Miller XR - AlumaPro User manual

300 Ampere (Air) Push-Pull Welding Gun
XR - AlumaPro
(Air-Cooled Guns)
Processes
Description
MIG (GMAW) Welding
OM-227 398L
2011−05
Semi-Automatic,Air-Cooled,
MIG (GMAW) Welding Gun
™
File: MIG (GMAW)
Visit our website at
www.MillerWelds.com

Miller Electric manufactures a full line
of welders and welding related equipment.
For information on other quality Miller
products, contact your local Miller distributor to receive the latest full
line catalog or individual specification sheets. To locate your nearest
distributor or service agency call 1-800-4-A-Miller, or visit us at
www.MillerWelds.com on the web.
Thank you and congratulations on choosing Miller. Now you can get
the job done and get it done right. We know you don’t have time to do
it any other way.
That’s why when Niels Miller first started building arc welders in 1929,
he made sure his products offered long-lasting value and superior
quality. Like you, his customers couldn’t afford anything less. Miller
products had to be more than the best they could be. They had to be the
best you could buy.
Today, the people that build and sell Miller products continue the
tradition. They’re just as committed to providing equipment and service
that meets the high standards of quality and value established in 1929.
This Owner’s Manual is designed to help you get the most out of your
Miller products. Please take time to read the Safety precautions. They
will help you protect yourself against potential hazards on the worksite.
We’ve made installation and operation quick
and easy. With Miller you can count on years
of reliable service with proper maintenance.
And if for some reason the unit needs repair,
there’s a Troubleshooting section that will
help you figure out what the problem is. The
parts list will then help you to decide the
exact part you may need to fix the problem.
Warranty and service information for your
particular model are also provided.
Miller is the first welding
equipment manufacturer in
the U.S.A. to be registered to
the ISO 9001 Quality System
Standard.
Working as hard as you do
− every power source from
Miller is backed by the most
hassle-free warranty in the
business.
From Miller to You
Mil_Thank 2009−09

TABLE OF CONTENTS
SECTION 1 −SAFETY PRECAUTIONS FOR GMAW WELDING GUNS − READ BEFORE USING 1........
1-1. Symbol Usage 1........................................................................
1-2. Arc Welding Hazards 1..................................................................
1-3. Proposition 65 Warnings 2...............................................................
1-4. EMF Information 2......................................................................
SECTION 2 − MESURES DE SÉCURITÉ VISANT LES PISTOLETS DE SOUDAGE GMAW − À LIRE AVANT
UTILISATION 3................................................................................
2-1. Signification des symboles 3.............................................................
2-2. Dangers relatifs au soudage à l’arc 3......................................................
2-3. Proposition californienne 65 Avertissements 4...............................................
2-4. Informations relatives aux CEM 4.........................................................
SECTION 3 − DEFINITIONS 5...................................................................
3-1. Symbols And Definitions 5...............................................................
SECTION 4 − INTRODUCTION 6.................................................................
4-1. Specifications 6........................................................................
4-2. Duty Cycle And Overheating 6............................................................
SECTION 5 − INSTALLATION 7..................................................................
5-1. Connections With A Constant Current (CC), Constant Voltage (CV) Or Constant Current/Constant
Voltage (CC/CV) Welding Power Source Having A 14-Socket Receptacle 7......................
5-2. Air-Cooled Gun Connections 8............................................................
5-3. Threading Welding Wire For AlumaPro Gun And Millermatic 350P 9.............................
5-4. Threading Welding Wire Through XR-Control Feeder 10.......................................
5-5. Adjusting Tension At Feeder 11............................................................
5-6. 10-Pin Plug Information 12................................................................
5-7. Opening Top Cover Of XR-AlumaPro Gun 12.................................................
5-8. Threading Welding Wire Through Gun 13....................................................
SECTION 6 − OPERATION 14....................................................................
6-1. Gun Controls 14.........................................................................
6-2. Gun Pressure Roll Tension Setting 14.......................................................
6-3. Shielding Gas 15........................................................................
6-4. Gun Drive Assembly Maintenance For An XR-AlumaPro Gun 15................................
6-5. Replacing Head Tube Liner In XR-AlumaPro Guns 16.........................................
6-6. Changing Gun Contact Tip 16.............................................................
6-7. Replacing The Gun Liner On XR-AlumaPro Guns 17..........................................
SECTION 7 − MAINTENANCE & TROUBLESHOOTING 18...........................................
7-1. Routine Maintenance For Aluminum Push/Pull Guns 18........................................
7-2. Cleaning The Gun Liner On XR-AlumaPro Guns 19...........................................
7-3. Troubleshooting Table 20.................................................................
SECTION 8 − ELECTRICAL DIAGRAMS 21........................................................
SECTION 9 − PARTS LIST 22.....................................................................
SECTION 10 − PARTS LIST INCLUDING CONSUMABLES 26........................................
WARRANTY

OM-227 398 Page 1
SECTION 1 −SAFETY PRECAUTIONS FOR GMAW
WELDING GUNS − READ BEFORE USING
SR7 (MIG) 2010−03
Protect yourself and others from injury — read and follow these precautions.
1-1. Symbol Usage
DANGER! − Indicates a hazardous situation which, if
not avoided, will result in death or serious injury. The
possible hazards are shown in the adjoining symbols
or explained in the text.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury. The possible
hazards are shown in the adjoining symbols or ex-
plainedin the text.
NOTICE − Indicates statements not related to personal injury.
.Indicates special instructions.
This group of symbols means Warning! Watch Out! ELECTRIC
SHOCK, MOVING PARTS, and HOT PARTS hazards. Consult sym-
bols and related instructions below for necessary actions to avoid the
hazards.
1-2. Arc Welding Hazards
The symbols shown below are used throughout this manual
to call attention to and identify possible hazards. When you
see the symbol, watch out, and follow the related instructions
to avoid the hazard. The safety information given below is
only a summary of the more complete safety information
found in the welding power source Owner’s Manual. Read
and follow all Safety Standards.
Only qualified persons should install, operate, maintain, and
repair this unit.
During operation, keep everybody, especially children, away.
ELECTRIC SHOCK can kill.
DAlways wear dry insulating gloves.
DInsulate yourself from work and ground.
DDo not touch live electrode or electrical parts.
DRepairor replace worn, damaged, or cracked gun or cable insula-
tion.
DTurn off welding power source before changing contact tip or gun
parts.
DKeep all covers and handle securely in place.
DKeep your head out of the fumes.
DVentilate area, or use breathing device.
DRead Material Safety Data Sheets (MSDSs)
and manufacturer’s instructions for material
used.
FUMES AND GASES can be hazardous.
DDo not weld near flammable material.
DDo not weld on closed containers.
DWatch for fire; keep extinguisher nearby.
WELDING can cause fire or explosion.
BUILDUP OF GAS can injure or kill.
DShut off shielding gas supply when not in use.
DAlways ventilate confined spaces or use ap-
proved air-supplied respirator.
MOVING PARTS can injure.
DKeep away from moving parts.
DKeep away from pinch points such as drive
rolls.
DWear welding helmet with correct shade of fil-
ter.
DWear correct eye and body protection.
DCover exposed skin with spatter-resistant
clothing.
ARC RAYS can burn eyes and skin.
HOT PARTS can burn.
DAllow gun to cool before touching.
DDo not touch hot metal.
DProtect hot metal from contact by others.
NOISE can damage hearing.
Noise from some processes or equipment can
damagehearing.
DCheck for noise level limits exceeding those
specifiedby OSHA.
DUse approved ear plugs or ear muffs if noise level is high.
DWarn others nearby about noise hazard.
WELDING WIRE can injure.
DKeephands and body away from gun tip when
triggeris pressed.
READ INSTRUCTIONS.
DRead and follow all labels and the Owner’s
Manualcarefully before installing, operating, or
servicing unit. Read the safety information at
the beginning of the manual and in each
section.
DUse only genuine replacement parts from the manufacturer.
DPerform maintenance and service according to the Owner’s
Manuals, industry standards, and national, state, and local
codes.

OM-227 398 Page 2
1-3. Proposition 65 Warnings
Welding or cutting equipment 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 Section 25249.5 et seq.)
This product contains chemicals, including lead, known to
the state of California to cause cancer, birth defects, or other
reproductiveharm. Wash hands after use.
1-4. EMF Information
Electric current flowing through any conductor causes localized electric
and magnetic fields (EMF). Welding current creates an EMF field
aroundthe welding circuit and welding equipment. EMF fields may inter-
fere with some medical implants, e.g. pacemakers. Protective meas-
ures for persons wearing medical implants have to be taken. For ex-
ample,access restrictions for passers−by or individual risk assessment
for welders. All welders should use the following procedures in order to
minimizeexposure to EMF fields from the welding circuit:
1. Keep cables close together by twisting or taping them, or using a
cable cover.
2. Do not place your body between welding cables. Arrange cables
to one side and away from the operator.
3. Do not coil or drape cables around your body.
4. Keep head and trunk as far away from the equipment in the
welding circuit as possible.
5. Connect work clamp to workpiece as close to the weld as
possible.
6. Do not work next to, sit or lean on the welding power source.
7. Do not weld whilst carrying the welding power source or wire
feeder.
About Implanted Medical Devices:
ImplantedMedical Device wearers should consult their doctor and the
device manufacturer before performing or going near arc welding, spot
welding,gouging, plasma arc cutting, or induction heating operations.
If cleared by your doctor, then following the above procedures is recom-
mended.

OM-227 398 Page 3
SECTION 2 − MESURES DE SÉCURITÉ VISANT LES
PISTOLETS DE SOUDAGE GMAW − À LIRE AVANT
UTILISATION
SR7(MIG)_2010−03fre
Se protéger, ainsi que toute autre personne travaillant sur les lieux, contre les étincelles et le métal chaud.
2-1. Signification des symboles
DANGER! − Indique une situation dangereuse qui si on
l’évitepas peut donner la mort ou des blessures graves.
Les dangers possibles sont montrés par les symboles
joints ou sont expliqués dans le texte.
Indique une situation dangereuse qui si on l’évite pas
peut donner la mort ou des blessures graves. Les dan-
gers possibles sont montrés par les symboles joints ou
sont expliqués dans le texte.
NOTE − Indique des déclarations pas en relation avec des blessures
personnelles.
.Indique des instructions spécifiques.
Ce groupe de symboles veut dire Avertissement! Attention! DANGER
DE CHOC ELECTRIQUE, PIECES EN MOUVEMENT, et PIECES
CHAUDES. Consulter les symboles et les instructions ci-dessous y
afférant pour les actions nécessaires afin d’éviter le danger.
2-2. Dangers relatifs au soudage à l’arc
Les symboles présentés ci-après sont utilisés tout au long du
présent manuel pour attirer votre attention et identifier les ris-
ques de danger. Lorsque vous voyez un symbole, soyez vigi-
lant et suivez les directives mentionnées afin d’éviter tout
danger. Les consignes de sécurité présentées ci-après ne
font que résumer l’information contenue dans les normes de
sécurité énumérées dans le manuel d’utilisation du poste de
soudage.Veuillez lire et respecter toutes ces normes de sé-
curité.
L’installation, l’utilisation, l’entretien et les réparations ne
doiventêtre confiés qu’à des personnes qualifiées.
Au cours de l’utilisation, tenir toute personne à l’écart et plus
particulièrementles enfants.
UN CHOC ÉLECTRIQUE peut tuer.
DPorter toujours des gants secs et isolants.
DS’isoler de la pièce et de la terre.
DNe jamais toucher une électrode ou des pièces
électriquessous tension.
DRéparer ou remplacer un pistolet ou la gaine d’isolement d’un
câble usée, endommagée ou fissurée.
DMettrela soudeuse hors tension avant de remplacer un bec con-
tact ou des pièces de pistolet.
DS’assurer que tous les couvercles et poignées sont fermement
assujettis.
LES VAPEURS ET LES FUMÉES
peuvent être nocives.
DÉloigner sa tête des endroits renfermant des
vapeurs.
DAérer la zone de travail ou porter un appareil re-
spiratoire.
DConsulter les fiches toxicologiques (MSDS) et les notices dufab-
ricant de chaque matériel utilisé.
LE SOUDAGE peut causer un incen-
die ou une explosion.
DNe pas souder à proximité de matériaux inflam-
mables.
DNe pas souder sur des récipients fermés.
DPrendre garde aux incendies et toujours avoir un extincteur à
proximité.
L’ACCUMULATION DE VAPEURS
peut causer des lésions ou la mort.
DQuand on n’utilise pas le gaz de protection,
fermerle robinet de la bouteille.
DAssurer toujours la ventilation des zones fer-
mées ou utiliser un appareil respiratoire avec
alimentationen air.
Les PIÈCES MOBILES peuvent
causer des blessures.
DNe pas s’approcher des organes mobiles.
DNe pas s’approcher des points de coincement
tels que des rouleaux de commande.
LE RAYONNEMENT DE L’ARC peut
brûler les yeux et la peau.
DPorter un casque de soudage muni d’un filtre
de protection oculaire approprié.
DPorter une protection oculaire et des vête-
ments de protection appropriés.
DProtégerla peau nue en portant des vêtements anti-éclabous-
sures.
LES PIÈCES CHAUDES peuvent
provoquer des brûlures.
DLaisser refroidir le pistolet avant de le toucher.
DNe pas toucher d’objets métalliques chauds.
DAbriterles objets métalliques contre tout con-
tact par les personnes à proximité.

OM-227 398 Page 4
Le BRUIT peut endommager l’ouie.
Le bruit des processus et des équipements peut
affecter l’ouïe.
DVérifiersi les niveaux de bruit excèdent les lim-
ites spécifiées par l’OSHA.
DUtiliserdes bouche-oreilles ou des serre-tête antibruit approuvés
si le niveau de bruit est élevé.
DAvertir les personnes à proximité au sujet du danger inhérent au
bruit.
LES FILS DE SOUDAGE peuvent
provoquer des blessures.
DÉloignerles mains et le corps de la buse du pis-
tolet après avoir appuyé sur la gâchette.
LIRE LES INSTRUCTIONS.
DLire et appliquer les instructions sur les
étiquettes et le Mode d’emploi avant
l’installation, l’utilisation ou l’entretien de
l’appareil.Lire les informations de sécurité au
débutdu manuel et dans chaque section.
DN’utiliser que les pièces de rechange recommandées par le
constructeur.
DEffectuer l’entretien en respectant les manuels d’utilisation,
les normes industrielles et les codes nationaux, d’état et locaux.
2-3. Proposition californienne 65 Avertissements
Les équipements de soudage et de coupage produisent des
fuméeset des gaz qui contiennent des produits chimiques
dont l’État de Californie reconnaît qu’ils provoquent des
malformations congénitales et, dans certains cas, des
cancers.(Code de santé et de sécurité de Californie, chapitre
25249.5et suivants)
Ce produit contient des éléments chimiques, dont le plomb,
reconnus par l’État de Californie pour leur caractère
cancérogène ainsi que provoquant des malformations
congénitalesou autres problèmes de procréation. Se laver
les mains après toute manipulation.
2-4. Informations relatives aux CEM
Le courant électrique qui traverse tout conducteur génère des champs
électromagnétiques (CEM) à certains endroits. Le courant de soudage
crée un CEM autour du circuit et du matériel de soudage. Les CEM
peuvent créer des interférences avec certains implants médicaux
commedes stimulateurs cardiaques. Des mesures de protection pour
les porteurs d’implants médicaux doivent être prises: par exemple, des
restrictions d’accès pour les passants ou une évaluation individuelle
des risques pour les soudeurs. Tous les soudeurs doivent appliquer les
procéduressuivantes pour minimiser l’exposition aux CEM provenant
du circuit de soudage:
1 Rassembler les câbles en les torsadant ou en les attachant avec
du ruban adhésif ou avec une housse.
2 Ne pas se tenir au milieu des câbles de soudage. Disposer les
câbles d’un côté et à distance de l’opérateur.
3 Ne pas courber et ne pas entourer les câbles autour de votre
corps.
4 Maintenir la tête et le torse aussi loin que possible du matériel du
circuit de soudage.
5 Connecter la pince sur la pièce aussi près que possible de la
soudure.
6 Ne pas travailler à proximité d’une source de soudage, ni
s’asseoir ou se pencher dessus.
7 Ne pas souder tout en portant la source de soudage ou le
dévidoir.
En ce qui concerne les implants médicaux :
Les porteurs d’implants doivent d’abord consulter leur médecin avant
de s’approcher des opérations de soudage à l’arc, de soudage par
points,de gougeage, du coupage plasma ou de chauffage par induc-
tion.Si le médecin approuve, il est recommandé de suivre les procédu-
res précédentes.

OM-227 398 Page 5
SECTION 3 − DEFINITIONS
3-1. Symbols And Definitions
AAmperes VVolts AlternatingCurrent XDuty Cycle
IP
Degree Of
Protection Hz Hertz Circuit Breaker Wire Feed
Jog Output Trigger Gun
Press To Set Increase Trigger Hold On Trigger Hold Off
Purge Spot Weld Time Percent Run-In
Burnback Time
U
1Primary Voltage
U
2Load Voltage Read Instructions
I
1Primary Current
I
2Rated Current Line Connection Water (Coolant) In-
put
Water (Coolant)
Output Fuse Continuous Spot Welding
Notes

OM-227 398 Page 6
SECTION 4 − INTRODUCTION
4-1. Specifications
Model Welding Output Range Electrode
Wire Diameter
Capacity
Wire Feed
Speed Range Net Weight
(Torch Only)
XR-AlumaPro Gun
(Air Cooled) 300 A at 100% Duty Cycle with 15, 25 or 35 ft
(4.6 or 7.6 m) gun
.030 To 1/16 in.
(0.8 To 1.6 mm)
aluminum wire
70 To 900 ipm
(1.8 To 23 mpm) 2.5 lb (1.1 kg) (less cables)
.When using 1/16 in (1.6 mm) wire, kit 230708 must be installed.
4-2. Duty Cycle And Overheating
Duty Cycle is percentage of 10 min-
utes that unit can weld at rated load
withoutoverheating.
NOTICE − Exceeding duty cycle
can damage unit and void warranty.
sduty1 5/95
ContinuousWelding
Air-Cooled Models
100% Duty Cycle At 300 Peak Amperage Using 100% Argon Gas w/15, 25 Or 35 Foot Guns
Notes

OM-227 398 Page 7
SECTION 5 − INSTALLATION
.Be sure that contact tip, liner, and drive rolls are correct for wire size and type. See Parts List to change parts as needed.
5-1. Connections With A Constant Current (CC), Constant Voltage (CV) Or Constant
Current/Constant Voltage (CC/CV) Welding Power Source Having A 14-Socket Re-
ceptacle
Ref. 804 653-A / 805 349-A
1 CC, CV Or CC/CV Welding Power
Source
2 24 VAC/Contactor Control 14-Pin
Plug
3 Negative (−) Weld Cable
4 Workpiece
5 Welding Gun
6 Wire Feeder
7 24 VAC/Contactor Control Cord
8 Positive (+) Weld Cable
9 Gas Cylinder
.Shieldinggas pressure not to exceed
100 psi (689 kPa).
4
Millermatic 350P
XR-D
5
1
9
5
1
2
6
9
3
8
7

OM-227 398 Page 8
5-2. Air-Cooled Gun Connections
Ref. 245 995-A / 246 218-A / 151 666-G
1 Gun Control Cable
Insertplug into Gun Control receptacle, and
tightenthreaded collar.
2 Gun Power Pin
3 Gun Bushing
4 Gun Securing Knob
5 Drive Casting
Loosen gun securing knob and insert gun
power pin through gun bushing until it
bottoms against drive casting. Tighten
knob.
5
4
1
Left Side
2
3

OM-227 398 Page 9
5-3. Threading Welding Wire For AlumaPro Gun And Millermatic 350P
1 Wire Spool
2 Welding Wire
3 Inlet Wire Guide
4 Drive Roll
5 Intermediate Wire Guide
6 Outlet Wire Guide
7 Pressure Adjustment Knob
8 Gun Conduit Cable
Lay gun cable out straight.
Tools Needed:
6 in.
(150 mm)
.Holdwire tightly to keep it
from unraveling.
Open pressure assembly. Pull and hold wire; cut off end.
Push wire thru guides into gun;
continue to hold wire. Close and tighten pressure
assembly, and let go of wire.
.Set pressure indicator
scale to 1/2 lb.
Ref. 803 544-A / 218 243-A / 218 244-A / S-0627-A
1
2
3
4
Pressure
Indicator
Scale
218243-A
IMPORTANT!
For Aluminum Push-Pull welding.
Thread hub tension nut loosely
IMPORTANT!
For Aluminum
Push-Pull welding.
1
2
3
4
218244-A
7
8
35621 4
See Section 5-8 for threading welding
wire through AlumaPro guns.
3/4 in.
Tighten to
1/2 lb.

OM-227 398 Page 10
5-4. Threading Welding Wire Through XR-Control Feeder
Ref. 246 218-A / 805 354
Tools Needed:
2
1
1 Cable Assembly
Lay cable assembly out straight.
2 Jog Switch
Push Jog switch up to feed wire through
cable assembly.
3 Torque Switch
.Select proper push feeder torque set-
ting for wire size being used. Use low
torque for .030 in. (0.8mm) wire. Use
high torque for all other wire sizes.
.XR-AlumaFeedtorque setting is auto-
maticallyset internally for wire sizes.
3
JOG / PURGE
Notes

OM-227 398 Page 11
5-5. Adjusting Tension At Feeder
Ref. 805 350-A / 242 517-A
Tools Needed:
Pull and hold wire; cut off end.
6 in.
(150 mm)
1 Tension Arm
Open tension arm.
Thread wire thru inlet guide, along drive roll groove, and
into wire conduit. Close tension arm. Adjust tension as
follows:
.Hold wire tightly to keep
it from unraveling.
1
1
Wire Size Welding Gun Calibration
3−4
3−4
1−2
0.035 in.
0.040 in.
3/64 in.
1/16 in.
Tension Settings
Install proper size drive rolls.

OM-227 398 Page 12
5-6. 10-Pin Plug Information
10 Pin* Pin Information
EF
DJG
CIH
BA
AElectrodesense lead
BMotor Common
G Trigger
CMotor 0 to +24 volts DC with respect to pin B
D Trigger
EWire speed Ref. +9 volts DC
HWire speed com
FWire speed 0 to +9 volts DC with respect to pin H
JGun sensing resistor with respect to pin H
INot used
5-7. Opening Top Cover Of XR-AlumaPro Gun
1 Top Cover
Squeeze sides of cover and lift up
as shown.
To close cover, pivot cover closed
on gun, and push cover down until
cover locks tight.
Ref. 804 544-B
1

OM-227 398 Page 13
!Welding wire is electrically live when
gun trigger is used to jog wire.
.Refer to Section 5-3 for instructions on feeding
wire through feeder.
5-8. Threading Welding Wire Through Gun
Ref. 804 544-B / 804 545-B
Tools Needed:
Lay gun cable out straight. Press Jog switch until about 6
in. (152 mm) of wire is sticking out end of contact tip.
Cut off wire. Close and
latch wire feeder door.
.Turn OFF coolant supply before threading wire
throughgun..
For XR-AlumaPro Gun:
.Verify pressure adjustment
on handle matches the wire
type. See Section 6-2.
JOG / PURGE

OM-227 398 Page 14
SECTION 6 − OPERATION
6-1. Gun Controls
1 Trigger
Press trigger to energize welding
power source contactor (if
applicable),start shielding gas flow,
and begin wire feed.
Switches inside the wire feeder can
be set to provide timed shielding gas
preflowand postflow when trigger is
pressed and released. When this
feature is turned Off, no preflow or
postflow is provided for the welding
operation.
2 Gun Wire Speed Control
Use control to fine adjust wire feed
speed set on XR-Control. Gun Wire
SpeedControl has 3-3/4 turns of ad-
justmentfrom minimum to maximum.
Rotatecontrol clockwise to increase
wire speed and counterclockwise to
decrease wire speed.
.Speed control can be rotated
morethan 3-3/4 turns in both di-
rectionswithout being damaged.
1
2
Ref. 804 545-B
6-2. Gun Pressure Roll Tension Setting
.Aluminum series specific -
Pressure roll tension setting
ensures smooth wire feeding
action.
.Gun Pressure Roll Tension is
factory set to 4XXX.
1 Pressure Roll Adjustment
Screw
Wire tension should be set to 4XXX
for 4000 series aluminum wire.
Rotate Pressure Roll Adjustment
Screw fully counterclockwise until
indicator line on adjustment knob
lines up with indicator line on handle
in the 4XXX position.
Wire tension should be set to 5XXX
for 5000 series aluminum and stain-
less wire.
Rotate Pressure Roll Adjustment
Screw fully clockwise until indicator
line on adjustment knob lines up
with indicator line on handle in the
5XXX position.
1
Ref. 804 545-B
Tools Needed:

OM-227 398 Page 15
6-3. Shielding Gas
Ref. 151 666-F / 804 545-B
1 ShieldingGas Cylinder
2 Valve
3 Gun Trigger
Open valve on cylinder just before
welding.
Gun trigger turns weld output and
gas flow on and off (see Section
6-1).
Close valve on cylinder when
finishedwelding.
3
1
2
6-4. Gun Drive Assembly Maintenance For An XR-AlumaPro Gun
Ref. 804 544-B / 805 194-A
Tools Needed:
3
1
7/64, 1/16 in.
2
3/8 in.
1 Lever Arm
Using lever arm open pressure roll
with bearing as shown.
Retract wire onto spool.
2 Drive Roll
Use wire brush to clean drive roll.
Install drive roll with hex opening
downtoward shaft hex, and secure
with screw.
3 Pressure Roll
Thread welding wire through gun.
Close pressure roll assembly and
idlerroll (located in XR control box).
Press jog switch until wire is stick-
ing out end of contact tip.
.When changing wire size and
using an XR control box you
shouldchange the control box
drive roll and idler. See XR
owners manual for details.
Close top cover.

OM-227 398 Page 16
6-5. Replacing Head Tube Liner In XR-AlumaPro Guns
Ref. 804 544-B
The standard head tube liner
(yellow) will accommodate wire
diametersfrom 3/64 in.- 1/16 in. wire
size.
When changing wire size, change
controlbox drive roll, idler and head
tube liner with appropriate sized lin-
er.
1 Head Tube
2 Head Tube Nut
Loosen head tube nut and remove
headtube from gun.
3 Head Tube Liner
Pull liner out of head tube.
Insertnew liner into head tube (install
taperedend first) and reinstall head
tube onto gun.
.A twisting motion may be need-
ed to feed liner thru head tube.
NOTICE − Be sure head tube is
seatedand head tube nut is securely
tightened before operating gun. If
headtube nut is not adequately tight-
ened, unwanted arcing may occur
betweenhead tube and gun housing.
1
2
3
Taperedend
6-6. Changing Gun Contact Tip
Ref. 804 709-A
2
1
Remove nozzle
1 Nozzle
2 FasTip
Unscrew FasTip.
Install new FasTip.
NOTICE − Make sure correct size
contact tip is being used. Incorrect
size may cause arcing inside tip,
poor feedability and poor arc start-
ing characteristics(see Section 9).
Reinstall nozzle.