MK Products Positioner 1/AirCrafter T-25 - Manual (Page 5)

1-3 ARC WELDING
Comply with precautions in 1-1, 1-2, and
this section. Arc Welding, properly done,
is a safe process, but a careless operator
invites trouble. The equipment carries
high currents at significant voltages.
The arc is very bright and hot. Sparks
fly, fumes rise, ultraviolet and infrared
energy radiates, weldments are hot,
and compressed gases may be used.
The wise operator avoids unnecessary
risks and protects himself and others
from accidents.
A. Burn Protection
Comply with precautions in 1-2.
The welding arc is intense and visibly
bright. Its radiation can damage eyes,
penetrate lightweight clothing, reflect
from light-colored surfaces, and burn
the skin and eyes. Skin burns resemble
acute sunburn; those from gas-shielded
arcs are more severe and painful.
DON’T GET BURNED; COMPLY WITH
PRECAUTIONS.
1. Protective Clothing
Wear long-sleeve clothing in addition to
gloves, hat, and shoes. As necessary,
use additional protective clothing such
as leather jacket or sleeves, flameproof
apron, and fire-resistant leggings. Avoid
outer garments of untreated cotton.
Bare skin protection. Wear dark,
substantial clothing. Button collar to
protect chest and neck, and button
pockets to prevent entry of sparks.
2. Eye and Head Protection
Protect eyes from exposure to arc. Eyes
may be damaged by radiant energy
when exposed to the electric arc, even
when not looking in the direction of the
arc. Never look at an electric arc without
protection.
Welding helmet or shield containing a
filter plate shade no. 12 or denser must
be used when welding. Place over face
before striking arc.
Protect filter plate with a clear cover
plate.
Cracked or broken helmet or shield
should NOT be worn; radiation can be
passed through to cause burns.
Cracked, broken, or loose filter plates
must be replaced IMMEDIATELY.
Replace clear cover plate when broken,
pitted, or spattered.
Flash goggles with side shields MUST
be worn under the helmet to give some
protection to the eyes should the helmet
not be lowered over the face before an arc
is struck. Looking at an arc momentarily
with unprotected eyes (particularly a high
intensity gas-shielded arc) can cause a
retinal burn that may leave a permanent
dark area in the field of vision.
3. Protection of Nearby Personnel
Enclose the welding area. For production
welding, a separate room or enclosed
bay is best. In open areas, surround
the operation with low-reflective,
noncombustible screens or panels. Allow
for free air circulation, particularly at floor
level.
Viewing the weld. Provide face shields for
all persons who will be looking directly at
the weld.
Others working in area. See that all persons
are wearing flash goggles.
Before starting to weld, make sure that
screen flaps or bay doors are closed.
B. Toxic Fume Prevention
Comply with precautions in 1-2B.
Generator engine exhaust must be vented
to the outside air. Carbon monoxide can
kill.
C. Fire and Explosion Prevention
Comply with precautions in 1-2C.
Equipment’s rated capacity. Do not
overload arc welding equipment. It may
overheat cables and cause a fire.
Loose cable connections may overheat or
flash and cause afire.
Never strike an arc on a cylinder or other
pressure vessel. It creates a brittle area that
can cause a violent rupture or lead to such a
rupture later under rough handling.
D. Compressed Gas Equipment
Comply with precautions in 1-2D.
E. Shock Prevention
Exposed electrically hot conductors or
other bare metal in the welding circuit, or in
ungrounded, electrically-HOT equipment
can fatally shock a person whose body
becomes a conductor. DO NOT STAND,
SIT, LIE, LEAN ON, OR TOUCH a wet
surface when welding without suitable
protection.
To protect against shock:
Keep body and clothing dry. Never work
in damp area without adequate insulation
against electrical shock. Stay on a dry
duckboard, or rubber mat when dampness
or sweat cannot be avoided. Sweat, sea
water, or moisture between body and an
electrically HOT part - or grounded metal
- reduces the body surface electrical
resistance, enabling dangerous and
possibly lethal currents to flow through
the body.
1. Grounding the Equipment
When installing, connect the frames of
each unit such as welding power source,
control, work table, and water circulator to
the building ground. Conductors must be
adequate to carry ground currents safely.
Equipment made electrically HOT by stray
currents may shock, possibly fatally. Do
NOT GROUND to electrical conduit, or to a
pipe carrying ANY gas or a flammable liquid
such as oil or fuel.
Three-phase connection. Check phase
requirement of equipment before installing.
If only three-phase power is available,
connect single-phase equipment to only
two wires of the three-phase line. Do
NOT connect the equipment ground
lead to the third (live) wire, or the
equipment will become electrically HOT
- a dangerous condition that can shock,
possibly fatally.
Before welding, check ground for
continuity. Be sure conductors are
touching bare metal of equipment frames
at connections.
If a line cord with a ground lead is provided
with the equipment for connection to a
switch box, connect the ground lead to
the grounded switch box. If a three-
prong plug is added for connection to a
grounded mating receptacle, the ground
lead must be connected to the ground
prong only. If the line cord comes with a
three-prong plug, connect to a grounded
mating receptacle. Never remove the
ground prong from a plug, or use a plug
with a broken ground prong.
2. Connectors
Fully insulated lock-type connectors
should be used to join welding cable
lengths.
3. Cables
Frequently inspect cables for wear,
cracks, and damage. IMMEDIATELY
REPLACE those with excessively worn
or damaged insulation to avoid possibly
lethal shock from bared cable. Cables
with damaged areas may be taped to give
resistance equivalent to original cable.
Keep cable dry, free of oil and grease,
and protected from hot metal and
sparks.
4. Terminals and Other Exposed
Parts
Terminals and other exposed parts of
electrical units should have insulating
covers secured before operation.
5. Electrode Wire
Electrode wire becomes electrically HOT
when the power switch of gas metal-arc
welding equipment is ON and welding
gun trigger is pressed. Keep hands and
body clear of wire and other HOT parts.
6. Safety Devices
Safety devices such as interlocks
and circuit breakers should not be
disconnected or shunted out.
Before installation, inspection, or service
of equipment, shut OFF all power, and
remove line fuses (or lock or red-tag
switches) to prevent accidental turning
ON of power. Disconnect all cables from
welding power source, and pull all 115
volts line-cord plugs.
Do not open power circuit or change
polarity while welding. If, in an emergency,
it must be disconnected, guard against
shock burns or flash from switch arcing.
Leaving equipment unattended. Always
shut OFF, and disconnect all power to
equipment.
Power disconnect switch must be
available near the welding power
source.