the bag is yellowish brown
(straw color) replace the bag.
F. Draining Coolant
Remove the old coolant from the Power Supply reservoir per the following procedure:
1. Remove the right side and top panels from the
Power Supply.
2. Disconnect the coolant hose input to the rear panel
filter assembly.
3. Carefully lower the hose out the right side of the
Power Supply and drain the coolant into an acceptable container .
CAUTION
Handle and dispose of the used coolant per recommended procedures.
A-01017
4.03 System Theor y
A. Circuit Description
The Merlin 3000 system is designed for mechanized
cutting only and consists of the Merlin 3000 plasma
power supply, the Maximizer 300 T orch, Torch Leads
Extension, and Arc Starter Box. An Optional Remote
Control (RC6010), Standoff Control (SC10 or SC1 1, see
notes) and Gas Control (GC3000) may be used in various combinations. Different interconnect and input/
output (I/O) cables may be used depending on which
options are installed. An Optional Dual Meter, Arc
Hours and Arc Starts Counter, may be included on
the Power Supply front panel.
NOTES
The Standoff Control SC10 must be used with the
Remote Control RC6010.
The Remote Control RC6010 is not used if the
Standoff Control SC1 1 is used.
B. Input Voltage Selection
The main transformer (T1) has busbar connections to
select one of three input voltage ranges. Each main
transformer secondary has two taps. One secondary
tap is automatically selected by the Voltage Selection
PC board when primary power is applied. If input
voltage is within the lower half of the selected voltage range (for example, 380V or 415V in the 380/415/
460V range), the higher voltage taps are selected. If
input voltage is within the upper half of the selected
voltage range (460V in the 380/415/460V range), the
lower voltage taps are selected. This arrangement
provides secondary voltages close to the optimum
levels. When the lower voltage taps are selected a
red indicator , D18, on the Voltage Selection PC Board
will be ON.
The auxiliary voltage taps, 115 VAC and 28 VAC circuits, are selected directly by relays on the Voltage
Coolant Hose
Coolant Hose
Connection
Selection PC Board. The fan and pump motors are
supplied by the Motor Control Contactors (MC1 and
MC2). MC1 is for the high voltage tap and MC2 is for
the low voltage tap. Three-phase primary power is
controlled by one of the Main Contactors (W1 for the
high voltage tap or W2 for the low voltage tap).
Figure 4-2 Draining Coolant From Reservoir
SERVICE TR OUBLESHOOTING 16 Manual 0-2533
C. Switch-Mode Power Supply Operation
Primary three-phase power is rectified by the threephase bridge diodes D1-D6. The resulting negative
DC voltage (approximately -320 VDC) is applied to
the switching transistor (Q1). The switching transistor controls the output current by pulse width modulation (PWM). PWM varies the duty cycle (or on-time
versus off-time) of the switch. The greater the on-time,
the higher the output current will be. Components
D7-10, R2-3, C13-14, L1, and the Suppression PC Board
are snubbers to limit voltage and current surges caused
by switching Q1 on and off. D1 1-14 are free wheeling
diodes. When Q1 is on, current flows through Q1 into
the output network. When Q1 is off, D11-14 provide
a path for current to continue flowing supported by
energy that was stored in the output network during
the time Q1 was on. The switching transistor output
is a series of pulses which are filtered back into pure
DC voltage by the output network. The output network consists primarily of the main inductor (L2A and
L2B), resistor R13, and capacitor C23.
D. Switching Control PC Board
The Switching Control PC Board compares the shunt
amp output with the current control pot setting and
generates logic level PWM signals. The shunt and
Shunt Amp PC Board are located between the input
bridge positive and work lead to measure the output
cutting current. The signals are sent to the driver PC
board, where they are converted into the curr ent and
voltage levels needed to drive the switching transistor.
The Switching Control PC Board senses if the Remote
Control (RC6010) is installed to route the curr ent control signal from the remote instead of the Merlin fr ont
panel control. The Switching Control PC Board r outes
the Shunt Amp signal to the remote’s curr ent display,
sends a torch voltage signal to the standoff control
and supplies POT HI and POT LOW signals to set
min and max output to both remote and front panel
current controls. CSR (output greater than 25A) and
over current shutdown (current greater than 175A)
are sent to the Logic PC Board.
A r elay on the Switching Control PC Board, controled
by the Remote Control (RC6010) ENABLE switch or
the ENABLE input on TB2, removes power from one
side of the motor (MC) and main (W) contactors coils
when the enable switch is off shutting off the coolant
flow and DC power to allow changing torch parts.
E. Logic PC Board Functions
The Logic PC Board controls the timing and sequencing of the system. It monitors the pressure, temperature, and flow interlocks and controls the gas flow in
run, set, and purge modes by turning on the plasma
and secondary solenoids. The Logic PC Board also
controls pre-flow and post-flow durations, which are
selectable by DIP switches on the board. The Logic
PC Board drives the sequence status LED indicators
and contains the circuit for measuring coolant conductivity.
After receiving the CNC (cutting machine controller)
START signal from either the remote control, the
standoff control, dir ect from the controller via the remote connector or TB2 the “simple” interface terminal strip, the Logic PC Board initiates gas preflow then
energizes the main contactor, W1 or W2 (as determined by the Voltage Selection PC Board).
The Logic PC Board closes the pilot contactor and
sends enable signals to the Switching Control PC
Board to start the PWM and turn on the main switching circuits producing open circuit output voltage
(OCV). When the Arc Starter Box senses OCV greater
than 220 V between the T orch plus (+) and minus (-) it
starts the CD (capacitor discharge) arc starting cir cuit
to fire the spark gap producing the high voltage spark
which starts the DC pilot arc. Once a constant DC
pilot is established the torch voltage drops below 220
V and shuts off the CD circuit. When the Torch is
close to the work the cutting arc “transfers” to the
work.
The resulting current in the work lead is sensed by
the Shunt Amp and the Switching Control PC Board
sends the CSR signal to the Logic PC Board which
opens the pilot contactor shutting off the pilot anf
generating an “OK-To-Move” signal. OK-To-Move
can be either contact closure or 24VAC through contacts selected by switch SW5 on the Logic PCB. OKTo-Move is sent to the remote control, the standoff
control or directly to the cutting machine controller.
It controls the optional High Flow Water Shield and
the Arc Hour/Starts Counter.
F. LED/Current Control PC Board
The LED and current control PC board contains the
sequence status LED indicators and the front panel
current control pot.
G. Remote Control
The Remote Control allows remotely controlling the
cutting current, setting reduced current for corner
slowdown, and enabling gas purge and set functions.
An ENABLE switch shuts down the power supply and
coolant pump for changing torch consumables. The
Digital Amperage display allows accurate setting and
monitoring of the cutting current. Connections to the
cutting machine controller (CNC) are electrically isolated to minimize interference. Both a rear panel con-
Manual 0-2533 17 SER VICE TROUBLESHOO TING
nector and an internal terminal strip are provided for
CNC connections. The remote includes internal connections to interface to the SC10 standoff control so
the single remote cable works for both.
A Merlin 3000 system may include the following:
• No Remote Control (RC6010)
• Remote Control Only (RC6010)
• Remote Control Only (RC6010) With Standoff
Control (SC10)
When an RC6010 is included the CNC signals are connected to the RC6010 through the rear panel CNC
connector , J29, or may be wired directly to J6, a terminal strip inside the RC6010. All CNC inputs are optically isolated to reduce noise interference. The RC6010
allows remotely controlling the cutting current, setting reduced current for corner slowdown and selecting gas PURGE and SET functions. A digital AMPS
display allows accurate setting and monitoring of the
output current. An ENABLE switch shuts down the
power supply and coolant pump for changing torch
consumables.
H. Standoff Control
1. Model SC10 Standoff Control
Move signals which are optically isolated. A remote cable connects from the Power Supply to
connector J41 supplying the Standoff Control
power. The cable connected to J42 supplies control signals between Power Supply and the Standoff Control. Refer to the individual Instruction
Manuals supplied with the equipment for more
detailed information.
The Power Supply must have an enable switch
connected to the terminal strip, TB2, inside the
Power Supply when the Standoff Control (SC11)
is used.
NOTE
Refer to Appendix VIII for a Signal Flow Block
Diagram of the main functions.
I. Gas Control
The Gas Control (GC3000) consists of additional gas
solenoids mounted on the Power Supply rear panel.
A remote switch box is used to select the desired
Plasma and Secondary gases. Up to four plasma and
three secondary gases can be connected to the manifolds and selected by the Gas Control. The secondary
water input to the Power Supply may also be selected
from the Gas Control.
The Standoff Control (SC10) includes an ARC
VOLTS display, a control to set the desired arc
voltage as well as PIERCE HEIGHT , PIERCE DELAY and END OF CUT RETRACT (%). There are
also manual UP and DOWN switches. The Standoff Control operates a lifter motor assembly moving the torch vertically to control torch tip to work
distance.
When used with the Remote Control (RC6010) all
inputs and outputs to the Standoff Control (except lifter motor drive) is via an internal ribbon
cable between Remote Control (RC6010) J5 and
Standoff Control (SC10) J7. No additional connections are required between Standoff Control
and Power Supply.
2. Model SC11 Standoff Control
Standoff Control (SC1 1) is used without a Remote
Control (RC6010). The Standoff Control has additional connectors on the rear panel, J40 for CNC,
J41 for EXT PWR and J42 for plasma (labeled PL).
A remote cable connects from the Power Supply
J15 to both J41 and J42 carrying power and signals to the Standoff Control. Connector J40 accepts the same CNC cable as the Remote Control
(RC6010) and like the Remote Control it has an
internal terminal strip, J11. Connections J40 and
J11 have only START/STOP, CSD, and OK-To-
4.04 Troubleshooting Guide
A. Troubleshooting and Repair
Troubleshooting and repairing the this unit is a process
which should be undertaken only by those familiar with
high voltage high power electronic equipment.
W ARNING
There are extremely dangerous voltage and power
levels present inside this unit. Do not attempt to
diagnose or repair unless you have had training in
power electronics measurement and troubleshooting techniques.
B. Advanced Troubleshooting
NOTE
For basic troubleshooting and parts replacement
procedures r efer to Merlin 3000 Power Supply Operating Manual 0-2532.
SERVICE TR OUBLESHOOTING 18 Manual 0-2533
The advanced troubleshooting covered in this Service
Manual requires Power Supply disassembly and live measurements. It is helpful for solving many of the common
problems that can arise with the Merlin 3000 Plasma Cutting System.
If major complex subassemblies are faulty, the unit must
be returned to an authorized service center for repair.
3. Faulty voltage selection board
a. Refer to Section 4.05-A, Voltage Selection PC
Board Check. Replace Voltage Selection PC
Board if necessary
B. AC indicator ON; Fan and pump not operating
1. ENABLE signal not ON
Follow all instructions as listed and complete each in
the order presented.
Specific test procedures and LED status identification
tables have been grouped together, and are referenced
by the troubleshooting guide.
C. How to use this Guide
The following information is a guide to help the Service
Technician determine the most likely causes for various
symptoms. This guide is set up in the following manner:
1. Perform operational check(s) on the equipment to isolate problem to possible circuit(s).
2. Determine symptom and isolate to defective assembly
using the following format:
X. Symptom (Bold Type)
Any Special Instructions (Text Type)
1. Cause (Italic Type)
a. Check/Remedy (Text T ype)
3. Locate your symptom in the appropriate Sub-Section.
a. Remote ENABLE or ENABLE at TB2 must be
on. Refer to Section 4.05-B, Enable Circuit T est.
2. Blown fuse (F1 or F2)
a. Check and replace fuse if necessary. Refer to
Section 4.05-C, Blown Fuse (F1 or F2).
3. Faulty ON/OFF switch (SW1)
a. Disconnect primary power . Check each section
for continuity. Replace switch if necessary
4. Faulty Voltage Selection PC Board
a. Refer to 4.05-A, Voltage Selection PC Board
Check. Replace Voltage Selection PC Board if
necessary
5. Faulty motor contactor (MC1 or MC2)
a. Refer to Section 4.05-D, Motor Control Contac-
tor Check (MC1 or MC2). Replace contactor if
necessary
6. Faulty ENABLE circuit
a. Refer to Section 4.05-B, Enable Circuit Test.
4. Check the causes (easiest listed first) for the symptom.
5. Check the remedies listed for each cause.
6. Repair as needed being sure to verify that unit is fully
operational after any repairs.
NOTE
Many signals are transfered between Printed
Circiut Board Assemblies on Ribbon Cables. If
these cables become faulty they can then cause various problems. Do not forget about these cables
when troubleshooting.
A. No front panel LED indicators ON; Fan and pump
not operating
1. No primary power. Refer to symptoms C and D also.
a. Check for proper three-phase power at input
terminal board
2. Faulty ON/OFF switch (SW1)
a. Disconnect primary power. Check each section
for continuity. Replace switch if necessary
C. No indicators are on for the RC6010 or SC10
remotes.
1. No +48 VDC power to the remotes.
a. 3 amp fuse blown on the Bias PCB, replace.
b. Defective Bias PCB, Refer to Section 4.05-P, 48
Volt Bias Test.
D. AMPS or VOLTS displays not on for RC6010 or
SC10.
1. Normal if ENABLE not on.
a. Turn on ENABLE at RC6010 or TB2 (if RC6010
not used)
b. Defective ENABLE circuit, Refer to Section 4.05-
B, Enable Circuit Test.
2. Faulty Remote Device
a. Replace as needed
Manual 0-2533 19 SER VICE TROUBLESHOO TING
E. Fuse blown at disconnect when primary power is
connected
1. V oltage selection busbars connected incorrectly
a. Check and correct if necessary.
2. One leg of three-phase primary connected to chassis
ground
a. Rewire input cable per Operating Manual.
3. Main transformer shorted
a. Replace main transformer
F. Fuse blown at disconnect when main contactor
(W1 or W2) closes
1. Shorted input diode (D1-D6)
a. Refer to Section 4.05-E, Diode Check. Replace
diode(s) as required.
2. Switching transistor (Q1) shorted to heatsink
4. Faulty LED/Current Control PC Board
a. Refer to Section 4.05-F , Thermal Sensing Cir cuit
Check. Replace LED/Current Control PC
Board if necessary.
H. No GAS indicator; Motor and Pump operating;
Other LED indicators normal; Both gases flow
1. Front panel RUN/SET/PURGE switch set to PURGE,
or PURGE selected at Remote Control
a. Normal operation (purges plasma line only , sec-
ondary pressure switch is not satisfied)
2. Gas pressure set too low
a. Adjust pressur e
3. Faulty pressure switch (PS1 or PS2)
a. Jump switches one at a time and check for indi-
cator to determine which has failed. Replace
switch if necessary.
a. Replace Q1, check heat-sink for possible dam-
age. Refer to Section 4.05-M, Switching Control Check (Q1).
3. Shorted input capacitor (C7-C12)
a. Replace capacitor if necessary
4. Shorted diode (D11-D14)
a. Check for proper 3-phase power at input termi-
nal board, check diodes. Refer to Section 4.05E, Diode Check.
5. Faulty Voltage Selection PC Board
a. If W1 and W2 come on simultaneously replace
Voltage Selection PC Board.
6. Faulty main contactor (W1 or W2)
a. Check both contactors for welded contacts and
replace contactor(s) if necessary
G. TEMP indicator on (red)
1. Unit overheated
a. Clean radiator and check for obstruction.
4. Faulty Logic PC Board
a. Refer to Section 4.05-G, Pressure Sensing Cir-
cuit. Replace Logic PC Board if necessary
5. Faulty LED/Current Control PC Board
a. Refer to Section 4.05-G, Pressure Sensing Cir-
cuit. Replace LED/Current Control PC Board
if necessary.
6. Faulty SW3-B (secondary mode set to O2 or H2O )
a. With secondary mode set to O2 or H2O, check
for continuity from wire #52 to #55 on SW3-B.
If open, replace SW3-B.
7. If using Gas Control Option (GC3000) set for Water
Secondary, faulty SW2-C in Gas Control.
a. With Merlin fr ont panel secondary mode set to
GAS and the Gas Control (GC3000) set to
W A TER, there should be continuity fr om wires
#52 to #55. If not, SW2-C or connections to it
are faulty.
I. GAS indicator off, plasma and/or secondary gas
does not flow
b. Excessive piloting; allow unit to cool
2. Faulty thermal sensor (TS1, TS2, or TS3)
a. Refer to Section 4.05-F , Thermal Sensing Circuit
Circuit Check. Replace sensor(s) if necessary
3. Faulty Logic PC Board
a. Refer to Section 4.05-F , Thermal Sensing Cir cuit
Check. Replace Logic PC Board if necessary
SERVICE TR OUBLESHOOTING 20 Manual 0-2533
1. Front panel RUN/SET/PURGE switch set to PURGE,
or PURGE selected at Remote Control.
a. Normal operation (purges plasma line only , sec-
ondary does not flow)
2. Secondary mode set to O2
a. No secondary flow is normal operation in O2
mode (but GAS indicator should be ON). Refer to symptom 'H' above.
3. Gas Control (GC3000) on wrong setting
NOTE
a. Select input that has gas connected.
4. Gas supply turned off (or tank empty)
a. Check gas supply
5. Faulty solenoid valve:
SOL1 - plasma gas,
SOL2 - secondary gas,
SOL3 - secondary water,
SOL4 through SOL9 - Optional Gas Select
a. Check solenoid for sticking or clogging. Check
coil resistance per the following:
SOL1 and SOL3 should be approximately 400
ohms)
SOL2 should be approximately 100 ohms)
SOL4 through SOL9 should be approximately
300 ohms)
6. Faulty switch (SW3-A) or Gas Control (GC3000) Secondary Select Switch
a. Check SW3-A for continuity (wire #75 to #88
for secondary gas, #75 to #89 for secondary water)
With a clogged internal coolant filter or Torch and
leads the Coolant Pressure Gauge will be normal,
but the Pressure LED, indicates flow , will be OFF.
3. Clogged torch or leads
a. Check torch and leads and replace if necessary.
Flush the old coolant from the system (see note
above).
4. Faulty flow switch (FS1)
a. Check and replace flow switch if necessary
5. Faulty Logic PC Board
a. Refer to Section 4.05-I, Coolant Flow Sensor
Circuit Check. Replace Logic PC Board if necessary.
6. Faulty LED/current control board
a. Refer to Section 4.05-I, Coolant Flow Sensor Cir-
cuit Check. Replace Logic PC Board if necessary.
K. Coolant conductivity indicator off
1. Ionized or contaminated coolant
a. Check coolant conductivity and deionizer car-
tridge. Replace both if necessary
7. Faulty Logic PC Board
a. Refer to Section 4.05-H, Gas Solenoid Circuits.
Replace Logic PC Board if necessary
8. Input gas pressure set too high, preventing solenoids
from operating
a. Remove input gas line and retry
b. Regulate input gas pressure between 90 to 110
psi (6.2 to 7.6 bar)
J. COOLANT indicator off
1. Little or no pressure shown on gauge
a. Check coolant level
b. Check motor rotation and rpm.
c. Check and replace pump if necessary
2. Clogged internal or external coolant filters
a. Check internal and external coolant filters.
Clean or replace if necessary . Flush the old coolant from the system (see note below).
2. Faulty (or contaminated) conductivity probe
a. Clean conductivity probe and replace if neces-
sary
3. Faulty Logic PC Board
a. Refer to Section 4.05-J, Coolant Conductivity
Circuit. Replace Logic PC Board if necessary.
4. Faulty LED/Current Control PC Board
a. Refer to Section 4.05-J, Coolant Conductivity
Circuit. Replace LED/Current Control PC
Board if necessary
L. Press cutting machine START and nothing hap-
pens or standoff finds height then nothing
happens (no gas flow or pilot)
1. Start signal not getting to the Power Supply or Power
Supply is defective.
a. Determine if Remote Control or Power Supply
is at fault. Remove Remote Control or CNC
cable from J15 (or TB2). Jumper TB2-1 & 2 to
enable unit, then jumper TB2-3 & 4 for ST AR T.
If the pilot starts, after preflow, Remote Control or CNC is faulty. Refer to Section 4.05-L,
Remote Control Start Circuit. If no pilot, refer
to Section 4.05-K for Power Supply Start Circuit.
Manual 0-2533 21 SER VICE TROUBLESHOO TING
M. DC indicator off (after pre-flow); Main contactor
comes on momentarily; No pilot arc; No main arc
transfer
1. Switching transistor (Q1) not turning on
a. Refer to Section 4.05-M, Switching Control
Check (Q1).
3. Broken conductor in torch lead
a. Check and replace if necessary
4. Shorted torch lead
a. Check and replace if necessary
5. Dirty or wet torch lead
N. No pilot arc; DC indicator on; Pilot indicator
OFF; PCR not energized
1. Faulty Logic PC Board, Switching Control PC Board,
or Shunt Amp PC Board.
a. Refer to Section 4.05-N, Pilot Circuit Check.
O. No pilot arc; PILOT indicator on; PCR energized
1. Faulty Arc Start Box
a. Refer to Section 4.05-N, Pilot Circuit Check.
2. Shorted torch
a. Refer to Section 4.05-N, Pilot Circuit Check.
P. Weak or sputtering pilot
1. Faulty torch consumable parts
a. Replace consumables as needed
2. Plasma gas pressure too high
a. Adjust pressur e
3. Low OCV (normal 290-350) caused by improper connection of voltage selection bus bars
a. Clean and dry torch lead
R. Pilot arc on; No main arc transfer (torch brought
within range of work)
1. Work cable not connected
a. Connect work cable securely
2. Defective current control pot (on front panel or r emote)
a. If Remote Control is used, disconnect J15 and
set current at power supply front panel. If transfer is correct or Remote Control is not used, r efer to Section 4.05-O, Current Control, Display,
and CSD Checks.
S. Main arc starts but goes out immediately; Main
contactor (W1 or W2) goes off
1. Fault condition causes output greater than 175 amps
a. Shorted Q1 or faulty Switching Control PC
Board. Refer to Section 4.05-M, Switching Control Check (Q1).
T. Main arc transfers but doesn’t pierce through the
plate or pierce is too slow
a. Check input voltage connections
4. Low OCV caused by faulty V oltage Selection PC Board
a. If three-phase input voltage is within the lower
half of range (refer to Operating Manual Section 3.07, Input V oltage Selection), D18 on Voltage Selection PC Board should be off. If D18 is
on, replace the Voltage Selection PC Board.
5. Input voltage low
a. Adjust pilot resistor for less r esistance. Refer to
Section 4.05-R, Pilot Resistor Adjustment.
Q. No pilot; PILOT indicator on; Strong spark
visible at spark gap points inside the Arc Starter
Box
1. Electrode shorted against tip
a. Thread electrode securely into torch head or
replace tip and electrode
2. Shorted torch head
a. Check and replace if necessary
1. Corner slowdown (CSD) setting too low on Remote
Control.
a. Most cutting machines activate CSD during
piercing, if so CSD must be set at or near maximum.
2. Cutting current too low
a. Set for higher current
b. Current control circuit defective. Refer to Sec-
tion 4.05-O, Current Control, Display and CSD
Checks.
3. Trying to pierce greater than 3/4 inch (19 mm) plate
a. Unit rated only for piercing upto 3/4 inch (19
mm)
4. Travel speed too high
a. T ry a stationary pierce, if pier cing is correct, then
adjust travel speed
SERVICE TR OUBLESHOOTING 22 Manual 0-2533
Loading...