MAC TOOLS MW250 User manual

March
1997
Form:
OM-154501E
Effective With
Serial
No.
KH321522
MW250
OWNERS
MANUAL
~
IMPORTANT: Read and understand the entire
contents
of
this
manual,
with
special emphasis
on
the
safety
material
throughout
the
manual,
before
installing,
operating,
or
maintaining
this
equipment.
This
unit
and
these
instructions
are
for
use
only
by
persons
trained and
experienced
in
the
safe
operation
of
welding
equipment.
Do
not
allow
untrained
persons
to
install,
operate,
or
maintain this unit. Contact
your
distributor if
you
do
not
fully
understand
these
instructions.
I
1~oLsfi
coven
5/92

ST-157
072-A
PRINTED
IN
USA

ARC WELDING
SAFETY
PRECAUTIONS
a
WARNING
ARC WELDING
can
be
hazardous.
PROTECT
YOURSELF
AND
OTHERS FROM
POSSIBLE SERIOUS
INJURY
OR
DEATH. KEEP CHILDREN
AWAY. PACEMAKER WEARERS KEEP AWAY UNTIL
CONSULTING
YOUR DOCTOR.
In
welding,
as
in
most
jobs,
exposure
to
certain hazards
occurs.
Welding
is
safe
when
precautions
are
taken. The
safety
information
given
below is
only
a
summary
of
the
more
complete
safety
information that
will
be found
in
the
Safety
Standards listed
on
the
next
page.
Read and follow
all
Safety
Standards.
HAVE ALL
INSTALLATION,
OPERATION,
MAINTENANCE,
AND
REPAIR WORK
PERFORMED
ONLY BY
QUALIFIED
PEOPLE.
WELDING
can cause
fire
or
explosion.
Sparks
and
spatter
fly
off from the
welding
arc.
The
flying
sparks
and
hot
metal,
weld
spatter,
hot
workpiece,
and
hot
equipment
can
cause
tires
and
burns.
Accidental
contact
of electrode
or
welding
wire
to
metal
objects
can
cause
sparks,
overheating,
or
fire.
1.
Protect
yourself
and
others from
flying
sparks
and
hot
metal.
2. Do
not
weld where
flying
sparks
can
strike
flammable
material.
3.
Remove
all
flammables
within
35
ft
(10.7
m)
of
the
welding
arc.
If
this is
not
possible,
tightly
cover
them
with
approved
covers.
4.
Be alert that
welding sparks
and hot materials from
welding
can
easily
go
through
small cracks and
openings
to
adjacent
areas.
5.
Watch
for
fire,
and
keep
a
fire
extinguisher
nearby.
6.
Be
aware
that
welding
on
a
ceiling,
floor,
bulkhead,
or
partition
can
cause
fire
on
the
hidden side.
7.
Do
not
weld
on
closed containers
such
as
tanks
or
drums.
8.
Connect
work
cable
to
the work
as
close
to
the
welding
area as
practical
to
prevent
welding
current
from
traveling
long,
possibly
unknown
paths
and
causing
electric
shock and fire
hazards.
9.
Do
not
use
welder
to
thaw
frozen
pipes.
10.
Remove
stick
electrode
from
holder
or
cut
oft
welding
wire
at
contact
tip
when
not
in
use.
11.
Wear oil-free
protective
garments
such
as
leather
gloves,
heavy
shirt,
cuffless
trousers,
high
shoes,
and
a
cap.
ELECTRIC
SHOCK
can
kill.
Touching
live
electrical
parts
can cause
fatal
shocks
or severe
burns. The
electrode
and
work circuit is
electrically
live
whenever the
output
is
on.
The
input
power
circuit and
machine
internal
circuits
are
also
live
when
power
is
on.
In
semiautomatic
or
automatic
wire
welding,
the
wire,
wire
reel,
drive
roll
housing,
and
all
metal
parts
touchin9
the
welding
wire
are
electrically
live.
Incorrectly
installed
or
improperly
grounded
equipment
is
a
hazard.
1.
Do
not
touch
live
electrical
parts.
2. Wear
dry,
hole-free
insulating
gloves
and
body
protection.
3. Insulate
yourself
from
work and
ground
using
dry insulating
mats or covers.
4.
Disconnect
input
power
or
stop
engine
before
installing
or
servicing
this
equipment.
5.
Properly
install
and
ground
this
equipment
according
to
its
Owners
Manual and
national,
state,
and
local codes.
6.
Turn
off
all
equipment
when
not
in
use.
7.
Do
not use
worn,
damaged,
undersized,
or
poorly
spliced
cables.
8.
Do
not
wrap
cables
around
your
body.
9.
Ground
the
workpiece
to
a
good
electrical
(earth)
ground.
10.
Do
not
touch electrode while
in
contact
with the
work
(ground)
circuit.
11.
Use
only
well-maintained
equipment.
Repair
or
replace
damaged
parts
at
once.
12.
Wear
a
safety
harness
to
prevent
falling
if
working
above
floor
level.
13.
Keep
all
panels
and
covers
securely
in
place.
/~
-2/
--
ARC RAYS
can
burn
eyes
and
skin;
NOISE
can
damage
hearing.
Arc
rays
from the
welding
process
produce
intense
heat and
strong
ultraviolet
rays
that
can
burn
eyes
and
skin. Noise
from
some
processes
can
damage
earing.
1.
2.
3.
4.
5.
Wear
a
welding
helmet
fitted
with
a
proper
shade
of
filter
(see
ANSI Z49.1 listed
in
Safety
Standards)
to
protect
your
face and
eyes
when
welding
or
watching.
Wear
approved
safety
glasses.
Side shields
recommended.
Use
protective
screens or
barriers
to
protect
others
from
flash
and
glare;
warn
others
not to
watch the
arc.
Wear
protective clothing
made
from
durable,
flame-resistant
material
(wool
and
leather)
and foot
protection.
Use
approved
ear
plugs
or
ear
muffs
if
noise
level is
high.
FUMES
AND
GASES
can
be
hazardous
5.
Work
in
a
confined
space
only
if it is
well
ventilated,
or
while
to
your
health.
I
Welding produces
fumes and
gases.
Breathing
=L~
~
I
I
these fumes and
gases
can
be hazardous
to
your
I
health.
I
6.
wearing
an
air-supplied respirator.
Shielding
gases
used for
welding
can
displace
air
causing
injury
or
death.
Be
sure
the
breathing
air
is safe.
Do
not
weld in
locations
near
degreasing, cleaning,
or
spraying
1.
Keep
your
head
out
of
the fumes.
Do
not
breathe the fumes.
2.
If
inside,
ventilate the
area
and/or
use
exhaust
at
the
arc
to
operations.
The
heat
and
rays
of the
arc can
react
with
vapors
to
form
highly
toxic
and
irritating
gases.
remove
welding
fumes and
gases.
7.
Do
not
weld
on
coated
metals,
such
as
galvanized,
lead,
or
3.
If
ventilation is
poor,
use
an
approved
air-supplied
respirator.
cadmium
plated
steel,
unless the
coating
is
removed
from
the
4.
Read
the
Material
Safety
Data
Sheets
(MSDSs)
and
the
weld
area,
the
area
is well
ventilated,
and
if
necessary,
while
manufacturers instruction for
metals, consumables,
coatings,
wearing
an
air-supplied respirator.
The
coatings
and
any
metals
and cleaners,
containing
these elements
can
give
off toxic
fumes
if
welded.
FLYING SPARKS AND HOT METAL
can
1.
Wear
approved
face
shield
or
safety
goggles.
Side
shields
cause
injury,
recommended.
Chipping
and
grinding
cause
flying
metal.
As
welds
2.
Wear
proper
body
protection
to
protect
skin.
cool,
they
can
throw
off
slag.

CYLINDERS
can
explode
if
damaged.
Shielding
gas
cylinders
contain
gas
under
high
pressure.
If
damaged,
a
cylinder
can
explode.
Since
gas
cylinders
are
normally
part
of
the
welding
process,
be
sure
to
treat
them
carefully.
1.
Protect
compressed
gas
cylinders
from excessive
heat,
mechanical
shocks,
and
arcs.
2.
Install and
secure
cylinders
in
an
upright
position
by
chaining
them
to
a
stationary
support
or
equipment
cylinder
rack
to
prevent
falling
or
tipping.
3.
Keep
cylinders
away
from
any
welding
or
other
electrical
circuits.
4.
Never
allow
a
welding
electrode
to
touch
any
cylinder.
5.
Use
only
correct
shielding
gas
cylinders,
regulators,
hoses,
and
fittings
designed
for
the
specific
application;
maintain
them
and
associated
parts
in
good
condition.
6. Turn
face
away
from valve outlet
when
opening
cylinder
valve.
7.
Keep
protective
cap
in
place
over
valve
except
when
cylinder
is
in
use
or
connected
for
use.
8.
Read
and
follow instructions
on
compressed
gas
cylinders,
associated
equipment,
and
CGA
publication
P-i listed in
Safety
Standards.
PRINCIPAL SAFETY
STANDARDS
Safety
in
Welding
and
Cutting,
ANSI
Standard
Z49.i,
from
American
Welding
Society,
550
N.W.
LeJeune
Rd,
Miami
FL 33126
Safety
and
Health
Standards,
OSHA
29
CFR
1910,
from
Superintendent
of
Documents,
U.S.
Government
Printing
Office,
Washington,
D.C. 20402.
Recommended
Safe Practices for
the
Preparation
for
Welding
and
Cutting
of Containers That Have Held Hazardous
Substances,
American Weld
ing
Society
Standard
AWS
F4.1,
from American
Welding Society,
550
N.W. LeJeune
IRd, Miami,
FL 33126
National Electrical
Code,
NFPA
Standard
70,
from National Fire Protection
Association,
Batterymarch
Park,
Quincy,
MA 02269.
Safe
Handling
of
Compressed
Gases
in
Cylinders,
CGA
Pamphlet
P-i,from
Compressed
Gas
Association,
1235 Jefferson Davis
Highway,
Suite
501,
Arlington,
VA
22202.
Code for
Safety
in
Welding
and
Cutting,
CSA
Standard
Wi
17.2,
from Canadian
Standards
Association,
Standards
Sales,
178
Rexdale
Boulevard,
Rexdale,
Ontario,
Canada M9W
1
R3.
Safe Practices
For
Occupation
And Educational
Eye
And Face
Protection,
ANSI
Standard Z87.
1
,from
American
National Standards
Institute,
1430
Broadway,
New
York,
NY
10018.
Cutting
And
Welding
Processes,
NFPA
Standard
51
B,
from
National Fire
Protection
Association,
Batterymarch
Park,
Quincy,
MA
02269.
EMF
INFORMATION
TABLE
OF
CONTENTS
SECTION
1

SAFETY INFORMATION
SECTION
2
SPECIFICATIONS
1
2-i.
Volt-Ampere
Curves
2
2-2.
Duty
Cycle
2
SECTION
3
INSTALLATION
3
3-1.
Installing
Work
Clamp
3
3-2.
Installing
Gas
Supply
4
3-3.
Gun
Polarity
Connections
5
3~4.
Installing
Drive Rolls And Wire
Inlet Guide
5
3-5.
Installing Welding
Gun
6
3-6.
Connecting
Input
Power
7
3-7.
Installing
Wire
Spool
And
Adjusting
Hub Tension....
9
3-8.
Threading
And
Feeding
Welding
Wire
9
3-1.
Threading
Welding
Wire 10
SECTION
4-
OPERATION
ii
SECTION
5-
MAINTENANCE
&
TROUBLESHOOTING
13
5-1.
Routine Maintenance
13
5-2.
Overload
Protection
14
5-3.
Aligning
Drive Rolls And
Wire
Guide
15
54
Gun Maintenance
16
5-5.
Troubleshooting
17
SECTION
6
ELECTRICAL
DIAGRAM
17
SECTION
7
PARTS
LIST
18
Figure
7-1.
Main
Assembly
18
Figure
7-2.
Baffle
wlComponents
19
Figure
7-3. Wire Drive
And
Gears 20
Figure
7-4.
MWG-23B
21
NOTE
D~
Magnetic
Fields
Considerations
About
Welding
And
The
Effects Of
Low
Frequency
Electric And
The
following
is
a
quotation
from
the
General Conclusions Section
of
the
U.S.
Congress,
Office of
Technology
Assessment,
Biological
Effects of
Power
Frequency
Electric
&
Magnetic
Fields

Background
Papei
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
people
which
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 scientific
understanding
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
to
offer
clear
science-based advice
on
strategies
to
minimize
or
avoid
potential
risks.
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
as
practical.
5.
Connect work
clamp
to
workpiece
as
close
to
the weld
as
possible.
About Pacemakers:
The
above
procedures
are
among
those also
normally
recommended
for
pacemaker
wearers.
Consult
your
doctor
for
complete
information.
modlO.1
4/93

SECTION
1
-
SAFETY INFORMATION

Read all
safety
messages
throughout
this
manual.

Obey
all
safety
messages
to avoid
injury.

Learn the
meaning
of
WARNING
and
CAUTION.
Figure
1-1.
Safety
Information
SECTION
2-
SPECIFICATIONS
Table
2-1.
Welding
Power
Source
modl.1
2/93
1
2
A~
WARNING
2
4A
CAUTION
/
MOVING PARTS
can
injure.
I
L~
ELECTRIC SHOCK
can
kiII.i
~%
S
Do
not
touch
live electrical
parts.
111
~
~
operating.
I

Keep
away
from
moving
parts.
I

Keep
all
panels
and
covers
closed
I
S
Disconnect
input
power
before
installing
or
servicing.
5
1
Safety
Alert
Symbol
2
Signal
Word
WARNING
means
possible
death
or
serious
injury
can
happen.
CAUTION
means
possible
minor
injury
or
equipment
damage
can
happen.
3
Statement
Of
Hazard And
Result
READ SAFETY BLOCKS
at start
of
I
~
Section
3-1
before
proceeding
7~1
NOTE
D~
Turn Off switch
when
using
high
frequency.
4
Safety
Instructions
To
Avoid
Hazard
5
Hazard
Symbol (If Available)
6
Safety
Banner
Read
safety
blocks for
each
sym
bol
shown.
7
NOTE
Special
instructions for best
oper
ation

not
related
to
safety.
Type
Of
Output
Specifications Description
Rated
Weld
Output
Type
Of
Input
Power
Input Amperes
At
Rated
Output
Maximum
Input
Amperes
While
Idling
KVA/KW Used
At Rated
Output
Maximum
KVAIKW
Used
While
Idling
Max.
Open-Circuit
Voltage
Control
Circuit
Voltage
At
Gun
Welding
Processes
Calculated
Speed
Range
At
No
Load
Wire
Diameter
Range
Overall Dimensions
Weight
Direct Current/Constant
Voltage (DC/CV)
200
Amperes,
28
Volts
DC,
60%
Duty
Cycle
(See
Section
2-2)
Single-Phase;
60
Hz;
At
200
Or 230 Volts AC
46
A
At 200
V,
40 A At 230
V
1.2AAt200V,
1
AAt23OV
9.5 kVN8.3
kW
0.24
kVNO.17
kW
42
Volts
DC
24
Volts
DC
Gas
Metal
Arc
(GMAW)
And
Flux
Cored
Arc
Welding
(FCAW)
128 To
1051
ipm (3.2
To
266.9
mpm)
.030 To
.045
in
(0.8
To
1.1
mm)
Flux
Cored
Wire,
.023
To
.045 in
(0.610
1.1
mm)
Hard Wire
Length:
37
in
(940 mm);
Width:
19
in
(483mm); Height:
30-1/4 in
(768 mm)
Net:
225
lb
(102
kg);
Ship:
271 lb
(123
kg)
Welding
Gun
Rated
Output
(Air Cooled)
Cable
Length
200
Amperes
At
60%
Duty Cycle Using CO2 Shielding
Gas
(See
Section
2-2)
15ft(4.5m)
OM-154
501
Page
1

2-1.
Volt-Ampere
Curves
Figure
2-1.
Volt-Ampere
Curves
2-2.
Duty
Cycle
a
CAUTION
x
Jo ~
Figure
2-2.
Duty Cycle
The
volt-ampere
curves
show
the
minimum and
maximum
voltage
and
amperage
output
capabilities
of the
welding
power
source.
Curves
of
other
settings
fall
be-
40
tween
the
curves
shown.
~2O
0
I I
I
0 25
60
75 100
125
160
175
200 226
DC
AMPERES
ssbl.1 10/91

SB-049
424-0
W
ELDING
LONGER
THAN
RATED DUTY CYCLE
can
damage
unit
or
gun
and
void
warranty.

Do
not
weld
at
rated
load
longer
than shown
below.
wfwarn8.2 8/93
0
Definition
0
Duty Cycle
is
percentage
of
10
minutes that
unit
or
gun
can
weld
at
rated
load
without
over-
Minutes
heating.
UNIT
60%
Duty Cycle
At 200
Amperes
~
6
Minutes
Welding
4
Minutes
Resting
Chart
~
x ourv
~
GUN
60%
Duty Cycle
At
200
Amperes
Using
CO2
g~-4g~
6 minutes
Welding
4
minutes
Resting
GUN
60%
Duty
Cycle
At 180
Amperes
Using
Mixed
Gas
6
minutes
Welding
4
minutes
Resting
sbl.3
8/93SB-150
215
OM-154
501
Page
2

SECTION
3-INSTALLATION
3-1.
Installing
Work
Clamp
Figure
3-1.
Installing
Work
Clamp
5
2
1
Work
Cable
2
Boot
Slide
boot
onto
work cable. Route
cable
out
front
panel
opening
from
inside.
3
Negative ()
Output
Terminal
Connect cable
to
terminal
and
cover
connection
with boot.
4
Hardware
5
Work
Clamp
Route
cable
through
clamp
handle
and
secure as
shown.
Close
door.
Tools
Needed:
~
1/2,3/4
in
Ref.
ST-BOO
918-B
OM-154
501
Page
3

3-2.
Installing
Gas
Supply
~
I BUILDUP OF
SHIELDING
GAS
can
harm
health
or
kill.

Shutoff
shielding
gas
supply
when
not
in
use.
warn4.1
9/91
1
Cylinder
Bracket
2
S-Hook
Crimp
between small hole
in
brack
et
and chain.
3 Chain
4
Snap
Crimp
onto
open
end ol
chain.
Obtain
gas
cylinder
and chain
to
running
gear.
5
Cap
6
Cylinder
Valve
Remove
cap,
stand
to
side of
valve,
and
open
valve
slightly.
Gas
flow
blows dust and dirt from
valve.
Close
valve.
7
Cylinder
8
Regulator/Flowmeter
Install
so
face
is
vertical.
9 Gas
Hose Connection
Fitting
has
5/8-18
right-hand
threads. Obtain and install
gas
hose.
10 Flow
Adjust
Typical
flow
rate
is
20 cfh
(cubic
feet
per
hour).
Check
wire
man
ufacturers
recommended
flow
rate.
Make
sure
flow
adjust
is closed
when
opening
cylinder
to
avoid
damage
to
the flowmeter.
11
CO2 Adapter
12
0-Ring
Install
adapter
with
0-ring
between
regulator/flowmeter
and
CO2
cylinder.
£~
WARNING
1~-.
CYLINDERS
can
explode
if
damaged.

Keep
cylinders
away
from
welding
and
other
electrical
circuits.

Never touch
cylinder
with
welding
electrode.

Always
secure
cylinder
to
running
gear,
wall,
or
other
stationary
support
Figure
3-2.
Typical Regulator/Flowmeter
Installation
Tools
Needed:
~
5/8,1-lI8in
ssb3.2 5/94

ST-I54
6231 Ref.
ST-I49 827-B
I
Ref. ST-I
58
697-A
OM-154501
Page4

3-3.
Gun
Polarity
Connections
4~
WARNING
ELECTRIC SHOCK
can
kill.

Do
not
touch live
electrical
parts.

Turn
Oft
welding
power
source,
and
disconnect
input
power
before
inspecting
or
installing.
3-4.
Installing
Drive Rolls And Wire Inlet Guide
Figure
3-4.
Installing
Drive Rolls
And
Wire
Inlet
Guide
swarnl.1 2/93
Shown
As
Shipped

Set
For
Electrode
Positive
(DCEP)
For
Solid Steel
Or
Aluminum
Wires
(GMAW Process).
Wire
Drive
Assembly
Lead
To Positive
(+)
Output
Terminal
5
Work
Clamp
Lead
To
Negative
() Output
Terminal
1
Polarity
Changeover
Label
2 Wire
Drive
Assembly
3
Positive
(+)
Output
Terminal
4
Negative () Output
Terminal
Always
read
and
follow wire
man
ufacturers recommended
polarity.
5
Circuit Breaker
CB1
(see
Section
5-2).
6 Pilot
Light (see
Section
5-2)
Close door.
Tools Needed:
~
3/4,11/16in
Ref. ST-801
103-B
GUN POLARITY
CHANGEOVER CONNECTIONS
Reverse
Lead Connections

For
Electrode
Negative
(DCEN)
For
Flux
Cored
Wires
(FCAW Process).
Drive
Assembly
Becomes
Negative
S-144
449-D
Figure
3-3.
Gun
Polarity
Connections
1
Securing
Screw
2
InletWireGuide
Loosen
screw.
Slide
tip
as
close
to
drive
rolls
as
possible
without
touching.
Tighten
screw.
3
Anti-Wear
Guide
Install
guide
as
shown.
4
Drive
Roll
Install
correct
drive roll for
wire size
and
type.
5
Drive
Roll
Securing
Nut
Turn
nut
one
click
to
secure
drive
Tools
Needed:
roll.
5/64
in
i~~zz~
7/16
in
ST-150 227-C
OM-154 501
Pages

3-5.
Installing
Welding
Gun
Figure
3-5. Gun Connections
Table 3-1. Electrical Service
Requirements
Input
Voltage
200
230
Input Amperes
At
Rated
Output
46 40
Max Recommended Standard
Fuse
Or
Circuit
Breaker
Rating
In
Amperes
70
60
Mm
Input
Conductor Size
In
AWG/Kcmil
88
Max
Recommended
Input
Conductor
Length
In
Feet
(Meters)
89
(27)
117
(36)
Mm
Grounding
Conductor
Size
In
AWGIKcmiI
8
10
Reference:
1996
National
Electrical
Code
(NEC).
S-oo92J
1
Wire Drive
Assembly
2
Gun
Securing
Knob
3
Gun End
Loosen
securing
knob.
Insert
gun
end
through opening
until it
bot
toms
against
drive
assembly.
Tighten
knob.
4
Gun
Trigger
Plug
Insert
into
receptacle,
and
tighten
threaded
collar.
Close
pressure
assembly.
Close
door.
Rel. ST801
101-B
OM-154
501
Page
6

3-6.
Connecting
Input
Power
a
WARNING
ELECTRIC SHOCK
can
kill.

Do
not
touch
live electrical
parts.

Turn Off
welding
power
source,
and disconnect
input
power
before
inspecting
or
installing.

Have
only
qualified
persons
install
unit.

Installation
must meet
National Electrical Code
and all other codes.
A.
Positioning
Jumper
Links
swarn3.1
2/93
230
VOLTS
2
3.
Check
input
voltage
available
at
site.
1
Jumper
Links Access
Door
Open
door.
2
Jumper
Link
Label
3
Input
Voltage
Jumper
Link
Move
jumper
link
to
match
Input
voltage.
Close
and
secure
access
door.
Close
side door.
Tools
Needed:
c~Z3~J
3/8
in
Ref.
ST~8O1
100-B
Figure
3-6.
Input Voltage Jumper
Links Location
OM-154
501
Page
7