Electrical safety in the workplace is an important topic that is addressed by NFPA 70E, Standard for Electrical Safety in the Workplace® (2015 edition). This standard addresses arc flash and shock hazards, and there is a need for more empirical incident data on the actual hazards that may be experienced when equipment faults or adverse electrical events occur. The availability of such information allows for better-informed decisions for on-going revisions to this standard.
There exists a dangerous misconception regarding the “Arc Rating” of infrared (IR) windows or viewing panes. Many reliability and maintenance professionals are under the impression that an IR window will protect them in the event of an arc blast; still others are under the impression that installing IR windows will turn non-arc-rated switchgear or electrical equipment into “arc-rated” cabinets. Neither is the case, and both misconceptions need to be corrected because they present very real safety concerns.
I am amazed when I still see companies fitting crystal infrared (IR) inspection windows into their 1kV and above electrical switchgear, IEEE C37 20.2.a.3.6 clearly mandates that all visual viewing windows irrespective of size, shape or material undergo an impact and load test, and as we know all fluoride based IR windows cannot pass any form of impact test!