Miller Electric Big Blue 251D Welding System User Manual


 
OM-480 Page 1
SECTION 1 SAFETY PRECAUTIONS READ BEFORE USING
rom _nd_8/03
Y Warning: Protect yourself and others from injury — read and follow these precautions.
1-1. Symbol Usage
Means Warning! Watch Out! There are possible hazards
with this procedure! The possible hazards are shown in
the adjoining symbols.
Y Marks a special safety message.
. Means “Note”; not safety related.
This group of symbols means Warning! Watch Out! possible
ELECTRIC SHOCK, MOVING PARTS, and HOT PARTS hazards.
Consult symbols and related instructions below for necessary actions
to avoid the hazards.
1-2. Arc Welding Hazards
Y 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 Safety Stan-
dards listed in Section 1-7. Read and follow all Safety Standards.
Y Only qualified persons should install, operate, maintain, and re-
pair this unit.
Y During operation, keep everybody, especially children, away.
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 touching the welding wire are electrically live. Incorrectly installed or
improperly grounded equipment is a hazard.
ELECTRIC SHOCK can kill.
D Do not touch live electrical parts.
D Wear dry, hole-free insulating gloves and body protection.
D Insulate yourself from work and ground using dry insulating mats or covers
big enough to prevent any physical contact with the work or ground.
D Do not use AC output in damp areas, if movement is confined, or if there is a
danger of falling.
D Use AC output ONLY if required for the welding process.
D If AC output is required, use remote output control if present on unit.
D Additional safety precautions are required when any of the following electri-
cally hazardous conditions are present: in damp locations or while wearing
wet clothing; on metal structures such as floors, gratings, or scaffolds;
when in cramped positions such as sitting, kneeling, or lying; or when there
is a high risk of unavoidable or accidental contact with the workpiece or
ground. For these conditions, use the following equipment in order present-
ed: 1) a semiautomatic DC constant voltage (wire) welder, 2) a DC manual
(stick) welder, or 3) an AC welder with reduced open-circuit voltage. In most
situations, use of a DC, constant voltage wire welder is recommended.
And, do not work alone!
D Disconnect input power or stop engine before installing or servicing this
equipment. Lockout/tagout input power according to OSHA 29 CFR
1910.147 (see Safety Standards).
D Properly install and ground this equipment according to its Owner’s Manual
and national, state, and local codes.
D Always verify the supply ground — check and be sure that input power cord
ground wire is properly connected to ground terminal in disconnect box or
that cord plug is connected to a properly grounded receptacle outlet.
D When making input connections, attach proper grounding conductor first
double-check connections.
D Frequently inspect input power cord for damage or bare wiring — replace
cord immediately if damaged — bare wiring can kill.
D Turn off all equipment when not in use.
D Do not use worn, damaged, undersized, or poorly spliced cables.
D Do not drape cables over your body.
D If earth grounding of the workpiece is required, ground it directly with a sep-
arate cable.
D Do not touch electrode if you are in contact with the work, ground, or anoth-
er electrode from a different machine.
D Use only well-maintained equipment. Repair or replace damaged parts at
once. Maintain unit according to manual.
D Wear a safety harness if working above floor level.
D Keep all panels and covers securely in place.
D Clamp work cable with good metal-to-metal contact to workpiece or work-
table as near the weld as practical.
D Insulate work clamp when not connected to workpiece to prevent contact
with any metal object.
D Do not connect more than one electrode or work cable to any single weld
output terminal.
SIGNIFICANT DC VOLTAGE exists in inverters after stop-
ping engine.
D Stop engine on inverter and discharge input capacitors according to
instructions in Maintenance Section before touching any parts.
Welding produces fumes and gases. Breathing these fumes
and gases can be hazardous to your health.
FUMES AND GASES can be hazardous.
D Keep your head out of the fumes. Do not breathe the fumes.
D If inside, ventilate the area and/or use exhaust at the arc to remove welding
fumes and gases.
D If ventilation is poor, use an approved air-supplied respirator.
D Read the Material Safety Data Sheets (MSDSs) and the manufacturer’s
instructions for metals, consumables, coatings, cleaners, and degreasers.
D Work in a confined space only if it is well ventilated, or while wearing an air-
supplied respirator. Always have a trained watchperson nearby. Welding
fumes and gases can displace air and lower the oxygen level causing injury
or death. Be sure the breathing air is safe.
D Do not weld in locations near degreasing, cleaning, or spraying operations.
The heat and rays of the arc can react with vapors to form highly toxic and
irritating gases.
D Do not weld on coated metals, such as galvanized, lead, or cadmium plated
steel, unless the coating is removed from the weld area, the area is well
ventilated, and if necessary, while wearing an air-supplied respirator. The
coatings and any metals containing these elements can give off toxic fumes
if welded.
BUILDUP OF GAS can injure or kill.
D Shut off shielding gas supply when not in use.
D Always ventilate confined spaces or use approved
air-supplied respirator.
Arc rays from the welding process produce intense visible
and invisible (ultraviolet and infrared) rays that can burn eyes
and skin. Sparks fly off from the weld.
ARC RAYS can burn eyes and skin.
D Wear a welding helmet fitted with a proper shade of filter to protect your face
and eyes from arc rays and sparks when welding or watching (see ANSI
Z49.1 and Z87.1 listed in Safety Standards).
D Wear approved safety glasses with side shields under your helmet.
D Use protective screens or barriers to protect others from flash and glare;
warn others not to watch the arc.
D Wear protective clothing made from durable, flame-resistant material (wool
and leather) and foot protection.