These INSTRUCTIONS are for experienced operators. If you are not fully familiar with the principles of operation and safe
practices for arc welding equipment, we urge you to read our booklet, Precautions and Safe Practices for Arc Welding,
Cutting, and Gouging, Form 52-529. Do NOT permit untrained persons to install, operate, or maintain this equipment. Do NOT
attempt to install or operate this equipment until you have read and fully understand these instructions. If you do not fully
understand these instructions, contact your supplier for further information. Be sure to read the Safety Precautions on page 2
before installing or operating this equipment.
I. INTRODUCTION
The ST-21M (P/N 690509) is a liquid-cooled, in-line body
style, machine torch designed exclusively for mechanized mig welding installations. The current carrying
capacity of this torch is 600 amperes continuous duty,
using all types of welding wire in sizes ranging from .030
inches (0.8 mm) through 7/64-inch (2.8 mm) diameters,
including flux cored wires.
The torch can be mounted directly to an EH-10A welding head, and can be easily adapted for remote mounting to the EH-10A Cold Wire guide attachments for use
with either mounting arrangement are available as optional accessories.
The ST-21M is attached to the welding head by means
of an accessory mounting adaptor. To facilitate maneuverability and installation fixturing, all service lines are
internally connected to the torch body and exit from the
rear of the torch barrel.
The torch is designed for use with either threadless type
contact tubes which are secured by a collet nut, or
threaded contact tips (see Table 2). The threadless contact tube can be quickly and easily replaced by unscrewing the metal nozzle and collet nut (in that order), and
then slipping the contact tube out. The threaded tips can
be replaced by removing the metal nozzle and unscrewing the tip. Six metal nozzles (one for spot welding use)
are available for use with this torch (see Table 1). Nozzle
sizes 8 and 10 require a spatter liner.
NOTE: Due to the high electrical conductivity, use of
tap water or commercial anti-freeze is NOT recommended for torch cooling. Use of the WC-9
or WC-8C coolant circulator (see below) using
a specially formulated torch coolant (P/N
156F05, 1 gal. container) is recommended for
torch cooling. The coolant also provides antifreeze protection down to -34° F.
II. ACCESSORY EQUIPMENT
A. REQUIRED EQUIPMENT
1. Torch Mounting Bracket, P/N 633885. The bracket
includes as insulator sleeve which insulates the torch
from the welding head. See Figs. 1 and 2.
2. Nozzle and Wire Feed Accessories. The ST-21M
also requires a nozzle, a nozzle spatter liner, and several wire feed accessories (contact tube or tip, liner,
and inlet guide tip) of the proper size for the wire being used. These accessories are listed in Tables0 1
and 2 following.
3. Service Line Connections and Extensions. Depending on mounting arrangements or welding head
to be used, there are several methods for connecting
the torch service lines to the gas, coolant, and power
supplies (see Fig. 4).
a. The lines can be connected directly to the optional
plumbing box (P/N 996067 - covered Instruction
Book F-12-332).
b. Connection block assembly (P/N 58V74) is avail-
able for mounting on the EH-10A welding head.
c. The following service lines and couplings are avail-
Gas Hose Coupling ................................................... 11N17
Power Coolant Out Coupling .................................... 11N19
Power Cable Adaptor .................................................45V11
Coolant Adaptor (connects hose to 1/4-in. NPT) ...... 11N16
4. Welding Head Accessories. Two other accessories
whose selection depends upon wire size and type,
are the feed roll and inlet guide insert on the welding
head. Selection of these accessories is covered in
the instruction booklet supplied with the welding head.
Be sure this information reaches the operator.
You can get extra copies through your supplier.
SAFETY PRECAUTIONS
WARNING: These Safety Precautions are for
your protection. They summarize precautionary information from the references listed in
Additional Safety Information section. Before
performing any installation or operating procedures, be
sure to read and follow the safety precautions listed below
as well as all other manuals, material safety data sheets,
labels, etc. Failure to observe Safety Precautions can result
in injury or death.
PROTECT YOURSELF AND OTHERS --
Some welding, cutting, and gouging
processes are noisy and require ear
protection. The arc, like the sun, emits
ultraviolet (UV) and other radiation and
can injure skin and eyes. Hot metal can cause burns.
Training in the proper use of the processes and equipment is essential to prevent accidents. Therefore:
1. Always wear safety glasses with side shields in any work
area, even if welding helmets, face shields, and goggles
are also required.
2. Use a face shield fitted with the correct filter and cover
plates to protect your eyes, face, neck, and ears from
sparks and rays of the arc when operating or observing
operations. Warn bystanders not to watch the arc and
not to expose themselves to the rays of the electric-arc
or hot metal.
3. Wear flameproof gauntlet type gloves, heavy long-sleeve
shirt, cuffless trousers, high-topped shoes, and a welding helmet or cap for hair protection, to protect against
arc rays and hot sparks or hot metal. A flameproof apron
may also be desirable as protection against radiated
heat and sparks.
4. Hot sparks or metal can lodge in rolled up sleeves,
trouser cuffs, or pockets. Sleeves and collars should be
kept buttoned, and open pockets eliminated from the
front of clothing
5. Protect other personnel from arc rays and hot sparks
with a suitable non-flammable partition or curtains.
6. Use goggles over safety glasses when chipping slag or
grinding. Chipped slag may be hot and can fly far.
Bystanders should also wear goggles over safety glasses.
FIRES AND EXPLOSIONS -- Heat from
flames and arcs can start fires. Hot slag
or sparks can also cause fires and explosions. Therefore:
1. Remove all combustible materials well away from the
work area or cover the materials with a protective nonflammable covering. Combustible materials include wood,
cloth, sawdust, liquid and gas fuels, solvents, paints and
coatings, paper, etc.
2. Hot sparks or hot metal can fall through cracks or
crevices in floors or wall openings and cause a hidden
smoldering fire or fires on the floor below. Make certain
that such openings are protected from hot sparks and
metal.“
3. Do not weld, cut or perform other hot work until the
workpiece has been completely cleaned so that there
are no substances on the workpiece which might produce flammable or toxic vapors. Do not do hot work on
closed containers. They may explode.
4. Have fire extinguishing equipment handy for instant use,
such as a garden hose, water pail, sand bucket, or
portable fire extinguisher. Be sure you are trained in its
use.
2
5. Do not use equipment beyond its ratings. For example,
overloaded welding cable can overheat and create a fire
hazard.
6. After completing operations, inspect the work area to
make certain there are no hot sparks or hot metal which
could cause a later fire. Use fire watchers when necessary.
7. For additional information, refer to NFPA Standard 51B,
"Fire Prevention in Use of Cutting and Welding Processes", available from the National Fire Protection Association, Batterymarch Park, Quincy, MA 02269.
ELECTRICAL SHOCK -- Contact with live
electrical parts and ground can cause
severe injury or death. DO NOT use AC
welding current in damp areas, if movement is confined, or if there is danger of
falling.
1. Be sure the power source frame (chassis) is connected
to the ground system of the input power.
2. Connect the workpiece to a good electrical ground.
3. Connect the work cable to the workpiece. A poor or
missing connection can expose you or others to a fatal
shock.
4. Use well-maintained equipment. Replace worn or damaged cables.
5. Keep everything dry, including clothing, work area, cables,
torch/electrode holder, and power source.
6. Make sure that all parts of your body are insulated from
work and from ground.
7. Do not stand directly on metal or the earth while working
in tight quarters or a damp area; stand on dry boards or
an insulating platform and wear rubber-soled shoes.
8. Put on dry, hole-free gloves before turning on the power.
9. Turn off the power before removing your gloves.
10. Refer to ANSI/ASC Standard Z49.1 (listed on next page)
for specific grounding recommendations. Do not mistake
the work lead for a ground cable.
ELECTRIC AND MAGNETIC FIELDS —
May be dangerous. Electric current flowing through any conductor causes localized Electric and Magnetic Fields
(EMF). Welding and cutting current creates EMF around welding cables and
welding machines. Therefore:
1. Welders having pacemakers should consult their physician before welding. EMF may interfere with some pacemakers.
2. Exposure to EMF may have other health effects which are
unknown.
3. Welders should use the following procedures to minimize
exposure to EMF:
A. Route the electrode and work cables together. Secure
them with tape when possible.
B. Never coil the torch or work cable around your body.
C. Do not place your body between the torch and work
cables. Route cables on the same side of your body.
D. Connect the work cable to the workpiece as close as
possible to the area being welded.
E. Keep welding power source and cables as far away
from your body as possible.
10/98
FUMES AND GASES -- Fumes and
gases, can cause discomfort or harm,
particularly in confined spaces. Do
not breathe fumes and gases. Shielding gases can cause asphyxiation.
Therefore:
1. Always provide adequate ventilation in the work area by
natural or mechanical means. Do not weld, cut, or gouge
on materials such as galvanized steel, stainless steel,
copper, zinc, lead, beryllium, or cadmium unless positive
mechanical ventilation is provided. Do not breathe fumes
from these materials.
2. Do not operate near degreasing and spraying operations. The heat or arc rays can react with chlorinated
hydrocarbon vapors to form phosgene, a highly toxic
gas, and other irritant gases.
3. If you develop momentary eye, nose, or throat irritation
while operating, this is an indication that ventilation is not
adequate. Stop work and take necessary steps to improve ventilation in the work area. Do not continue to
operate if physical discomfort persists.
4. Refer to ANSI/ASC Standard Z49.1 (see listing below)
for specific ventilation recommendations.
5. WARNING: This product, when used for welding or
cutting, produces fumes or gases which
contain chemicals known to the State of
California to cause birth defects and, in
some cases, cancer. (California Health &
Safety Code §25249.5 et seq.)
CYLINDER HANDLING -- Cylinders, if
mishandled, can rupture and violently
release gas. Sudden rupture of cylinder, valve, or relief device can injure or
kill. Therefore:
1. Use the proper gas for the process and use the proper
pressure reducing regulator designed to operate from
the compressed gas cylinder. Do not use adaptors.
Maintain hoses and fittings in good condition. Follow
manufacturer's operating instructions for mounting regulator to a compressed gas cylinder.
2. Always secure cylinders in an upright position by chain
or strap to suitable hand trucks, undercarriages, benches,
walls, post, or racks. Never secure cylinders to work
tables or fixtures where they may become part of an
electrical circuit.
3. When not in use, keep cylinder valves closed. Have
valve protection cap in place if regulator is not connected. Secure and move cylinders by using suitable
hand trucks. Avoid rough handling of cylinders.
4. Locate cylinders away from heat, sparks, and flames.
Never strike an arc on a cylinder.
5. For additional information, refer to CGA Standard P-1,
"Precautions for Safe Handling of Compressed Gases in
Cylinders", which is available from Compressed Gas
Association, 1235 Jefferson Davis Highway, Arlington,
VA 22202.
EQUIPMENT MAINTENANCE -- Faulty or
improperly maintained equipment can
cause injury or death. Therefore:
1. Always have qualified personnel perform the installation, troubleshooting, and maintenance work. Do not
perform any electrical work unless you are qualified to
perform such work.
2. Before performing any maintenance work inside a power
source, disconnect the power source from the incoming
electrical power.
3. Maintain cables, grounding wire, connections, power
cord, and power supply in safe working order. Do not
operate any equipment in faulty condition.
4. Do not abuse any equipment or accessories. Keep
equipment away from heat sources such as furnaces,
wet conditions such as water puddles, oil or grease,
corrosive atmospheres and inclement weather.
5. Keep all safety devices and cabinet covers in position
and in good repair.
6. Use equipment only for its intended purpose. Do not
modify it in any manner.
ADDITIONAL SAFETY INFORMATION -- For
more information on safe practices for electric arc welding and cutting equipment, ask
your supplier for a copy of "Precautions and
Safe Practices for Arc Welding, Cutting and
Gouging", Form 52-529.
The following publications, which are available from the
American Welding Society, 550 N.W. LeJuene Road, Miami, FL 33126, are recommended to you:
1. ANSI/ASC Z49.1 - "Safety in Welding and Cutting"
2. AWS C5.1 - "Recommended Practices for Plasma Arc
Welding"
3. AWS C5.2 - "Recommended Practices for Plasma Arc
Cutting"
4. AWS C5.3 - "Recommended Practices for Air Carbon
Arc Gouging and Cutting"
5. AWS C5.5 - "Recommended Practices for Gas Tungsten
Arc Welding“
6. AWS C5.6 - "Recommended Practices for Gas Metal Arc
Welding"“
8. ANSI/AWS F4.1, "Recommended Safe Practices for
Welding and Cutting of Containers That Have Held
Hazardous Substances."
MEANING OF SYMBOLS - As used throughout this manual: Means Attention! Be Alert!
Your safety is involved.
Means immediate hazards which, if
not avoided, will result in immediate,
serious personal injury or loss of life.
Means potential hazards which could
result in personal injury or loss of life.
Means hazards which could result in
minor personal injury.
3
PRÉCAUTIONS DE SÉCURITÉ
AVERTISSEMENT: Ces règles de sécurité ont pour objet
d assurer votre protection. Veillez à lire et à observer les
précautions énoncées ci-dessous avant de monter l
équipement ou de commercer à lutiliser. Tout défaut
dobservation de ces précautions risque dentraîner des
blessures graves ou mortelles.
1. PROTECTION INDIVIDUELLE-- Les brûlures de la
peau et des yeux dues au rayonnement de larc
électrique ou du métal incandescent, lors du soudage
au plasma ou à lélectrode ou lors du gougeage à
larc, peuvent savérer plus graves que celles résultant
dune exposition prolongée au soleil. Aussi convient-il
dobserver les précautions suivantes:
a. Portez un écran facial adéquat muni des plaques
protectrices et des verres filtrants appropriés afin de
vous protéger les yeux, le visage, le cou et les oreilles
des étincelles et du rayonnement de larc électrique
lorsque vous effectuez des soudures ou des coupes
ou lorsque vous en observez lexécution.
AVERTISSEZ les personnes se trouvant à proximité
de façon à ce quelles ne regardent pas larc et à ce
quelles ne sexposent pas à son rayonnement, ni à
celui du métal incandescent.
b. Portez des gants ignifugés à crispins, une tunique
épaisse à manches longues, des pantalons sans
rebord, des chaussures à embout dacier et un casque
de soudage ou une calotte de protection, afin déviter
dexposer la peau au rayonnement de larc électrique
ou du métal incandescent. ll est également souhaitable
dutiliser un tablier ininflammable de façon à se
protéger des étincelles et du rayonnement thermique.
c. Les étincelles ou les projections de métal incandes-
cent risquent de se loger dans des manches
retroussées, des bords relevés de pantalons ou dans
des poches. Aussi convient-il de garder boutonnés le
col et les manches et de porter des vêtements sans
poches à lavant.
d. Protégez des étincelles et du rayonnement de larc
électrique les autres personnes travaillant à proximité
à laide dun écran ininflammable adéquat.
e. Ne jamais omettre de porter des lunettes de sécurité
lorsque vous vous trouvez dans un secteur où lon
effectue des opérations de soudage ou de coupage à
larc. Utilisez des lunettes de sécurité à écrans ou
verres latéraux pour piquer ou meûler le laitier. Les
piquetures incandescentes de laitier peuvent être
projetées à des distances considérables. Les
personnes se trouvant à proximité doivent également
porter des lunettes de protection.
f. Le gougeage à larc et le soudage à larc au plasma
produisent un niveau de bruit extrêmement élevé (de
100 à 114 dB) et exigent par conséquent lemploi de
dispositifs appropriés de protection auditive.
2. PRÉVENTION DES INCENDES-- Les projections de
laitier incandescent ou détincelles peuvent provoquer
de graves incendies au contact de matériaux combustibles solides, liquides ou gazeux. Aussi faut-il
observer les précautions suivantes:
a. Éloigner suffisamment tous les matériaux combus-
tibles du secteur où lon exécute des soudures ou des
coupes à larc, à moins de les recouvrir complètement
dune bâche non-inflammable. Ce type de matériaux
comprend notamment le bois, les vêtements, la sciure,
lessence, le kérosène, les peintures, les solvants, le
gaz naturel, lacétylène, le propane et autres substances combustibles semblables.
b. Les étincelles ou les projections de métal incandes-
cent peuvent tomber dans des fissures du plancher ou
dans des ouvertures des murs et y déclencher une
ignition lente cachée. Veiller à protéger ces ouvertures
des étincelles et des projections de métal.
c. Nexécutez pas de soudures, de coupes, dopérations
de gougeage ou autres travaux à chaud à la surface
de barils, bidons, réservoirs ou autres contenants
usagés, avant de les avoir nettoyés de toute trace de
substance susceptible de produire des vapeurs
inflammables ou toxiques.
d. En vue dassurer la prévention des incendies, il
convient de disposer dun matériel dextinction prêt à
servir immédiatement, tel quun tuyau darrosage, un
seau à eau, un seau de sable ou un extincteur portatif.
e. Une fois le travail à larc terminé, inspectez le secteur
de façon à vous assurer quaucune étincelle ou projection de métal incandescent ne risque de provoquer
ultérieurement un feu.
3. CHOC ÉLECTRIQUE-- Le gougeage à larc et à larc
au plasma exige lemploi de tensions à vide relativement
importantes; or, celles-ci risquent de causer des
dommages corporels graves et même mortels en cas
dutilisation inadéquate. La gravité du choc électrique
reçu dépend du chemin suivi par le courant à travers le
corps humain et de son intensité.
a. Ne laissez jamais de surfaces métalliques sous ten-
sion venir au contact direct de la peau ou de vêtements
humides. Veillez à porter des gants bien secs.
b. Si vous devez effectuer un travail sur une surface
métallique ou dans un secteur humide, veillez à assurer votre isolation corporelle en portant des gants secs
et des chaussures à semelles de caoutchouc et en
vous tenant sur une planche ou une plate-forme
sèche.
c. Mettez toujours à la terre le poste de soudage/coupage
en le reliant par un câble à une bonne prise de terre.
d. Nutilisez jamais de câbles usés ou endommagés. Ne
surchargez jamais le câble. Utilisez toujours un
équipement correctement entretenu.
e. Mettez léquipement hors tension lorsquil nest pas en
service. une mise à la masse accidentelle peut en effet
provoquer une surchauffe de léquipement et un danger dincendie. Ne pas enrouler ou passer le câble
autour dune partie quelconque du corps.
f. Vérifiez si le câble de masse est bien relié à la pièce en
un point aussi proche que possible de la zone de
travail. Le branchement des câbles de masse à
lossature du bâtiment ou en un point éloigné de la
zone de travail augmente en effet le risque de passage dun courant de sortie par des chaînes de
4
levage, des câbles de grue ou divers chemins
électriques.
g. Empêchez lapparition de toute humidité, notamment
sur vos vêtements, à la surface de lemplacement de
travail, des câbles, du porte-électrode et du poste de
soudage/coupage. Réparez immédiatement toute fuite
deau.
4. VENTILATION-- La respiration prolongée des fumées
résultant des opérations de soudage/coupage, à
lintérieur, dun local clos, peut provoquer des malaises et des dommages corporels. Aussi convient-il
dobserver les précautions suivantes:
a. Assurez en permanence une aération adéquate de
lemplacement de travail en maintenant une ventilation naturelle ou à laide de moyens mécaniques.
Neffectuez jamais de travaux de soudage ou de
coupage sur des matériaux de zinc, de plomb, de
beryllium ou de cadmium en labsence de moyens
mécaniques de ventilation capables dempêcher
linhalation des fumées dégagées par ces matériaux.
b. Neffectuez jamais de travaux de soudage ou de
coupage à proximité de vapeurs dhydrocarbure chloré
résultant dopérations voisines de dégraissage ou de
pulvérisation. La chaleur dégagée ou le rayonnement
de larc peut déclencher la formation de phosgène -gaz particulièrement toxique -- et dautres gaz irritants, à partir des vapeurs de solvant.
c. Une irritation momentanée des yeux, du nez ou de la
gorge constatée au cours de lutilisation de
léquipement dénote un défaut de ventilation. Arrêtezvous de travailler afin de prendre les mesures nécessaires à lamélioration de la ventilation. Ne poursuivez
pas lopération entreprise si le malaise persiste.
d. Certaines commandes comportent des canalisations
où circule de lhydrogène. Larmoire de commande est
munie dun ventilateur destiné à empêcher la formation de poches dhydrogène, lesquelles présentent un
danger dexplosion; ce ventilateur ne fonctionne que
si linterrupteur correspondant du panneau avant se
trouve placé en position ON (Marche). Veillez à
manuvrer cette commande en vérifiant si le couvercle
est bien en place, de façon à assurer lefficacité de la
ventilation ainsi réalisée. Ne jamais débrancher le
ventilateur.
e. Les fumées produites par lopération de soudage ou
de coupage peuvent savérer toxiques. Aussi est-il
nécessaire de disposer en permanence dun dispositif
adéquat de ventilation de type aspirant, afin déliminer du voisinage de lopérateur tout dégagement de
fumée visible.
f. Consultez les recommandations particulières en matière
de ventilation indiquées à lalinéa 6 de la norme Z49.1
de lAWS.
5. ENTRETIEN DE LÉQUIPEMENT-- Un équipement
entretenu de façon défectueuse ou inadéquate risque
non seulement de réaliser un travail de mauvaise
qualité mais, chose plus grave encore, dentraîner des
dommages corporels graves, voire mortels en
déclenchant des incendies ou des chocs électriques.
Observez par conséquent les précautions suivantes:
a. Efforcez-vous de toujours confier à un personnel qua-
lifié linstallation, le dépannage et lentretien du poste
de soudage et de coupage. Neffectuez aucune
réparation électrique sur léquipement à moins dêtre
qua-lifié à cet effet.
b. Ne procédez jamais à une tâche dentretien quelconque
à lintérieur du poste de soudage/coupage, avant
davoir débranché lalimentation électrique.
c. Maintenez en bon état de fonctionnement les câbles,
le câble de masse, les branchements, le cordon
dalimentation et le poste de soudage/coupage.
Nutilisez jamais le poste ou léquipement sil présente
une défectuosité quelconque.
d. Prenez soin du poste de soudage et de coupage et des
équipements accessoires. Gardez-les à lécart des
sources de charleur, notamment des fours, de
lhumidité, des flaques deau maintenez-les à labri des
traces dhuile ou de graisse, des atmosphères corrosives et des intempéries.
e. Laissez en place tous les dispositifs de sécurité et tous
les panneaux de larmoire de commande en veillant à
les garder en bon état.
f. Utilisez le poste de soudage/coupage conformément à
son usage prévu et neffectuez aucune modification.
6. INFORMATIONS COMPLÉMENTAIRES RELATIVES
À LA SÉCURITÉ--
Pour obtenir des informations complémentaires sur les
règles de sécurité à observer pour le montage et
lutilisation déquipements de soudage et de coupage
électriques et sur les méthodes de travail
recommandées, demandez un exemplaire du livret N°
52529 Precautions and Safe Practices for Arc Welding, Cutting and Gouging publié par ESAB. Nous
conseillons également de consulter les publications
sui-vantes, tenues à votre disposition par lAmerican
Welding Society, 550 N.W. LeJuene Road, Miami, FL
32126:
a. Safety in Welding and Cutting AWS Z49.1
b. Recommended Safe Practices for Gas-Shielded Arc
Welding AWS A6. 1.
c. Safe Practices for Welding and Cutting Containers
That Have Held Combustibles AWS-A6.0.
d. Recommended Safe Practices for Plasma Arc Cutting
AWS-A6. 3.
e. Recommended Safe Practices for Plasma Arc Weld-
ing AWS-C5. 1.
f. Recommended Safe Practices for Air Carbon Arc
Gouging and Cutting AWS-C5. 3.
g. Code For Safety in Welding and Cutting CSA-Standard
W117. 2.
5
Mounting bracket, Part No. 996497, can be used to
mount an EH-10 to angle bracket P/N 29N04 or adjustable slide P/N 25V39 (Fig. 2) or to user designed
set-up.
5. Power Cable. Customer supplied 4/0 power cable
with connector lug (P/N 97W01).
6. Coolant Circulator, P/N 33540 (WC-9) or P/N 33739
(WC-8C) - Both units are capable of circulating cool-
ant at the rate of 1 gpm which is more than adequate
for protecting the torch. They are equipped with 8-ft.
input power cord that plugs into a standard 115V AC
receptacle. The WC-8C with its 9-1/2-in. square base
fits into a cylinder rack of any power source track.
Use Torch Coolant, P/N 156F05 (1 gal. container) only.
Both units have a tank capacity of 1.5 gal.)
NOTE: The circulator cannot be set up for solenoid valve
ing of torch is desired, mounting bracket (39V37), rack
& tube assembly, conduit, conduit liner (if using aluminum wire), torch-to-conduit adaptor (61N59 and
welding head wire outlet guide are required. Refer to
Fig. 2 and Tables 3 and 4 for the proper accessories.)
2. Cold Wire Accessories. The cold wire guide attachments are available. P/N 40V71 (illustrated in Fig. 1)
has adjustments in four planes and can be adjusted
while welding is in progress. This cold wire attachment must be used with mounting bracket P/N 53N93
and it is recommended only for the direct mounted
torch setup. The low cost cold wire attachment, P/N
39V38 (illustrated in Figs. 2 and 5), is used with mounting bracket, P/N 39V37, on either direct or remote
torch set-ups.
3. Centering Bushing, Part No. 994330 (for use with 8
and 10 nozzles). Eliminates any possibility of spatter
bridging in the torch. This is accomplished by using
this one-piece centering bushing/spatter liner in place
of the two individual pieces normally used. Note that
it can only be used at maximum currents of 350 amps
with Argon or 550 amps with CO2.
(a) Use No. 12M nozzle (P/N 997310) for cored wire.
(b) Also requires a support tube liner, (P/N 993901).
(c) A drawback to using this size wire is that a torch liner cannot be used and wire guide wear can occur.
6
4. Collet Nut Wrench, Part No. 996109. Permits loosening of the collet nut without removing the nozzle.
Particularly recommended when using the above centering bushing. The wrench employs a stop-pin to assure proper position of contact tube when tightening
the collet nut.
III.INSTALLATION
Depending on the choice of mounting system used, either direct or remote, install the wire feed components
as outlined below and illustrated in Figures 1 and 2.
A. DIRECT MOUNTING TO EH-10A WELDING HEAD
Table 3 - Mounting Accessories
Type ofWire GuideMtg.ConduitRack/Tube
MountingAttachmentBracketConduit*LinerAssembly
Direct w/Cold39V3839V37NotNotNot
Wire - Fig. 140V7153N93UsedUsedUsed
* Requires adaptor, P/N 61N59, in place of torch inlet guide tip (on torch mounting bracket).
** Conduit liners must be cut to the proper length to allow 1/16-in. clearance between liner and contact tube.
Includes replaceable sleeve (995692).
Includes replaceable sleeve (995693)
7
MOUNTING
BRACKET 996497
WELDING
HEAD
TORCH INLET
GUIDE TIP
(SEE TABLE 2)
COLD WIRE GUIDE
ATTACHMENT 40V71 (AS SHOWN)
-OR39V38 (SEE FIG. 2)
CONNECTION BLOCK
ASSY - 58V74
*ADAPTOR (PART OF
CONN. BLK. ASSY).
TORCH MOUNTING
BRACKET - 633885
MOUNTING BRACKET
53N93 (AS SHOWN)
-OR39V37 (SEE FIG. 2)
ST-21M MIG MACHINE
TORCH - 690509
MOUNTING PLATE
493195
ADJUSTABLE SLIDE
ASSEM.
COLD WIRE GUIDE
ATTACHMENT - 39V38
25V39
RACK & TUBE
39V34 (8-IN.)
39V35 (12-IN.)
39V36 (16-IN.)
ANGLE BRACKET
29N04
TORCH HOLDER ASSEM. - 40V26
TO WELDING HEAD
(See Table 4)
CONDUIT LINER
(SEE TABLE 4)
CONDUIT (See Table 4)
ADAPTOR - 61N59
TORCH MOUNTING
BRACKET - 633885
ST-21M MIG MACHINE
TORCH - 690509
MOUNTING BRACKET
39V37
* If desired, the adaptor and the lug can be switched to the opposite
sides of the connection block.
Fig. 1 - ST-21M Torch with Cold Wire Guide Attachment-
Direct Mounting
2. Insert a torch liner (and support liner, if used) through
the mounting bracket on the rear of torch until it is
firmly seated within the torch.
3. Slip a torch inlet guide tip, of the proper size, over the
protruding end of the liner and screw it into the end of
the mounting bracket.
4. With the insulator sleeve (14N14) in place over the
mounting bracket (step 1-d), insert the bracket into
the clamp on the accessory support assembly of the
welding head. Secure the bracket by tightening the
locking handle on support assembly clamp. Connect
the service lines to plumbing box, connection block,
or directly to supply sources using service line extensions and couplings where necessary.
5. With the nozzle and contact tube removed and wire
in the feed rolls, use the inching switch on the control
to feed wire through the mounting bracket and torch
until it protrudes from the end of the torch.
6. Select the correct contact tube or tip. If using contact
tube, slip the tube and collet nut (632811) over the
wire, and screw the nut into the torch to hold the tube
in place.
7. Place a spatter liner (633603, if one is required) in
the proper size nozzle and install into the front end of
the torch.
Fig. 2 - ST-21M Torch with 39V38 Cold Wire Guide
Attachment- Remote Mounting
B. REMOTE MOUNTING
Follow the steps as described above in section III-A.
except in step 3, install adaptor (61N59) in place of torch
inlet guide tip. The torch is then mounted to mounting
bracket (see Fig. 2) and conduit (with conduit liner installed if required) is to be connected to torch and to
wire outlet guide on welding head.
ADJUSTMENT AND OPERATION
Before adjustments are made, disengage the pressure
roll to prevent wire from feeding and arcing to an accidental ground. To set the shielding gas flow rate, press
the weld start button to open the gas solenoid valve and
adjust the flowmeter to the desired flow rate.
Make sure the coolant system is completely filled, and
be sure to plug in the coolant recirculator to a standard
115 volt receptacle before operating the torch.
Specific operation of the torch depends on the particular
wire feeder with which it is to be used. Therefore, consult the instruction booklet supplied with the wire feeder.
When changing wires switch to one of different size
and composition make sure you refer to the wire Feed
8
WIRE GUIDE, BODY & TUBE ASS'Y - 997032
INCLUDES:
WIRE GUIDE INSULATOR - 997031
NOZZLE BODY - 633881
CENTERING BUSHING - 17782
NOZZLE (ACCESSORY)
(SEE TABLE 1)
INSULATING SLEEVE - 633880
LOCKING NUT - 598787
CLAMP - 950626
A
BARREL - 690524
SETSCREW - #10-32 X 3/16" (61330907)
(Supplied with 997032) (Align hole in barrel over setscrew.)
CLAMP - 53N46
TORCH MOUNTING BRACKET -
INCLUDES
SPACER - 633887
INSULATOR SLEEVE - 14N14
633885
ACCESSORY
TORCH INLET
GUIDE TIP &
TORCH LINER
(ACCESSORY)
(SEE TABLE 2)
END
FITTING996403
(Supplied with 997032)
SPATTER LINER
(SEE TABLE 1)
COLLET NUT 632811
CONTACT TUBE (ACCESSORY)
(SEE TABLE 2)
EH-10 WELDING HEAD
INSULATOR SLEEVE
14N14 (SUPPLIED WITH
633885)
MOUNTING BRACKET
633885
ST-21M MACHINE
TYPE MIG TORCH
690509
1/8" NPT
A
(2) SETSCREW - 10-32 X 3/16" (61330907)
GASKET - 633884
CAPSCREW - 1/4"-20 X 5/8"
(Supplied with 633885)
SPACER - 633887
(SUPPLIED WITH
633885)
MOUNTING ARRANGEMENT OF
ST-21 M MACHINE TORCH TO
EH-10 WELDING HEAD
CONNECTION BLOCK
ASS'Y. - 58V74
(SHOWN ATTACHED
TO EH-10 HEAD)
Accessories Table. The listed parts are to be used for a
particular wire size DO NOT SUBSTITUTE PARTS.
V. MAINTENANCE & REPLACEMENT PARTS
A. POWER CABLE
If the power cable assembly becomes damaged, it is
recommended that (1) a new one be purchased, or (2)
the damaged unit be turned over to ESAB authorized
repair station for repair. The connection fittings are
crimped on at the factory by special crimping tools to
ensure strong connections and prevent leakage. A satisfactory job cannot be done without these tools.
COOLANT HOSE
ASSY. - 17980
(29-IN. LG.)
includes:
CLAMP - 950626
POWER CABLE
ASS'Y. - 46V12
(24-IN. LG.)
GAS HOSE
ASS'Y. - 46V11
(26 - 1/2-IN. LG.)
CONDUIT
POWER/COOLANT OUT
GAS
COOLANT HOSE CLAMP
(position as shown)
CENTERING BUSHING
REMOVAL TOOL
SUPPLIED
996300
1 3/8"
DIA.
5/8"-18 L. H.
7/8"-14 L. H.
5/8" 18
Sect. A-A
sert the hose over the grooved sealing area of the
hose fitting on the torch.
4. Using a pair of pliers, pull on the hose clamp tightly
over the grooved sealing surface and apply 1/2 twist.
Be sure to position the wire hose clamp so that the
twist does not interfere with another part or the inside
of the handle.
5. Reposition the pliers about 1/8-in. from the hose and
twist an additional 1-1/2 turns.
6. Snip off excess wire about 1/8-in. from hose and bend
the twisted ends as shown below.
B. GAS AND COOLANT HOSE ASSEMBLIES
(Refer to Fig. 3)
If shielding gas or coolant hose assemblies require replacement, loosen the two No. 1032 x 3/16-in. set
screws on the locking nut and pull back barrel.
To replace a gas hose assembly, proceed as follows:
1. Clip off wire hose clamp (53N46) and remove hose.
2. Clean off the fitting, and then brush on some 3M type
1711 adhesive (P/N 71200733 - 5 oz. tube) onto the
fitting.
3. Slide new wire hose clamp on the new hose and in-
To replace the coolant hose assembly, proceed as follows:
1. Snip off the ear of the hose clamp by cutting into the
sides with pliers. Then remove hose.
2. Clean off the fitting, and then brush on some 3M type
1711 adhesive (P/N 71200733 - 5 oz. tube) onto the
fitting.
3. Slide hose clamp (950626 - supplied with hose assembly) over the new hose assembly.
4. Push the new hose onto the short coolant connection
GAS HOSE, 3 -FT. ........................................... 31504
GAS HOSE, 12-1/2-FT. .................................... 40V77
GAS HOSE, 25-FT. .......................................... 34V38
POWER CABLE, 12-1/2-FT. ............................ 40V78
TO GAS
TO GAS
4/0 POWER CABLE
(Customer Supplied)
WC-9 or WC-8C
COOLANT
CIRCULATOR
WC-9 or WC-8C
COOLANT
CIRCULATOR
POWER
SOURCE
POWER
SOURCE
POWER
SOURCE
Fig. 4 - ST-21M Service Line Connection Diagram
tube of the torch body and tube assembly. Position
the hose clamp over the grooved section of the short
tube.
5. Crimp the ear of the hose clamp with pincers as illustrated below.
6. Rotate the hose clamp so that the ear is positioned
close to the power connection tube as shown in section A-A of Figure 3.
10
C. CONDUIT LINER (For remote mounting installa-
tions only.)
The plastic lined conduit liners (42V73, 42V74, and
42V75) used to feed aluminum should be cleaned periodically to remove any accumulation of dust or dirt. A
solvent, such as oxylene (trichlorotrifluoroethane,
CCL3CF3) should be forced through the conduit and then
blown out with air. Flushing the solvent through the conduit 5 or 6 times will be sufficient. The solvent can be
purchased from the J.B. Moore Corp., Nutley, New Jersey.
CAUTION: Do not clean the liner while it is assembled
in the conduit. The solvent will attack and
destroy the conduits rubber covering.
ACCESSORIES (NOT SUPPLIED)
Part No.Description
54N88 Guide Tip for .035" Dia. Wire
54N89 Guide Tip for 3/64" Dia. Wire
54N90 Guide Tip for 1/16" Dia. Wire
54N91 Guide Tip for 3/32" Dia. Wire
ALL PARTS WITH THIS SYMBOL
ARE INCLUDED IN 39V27
STEM - 07N37
CAPSCREW - 5/16"-18 x 1"
SPRING - 07N53
PIN - 07N36
HOLDER - 07N38
GUIDE TIP
(SEE TABLE)
NOZZLE BLOCK ASSEMBLY - 39V27
Fig. 5 - Wire Guide Attachment - P/N 39V38
SETSCREW-10 - 32 x 1/4"
HEX NUT-10 - 32 AM. STD.
SETSCREW-10 - 32 x 1"
(2) CONNECTION - 81Z49
CONNECTION - 04N68
D. NOZZLES
Nozzle spatter will be minimal and will wipe off easily
due to efficient nozzle cooling. If necessary, occasional
tightly adhering spatter can be removed from the inside
of nozzles with a hand reamer or file. Exercise care not
to damage the spatter liner or that spatter does not drop
back into the nozzle or contact tube. Ideally, the nozzle
should be removed for cleaning. Adherence of spatter
can be removed for cleaning. Adherence of spatter can
be further minimized and removal made easier by thinly
coating the inside of the nozzle with No. 65 Nozzle Compound (4 oz. can - 08N65; 1 qt. can - 08N75). If spatter
liner is damaged or cracked it should be replaced.
E. CENTERING BUSHING
(Refer to Fig. 3.)
To remove the centering bushing (17782) for replacement or inspection purposes, proceed as follows:
1. Turn off power supply.
2. Unscrew nozzle (and collet nut, if necessary) and remove contact tube.
3. Insert centering bushing removal tool 996300, (supplied with torch assembly) through two adjacent bushing slots and then hook over two opposite bushing
ribs. The centering bushing can then be removed by
pulling the tool straight out.
F. GASKET, INSULATOR AND END FITTING
(Refer to Fig. 3.)
To remove gasket (633884), insulator (997031) or wire
guide end fitting (996403) for replacement or inspection
purposes, proceed as follows:
2. Remove nozzle, contact tube, and collet nut or contact tip.
3. Loosen the two setscrews on locking nut (598787)
and pull back torch barrel (mounting bracket attached)
enough to allow the locking nut to rotate freely.
4. Unscrew the locking nut from the nozzle body
(633881).
5. Pull nozzle body away from the wire guide assembly
(997032). The centering bushing (17782) will fall free.
6. Check the gasket for cracks and deformed sealing
surfaces. When replacing the old or installing a new
gasket, apply a thin film of Dow Corning DC 111 silicone grease (73585007) or equivalent to the O.D.
and sealing surfaces of the gasket.
To reassemble the gasket for proper seating over the
pliable silicone rubber insulator (997031), pull the insulator out partially and then slide the gasket over the
insulator until the side of the gasket, that will seat
against the torch body, and the end of the insulator
are flush. Push the gasket and insulator together until the gasket is properly seated against the torch body.
7. To remove the wire guide end/fitting (996403), clamp
the torch body in a vise or use a vise-grip type pliers
on the wire guide and then unscrew the end fitting
using a 7/16-in. open-end wrench. Before installing a
new fitting, apply a thin film of Dow Corning Heat Sink
Compound No. 340 (73585976) to both the male and
female threads.
8. Reassemble the torch in reverse order.
1. With power supply turned off, disconnect all torch service lines.