Miller OBT-600 User manual

Torches for
Automated Applications
Process
OBT-600 And OBT- 1200
SubmergedArc Welding
(SAW)
OM-1596 192 709B
April 2003
Description
Torches For Automatic Welding Sys-
tems Using The Submerged Arc Weld-
ing (SAW) Process
Automatic Welding
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 orindividual catalog 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 9001:2000 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
Milleroffers a Technical
Manual which provides
more detailed service and
parts information for your
unit. To obtain a Technical
Manual, contact your local
distributor. Your distributor
can also supply you with
Welding Process Manuals
such as SMAW, GTAW,
GMAW, and GMAW-P.

TABLE OF CONTENTS
SECTION 1 – SAFETY PRECAUTIONS - READ BEFORE USING 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-1. Symbol Usage 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2. Arc Welding Hazards 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5. EMF Information 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 2 – Specifications 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1. Welding Torches 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2. Overall Dimensions 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 3– INSTALLATION 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1. Installing Torch Into Drive Assembly (OBT-1200 Shown) 4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2. Breakaway Torch Protection (OBT-1200 Models Only) 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3. Adding Body Extension (1200 Models Only) 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 4 – OPERATION 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1. Safety Equipment 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 5 – MAINTENANCE AND TROUBLESHOOTING 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-1. Maintenance Schedule 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-2. Troubleshooting Table 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 6 – PARTS LIST 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

OM-1596 Page1
SECTION 1 – SAFETY PRECAUTIONS – READ BEFORE USING
1-1. Symbol Usage
OM-1596 -9/98, safety_saw torch 9/98
Means Warning! Watch Out! There are possible hazards
with this procedure! The possible hazards are shown in
the adjoining symbols.
YMarks a special safety message.
.Means “Note”; not safety related.
This group of symbols means Warning! Watch Out! possible
ELECTRIC SHOCK, WELDING WIRE, and HOT PARTS hazards.
Consultsymbols and related instructions below for necessary actions
to avoid the hazards.
1-2. Arc Welding Hazards
YThe 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 Safety Standards listed in the wire feeder and welding
power source Owner’s Manuals. Read and follow all Safety
Standards.
YOnly qualified persons should install, operate, maintain, and
repair this unit.
YDuring 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.
DRepair or replace worn, damaged, or cracked
torch or cable insulation.
DTurn off welding power source before changing contact tip or
torch parts.
DKeep all connections tight and secure.
FLYING PARTICLES can injure eyes.
DFlux granules, slag, welding, chipping, wire
brushing,and grinding cause sparks and flying
flux and metal. As welds cool, they can throw
off slag.
DWear approved safety glasses with side
shields.
DWear body protection and cover exposed skin.
HOT PARTS can burn skin.
DAllow gun to cool before touching.
DDo not touch hot metal.
DProtect hot metal from contact by others.
MAGNETIC FIELDS can affect pacemakers.
DPacemaker wearers keep away.
DWearers should consult their doctor before
going near arc welding, gouging, or spot
weldingoperations.
MOVING PARTS can cause injury.
DKeep away from moving parts.
DKeep away from pinch points such as drive
rolls.
WELDING can cause fire or explosion.
DDo not weld near flammable material.
DDo not weld on closed containers.
DWatch for fire; keep extinguisher nearby.
WELDING WIRE can cause injury.
DKeephands and body away from torch tip when
weldingsystem is energized.
DDo not put hands or other body parts near the
nozzle when threading welding wire.
FUMES AND GASES can be hazardous.
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.
READ INSTRUCTIONS.
DUse only genuine MILLER replacement parts.
DRead and follow the safety information in the
wire drive system and welding power source
Owner’s Manuals for more complete welding
safety information.
ARC WELDING can cause interference.
DElectromagnetic energy can interfere with
sensitive electronic equipment such as
computers and computer-driven equipment
such as robots.
DBe sure all equipment in the welding area is
electromagneticallycompatible.
DTo reduce possible interference, keep weld cables as short as
possible, close together, and down low, such as on the floor.
DLocate welding operation 100 meters from any sensitive elec-
tronic equipment.
DBe sure this torch and welding system are installed and
groundedaccording to their manuals.
DIf interference still occurs, the user must take extra measures
such as moving the welding machine, using shielded cables,
using line filters, or shielding the work area.

OM-1596 Page 2
1-3. EMF Information
Considerations About Welding And The Effects Of Low Frequency
Electric And Magnetic Fields
The following is a quotation from the General Conclusions Section of the
U.S. Congress, Office ofTechnology Assessment, Biological Effects of
Power Frequency Electric & Magnetic Fields – Background Paper,
OTA-BP-E-53(Washington, DC: U.S. Government Printing Office,May
1989):“. . . there is now a very large volume of scientific findings based
on experiments at the cellular level and from studies with animals and
peoplewhich clearly establish that low frequency magnetic fields can
interact with, and produce changes in, biological systems. While most
of this work is of very high quality, the results are complex. Current
scientificunderstanding does not yet allow us to interpret the evidence
in a single coherent framework. Even more frustrating, it does not yet
allow us to draw definite conclusions about questions of possible risk
or tooffer clear science-based advice on strategies to minimize or avoid
potentialrisks.”
To reduce magnetic fields in the workplace, use the following
procedures:
1. Keep cables close together by twisting or taping them.
2. Arrange cables to one side and away from the operator.
3. Do not coil or drape cables around the body.
4. Keep welding power source and cables as far away from opera-
tor as practical.
5. Connect work clamp to workpiece as close to the weld as possi-
ble.
About Pacemakers:
The above procedures are also recommended for pacemaker wearers.
Consultyour doctor for complete information.

OM-1596 Page 3
SECTION 2 – SPECIFICATIONS
2-1. Welding Torches
Model
Rating: 100%
Duty Cycle DCEP
Wire Diameter Capacity
Cooling
Method
Weight
Model
Rating: 100%
Duty Cycle DCEP
Wire Diameter Capacity
Cooling
Method Net
OBT-600 600 Amperes
Submerged Arc 1/16, 5/64, 3/32, 7/64, 1/8, 5/32, 3/16, 7/32 in (1.6, 2.0, 2.4, 2.8, 3.2, 4.0, 4.8, 5.6 mm) Hard Wire Air 2 lb (0.91 kg)
OBT-1200 1200 Amperes
Submerged Arc 1/16, 5/64, 3/32, 7/64, 1/8, 5/32, 3/16, 7/32 in (1.6, 2.0, 2.4, 2.8, 3.2, 4.0, 4.8, 5.6 mm) Hard Wire Air 7 lb (3.2 kg)
14-3/4 in
(374.7 mm)
17-1/4 in
(438.2 mm) 10-1/4 in
(260.4 mm)
11-1/4 in
(285.8 mm)
SA-802 264-A
OBT-1200 Model OBT-600 Model
2-2. Overall Dimensions
7-1/2in
(190.5 mm)

OM-1596 Page 4
SECTION 3 – INSTALLATION
For complete installation into wire drive assembly, see wire drive Owner’s Manual.
Note
3-1. Installing Torch Into Drive Assembly (OBT-1200 Shown)
Ref. ST-080 847-A
1 Breakaway Device With Wire
Inlet Guide
2 Torch Body
3 Torch Securing Handle
4 Torch End With Inet Guide
5 Wire Drive Assembly
Turn Off power, loosen handle (3),
insert torch end (1) into drive as-
sembly, and tighten handle (3).
1
2
3
4
5
3-2. Breakaway Torch Protection (OBT-1200 Models Only)
Ref. ST-049 258-C
1 Torch Body
2 Breakaway Device
3 Breakaway Device After
Impact
The Breakaway Device is designed
to shear if the torch hits an object.
This action prevents damage to the
torch itself. To continue operation,
turn off power, retract welding wire,
and simply remove old device and
replacewith a new one.
The OBT-1200 torch is equipped with a Breakaway
Device to protect the torch from damage if a strong impact
occurs.
1
2
3

OM-1596 Page 5
3-3. Adding Body Extension (1200 Models Only)
YELECTRIC SHOCK and WIRE WOUND HAZARDS. Re-
tract welding wire and turn Off welding power source,
wire feeding system, and flux supply before adding
body extension.
1 Body Extension
2 Clamp
3 Nozzle Assembly
Loosen clamp and remove nozzle
assembly.
4 Nut
5 Contact Tiip
6 Tip Extender
7 Liner
Removenut, contact tip, tip extend-
er, and liner.
8 Torch Body
9 Extension Liner
Install extension onto body (exten-
sion liner must be cut to length prior
to final installation). Reinstall re-
moved parts as shown.
10 Completed Job
SB-088 001-A
1
2
3
7
6
4
5
8
10
9

OM-1596 Page 6
SECTION 4 – OPERATION
4-1. Safety Equipment
Wear the following while handling
flux or welding:
1 Dry, Insulating Gloves
2 Safety Glasses With Side
Shields or Goggles
sb3.1 1/94
12
SECTION 5 – MAINTENANCE AND TROUBLESHOOTING
5-1. Maintenance Schedule
YTurn Off all power before maintaining.
Each Spool Of Wire 3 Months
Blow out gun liner. Clean nozzle
and check contact tip. Replace cracked parts.
5-2. Troubleshooting Table
Trouble Remedy
Wire does not feed. Check contact tip. Check for kinks in outlet cable. Check connections at wire drive assembly. Have
nearest Factory Authorized Service Station/Service Distributor check automatic equipment and weld-
ing power source.
Wire is not energized. Check contact tip. Check connections at wire drive assembly. Have nearest Factory Authorized Ser-
vice Station/Service Distributor check automatic equipment and welding power source.
Wire feeds unevenly. Check contact tip. Check for kinks in outlet cable. Blow out gun liner and outlet cable casing.