Intelligent Power Today Magazine

Absence of voltage testing is a vital step in the process of verifying and establishing a de-energized state of any electrical system. As detailed in NFPA 70E clause 4.2.5., there is a specific and approved approach to establishing an electrical safe work condition with the following steps:

• determine all possible source of electrical supply
• interrupt the load current, open the disconnecting device for each possible source
• verify where possible that all blades of the disconnecting devices are open
• release or block any stored energy
• apply lockout device in accordance with documented and established work procedures
• using an adequately rated portable...

Over the last few decades, arc-fl ash hazards have been a significant concern for many electrical workers and employers. Many methods have been developed through the years to assess incident energy.
The most common is that of the IEEE 1584, Guide for Performing Arc-Flash Hazard Calculations. These equations have remained the same since the standard was first published in 2002. Based on the results of more than 1,800 tests, the 2018 edition of the guide provides new formulas that are both more accurate and more complex. These formulas also take more parameters into account now, including the conductor orientation at...