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...

Advanced approaches to addressing direct-current arcing faults

BY MICHAEL FURTAK & LEW SILECKY, Mersen

Let’s face it: there is not very much information available about direct current (DC) arc flashes. And, if you have searched in vain, well hopefully this feature will give you some insight into arc flash with relevance to DC circuits. Essentially, we want customers to be armed with information so that they can accurately determine the necessary level of protection required when working around these circuits.

In this feature, direct-current arcing fault incident energy calculations are presented to assess the level of risk involved when working...