Arc flash, short circuit current and available fault currents are all hazards that spawn from uncontrolled energy. The NFPA 70E standard, lockout / tagout and wire and cable marking are some of the ways that these hazards can be minimized and help keep you safe when dealing with electricity.
The following is a transcript of the Electrical Safety Infographic:
What is the cost of compromised electrical safety?
LO/TO was the eighth most cited OSHA violation in 2013, accounting for 12% of U.S. fatalities. One amputation in the workplace caused by failure to LO/TO will cost* directly over $60,000 and indirectly over $2 million.
Four steps to isolating equipment during Lockout/Tagout:
Identify the energy source.
Isolate the energy source.
Lockout and/or tagout the energy source.
Test that the isolation is effective.
According to OSHA each year proper LO/TO safeguards 3 million people, prevents 120 deaths, and eliminates 50,000 injuries.
The most common clothing item that workers fail to use as last protection against an Arc Flash burn are gloves.
Skin temperature for curable burn: 176°F
Skin temperature causing cell death: 205°F
Ignition of clothing: 752°F - 1,472°F
Metal droplets from arcing: 1,832°F
Surface of sun: 9,000°F
Arc terminals: 35,000°F
One curable burn injury from Arc Flash at a workplace directly costs nearly $40,000 and over $150,000 indirectly.
Flash suit protects skin and face. Hearing protection from Arc Flash explosion, Respirator protects from inhalation of toxic substances. Flame retardant hat for head protection. Gloves can prevent electrocution.
The intent of NFPA 70E, regarding Arc Flash is to provide guidelines—starting with most preferred, to the last line of defense—that will limit injury of second degree burns.
Eliminate the hazard.
Lock out the hazard—or isolate it.
Education, training, and an upkeep of visual communication is required.
The last line of defense is personal protection equipment (PPE).
Cable and Wire Marking
Prevention of serious injuries or fatalities start with indentifying electrical energy sources. Cable markers and tags are indentifiers critical to safety.
9% of U.S. workplace fatalities in construction were electrocutions. One electric shock injury directly costs* over $100,000 and indirectly over $215,000.
Available Fault Current
Also known as the short circuit current, the available fault current is the maximum current available if a short circuit occurred. It is critical to understand what the available fault current is, such as in a ground fault, in order to know what arc flash could occur.
A utility transformer needs to be labeled with it's available fault current in order to calculate what the available fault current is for the electrical equipment and panels in your facility.
Short Circuit Current Rating
The Short Circuit Current Rating (SCCR) is a rating to help protect workers from a hazardous situation. It is the maximum short-circuit current that equipment can function without damage or causing a dangerous exposure.
The nameplate label on equipment displays the SCCR, the name and location of the manufacturer, the panel type, the electrical wiring diagram or a reference number to such a diagram. NFPA recommends that this label be permanent. Labels and signs are needed to visually communicate all steps to LO/TO, cable and wire marking, and preventing arc flash. You can create your own arc flash and available fault current labels, electrical warning and danger signs right at your own facility.