Working Safely Around Electricity

You do not have to be an electrician to be hurt by electricity. Painters, roofers, tree crews, mechanics, cleaners and machine operators all work near it every day. Contact with electricity is one of the leading causes of death in construction, and many of those killed were not doing electrical work. They were moving a ladder, raising a dump bed or drilling a wall. This guide is about working near electricity safely, and about knowing where your job stops.

What You Will Be Able to Do

• Explain what electricity does to the body, and why a breaker does not protect you.
• Tell the difference between what you may do and what only a qualified person may do.
• Inspect cords and use GFCI protection before you plug in.
• Keep yourself and your equipment a safe distance from overhead lines.
• Respond correctly to a downed line or a person being shocked.

What Electricity Does to the Body

Current through the body causes the damage. These are the approximate effects OSHA describes for a one-second, hand-to-foot shock at 60 hertz:

A milliamp is one-thousandth of an amp. A household 15-amp breaker does not trip until current passes 15,000 milliamps. It protects the wire. It was never designed to protect you. Wet skin, sweat and standing on damp ground all lower your body's resistance, so the same voltage drives more current through you.

Shock is not the only harm:

• Arc flash: a fault in equipment can release an explosive burst of heat, light and pressure. It can burn someone standing several feet away who never touched anything.
• Burns: contact burns can be deep inside the body, with only small marks on the skin.
• Falls: a shock that would not otherwise be serious can throw you off a ladder.
• Fire: overheated cords and overloaded circuits start fires long after you leave.

Know Where Your Job Stops

OSHA separates workers into two groups. A qualified person has been trained to recognize and avoid the hazards of specific electrical equipment and is authorized to work on it. An unqualified person has not. Being handy, or having done it at home, does not make you qualified.

If you are not qualified for the equipment in front of you:

• Do not open panels, disconnects, junction boxes or control cabinets.
• Do not remove covers, guards or the dead-front panel behind a breaker door.
• Do not repair, splice or rewire anything, including cords.
• Do not test line-voltage circuits with a meter.
• Do not bypass an interlock, a safety switch or a tripped device to keep working.
• Do not reach into equipment that a qualified person has opened.

Equipment that is being serviced has to be shut off and locked out by the people working on it. If you service machines, follow your site's lockout procedure and keep your own lock and key.

Panels and Disconnects

Electrical panels must stay reachable in an emergency. Keep at least 36 inches of clear floor space in front of them, 30 inches wide. Do not stack boxes, park carts or store cleaning supplies there. Never hang anything from conduit or use it as a ladder or anchor.

Learn where the shutoffs are in the areas you work. If something catches fire or someone is hurt, seconds matter.

If a breaker trips, it did so for a reason. If your employer lets you reset it, turn it fully off and then on, once. Stand to the side and look away as you move the handle. If it trips again, stop and report it. Never hold a breaker on, tape it or replace it with a bigger one.

Cords and Portable Tools

Most everyday shock injuries on a job site come from damaged cords and tools.

Before each use, check:

1. The cord jacket has no cuts, crushing or exposed inner wires.
2. The plug has its ground pin, and the blades are straight.
3. The strain relief at each end is in place.
4. The tool housing is not cracked.

Take a damaged cord out of service and tag it. Do not tape it and carry on.

Use these habits:

• Use cords rated for the job, and outdoor-rated cords outside.
• Use the shortest cord that reaches, and uncoil it fully so it does not heat up.
• Do not run cords through doorways, under carpet, or over sharp edges.
• Do not lift a tool by its cord, and do not pull a plug out by the cord.
• Do not daisy-chain power strips or use an extension cord in place of permanent wiring.

Use GFCI protection. A ground-fault circuit interrupter watches for current leaking out of a circuit, and shuts it off in a fraction of a second at about 5 milliamps. On construction sites, OSHA requires employers to use GFCIs or an assured equipment grounding conductor program for temporary power. Use a portable GFCI if you are not sure the outlet has one, especially outdoors, near water or on damp floors. Press TEST before you start.

Water and Electricity

Water makes every electrical hazard worse.

• Keep cords, plugs and tools out of standing water.
• Do not operate electrical equipment with wet hands.
• Do not enter a flooded room or basement until a qualified person has shut off the power. Water can carry voltage from a submerged outlet to you.
• Do not spray or mop into receptacles, control panels or motors.

Overhead Power Lines

Overhead lines are the most deadly electrical hazard for people who are not electricians. The coating you may see on a line is weather protection, not insulation you can trust. Treat every line as live until the utility says otherwise.

Keep at least 10 feet between you, or anything you are holding, and any overhead line up to 50,000 volts. Higher voltage lines need more clearance, and OSHA adds 4 inches for each 10,000 volts above that. You usually cannot tell the voltage by looking, so call the utility if you are working anywhere near. Cranes and similar equipment have their own, stricter rules, which may require larger distances.

Plan before you start:

1. Look up. Walk the site and find every line before you set up.
2. Carry ladders, pipe, gutters and long tools horizontally, low to the ground.
3. Know how far your equipment can reach. Add the length of a ladder, boom, dump bed or tree limb.
4. Use a spotter whose only job is watching the line.
5. Call the utility if you need to work closer. They can de-energize or insulate the line.

Metal ladders conduct, and wood or fiberglass ladders can conduct when wet or dirty. Tree limbs can carry current too. Never trim a tree near a line unless you are trained and authorized for that work.

Downed Lines

If you see a downed line, assume it is live, even if it is not sparking.

1. Stay well back. A common guideline is at least 35 feet, about three car lengths, and some utilities say more. The ground around a line can be energized.
2. Call 911 and the utility.
3. Keep others away. Do not try to move the line with anything.
4. If you feel tingling in your feet, shuffle away with small steps, keeping both feet together and on the ground.

If a line falls on your vehicle or equipment, stay inside and call for help. Warn people to stay back. If fire forces you out, open the door, jump clear with your feet together so you never touch the vehicle and the ground at the same time, and shuffle away. Do not go back.

Digging and Drilling

Before you drive a stake, dig a trench or set a post, the buried lines have to be located. In the United States, call 811 or use your state's online request a few working days ahead. Before you cut or drill into a wall, floor or ceiling, ask what is behind it, and use the site's scanning or layout process. Hitting a buried or concealed cable can energize your tool.

Batteries and Stored Energy

Equipment can stay dangerous after it is turned off.

• Vehicle and equipment batteries can deliver hundreds of amps into a short. A wrench across the terminals can melt, and a ring or watch can burn your skin. Charging batteries also give off hydrogen, which can explode, so keep sparks and flames away.
• Hybrid and electric vehicles carry high-voltage DC in orange cables. Do not touch or cut them unless you are trained for that system.
• Solar panels and battery backups produce power whenever there is light or charge, even if the main power is off. Do not touch their wiring.
• Capacitors in motors, drives and power supplies can hold a dangerous charge after shutoff.

If Someone Is Being Shocked

The instinct to grab the person can kill you too. Their body may be live.

1. Do not touch them while they may be in contact with the source.
2. Shut off the power at the switch, breaker or disconnect, if you can do it safely. Otherwise wait for help.
3. Call 911, or your site's emergency number.
4. Once the power is off and the scene is safe, check for breathing. Start CPR if they are not breathing normally and you are trained. Use an AED if one is available.
5. Treat them for burns and shock, and keep them still and warm.
6. Get medical care even if they seem fine. Internal burns and heart rhythm problems can show up later. Report every shock to your supervisor, however small.

If the source is an overhead or high-voltage line, stay away and wait for the utility, however hard that is. A wooden pole will not protect you.

Common Mistakes

Check Your Understanding

1. A receptacle on your site feels warm and the plastic is discolored. You are a painter. What do you do?

Stop using it, keep others away and report it. A hot receptacle may have a bad connection. The repair belongs to a qualified electrician.

2. You need to carry a 24-foot ladder across a yard with a service drop running over it. How do you handle it?

Find the line first, and carry the ladder horizontally and low with a helper. Do not stand it up anywhere that it could reach within 10 feet of the line.

3. A dump truck has touched a power line and the driver is unhurt. Fire is not involved. What should the driver do?

Stay in the cab, call for help, and warn others to stay away until the utility confirms the line is dead.

4. A coworker collapses against a machine and is shaking. What is your first action?

Do not touch them. Hit the machine's disconnect or emergency stop, if that can be done safely, and call for help. Once the power is off, check for breathing and start CPR if you are trained and they need it.

5. A breaker trips while you are running a floor machine. You reset it once and it trips again. Next step?

Stop, unplug the machine and report it. A repeat trip means there is a fault. Do not try again.

Key Takeaways

• Current through the body is what injures you, and a breaker does not protect people.
• If you are not qualified for the equipment, keep panels shut and covers on.
• Inspect cords and tools, and use GFCI protection, especially near water.
• Stay at least 10 feet from overhead lines, and more for higher voltages.
• Treat every downed line as live.
• Never touch someone in contact with a live source. Shut off the power first.