The title of NFPA 70E-2004 is Standard for Electrical Safety in the Workplace. It relates to the National Electrical Code (NFPA standard 70) in the following ways:
The National Electrical Code (NEC) tells you the best way to design and install electrical systems, but it doesn’t entail how this work should actually be done. NFPA 70E, on the other hand, outlines safe practices for electrical construction and maintenance without telling you about the design and installation of electrical systems. They are two sides of the same coin.
The two standards have the same scope and many similar definitions. Both cover practices for wiring the inside of buildings, and neither speak to outdoor utility line maintenance or installation.
It’s important to remember that construction sites are a place of work. The NEC covers the installation of electrical systems and safety issues related to that installation. NFPA 70E covers electrical safety in workplaces. While NFPA 70E covers all workplaces — including offices, hospitals, schools, and more — it is most often enforced on construction sites and in industrial plants. Any site where construction or maintenance work is occurring is a workplace. It is, therefore, covered by the NFPA 70E standard.
How It Is Enforced
The NEC is enforced by electrical inspectors. Those inspectors report to states, cities, and counties. NFPA 70E is not for regulatory use, so its customers require electrical contractors to follow it. Customers are the ones who enforce NFPA 70E.
What NFPA 70E Covers
NFPA 70E is used to protect electricians, contractors, and engineers from three sorts of hazards:
- Electrocution and electric shock
- Arc-flash (otherwise known as an electrical fireball)
- Arc-blast (also known as an electrical explosion at high energy levels)
Four Steps to Safety
NFPA 70E recommends a four-step safety strategy to protect workers from hazards on the job site:
- Turn off the power – Work with the power off whenever it’s feasible. It’s not always possible, but when you can, it will go a long way toward keeping you safe.
- Use a live work permit – You should have the customer sign an Energized Electrical Work Permit.
- Make a plan – In order to maintain safety on the jobsite, you should have a written plan for how the live work will be performed and how safety standards will be maintained.
- Use personal protective equipment – The appropriate personal protective equipment must be worn at all times when you’re working in hazardous situations. This equipment includes face shields, flash suits, flame retardant clothing, and insulated tools.
There are several methods that NFPA 70E outlines for turning off electrical power while work is being performed. The three methods include:
- Individual qualified employee control
- Simple lockout/tagout
- Complex lockout/tagout
Safely Working “Live”
When you must work “live” and near exposed energized parts, NFPA 70E outlines a series of requirements. The customer must sign an Energized Electrical Work Permit. The permit outlines what work is to be done. It also describes why such work must be performed live.
There are also three approach boundaries described by NFPA 70E in order to maintain a safe environment around exposed energized parts. The shock hazard boundaries include:
- Limited approach boundary
- Restricted approach boundary
- Prohibited approach boundary
These approach boundaries, once determined, show you who should be near exposed energized parts and how close they should get. Within the restricted approach boundary, only qualified people are allowed. Entering the prohibited approach boundary is as dangerous as touching live electrical parts. It should be avoided unless absolutely necessary. These boundaries also help workers determine when they should use voltage-rated gloves and tools.
Flash Protection Boundary
The last boundary described by the NFPA 70E standard is the flash protection boundary. For a system operating at 600 volts, the flash protection boundary is 48 inches. Within the flash protection boundary, workers must wear appropriate protective gear. They must also be attentive to whether the gear they are employing is protecting them from the particular hazards involved.
When properly followed, NFPA 70E helps keep electrical workers safe. Before attempting to perform the sort of hazardous electrical work that the standard covers, you should familiarize yourself with the full safety rules and procedures.
CC Photo by Western Area Power