Fire Power FP-18 User manual

Manual No. 0-2692
April 26, 2000
Service Manual
A-02032
Includes:
• 12 Amp Power Supply
• PCH-10 Torch with Leads
• Work Cable with Clamp
• Input Power Cable
For Model:
• 120VAC 60Hz

Read and understand this entire manual and your employer’s
safety practices before installing, operating, or
servicing the equipment.
While the information contained in this manual represents our
best judgement, Firepower® assumes no liability for its use.
Firepower FP-18 Plasma Cutting System
Service Manual Number 0-2692
Published by:
Thermal Dynamics Corporation
Industrial Park No. 2
West Lebanon, New Hampshire, USA 03784
[phone]
Copyright 1999 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 liabil-
ity to any party for any loss or damage caused by any error or
omission in the Firepower FP-18 Plasma Cutting System Service
Manual, whether such error results from negligence, accident, or
any other cause.
Printed in the United States of America
April 2000
WARNING
WARNING

TABLE OF CONTENTS
1.0 GENERAL INFORMATION ............................................................................................................1
1.1 Notes, Cautions, Warnings ..............................................................................................1
1.2 Important Safety Precautions ..........................................................................................1
1.3 Publications ....................................................................................................................2
1.4 Note, Attention et Avertissement......................................................................................2
1.5 Precautions De Securite Importantes...............................................................................3
1.6 Documents De Reference.................................................................................................4
1.7 Declaration of Conformity ...............................................................................................5
1.8 Statement of Warranty ....................................................................................................6
2.0 INTRODUCTION ..........................................................................................................................7
2.1 Scope Of Manual.............................................................................................................7
2.2 General Service Philosophy..............................................................................................7
2.3 Service Responsibilities ...................................................................................................7
2.4 Technical Specifications ..................................................................................................7
3.0: SERVICE TROUBLESHOOTING ..................................................................................................8
3.1 Introduction....................................................................................................................8
3.2 Periodic Inspection & Maintenance ..................................................................................8
3.3 Common Cutting Faults ..................................................................................................8
3.4 Common Operating Problems ..........................................................................................9
3.5 Troubleshooting Guide ....................................................................................................9
3.6 Torch & Leads Troubleshooting ..................................................................................... 12
4.0 REPAIRS & REPLACEMENT PROCEDURES ............................................................................... 12
4.1 General Information ...................................................................................................... 12
4.2 Removing Cover/Handle................................................................................................ 13
4.3 Torch Head Assembly Replacement ............................................................................... 13
4.4 Torch Switch Only Replacement ....................................................................................14
4.5 Air Compressor Replacement......................................................................................... 15
4.6 Capacitor Replacement.................................................................................................. 15
4.7 Control PC Board Replacement...................................................................................... 16
4.8 Power Relay Replacement .............................................................................................. 16
4.9 ON/OFF Power Switch Replacement .............................................................................. 17
4.10 Fan Replacement......................................................................................................... 17
4.11 Diode Bridge Rectifier Replacement .............................................................................17
4.12 Resistor Replacement .................................................................................................. 17
4.13 Transformer/Ferrite Core Assembly Replacement ........................................................ 18
5.0 PARTS LIST ............................................................................................................................... 18
5.1 Returns ........................................................................................................................ 18
5.2 Parts Replacement ........................................................................................................ 19
5.3 Power Supply Replacement Parts................................................................................... 20
5.4 Torch Replacement Parts................................................................................................22
APPENDIX I - LEADS CONNECTIONS ............................................................................................... 23
APPENDIX II - INTERCONNECTING DIAGRAM .................................................................................. 24
APPENDIX III - INTERCONNECTING DIAGRAM ................................................................................. 26

Special 6/22/99 1 GENERAL INFORMATION
1.0 GENERAL
INFORMATION
1.1 Notes,Cautions, 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 background information which
requires additional emphasis or is helpful in efficient opera-
tion of the system.
CAUTION
A procedure which, if not properly followed, may cause dam-
age to the equipment.
WARNING
A procedure which, if not properly followed, may cause in-
jury to the operator or others in the operating area.
1.2 ImportantSafetyPrecautions
WARNING
OPERATION AND MAINTENANCE OF PLASMA ARC
EQUIPMENT CAN BE DANGEROUS AND HAZARD-
OUS TO YOUR HEALTH.
Plasma arc cutting produces intense electric and magnetic
emissions that may interfere with the proper function of car-
diac pacemakers, hearing aids, or other electronic health equip-
ment. Persons who work near plasma arc cutting applica-
tions 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 1-603-298-5711 or your local distribu-
tor if you have any questions.
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. You must be very careful when cutting or
welding any metals which may contain one or more of the fol-
lowing:
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 work-
place, refer to item 1 in Subsection 1.3, 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 chlori-
nated solvents and cleansers. Remove all sources of these va-
pors.
ELECTRIC SHOCK
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.
•Never touch any parts that are electrically “live”or “hot”.
•Wear 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 1.3, Publications.
•Disconnect power source before performing any service or re-
pairs.
•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 pro-
tected.
•Ventilate all flammable or explosive vapors from the workplace.
•Do not cut or weld on containers that may have held combus-
tibles.
•Provide a fire watch when working in an area where fire haz-
ards 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

GENERAL INFORMATION 2 Special 6/22/99
a water table unless the hydrogen gas can be eliminated or
dissipated. Trapped hydrogen 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.
•To protect your hearing from 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 Subsec-
tion 1.3, Publications, in this manual.
PLASMA ARC RAYS
PlasmaArc 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 protected.
•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 recommended in Subsection 1.3, item 4.
1.3 Publications
Refer to the following standards or their latest revisions for more in-
formation:
1. OSHA, SAFETY AND HEALTH STANDARDS, 29CFR 1910,
obtainable from the Superintendent of Documents, U.S. Gov-
ernment Printing Office, Washington, D.C. 20402
2. ANSI Standard Z49.1, SAFETYIN WELDING AND CUTTING,
obtainable from the American Welding Society, 550 N.W.
LeJeune Rd, Miami, FL 33126
3. NIOSH, SAFETYAND HEALTH INARC WELDING AND GAS
WELDING AND CUTTING, obtainable from the Superinten-
dent of Documents, U.S. Government Printing Office, Wash-
ington, D.C. 20402
4. ANSI Standard Z87.1, SAFE PRACTICES FOR OCCUPATION
AND EDUCATIONAL EYE AND FACE PROTECTION, ob-
tainable 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 Stan-
dards 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 Standards Institute, 1430 Broadway, New
York, NY 10018
7. AWS Standard A6.0, WELDING AND CUTTING CONTAIN-
ERS WHICH HAVE HELD COMBUSTIBLES, obtainable from
American Welding Society, 550 N.W. LeJeune Rd, Miami, FL
33126
8. NFPAStandard 51, OXYGEN-FUELGAS SYSTEMS FORWELD-
ING, CUTTING AND ALLIED PROCESSES, obtainable from
the National Fire Protection Association, Batterymarch Park,
Quincy, MA 02269
9. NFPA Standard 70, NATIONAL ELECTRICAL CODE, obtain-
able from the National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269
10. NFPAStandard 51B, CUTTINGAND 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, Arling-
ton, VA 22202
12. CSA Standard W117.2, CODE FOR SAFETY IN WELDING
AND CUTTING, obtainable from the Canadian Standards As-
sociation, Standards Sales, 178 Rexdale Boulevard, Rexdale,
Ontario, Canada M9W 1R3
13. NWSA booklet, WELDING SAFETY BIBLIOGRAPHY obtain-
able from the National Welding Supply Association, 1900Arch
Street, Philadelphia, PA 19103
14. American Welding Society Standard AWSF4.1, RECOM-
MENDED SAFE PRACTICES FOR THE PREPARATION FOR
WELDING AND CUTTING OF CONTAINERS AND PIPING
THAT HAVE HELD HAZARDOUS SUBSTANCES, obtainable
from theAmerican Welding Society, 550 N.W. LeJeune Rd, Mi-
ami, FL 33126
15. ANSI Standard Z88.2, PRACTICE FOR RESPIRATORY PRO-
TECTION, obtainable from American National Standards In-
stitute, 1430 Broadway, New York, NY 10018
1.4 Note,AttentionetAvertissement
Dans ce manuel, les mots “note,”“attention,”et “avertissement”sont
utilisés pour mettre en relief des informations àcaractère important.
Ces mises en relief sont classifiées comme suit :
NOTE
Toute opération,procédureourenseignement général surlequel
il importe d’insister davantage ou qui contribue à l’efficacité
de fonctionnement du système.
ATTENTION
Toute procédure pouvant résulter l’endommagement du
matériel en cas de non-respect de la procédure en question.
AVERTISSEMENT
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.

Special 6/22/99 3 GENERAL INFORMATION
1.5 PrecautionsDeSecurite
Importantes
AVERTISSEMENT
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 votre distributeur
local si vous avez des questions.
FUMÉE et GAZ
La fumée et les gaz produits par le procédéde 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 àalimentation 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 différents procédés. Vous devez
prendresoin lorsquevous coupezou soudeztout 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 sécuritédes matières
(sigle américain “MSDS”); celles-ci devraient être fournies avec
le matériel que vous utilisez. Les MSDS contiennent des
renseignements quant àla quantitéet 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 àla page 4.
•Utilisez un équipement spécial tel que des tables de coupe àdébit
d’eau ou àcourant 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 générépar la fumée provenant
dessolvants etdes produitsdenettoyage chlorés.Elimineztoute
source de telle fumée.
CHOC ELECTRIQUE
Les chocs électriques peuvent blesser ou même tuer. Le
procédéau jet de plasma requiert et produit de l’énergie 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 tra-
vail 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 4, article 9.)
•Débranchez l’alimentation électriqueavanttout travaild’entretien
ou de réparation.
•Lisez et respectez toutes les consignes du Manuel de consignes.
INCENDIE ET EXPLOSION
Les incendies et les explosions peuvent résulter des scories chaudes,
desétincelles oude l’arc deplasma. Le procédéàl’arcde 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.
•Necoupez paset nesoudez pasles conteneursayant 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 PAS couper les alliages en aluminium
sous l’eau ou sur une table d’eau àmoins que le gas hydrogène
peut s’échapper ou se dissiper. Le gas hydrogène accumulé
explosera si enflammé.
RAYONS D’ARC DE PLASMA
Les rayons provenant de l’arc de plasma peuvent blesser vos yeux et
brûler votre peau. Le procédéàl’arc de plasma produit une lumière
infra-rouge et des rayons ultra-violets très forts. Ces rayons d’arc
nuiront àvos 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 sécuritémunies 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.

GENERAL INFORMATION 4 Special 6/22/99
•Protégez les autres personnes se trouvant sur la zone de travail
contrelesrayons del’arcenfournissant descabines ou desécrans
de protection.
•Respectez le teint de lentille recommandédans le article 4, page
4.
BRUIT
Le bruit peut provoquer une perte permanente de l’ouïe. Les procédés
de soudage àl’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 tam-
pons protecteurs et/ou des protections auriculaires. Protégez
également les autres personnes se trouvant sur le lieu de tra-
vail.
•Il faut mesurer les niveaux sonores afin d’assurer que les décibels
(le bruit) ne dépassent pas les niveaux sûrs.
•Pourdes renseignementssur lamanièrede tester lebruit, consultez
l’article 1, page 4.
1.6 DocumentsDeReference
Consultez les normes suivantes ou les révisions les plus récentes ayant
étéfaites àcelles-ci pour de plus amples renseignements :
1. OSHA, NORMES DE SÉCURITÉDU TRAVAIL ET DE PRO-
TECTION DE LA SANTÉ, 29CFR 1910, disponible auprès du
Superintendent of Documents, U.S. Government Printing Of-
fice, Washington, D.C. 20402
2. Norme ANSI Z49.1, LA SÉCURITÉDES 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, LASÉCURITÉET LASANTÉLORS DES OPÉRATIONS
DE COUPE ET DE SOUDAGEÀL’ARC ETAU GAZ, disponible
auprès du Superintendent of Documents, U.S. Government
Printing Office, Washington, D.C. 20402
4. Norme ANSI Z87.1, PRATIQUES SURES POUR LA PROTEC-
TION DES YEUX ET DU VISAGEAU TRAVAIL ET DANS LES
ECOLES, disponible de l’Institut Américain des Normes
Nationales(American NationalStandardsInstitute), 1430Broad-
way, 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. NormeANSI 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 (AWS),
LE SOUDAGE ET LA COUPE DE CONTENEURS AYANT
RENFERMÉDES PRODUITS COMBUSTIBLES, disponible
auprès de la American Welding Society, 550 N.W. LeJeune Rd.,
Miami, FL 33126
8. Norme 51 de l’Association Américaine pour la Protection contre
les Incendies (NFPA), LES SYSTEMES ÀGAZ AVEC ALIMEN-
TATION EN OXYGENE POUR LE SOUDAGE, LACOUPE 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 Associa-
tion), 1235 Jefferson Davis Highway, Suite 501, Arlington, VA
22202
12. Norme CSA W117.2, CODE DE SÉCURITÉPOUR LE
SOUDAGE ET LA COUPE, disponible auprès de l’Association
des Normes Canadiennes, Standards Sales, 178 Rexdale Boule-
vard, Rexdale, Ontario, Canada, M9W 1R3
13. ivret NWSA, BIBLIOGRAPHIE SUR LA SÉCURITÉDU
SOUDAGE, disponible auprès de l’Association Nationale de
Fournitures de Soudage (National Welding Supply Association),
1900 Arch Street, Philadelphia, PA 19103
14. Norme AWSF4.1 de l’Association Américaine de Soudage,
RECOMMANDATIONS DE PRATIQUES SURES POUR LA
PRÉPARATION ÀLA COUPE ET AU SOUDAGE DE
CONTENEURS ET TUYAUX AYANT RENFERMÉDES
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

Special 6/22/99 5 GENERAL INFORMATION
1.7 Declarationof Conformity
Manufacturer: Thermal Dynamics Corporation
Address: Industrial Park #2
West Lebanon, New Hampshire 03784
USA
The equipment described in this manual conforms to all applicable aspects and regulations of the‘Low Voltage Direc-
tive’(European Council Directive 73/23/EEC as amended by Council Directive 93/68/EEC) and to the National leg-
islation for the enforcement of this Directive.
Serialnumbers areunique with each individual piece of equipment and details description, parts used tomanufacture
a unit and date of manufacture.
National Standard and Technical Specifications
The product is designed and manufactured to a number of standards and technical requirements among them are:
* CSA(Canadian StandardsAssociation) standard C22.2 number 60 forArc welding equipment.
* UL(Underwriters Laboratory) rating 94VO flammability testing for all printed-circuit boards used.
* ISO/IEC 60974-1 (BS 638-PT10) (EN 60 974-1) applicable to welding equipment and associated 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 according to instructions in this manual and
related industry standards, and performs as specified. Rigorous testing is incorporated into the manufacturing pro-
cess to ensure the manufactured product 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 representative: Steve Ward
Director of Operations
ThermadyneUK
ChorleyEngland

GENERAL INFORMATION 6 Special 6/22/99
1.8 StatementofWarranty
LIMITED WARRANTY: Firepower®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 Firepower products as stated below,
Firepower shall, upon notification thereof and substantiation that the product has been stored, installed, operated, and
maintained in accordance with Firepower’s specifications, instructions, recommendations and recognized standard industry
practice, and not subject to misuse, repair, neglect, alteration, or accident, correct such defects by suitable repair or
replacement, at Firepower’s sole option, of any components or parts of the product determined by Firepower to be defective.
THIS WARRANTY IS EXCLUSIVE AND IS IN LIEU OF ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE.
LIMITATION OF LIABILITY: Firepower 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 distributors (hereinafter
“Purchaser”) for service interruption. The remedies of the Purchaser set forth herein are exclusive and the liability of Firepower
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 Firepower 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.
THISWARRANTYBECOMESINVALID IF REPLACEMENT PARTS ORACCESSORIES ARE USED WHICHMAY IMPAIR
THE SAFETY OR PERFORMANCE OF ANY FIREPOWER PRODUCT.
THIS WARRANTY IS INVALID IF THE PRODUCT IS SOLD BY NON-AUTHORIZED PERSONS.
The limited warranty periods for Firepower FP-18 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
following further limitations on such two (2) year period.
POWER SUPPLY PARTS LABOR
MAIN POWER MAGNETICS .............................................................................................1 YEAR ................. 1 YEAR
ORIGINAL MAIN POWER RECTIFIER ............................................................................ 1 YEAR ................. 1 YEAR
CONTROL PC BOARD ........................................................................................................ 1YEAR .................. 1 YEAR
ALL OTHER CIRCUITS AND COMPONENTS ............................................................... 1 YEAR ................. 1 YEAR
INCLUDING, BUT NOT LIMITED TO, STARTING
CIRCUIT, CONTACTORS, RELAYS, SOLENOIDS, PUMPS,
POWER SWITCHING SEMI-CONDUCTORS
TORCH AND LEADS ............................................................................................................. 180 DAYS............. 180 DAYS
REPAIR/REPLACEMENT PARTS ......................................................................................... 90 DAYS.................NONE
Warranty repairs or replacement claims under this limited warranty must be submitted by an authorized Firepower 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 Firepower warranties.
Effective April 1998

Service Manual 0-2692 7 Firepower FP-18 Plasma Cutter
2.3 Service Responsibilities
The Service Technician should be familiar with the equip-
ment and its capabilities and should be prepared to rec-
ommend arrangements of components which will pro-
vide 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 the Technical Ser-
vices Department in West Lebanon for assistance.
2.4 Technical Specifications
A. System Specifications
System Specifications
InputPower 120VAC ± 10%, 60Hz, SinglePhase
OutputPower 12 Ampsmaximum@70VDC
Duty Cycle 30% at70VDC, 12 amps output
MaximumOCV 280 VDC
PilotCircuitry Capacitive Discharge (CD), ConstantDC
Weightwith Leads 55 lbs
Power Supply L 16 in. (406 mm)
Dimensions W 9in. (229mm)
H 10 in. (254 mm)
Work Cable 15ft. (4.57 m)
InputPower Cable 6.6 ft. (2 m) minimum
Torch Style PCH-10 70°
Torch Dimensions L 7.98 in. (203 mm)
W 2.95 in. (75 mm)
Cutting Rating 12 Amps Max. StraightPolarity
CutCapacity Mostmetalsup to 1/8 in. (3.2mm)
Severance Mostmetalsupto 3/16in. (4.76mm)
Pierce Rating 1/16 in. (1.59 mm)
Transfer Distance Approx. 1/8 in. (3.2mm)
Gas Requirements Compressed Air (Built-in)
LeadsLength 20ft. (6.10 m)
2.0 INTRODUCTION
2.1 Scope Of Manual
This manual provides service instructions for the Fire-
power ®FP-18 Plasma Cutter.
Information in this edition is particularly applicable to
the Troubleshooting and Repair of the equipment, and is
intended for use by properly trained Service Technicians
familiar with this equipment.
Read this manual and the Firepower FP-18 Plasma Cut-
ter Operating Manual, 0-2691, thoroughly. A complete
understanding of the capabilities and functions of the
equipment will assure obtaining the performance for
which it was designed.
2.2 General Service Philosophy
Several key points are essential to properly support the
application and operation of this equipment.
A. Application
The equipment should satisfy the customer’s require-
ments 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 selec-
tion of standard options and accessories are to be made
to this equipment.
C. Customer/Operator Responsibilities
It is the customer/operator's responsibility to maintain
the equipment and peripheral accessories in good oper-
ating order in accordance with the procedures outlined
in the Operating Manual, and to protect the equipment
from accidental or malicious damage.
D. Repair Restrictions
Theelectronicsconsists of a Printed Circuit BoardAssem-
bly which must be carefully handled, and must be re-
placed as a unit. No replacement of printed circuit sol-
der-mounted components is allowed except as noted in
this manual. If PC Board is to be returned, the replaced
Printed Circuit Board Assembly must be properly pack-
aged in protective material and returned intact per nor-
mal procedures.

Firepower FP-18 Plasma Cutter 8 Service Manual 0-2692
B. Dimensions
16.0 in
(406 mm) 9.0 in
(229 mm)
10.0 in.
(254 mm)
A-02004
Figure 2-1 Power Supply Dimensions
A-02006
7.98 in (203 mm)
1.06 in (27 mm)
2.95 in
(75 mm)
Figure 2-4 Torch Dimensions
3.0: SERVICE
TROUBLESHOOTING
3.1 Introduction
This section provides service diagnostics for the Fire-
power FP-18 Plasma Cutter with PCH-10 Torch, aiding
the technician to isolate faulty subassemblies.
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 fac-
tory warranty.
WARNING
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 troubleshoot-
ing techniques.
3.2 Periodic Inspection &
Maintenance
TheFirepowerFP-18 Operating Manual 0-2691, describes
theinspection andmaintenance procedureswhich should
be performed at periodic intervals. Routine Maintenance
ensures optimum performance of equipment and can pre-
venttheuser fromencountering problemswiththisequip-
ment. Refer to that manual for instructions on power
supply and torch maintenance.
3.3 Common Cutting Faults
Poor or lackluster performance can often be improved
by slight modifications to technique or equipment. For
example:
A. Insufficient Penetration
1. Cutting speed too fast
2. Torch tilted too much
3. Metal too thick
4. Worn torch parts
5. Standoff too high
6. Line voltage too low
7. Extension cord with inadequate rating
B. Main Arc Extinguishes
1. Cutting speed too slow
2. Torch standoff too high from workpiece
3. Work cable disconnected
4. Worn torch parts
C. Excessive Dross Formation
1. Cutting speed too slow
2. Torch standoff too high from workpiece
3. Worn torch parts
D. Short Torch Parts Life
1. Exceeding system capability (material too thick)
2. Excessive pilot arc time
3. Improperly assembled torch
4. Inadequate air supply (check filter on Compressor)
5. Faulty Air Compressor
6. Ground or work lead not connected

Service Manual 0-2692 9 Firepower FP-18 Plasma Cutter
3.4 Common Operating
Problems
Gettingused to theway thesystem sounds andfeels while
it is operating properly will help to determine the nature
of problems if they arise.
A. Compressor Related
If the unit is cold, theAir Compressor may not start up or
may run sluggishly. Most likely, when the torch switch is
depressed, the unit will click once and nothing more will
happen. Let the unit warm up to room temperature ap-
proximately 50°F (10°C) and try again.
If the air filter on the compressor becomes clogged, the
compressormaysound more labored,cut speed and qual-
ity will be reduced, and the arc may have a more green
color. The air filter element can be cleaned - remove it,
blow air through it, then reinstall it.
B. Power Source Related
This system draws about 20 amps rms from the 120 VAC
service under normal operating conditions. If the 120V
service available is saggy, pilot and cut performance will
be degraded. In some cases, the service circuit breaker
may open during use. Some things that will help:
•Use a service fused or circuit breaker for 20 amps.
•Use as short an extension cord as possible.
•Use heavy gauge extension cords (Refer to Operat-
ing Manual 0-2691 for sizes).
•Try different outlets on different branch circuits. Use
the one that gives the strongest pilot.
C. Power Supply/Torch Related
In some instances when the torch switch is pressed there
is no pilot. You may need to try several times before the
torch fires.
If the torch does not fire (no pilot arc) soon after the torch
switch is activated, try releasing the torch switch and let-
tingthe leads bleeddown beforetryingagain. This should
help because the torch fires best at a lower voltage with
lower air pressure at the torch.
D. Cutting Related
1. Piloting
One of the features of this plasma cutter is the con-
stant DC pilot. This means the plasma arc is always
“on”- either as a pilot arc, or a cutting arc, resulting in
avery smooth, forgiving system. This also means that
the torch tip will wear fairly rapidly if you pilot for
an extended time or cut with too great a standoff (es-
sentiallyswitching froma transferredcuttingarcback
to the constant DC pilot arc).
The best way to prevent this is to pilot for no more
than 5 seconds at a time (or start with the torch in
contact with the material) and “drag cut”, that is, hold
the tip in direct contact with the material to be cut.
For some materials, holding a slight standoff (1/16")
may provide a better cut.
NOTE
Piloting is harder on parts life than actual cutting
because the pilot arc is directed from the electrode
to the tip rather than to a workpiece. Whenever
possible, avoid excessive pilot arc time to improve
parts life.
2. Torch Standoff
Improper standoff (the distance between the torch tip
and workpiece) can adversely affect tip life as well as
shield cup life. Reducing standoff will generally re-
sult in a more square cut.
NOTE
Although the FP-18 will cut using standoff, this
unit is primarily a drag-cutting machine.
3.5 Troubleshooting Guide
A. General
The troubleshooting covered in this Service Manual re-
quirespower supply disassembly andlive measurements.
Troubleshootingand repairingthis unit is a processwhich
should be undertaken only by those familiar with high
voltage high power electronic equipment.
WARNING
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 troubleshoot-
ing techniques.
B. How To Use This Guide
The following information is a guide to help determine
the most likely causes for various symptoms. The guide
is set up in the following manner:
X. Symptom (Bold Type)
1. Cause (Italic Type)
a. Check/Remedy (Test Type)

Firepower FP-18 Plasma Cutter 10 Service Manual 0-2692
Locate your symptom, check causes (easiest is usually
first; sometimes the order is important, if noted), then
remedies. Repair as needed being sure to verify that the
unit is fully operational after any repairs.
C. No Power, AC switch on, red indicator
dark, no fan.
1. No power from wall unit.
a. Test electrical outlet with voltmeter or some
other known good load (trouble light, hand
drill, etc).
If AC line voltage is present, go to step #C2.
If AC line voltage is not present, replace fuse
or reset circuit breaker.
2. Damaged power cord.
a. Confirm with voltmeter if ac line voltage is
present at input to power switch.
If ac voltage is present, proceed to subsection
C3.
If ac line voltage is not present, replace power
cord.
3. Power switch faulty.
a. Confirm with voltmeter if AC line voltage is
present at main capacitor terminals when
power switch is on.
If ac line voltage is not present, replace power
switch.
D. Power OK, service circuit breaker or
fuse opens after the power switch is
switched on.
NOTE
Proceed with troubleshooting for these components
in order:
1. Faulty Fan.
a. Disconnect the Fan and insulate the two wires
going to the Fan with tape (separately), then
reapply power.
If the circuit breaker or fuse opens after the
power switch is switched on, go to step #D2.
If the circuit breaker or fuse is okay, replace
Fan.
2. Faulty Transformer Assembly or Capacitor.
a. With the Fan still disconnected, disconnect two
leads from the transformer that are connected
to the Capacitor , then apply power.
If the circuit breaker or fuse opens after power
is applied, the Capacitor is shorted. Replace
Capacitor.
If the circuit brreaker or fuse is okay, replace
Transformer.
E. Power OK, fan runs, no compressor
operation or pilot when torch switch
pressed.
1. Shield cup loose, PIP not making contact.
a. Reseat the torch parts, tighten shield cup.
2. Unit overtemp.
a. Leave power on so fan can cool unit, test again
after 10 min.
3. Shorted torch parts.
a. Replace torch consumables.
4. Torch switch may have broken or shorted wires.
a. Referto subsection 3.6, Torchand Leads Trouble-
shooting.
5. Overheated or faulty Compressor.
a. Press the torch switch. If a clicking can be heard
and/or the Relay is actuating (test button on
side pulls in), the Compressor motor may have
failed or overheated. If the Case of the Com-
pressor motor feels very warm, allow it to cool
and try again. The Compressor has its own
overtemp cutout switch.
If the unit fails to operate once it has cooled
down, replace the compressor.
6. Shorted Bridge Rectifier (BR2)
a. If the Rectifier (upper) is hot and the Trans-
former is buzzing or heating up, the rectifier is
shorted. Replace Rectifier.

Service Manual 0-2692 11 Firepower FP-18 Plasma Cutter
7 . Faulty Control PCB or Relay
CAUTION
Be sure torch is directed away from people or haz-
ards. A pilot arc may start!
a. Push the test button on the side of the Relay. If
the Compressor starts and the torch operates,
the PCB or Relay has most likely failed.
ThePCB can be isolated by removingthe push
on connectors from the Relay coil and measur-
ing the relay coil with an ohmmeter. If the coil
measures between 50 - 100ohms, the Relay is
good and the PCB should be replaced.
If the Compressor runs intermittently and arc-
ingcan be seen in theRelay casewhile the torch
switch is held on, the relay contacts are worn
and the Relay should be replaced.
F. Power OK, fan runs, compressor runs
intermittently, Relay Case shows
arcing when the torch switch is held
on.
1. Faulty Relay.
a. If the Compressor runs intermittently and arc-
ingcan be seen in theRelay Casewhile the torch
switch is held on, the relay contacts are worn
and the Relay should be replaced.
G. Power OK, fan runs, compressor starts
then shuts down as soon as the torch
switch is pressed.
1. Shorted, damaged, or incorrect torch parts.
a. Check that all torch parts are in good condition
and designed for use in the PCH-10 torch.
2. Faulty (open) Voltage Divider Resistor.
a. The voltage divider is the top Resistor. Discon-
nect the push-on connectors and measure the
Resistor with an ohmmeter. It should read 1K
ohms. If measurement is not 1K ohms, replace
Resistor.
3. Shorted Bridge Rectifier (BR1).
a. Probable if a loud hum or buzz is heard from
the main transformer after the Relay actuates.
If hum or buzzing noise exists, replace Bridge
Rectifier. (replace lower Bridge Rectifier, clos-
est to Chassis).
H. Power OK, fan runs, compressor runs,
no pilot or cutting arc with the torch
switch pressed.
1. Worn, contaminated, or incorrect torch parts.
a. Check that all torch parts are in good condition
and designed for use in the PCH-10 torch. Re-
place worn parts as necessary.
2. Parts not assembled correctly.
a. Reassemble torch parts.
3. Damaged torch or leads.
a. Check per subsection 3.6, Torch and Leads
Troubleshooting.
4. Faulty Control PCB.
a. Listen for a faint, sharp clicking noise, at about
3-4 clicks/second from the Ferrite Core Assem-
bly. If nothing is heard, the PCB should be re-
placed.
5. Faulty (open) Pilot Resistor.
a. ThePilot Resistoris mounted closest to the chas-
sis. Disconnect the the push on connectors and
measure the resistor with an ohmmeter. It
should read 0.5 ohms (essentially a short).
6. AC input too low.
a. If the AC line is below about 105vac, the torch
may not always start. Try an outlet on a differ-
ent branch circuit.
7. Faulty Ferrite/Transformer Assembly.
a. The Ferrite Transformer Assembly is used to
generate a high voltage pulse to establish the
pilot arc. Troubleshooting is limited to visual
inspection. The two primary connections and
two secondary connections should be checked
for general integrity and snug fit onto the push
on connectors. The Transformer Assembly it-
self should be free of large ferrite chips and
cracks along the core.
I. Torch pilots but does not cut well.
1. AC input power too low.
a. Use shortest service from AC outlet to breaker
panelas possible orlargergaugeextensioncord.
2. Work cable not attached.
a. Check work cable connection.
3. Restricted air flow.
a. Check lead for kinks or pinching restricting air
flow.

Firepower FP-18 Plasma Cutter 12 Service Manual 0-2692
4. Loose shield cup.
a. Tighten shield cup.
5. One or more gas distributor holes blocked.
a. Replace Gas Distributor.
6. Excessive parts wear.
a. Inspect torch consumables and replace as nec-
essary.
7. Damaged torch insulator
a. Check insulator between anode and cathode for
charring per subsection 3.6, Torch and Leads
Troubleshooting.
3.6 Torch & Leads
Troubleshooting
WARNINGS
Disconnectprimary power to the system beforedis-
assembling the torch, leads, or power supply.
DO NOT touch any internal torch parts while the
AC indicator light on the front panel of the power
supply is on.
Torch parts may get quite hot during normal op-
eration. Always wear light cutting gloves when
changingtorchparts just after operating the FIRE-
POWER system.
A. Checking the Center Insulator
The Center Insulator separates the negative and positive
charged sections of the torch. If the center insulator does
not provide adequate resistance, current which is in-
tended for the pilot arc may be dissipated into the torch
head, resulting in torch failure.
1. Remove the shield cup, tip, gas distributor, and elec-
trode from the torch.
Torch Head Assembly
Electrode Tip Standard
Shield Cup
Gas
Distributor
PCH-10
A-02007
Figure 3-1 PCH-10 Torch Head Parts Removal
2. Disconnect the torch lead from the power supply to
isolate the torch from power supply circuits. Refer to
Appendix I for Leads connections.
3. Using an ohmmeter (set to 10K or higher), check for
continuity between the electrode seat (negative) and
the brass threads of the torch assembly. Infinite resis-
tance (no continuity) should be found. If there is con-
tinuity between the two, remove the torch head from
the lead and check the torch head separately.
B. Checking Torch Lead
If the torch head assembly is okay, check the torch lead
by measuring the resistance between the positive pilot
lead connector and the negative lead fitting. If continu-
ity is found, the insulation between the torch leads is
breaking down and the torch and leads assembly should
be replaced.
NOTE
The lead cannot be replaced without replacing the
torch assembly as well.
If no continuity is found, check the resistance between
the negative plasma lead fitting and the electrode seat in
torch head. If no continuity is found, replace the torch
and leads assembly.
C. Checking Pilot and Switch Control
Wires
Check the pilot and switch control wires for continuity
from one end of the torch lead to the other. If no continu-
ity exists, replace torch and lead assembly.
D. Reassembling Torch and Leads
Replace parts as required, then recheck the torch head,
and lead connections to confirm proper measurements.
If each component is okay, reassemble torch and leads.
4.0 REPAIRS &
REPLACEMENT
PROCEDURES
4.1 General Information
•Failures identified on the Transformer/Inductor/
Chassis Assembly cannot be repaired - the entire
power supply must be replaced. Refer to the Parts
List for the catalog number for a replacement power
supply.
•The torch head, torch switch, and torch & leads as-
sembly are replaceable parts. The torch leads alone
arenotserviceable;problemsencountered in the leads
will require the torch & leads assembly to be replaced.

Service Manual 0-2692 13 Firepower FP-18 Plasma Cutter
•For instructions on replacing the torch & leads, work
cable & clamp, and input power cable, refer to Oper-
ating Manual 0-2691. (Refer to Appendix I, in this
manual, for leads connection diagram.)
•Most replacement hardware can be purchased locally.
•One of two harnesses has been used in this unit. For
units which are rev "C" or earlier, refer to the sche-
matic in Appendix II. For units which are rev "D" or
later, refer to the schematic in Appendix III. Check
the data tag on your unit for the rev level of your unit
andfollow instructions in this sectionwhereaplicable,
as they pertain to your unit.
WARNINGS
Disconnectprimary power to the system beforedis-
assembling the torch, leads, or power supply.
4.2 Removing Cover/Handle
1. Remove 2 screws in handle, 2 screws in end pan-
els,and four screwsnear base to removecover and
handle from unit.
NOTE
When replacing cover, make sure all wires are care-
fully positioned so that the wires are not pinched
when the cover and handle are secured.
4.3 Torch Head Assembly
Replacement
WARNINGS
Disconnectprimary power to the system beforedis-
assembling the torch or power supply.
Torch parts may get quite hot during normal op-
eration. Always wear light cutting gloves when
changing torch parts just after operating the FP-
18 System.
To Remove Torch Head Assembly:
NOTE
Refer to Figure 4-1 for parts identification.
1. Remove consumable parts from front end of torch.
2. Removesix screwsfromtorch handle assembly (A).
3. Remove both torch handle halves from the torch
and leads assembly , then complete the following:
a. Disconnect positive pilot lead connection at
torch head by removing pilot lead screw (B).
b. Cut tie wrap from torch hose (C).
c. Using X-acto knife or other small cutting tool,
cuttorchlead 1" (2.54 cm) from the end ofblack
sleeve (D) to reveal butt splice.
4. Pull torch head away from torch lead to expose 1/
2"-3/4" of cable.
5. Clamp down with vise grips on black sleeve of
lead so that cable cannot spring back into lead (E).
6. Cut cable at end of butt splice and remove torch
head assembly (F).
7. Removeorange insulatingsleeving from torch head
gas input (G). Note: Sleeving is optional. Some
torch assemblies may not have sleeving.
8. Remove torch O-ring from torch split holder (H).
9. Remove the two screws from the torch head split
holder and separate the halves (I).
10. Remove the torch head from the holder. Do not
disturb PIP connections.
1.000
O-Ring
Remove Screws
Orange Torch
Sleeving
(Optional)
Cut Cable Here
Place Vise
Grips Here
Remove Pilot
Lead Screw
Cut Black
Hose
Cut Tie Wrap
Remove Six Screws
Switch
A
B
C
D
E
F
G
H
I
A-02295
Washer
Figure 4-1 Removing Torch HeadAssembly

Firepower FP-18 Plasma Cutter 14 Service Manual 0-2692
To Install Replacement Torch Head Assembly:
NOTE
Refer to Figure 4-2 for parts identification.
1. Place replacement torch head in torch head split
holder halves and secure with 2 screws removed
in step 9 above (K). Do not disturb PIP connec-
tions.
2. Install O-ring removed in step 8 above (L).
3. Optional: Install orange sleeving on replacement
torch head gas input.
4. Place torch head in correct orientation, then insert
lead cable into torch butt slice and crimp (M).
5. Remove vise grips.
6. Lubricate torch head glands lightly with silicone
and push hose back onto barbs up to the point
where the teflon tubing and brass fitting meet (N).
7. Install tie wrap onto hose in correct position (C),
removing any excess.
8. Connect pilot lead to pilot lead terminal by placing
washer between terminal and connector and in-
stalling screw (O).
9. Push pilot lead under cable jacket until there is no
excess.
Install Pilot
Lead Screw
Butt Splice
Insert Cable Into
Butt Splice & Crimp
Install
O-Ring
Install Screws
New Torch Head
J
K
M
N
Teflon Tubing
A-02296
L
O
Washer
4-2 Installing Torch Head Assembly
4.4 Torch Switch Only
Replacement
NOTE
This procedure requires the following tools (or
equivalent): screwdriver, soldering iron, Nokorde
Flux.
WARNING
Disconnectprimary power to the system beforedis-
assembling the torch, leads, or power supply.
1. Remove consumable parts from front end of torch.
2. Remove the six screws from the torch handle as-
sembly and remove torch and leads assembly.
3. Usingsoldering iron, carefullyremovesolderwhere
orange wire connects to switch terminal.
NOTE
Be careful not to overheat the torch switch while
removing soldering from terminals.
4. Apply Nokorde Flux to orange wire and to switch
post. Insert orange wire in switch post hole and
solder, keeping solder at a minimum required for
good joint.
5. Repeat steps 3 and 4, this time for the white wire.
Torch Switch
PIP Pin
PIP Pin Shield Cup
To Control
Cable Wiring
Butt Splice A-00784
Figure 4-3 Torch Switch Schematic
6. Place the torch head in the torch handle bottom.
Carefully return the torch switch and button w/
springs to their proper position. Replace cover on
the handle assembly, and screw together with six
screws.
NOTE
Make sure torch switch wires are seated in their
guides so that the wires are not pinched when the
handle is secured.
7. Install consumables parts in front end of torch.

Service Manual 0-2692 15 Firepower FP-18 Plasma Cutter
4.5 Air Compressor
Replacement
NOTES
Refer to subsection 4.1, General Information, for
information about wire harnesses.
Refer to Appendix II for parts location and orien-
tation.
1. Removecover/handle fromunitper subsection 4.2.
2. Locate the nylon nut on the 90°nylon fitting on
side of Air Compressor. Loosen the nylon nut and
slide the brass torch lead fitting/faston connector
out.
3. Complete one of the following, as it pertains to
your unit:
•Rev C units or earlier - Disconnect black wire
from Compressor to faston splice & wire #21.
Disconnect red wire from Compressor to up-
per diode piggy back terminal.
•RevD units or later - Disconnect black wirefrom
Compressor to faston splice & wire #29. Dis-
connectredwirefrom Compressor to upper di-
ode piggy back terminal.
4. Slide Compressor out of bracket.
5. Note position and angle of 90°nylon nut connected
to the Air Compressor. Remove fitting.
6. Clean old teflon thread sealant from nylon fitting,
apply new thread sealant and install nylon fitting
on replacement Air Compressor. Make sure fit-
ting is in proper position.
7. Remove "feet" from Compressor and install on re-
placement Compressor.
8. Insert replacement Air Compressor into bracket,
insuring "feet" have dropped into slots in bracket.
9. Apply a small amount of O-Ring lubricant to brass
torch fitting and insert into 90°nylon fitting.
Tighten nylon nut.
NOTE
Be careful not to remove the nylon nut completely
as there are small parts inside that could fall out.
10. Connect the following as it pertains to your unit:
•Rev C units (or earlier) - Connect black wire
from Compressor to faston splice & wire #21.
Connect red wire from Compressor to upper
diode piggyback terminal.
•Rev D units (or earlier) - Connect black wire
from Compressor to faston splice & wire #29.
Connect red wire from Compressor to upper
diode piggyback terminal.
11. Position wire connector L4 so that it runs along
side the Transformer, NOT across the top of the
Transformer.
12. Install cover/handle by reversing steps in sub-
section 4.2, keeping in mind the following:
a. The Air Compressor is secured in position by
one of the handle screws on the top side of the
power supply. Make sure that no wires ob-
struct the cover when it is installed.
4.6 Capacitor Replacement
WARNING
Disconnectprimary power to the system beforedis-
assembling the torch, leads, or power supply.
NOTE
Refer to subsection 4.1, General Information, for
information about wire harnesses.
1. Removecover/handle fromunitper subsection 4.2.
2. Make note of all wire connections and locations to
Capacitor.
3. Remove all wire connections to Capacitor.
4. The Capacitor is held in place by a tab located on
the Transformer frame. Using a screw driver or
similar tool, pry the tab back slightly to allow the
Capacitor to slide out of the bracket.
5. Install replacement Capacitor, by reversing steps
1-4, keeping in mind the following:
a. Make sure the Capacitor is securely positioned
behind tab. Tab may need to be bent.
b. Position wire connector L4 so that it runs along
side the Transformer, avoiding contact with
metal parts.

Firepower FP-18 Plasma Cutter 16 Service Manual 0-2692
4.7 Control PC Board
Replacement
The FIREPOWER Plasma Cutter has been manufactured
using one of two styles of PC Board Assemblies. The
Board will either have round mounting holes in the cor-
ners or key slotted mounting holes in the corners. Fol-
low procedures as they apply to your unit.
NOTES
It may be easier to remove the PC Board if the Ca-
pacitor is removed first.
All replacement PC Boards have key slotted holes.
WARNING
Disconnectprimary power to the system beforedis-
assembling the torch, leads, or power supply.
A. To Remove PC Board:
1. Removecover/handle fromunitper subsection 4.2.
2. Remove Capacitor (optional) per subsection 4.6.
3. Note all wiring connections and locations to the
PC Board.
4. Disconnect all wire connections to the PC Board,
removing any tie wraps where necessary.
5. Remove PC Board from unit by completing the fol-
lowing, as it applies to your unit:
PC Board with round mounting holes:
a. Remove the two (2) metal "C" clips located on
the top two standoffs that secure the PC Board
to the unit.
b. Gently pry PC Board off the standoffs then re-
move the second set of metal "C" clips (2).
NOTE
In some cases, the PCB may be mounted on stand-
offs and secured with RTV over the ends. Remove
the RTV and then remove the PCB from the unit.
PC Board with key slotted mounting holes:
a. Remove two (2) fastener plastic push ons from
key slotted holes in corners of PC Board.
b. Slide PC Board up or down to disengage, then
remove from unit.
B. To Install Replacement PC Board:
1. Install replacement key slotted PC Board by plac-
ing PC Board over standoffs and sliding Board
down into position.
2. Push a white fastener plastic push on into each
keyhole (just above standoffs) to secure the PC
Board into position.
3. Reverse steps 1-4, keeping in mind the following:
a. Make sure J2 is not offset by one or more pins.
b. Install new tie wraps on wires connected to the
PC Board, as necessary.
4.8 Power Relay Replacement
NOTES
The Control PC Board must be moved out of the
waybeforethe PowerRelay canbe replaced.(It may
be easier to move the Contrl PC Board if the Ca-
pacitor is removed first.)
Refer to subsection 4.1, General Information, for
information about wire harnesses.
WARNING
Disconnectprimary power to the system beforedis-
assembling the torch, leads, or power supply.
1. Removecover/handle fromunitper subsection 4.2.
2. Remove Capacitor (optional step) per instructions
in 4.6.
3. Remove PCB from standoffs per subsection 4.7.B.
4. Slide PC Board away from Relay.
5. Note all wiring connections and locations to the
Relay.
6. Remove wirings connected to Relay.
7. Slide Relay out from bracket, towards the center of
the unit.
8. Install replacement Relay, by reversing the above
steps, keeping in mind the following:
a. Position wire connector L4 so that it runs along
sidethe Transformer, NOT acrossthetop of the
Transformer.