Infrared windows applied in switchgear assemblies: Taking another look

Maintenance of electrical power distribution assemblies applied in industry has been critical in assuring facility uptime and reliability. One important metric in assuring reliability is electrical terminations of energized conductors. During normal energized service, terminations both at conductor bus joints and at cable terminations are subject over time to thermal expansion and contraction, ultimately resulting in loosened connections and excessive heat. Deteriorating terminations left unchecked will ultimately fail, resulting in electrical hazards for personnel and also costly loss of production. Infrared (IR) inspection has proved to be an excellent maintenance method used to identifying problems with loose electrical terminations. However, the design of Internal Arc Classified (IAC) switchgear assemblies to address arc-flash concerns has changed assembly designs that now limiting line of sight access necessary for IR inspection via windows. This paper will discuss global Standards, how they affect switchgear designs and application of IR windows, then present some alternative technologies that in some applications may be more suitable.