Thermal Dynamics C-20A Cutskill User manual

PLASMA
CUTSKILL®
Service Manual
C-20A
PLASMA CUTTING
SYSTEM
Rev. AA.01 Issue Date: March 26, 2007 Manual 0-4697
Operating Features:

WARNINGS
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 the Manufacturer's best judgement,
the Manufacturer assumes no liability for its use.
Plasma Cutting Power Supply
CutSkill®
SL60™ 1Torch™
Operation Manual Number 0-4697
Covered under U.S. Patents.
Published by:
Thermadyne Corporation
82 Benning Street
West Lebanon, New Hampshire, USA 03784
[phone]
www.thermal-dynamics.com
©Copyright 2005, 2006, 2007 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 this Manual, whether such error results from negligence, accident, or
any other cause.
Printed in the United States of America
Publication Date: March 26, 2007
Record the following information for Warranty purposes:
Where Purchased:____________________________________
Purchase Date:_______________________________________
Power Supply Serial #:________________________________
Torch Serial #:________________________________________

TABLE OF CONTENTS
SECTION 1:
GENERAL INFORMATION ................................................................................................ 1-1
1.01 Notes, Cautions and Warnings ...................................................................... 1-1
1.02 Important Safety Precautions ....................................................................... 1-1
1.03 Publications .................................................................................................. 1-2
1.04 Statement of Warranty .................................................................................. 1-4
SECTION 2:
INTRODUCTION ............................................................................................................... 2-1
2.01 Overview ...................................................................................................... 2-1
2.02 General Specifications .................................................................................. 2-1
2.03 Features ....................................................................................................... 2-1
2.04 Torch Ratings ................................................................................................ 2-2
2.05 System Contents .......................................................................................... 2-2
2.06 Transporting Methods ................................................................................... 2-2
SECTION 3:
INSTALLATION .................................................................................................................. 3-1
3.01 Site Selection ............................................................................................... 3-1
3.02 Electrical Input Connections ......................................................................... 3-1
3.03 Compressed Air Connection ......................................................................... 3-1
SECTION 4:
OPERATION ...................................................................................................................... 4-1
4.01 Front Control Panel ....................................................................................... 4-1
4.02 Preparations For Operating ........................................................................... 4-2
SECTION 5: MAINTENANCE .................................................................................................... 5-1
5.01 General Maintenance .................................................................................... 5-1
5.02 Maintenance - Torch O-Rings ........................................................................ 5-2
SECTION 6:
TROUBLESHOOTING ....................................................................................................... 6-1
6.01 Setup and Operation .................................................................................... 6-1
6.02 Basic Trouble Shooting Guide ....................................................................... 6-2
6.03 Control PCB Indicators ................................................................................. 6-3
6.04 Open Circuit Voltage Check .......................................................................... 6-4
6.05 Detailed Fault Finding / Error Indicators ........................................................ 6-4
6.06 Torch Tests ................................................................................................... 6-8
SECTION 7:
PARTS LIST ...................................................................................................................... 7-1
Replacement Hand Torch Parts ............................................................................. 7-8
Appendix 1: Operating Sequence, Block Diagram ..................................................................... A-1
Appendix 2: Torch Connection ................................................................................................... A-2
Appendix 3: Microchip Pin-Out .................................................................................................. A-3
Appendix 4: System Schematic ................................................................................................ A-4

Manual 0-4697 1-1 GENERAL INFORMATION
SECTION 1:
GENERAL INFORMATION
1.01 Notes, Cautions and Warnings
Throughout this manual, notes, cautions, and warnings
are used to highlight important information. These high-
lights are categorized as follows:
NOTE
An operation, procedure, or background informa-
tion which requires additional emphasis or is help-
ful in efficient operation of the system.
CAUTION
A procedure which, if not properly followed, may
cause damage to the equipment.
WARNING
A procedure which, if not properly followed, may
cause injury to the operator or others in the oper-
ating area.
1.02 Important Safety Precautions
WARNINGS
OPERATION AND MAINTENANCE OF
PLASMA ARC EQUIPMENT CAN BE DAN-
GEROUS AND HAZARDOUS TO YOUR
HEALTH.
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 instruc-
tions before using the equipment. Call 1-603-298-
5711 or your local distributor if you have any ques-
tions.
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 met-
als which may contain one or more of the follow-
ing:
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 in-
formation 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 com-
bustible 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.
• This product, when used for welding or cutting, pro-
duces fumes or gases which contain chemicals
known to the State of California to cause birth de-
fects and, in some cases, cancer. (California Health
& Safety Code Sec. 25249.5 et seq.)
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 op-
erator or others in the workplace.

GENERAL INFORMATION 1-2 Manual 0-4697
• 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 1.03, Publications.
• Disconnect power source before performing any ser-
vice or repairs.
• Read and follow all the instructions in the Operat-
ing 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 mate-
rial 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 where
fire hazards may exist.
• Hydrogen gas may be formed and trapped under
aluminum workpieces when they are cut underwa-
ter or while using a water table. DO NOT cut alu-
minum alloys underwater or on a water table un-
less 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 pro-
cesses can cause noise levels to exceed safe limits. You
must protect your ears from loud noise to prevent per-
manent loss of hearing.
• To protect your hearing from loud noise, wear pro-
tective ear plugs and/or ear muffs. Protect others
in the workplace.
• Noise levels should be measured to be sure the deci-
bels (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.
PLASMAARC 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 protected.
• To protect your eyes, always wear a welding hel-
met or shield. Also always wear safety glasses with
side shields, goggles or other protective eye wear.
• Wear welding gloves and suitable clothing to pro-
tect 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, Washington, D.C.
20402
2. ANSI Standard Z49.1, SAFETY IN WELDING AND
CUTTING, obtainable from the American Welding So-
ciety, 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, Washington, D.C. 20402
4. ANSI Standard Z87.1, SAFE PRACTICES FOR OCCU-
PATION AND EDUCATIONAL EYE AND FACE PRO-
TECTION, obtainable from American National Stan-
dards Institute, 1430 Broadway, New York, NY 10018
5. ANSI Standard Z41.1, STANDARD FOR MEN’S
SAFETY-TOE FOOTWEAR, obtainable from theAmeri-
can National Standards Institute, 1430 Broadway, New
York, NY 10018

Manual 0-4697 1-3 GENERAL INFORMATION
6. ANSI Standard Z49.2, FIRE PREVENTION IN THE
USE OF CUTTING AND WELDING PROCESSES, ob-
tainable from American National Standards Institute,
1430 Broadway, New York, NY 10018
7. AWS Standard A6.0, WELDING AND CUTTING
CONTAINERS WHICH HAVE HELD COMBUS-
TIBLES, obtainable from American Welding Society,
550 N.W. LeJeune Rd, Miami, FL 33126
8. NFPA Standard 51, OXYGEN-FUEL GAS SYSTEMS
FOR WELDING, CUTTING AND ALLIED PRO-
CESSES, obtainable from the National Fire Protection
Association, Batterymarch Park, Quincy, MA 02269
9. NFPA Standard 70, NATIONAL ELECTRICAL CODE,
obtainable from the National Fire Protection Associa-
tion, Batterymarch Park, Quincy, MA 02269
10. NFPAStandard 51B, CUTTING AND WELDING PRO-
CESSES, obtainable from the National Fire Protection
Association, Batterymarch Park, Quincy, MA 02269
11. CGA Pamphlet P-1, SAFE HANDLING OF COM-
PRESSED 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 WELD-
ING 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 Associa-
tion, 1900 Arch Street, Philadelphia, PA 19103
14. American Welding Society Standard AWSF4.1, RECOM-
MENDED SAFE PRACTICES FOR THE PREPARA-
TION FOR WELDING AND CUTTING OF CONTAIN-
ERS 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

GENERAL INFORMATION 1-4 Manual 0-4697
1.04 Statement of Warranty
LIMITED WARRANTY: Subject to the terms and conditions established below, Thermadyne® Corporation warrants to the original retail
purchaser that new Thermadyne CutSkill Series plasma cutting systems sold after the effective date of this warranty are free of defects in
material and workmanship. Should any failure to conform to this warranty appear within the applicable period stated below, Thermadyne
Corporation shall, upon notification thereof and substantiation that the product has been stored operated and maintained in accordance
with Thermadyne’s specifications, instructions, recommendations and recognized industry practice, correct such defects by suitable repair
or replacement.
This warranty is exclusive and in lieu of any warranty of merchantability or fitness for a particular purpose.
Thermadyne will repair or replace, at its discretion, any warranted parts or components that fail due to defects in material or workmanship
within the time periods set out below. Thermadyne Corporation must be notified within 30 days of any failure, at which time Thermadyne
Corporation will provide instructions on the warranty procedures to be implemented.
Thermadyne Corporation will honor warranty claims submitted within the warranty periods listed below. All warranty periods begin on the
date of sale of the product to the original retail customer or 1 year after sale to an authorized Thermadyne Distributor.
LIMITED WARRANTY PERIOD
Product Power Supply Components
(Parts and Labor) Torch and Leads (Parts and Labor)
C-20A 1 Year 1 Year
C-35A 1 Year 1 Year
C-70A 1 Year 1 Year
C-100A 1 Year 1 Year
This warranty does not apply to:
1. Consumable Parts, such as tips, electrodes, shield cups, o - rings, starter cartridges, gas distributors, fuses, filters.
2. Equipment that has been modified by an unauthorized party, improperly installed, improperly operated or misused
based upon industry standards.
In the event of a claim under this warranty, the remedies shall be, at the discretion of Thermadyne Corporation:
1. Repair of the defective product.
2. Replacement of the defective product.
3. Reimbursement of reasonable costs of repair when authorized in advance by Thermadyne.
4. Payment of credit up to the purchase price less reasonable depreciation based on actual use.
These remedies may be authorized by Thermadyne and are FOB West Lebanon, NH or an authorized Thermadyne service station. Product
returned for service is at the owner’s expense and no reimbursement of travel or transportation is authorized.
LIMITATION OF LIABILITY: Thermadyne Corporation 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 customer of distributors (hereinafter “Purchaser”)
for service interruption. The remedies of the Purchaser set forth herein are exclusive and the liability of Thermadyne 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 the goods covered by or furnished by Thermadyne 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 liability is based.
This warranty becomes invalid if replacement parts or accessories are used which may impair the safety or performance of any
Thermadyne product.
This warranty is invalid if the Thermadyne product is sold by non - authorized persons.
Effective August 28, 2005

Manual 0-4697 2-1 Introduction
SECTION 2:
INTRODUCTION
2.01 Overview
Plasma is a gas which has been heated to an extremely
high temperature and ionized so that it becomes elec-
tricallyconductive. The plasma arccuttingprocessuses
this plasma to transfer an electrical arc to the work-
piece. The metal to be cut is melted by the heat of the
arc and then blown away.
2.02 General Specifications
System Description C-20A
Maximum Output 25 Amps @ 230V
Input Voltage & Phase 115 - 230,
Single Phase
Frequency
50/60Hz
Input power 2.4 (kVA)
Current Input fuse 20 Amps
No Load Voltage
330V
Load Voltage 88V
Output Current 120V
15-20 Amps
Output Current 230V
15-25 Amps
Post Flow Time 10 Seconds
Operating Air Pressure 65 psi (4.5 bar)
(.45 Mpa)
Maximum Air Pressure 125 psi (8.6 bar)
(.86 Mpa)
Air flow 400 scfh
6.6 scfm
(188.7 lpm)
System Duty Cycle Ratings*
at Ambient Air Temperatures
of 40° C / 104° F. 30% @ 20Amps
System Duty Cycle Ratings*
at Ambient Air Temperatures
of 40° C / 104° F. 60% @ 15Amps
System Duty Cycle Ratings*
at Ambient Air Temperatures
of 40° C / 104° F. 100% @ 10Amp
s
Cutting Capacity 115V
@ 20 Amps
1/4" (6mm)
Cutting Capacity 230V
@ 25 Amps 3/8" (10mm)
Dimensions (W x D x H)
8.3" x 20" x 14.8"
(210 mm x 510
mm x 350 mm )
Net Weight 44 lbs. (20 kg )
10A
15A
25A
30% (3 min) 60% (6 min) 100% (10 min)
OFF
OFF
CUT
CUT
CUT
Art # A-0450
4
NOTE:
*Duty Cycle is the percentage of time the sys-
tem can be operated without overheating. Duty
cycle is reduced if primary input voltage (AC) is
low or the DC voltage is higher than shown in
previous chart.
Certain cutting conditions using 120V input
power may cause nuisance tripping of 20 Amp
Input fuse.
2.03 Features
• PORTABLEAND POWERFUL- Weighing just 44
lbs., (20 kg) it is easily moved from location to
location. This inverter based power supply auto-
matically links the unit to primary voltage from
115 to 230V single phase 50/60 Hz.
• POWERFULCUTTING PERFORMANCE - 115V
cutting capacity is 1/4” (6mm) and for 230V it’s
3/8” (10 mm).
• CUTS MOST METALS - Useful for most metals
such as stainless steel, aluminum, mild steel, cop-
per and alloys.
• NO HIGH FREQUENCY - Starts without high-
frequency so it won’t interfere with controls or
computers.
• MORE TORCH, LESS MONEY - The SL60™
1Torch™ provides state of the art technology and
performance of more expensive torches.

Introduction 2-2 Manual 0-4697
2.04 Torch Ratings
Torch Configuration Torch Head at 75° to
Torch Handle
Torch Leads Length 20 feet / 6.1 m
Ambient
Temperature
104° F
40° C
Torch Duty Cycle 100% @ 60 Amps
@ 400 scfh
Maximum Current 60 Amps, DC,
Straight Polarity
Voltage (V
peak
)500V
Arc Striking Voltage 7kV
Type of Cooling Ambient air and gas
stream through torch
Parts-in-Place: Built-in Switch
in Torch Head
Gas Requirement: Single Gas,
Compressed Air Only
Input
Gas Pressure
6
5 psi (4.5 bar)
(.45 Mpa)-
1
25 psi (8.6 bar)
(.86 Mpa)
Minimum Gas Flow 400 scfh - 6.6 scfm
(188.7 lpm)
Plasma Power
Supply Used
C-20A
SL60™ 1Torch™ Ratings for C-20A
2.05 System Contents
Items
Description
Q'ty
Power Source Model C-20A 1
Torch Set SL 60™, with 20' (6.1m)
leads
1
Accessories &
Consumables
Air Regulator
Work Cable
Manual
Torch Electrodes
Torch Tips
1
1
1
2
3
Input Power
Cable 12/3 AWG SOW with molded 5-20 plug 1
If you have questions or concerns regarding your sys-
tem, please contact:
Thermal Dynamics Technical Service Dept.
Tel: [phone] (1-800-PLASMA2)
Fax: [phone]
e-mail address: [email protected]
2.06 Transporting Methods
Lift unit with handle on top of case. Use handcart or
similar device of adequate capacity for transporting.
WARNINGS
ELECTRIC SHOCK can kill. DO NOT
TOUCH live electrical parts. Disconnect input
power from supply before moving the power
source.
FALLING EQUIPMENT cancause serious per-
sonal injury and equipment damage.

Manual 0-4697 3-1 Installation
SECTION 3:
INSTALLATION
3.01 Site Selection
• Place in a clean and dry area.
• Provide adequate ventilation and fresh air sup-
ply.
• Ideal ambient temperature should not exceed
40°C / 104°F. Temperatures exceeding that may
diminish cutting capacity or quality.
• The cutting machine must be placed on an even,
firm surface so that it stands firmly.
3.02 Electrical Input Connections
CAUTION
Check your power source for correct voltage be-
fore plugging in or connecting the unit. The
primary power source, fuse, and any extension
cords used must conform to local electrical code
andthe recommended circuitprotectionand wir-
ing requirements as specified in Section 2.0.
• This power supply includes an input power cord
and plug suitable for 115 VAC, 20 Amp, Single -
Phase input power.
A-04488
115 V, 20A, 1Ø
For 208 / 230 VAC input power, replace the supplied
power plug. Use only an approved replacement input
power plug with ground.
Replace the plug as follows:
1. Cut the original cord close to the plug.
2. Strip back the outer cord cover as needed to con-
nect the inner conductors to the replacement plug.
3. Connect conductors to the plug contacts according
to the plug manufacturer's instructions. All three
conductors must be connected to the plug.
Connect the input power cord as follows:
1. Check the power source for correct voltage before
plugging in the unit.
2. Connect the input power cable (or close the main
disconnect switch) to supply power to the system.
3.03 Compressed Air Connection
• An air compressor is required and should be con-
nected to rear panel of power source by air hose.
To replace fittings, use 1/4” NPT.
• Air pressure should be 65 psi (4.5 bar) (.45 MPa)
and air should be dry and clean.
• Air flow should be 400 scfh - 6.6 scfm (188.7 lpm)
minimum.
Connect
Air Here Input
Power
Art # A-04485
DANGER
Do not cut in humid or wet surroundings.
• Before you maintain or replace torch parts, wait
for the post flow air cycle (approximately 10 sec-
onds), to stop, then turn the machine off.
• Always use original manufacturersparts. The use
of aftermarket parts could result in shorter parts
lifeandin unsatisfactory cutting results. Any war-
ranty claims would be waived.
NOTE
Repairs must be done by skilled and qualified
personnel only.

Installation 3-2 Manual 0-4697
This Page Left Blank

Manual 0-4697 4-1 Operation
SECTION 4:
OPERATION
4.01 Front Control Panel
Overheating
Indicator
AC Power
Indicator
Air Error Indicator
Torch Switch
Latch Indicator
Torch Switch
Latch Button
Air Set
Button
Air Vents
Work Lead
Connection
"On / Off"
Switch
Art # A-04427
Torch
Connection
I
O115VAC
230VAC
8
10
12
14
10
11
12
13
14
15
17
18
19
20
21
22
23
24
25
A
20A
16
18
20
16
Current
Control Knob
A. Indicator Lamp
• Power Indicator
Lights when primary power switch is turned
on.
• TEMPERATURE Indicator
Indicator is normally OFF. Indicator is ON
when internal temperature exceeds normal
limits.
• Air Error Indicator
This indicator lights and is accompanied by an
intermittent audible tone when there is not
enough air pressure to operate the power sup-
ply. Indicator is normally off.
NOTE
It is possible to have enough air pressure to op-
erate the power supply but not enough air flow
to operate the torch.
• Torch Switch Latch Indicator
This indicator lights when the Torch Switch
Latch Button has been pressed for continuous
cutting.
B. Buttons
• Torch Switch Latch Button
For continuous cutting performance. Depress
this button ( turn “On” ) while cutting with the
torch. Release the torch trigger and the torch
willcontinue to cut withoutdepressingthe torch
trigger.
• Air Set Button
To adjust air pressure and to cool down heated
torch.
Art # A-04503
Air will flow from gap
next to shield cup.
C. Main Current Control Knob
To adjust cutting current. Turning clockwise in-
creases the cutting current and counter clock-
wise decreases the cutting current.
115VAC
230VAC
8
10
12
14
10
11
12
13
14
15
17
18
19
20
21
22
23
24
25
A
16
18
20
16
Art # A-04428
O
uter numbers
2
30V Input
Inner numbers
115V Inpu
t
D. Primary Power Switch, ON / OFF
The power switch is located on the front panel.
Placing the primary power switch to the “ON”
position energizes the power source and acti-
vates the Power Indicator.
WARNING
When the power source is overloaded, the switch
turns to the OFF position automatically. DO
NOT TURN ON BY FORCE.

Operation 4-2 Manual 0-4697
4.02 Preparations For Operating
At the start of each operating session:
WARNING
Disconnect primary power at the source before
assemblingor disassembling powersupply,torch
parts, or torch and leads assemblies.
A. Torch Parts Selection
Check the torch for proper assembly and appro-
priatetorchparts. The torchparts must correspond
with the type of operation, and with the amperage
output of this Power Supply (25 amps maximum).
Use only genuine manufactured parts with this
torch.
Electrode
9-8215
Start Cartridge
9-8213 Tip
9-8206
Shield Cup
9-8218
Art # A-04429
B. Torch Connection
Check that the torch is properly connected.
C. ConnectWork Cable
Make a clean work cable
connection to the work-
piece or cutting table
W
ork Cable
A
nd Clamp
Art # A-04389
D. Torch Operation
• Refer to Section 1 for necessary safety precau-
tions.
3
4
Art # A-0338
3
Trigger
2
1
Trigger Release

Manual 0-4697 4-3 Operation
E. Typical Cutting Speeds
Cutting speeds vary according to torch output, the type of material being cut, and operator skill. Speeds
shown are typical for this cutting system using air plasma to cut mild steel, with output current at the
highest setting and the torch used in the Drag mode only.
Inches per
minute Milimeters per minute Inches per minute Milimeters per minute
C-20A Drag Only (10GA) 0.135" (3mm) 42.7 1067 34.1 853
C-20A Drag Only (7GA) 0.179" (4.5mm) 26.2 655 21.0 524
C-20A Drag Only 1/4" (6mm) 16.0 401 12.8 321
Recommended Travel Speed
Unit Standoff Material
Thickness
Maximum Travel Speed
NOTE:
Drag or Drag mode refers to the torch tip being in contact with the work piece at all times.

Operation 4-4 Manual 0-4697
This Page Left Blank

Manual 0-4697 5-1 Maintenance
SECTION 5: MAINTENANCE
5.01 General Maintenance
Warning!
Disconnect input power before maintaining.
Each Use
Visual check of
regulator and pressure
Visual check of
torch tip and electrode
Weekly
Visually inspect the torch body
tip, electrode and shield cup
Visually inspect the
cables and leads.
Replace as needed
3 Months
Clean
exterior
of power supply
6 Months
Replace all
broken parts
Visually check and
Carefully clean the
interior
Maintain more often
if used under severe
conditions
Gas and
air lines
Art # A-04929

Maintenance 5-2 Manual 0-4697
5.02 Maintenance - Torch O-Rings
O-rings on the Torch require lubrication on a regular basis, depending on how frequently the torch shield cup
is disconnected and re-connected. This will allow the O-rings to remain pliable and provide a proper seal. The
O-rings will dry out, becoming hard and cracked, if the O-ring lubricant is not used on a regular basis. This can
lead to potential performance problems.
Remove and apply a very light film of O-ring lubricant (Catalog # 8-4025) to the O-rings on a weekly basis.
NOTE
DO NOT use other lubricants or grease on the torch O-rings. They may not be designed to operate
within high temperatures or may contain “unknown elements” that may react with the atmosphere.
This reaction can leave contaminants inside the torch. Either of these conditions can lead to inconsis-
tent performance or poor parts life.
Lower O-Rin
g
Cat. #8-3486
U
pper O-Ring
i
n Correct Groove
C
at. #8-3487
U
pper Groove
w
ith Vent Holes
M
ust Remain Open
Threads
Art # A-04394