Electric safety for builders and remodelers

Always check wiring and fixtures you may come into contact with using a voltage detector. If it beeps and lights up, the circuit is live.

Electricity powers the tools, equipment, and lighting needed for building and remodeling work, but it can turn deadly if treated carelessly. Electrical accidents can cause equipment damage, fires, personal shocks, burns, and even electrocution. Following a combination of Occupational Safety and Health Administration (OSHA) guidelines and some common sense rules should keep you safer around electricity.

The most common violations

According to OSHA, the electric hazards found most on the jobsite are exposed live conductors in equipment being used by contractors. The common culprit is a cut in the outer jacket of a power cord or extension cord.

Even if the insulation on the individual wires inside the cord seems unscathed, this type of damage must be repaired or replaced. An acceptable repair is to cut the cord at the damaged part and install a new plug end approved for type for the work environment. However, per OSHA rules, anyone repairing or replacing an electrical cord must be a “qualified” person (as defined by OSHA).

Exposed conductors are also found on electric devices – although not intended for the rigors of the jobsite. Plastic household power strips with a row of outlets may seem like a good way to plug in a lot of tools at once, but their flimsy bodies crack easily which can expose the wiring inside.

Similarly, extension cords that have been fitted with an electric box with multiple outlets on the end must be made with the correct type of utility or exterior rated box and must have cable clamps suitable to provide strain relief for the cord. Using plastic “handy” boxes intended for use behind drywall or other electric boxes with large holes are not adequate for construction and will be considered unacceptable by an OSHA inspector.

Another common problem is a plug end with a missing ground prong. Proper grounding is important for safe operation of a tool.

With OSHA fines for power cord violations ranging from $300 to $3,000, it’s not worth taking a chance on getting a citation. The cost of properly repairing or replacing cords and using multiple outlet devices designed for the job is far less expensive.

More on cords

Another frequently overlooked OSHA rule states that any time you use an extension cord on a new construction or remodeling jobsite, it must be connected to a circuit protected by a Ground Fault Circuit Interrupter (GFCI) device.

If the circuit you are using has no GFCI device in the circuit breaker or in the electric outlet, a portable GFCI must be connected to or be part of the extension cord. This only applies to extension cords so this requirement can be avoided by plugging equipment directly into an outlet. Make it a habit to push the “test” and “reset” buttons on your GFCI device frequently to verify it is working.

Safety tips for working near installed wiring

• Don’t assume the electricity to a fixture is off just because the switch is off. Lights with a switch leg will still have a hot wire in the ceiling box, and installers have been known to erroneously connect the neutral wire to the light switch instead of the hot wire. Neither of these conditions would be apparent from the outside so always use a non-contact voltage detector to check wires or fixtures you are working near.
• Be aware that not just black and red wires are hot, sometimes white wires are wired to be hot, as in switch legs to a light through a light switch or in some 230-volt applications. White wires used as “hot” conductors should be marked with black ink or tape, but this is not always done.
• You’ve heard it 1,000 times but it’s too often overlooked and so bears repeating: Whenever your work requires excavating around a house with the power lines run underground, call 811 to arrange for local utility companies to come out to locate and mark buried lines.
• When doing work that affects an electric supply panel, supply lines going into a structure, or a power mast on the roof, you may need to have the supply lines to the structure disconnected by the power company. Don’t move or alter panels or roof masts without the supervision of a qualified electrician.
• When working near the power lines coming into a structure at the roof line, temporary insulation around the supply lines must be applied by a qualified person to protect workers in case of accidental contact.
• Be careful when drilling or cutting into enclosed wall and ceiling cavities because wiring can be hidden where you don’t expect it. Besides the shock hazard to the worker, accidental contact with wiring could create unseen damage that could cause a fire later.
• Look up. Overhead high voltage lines are deadly when a ladder, building materials or a person gets too close. Direct contact isn’t required for a deadly shock since high voltage electricity can arc through the air to find a path to ground, so stay 10 feet away.
• Don’t install or modify circuits or electrical devices if you are not a qualified electrician.

Temporary lighting fixtures must have guards over the bulbs, and must be hung without any strain on the conducting cord.

Rules for tools and lighting

Use double-insulated power tools. The outer surface can’t become energized in the event of an internal short. Older metal-bodied tools often lack this protection.

Don’t lift or lower tools or equipment by the cords. Wires in the cords are not designed to take the strain.

Temporary lighting fixtures must have guards over the bulbs, and must be hung without any strain on the conducting cord.

In case of emergency

Have a plan of action in case of any electrical accident on the job. Know where the main breaker or supply shut off switch is for the building you are working on so you could turn off the electricity in an emergency. If you work on older homes without a main breaker or shut off switch, learn how to pull out the electrical meter to disconnect the power ahead of the main service panel (the power company has to come and reconnect it so this should only be done in an emergency).

For electric fires, have a Class B/C or A/B/C fire extinguisher available. The C rating means that the extinguisher foam is nonconductive and is the only type to spray on anything plugged into electricity.

For personal injury, know the proper first aid response for shocks and burns. Never touch a victim that is still in contact with a live wire; you could be shocked, too. Before administering aid, shut off the electricity or carefully move the wire off the victim with a nonconductive material such as a dry piece of wood.

– By Michael Springer