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 in- frared energy radiates, weldments are hot, and com- pressed gases may be used. The wise operator avoids unnecessary risks and protects himself and others from accidents. Precautions are described here and in stan- dards referenced in index.

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 (particularly for gas-shielded arc) in addition to gloves, hat, and shoes (1-2A). As nec- essary, use additional protective clothing such as leather jacket or sleeves, flame-proof apron, and fire-re- sistant leggings. Avoid outer garments of untreated cot- ton.

Bare skin protection. Wear dark, substantial clothing. Button collar to protect chest and neck and button pock- ets to prevent entry of sparks.

2.Eye and Head Protection

Protect eyes from exposure to 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 pass 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

Enclosed welding area. For production welding, a sepa- rate room or enclosed bay is best. In open areas, sur- round the operation with low-reflective, non-combusti- ble screens or panels. Allow for free air circulation, par- ticularly 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 out- side air. Carbon monoxide can kill.

C. Fire and Explosion Prevention

Comply with precautions in 1-2C.

Equipment’s rated capacity. Do not overload arc weld- ing equipment. It may overheat cables and cause a fire.

Loose cable connections may overheat or flash and cause a fire.

Never strike an arc on a cylinder or other pressure ves- sel. It creates a brittle area that can cause a violent rup- ture or lead to such a rupture under rough handling.

D. Compressed Gas Equipment

Comply with precautions in 1-2D.

E. Shock Prevention

Exposed hot conductors or other bare metal in the weld- ing circuit, or in ungrounded, electrically-HOT equip- ment 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:

Wear dry insulating gloves and body protection. 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 can not be avoided. Sweat, sea water, or moisture be- tween body and an electrically HOT part or grounded metal reduces the electrical resistance, and could en- able dangerous and possibly lethal currents to flow through the body.

A voltage will exist between the electrode and any con- ducting object in the work circuit. Examples of conduct- ing objects include, but are not limited to, buildings, elec- trical tools, work benches, welding power source cases, workpieces, etc. Never touch the electrode and any metal object unless the welding power source is off.

1.Grounding the Equipment

Arc welding equipment must be grounded according to the National Electrical Code, and the work must be grounded according to ANSI Z49.1 “Safety In Welding And Cutting.”

When installing, connect the frames of each unit such as welding power source, control, work table, and water cir- culator to the building ground. Conductors must be ade-

OM-877 Page 4

Page 8
Image 8
Miller Electric wire feeder owner manual ARC Welding, Burn Protection, Shock Prevention