Intelligent Power Today Magazine

I recently viewed a destroyed 600-volt electrical panel board that had exploded when an operator reset an 800-ampere (A) breaker. His leather-palmed gloves had synthetic backs that ignited and seriously burned the back of his hands. His flame-resistant (FR) shirt was untucked and he was burned on his right side.

It is unfortunate that he was not following Canadian Standards Association’s CSA Z462 standard: “Workplace Electrical Safety” clause 4.3.7.3.10 (d). It is incredibly fortunate that his employer provided arc-rated clothing, as only a few years ago, he would have been wearing cotton coveralls.

Consequently, this incident would have resulted...

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...