“Kill the Circuit.” This phrase is a colorful way of saying de-energize the circuit. Easy enough—just open a switch or other protective device and the circuit is “dead.” It should then be safe to work on, right? Wrong! Simply opening a switch does not guarantee the circuit is de-energized. Really?
The 2012 Edition of NFPA 70E, the Standard for Electrical Safety in the Workplace, has made a significant change to the information requirements for arc flash warning labels.
According to Section 130.5(C), the following is now required: