These devices are mainly effective for general electrical work and may not prevent an arc flash incident from occurring.
Warning Indicator Light
For safety, all metal on machines should be tied to ground (a wire fastened from the metal to a copper rod driven into the earth). Thus, if a wire should come loose/break and touch any metal surface, current will flow (be shorted) to ground, tripping a safety device in the cabinet. If the metal parts of a machine were not tied to ground and a "live" or "hot" wire were to touch the metal, then the machine would become "live". If a person were to touch the machine, they would complete the circuit to ground (through their body) and could be electrocuted.
Some electrical panels are equipped with ground indicator lights:
Current Limiting Fuses/Circuit Breakers
Current limiting fuses and circuit breakers, when operated in the current limiting range, operate extremely fast to reduce the arcing current and diminish the energy levels produced.
Ground Fault Circuit Interrupters (GFCI)
An electrical wiring device that disconnects a circuit whenever it detects that the flow of current is not balanced between the phase ("hot") conductor and the neutral conductor.
In NFPA 70E 21015 Article 110.4(C)(2) Maintenance and Construction (GFCI) Protection:
When to Use
Ground fault circuit interrupters should be used any time electrical equipment is used around moisture. This would include the use of electrical power tools outdoors or in damp locations.
How to Use:
Infrared cameras are one of the tools used to identify problems in electrical systems by detecting the IR wavelengths generated by heat. An infrared camera can be used to identify a failing component prior to a complete failure which can cause electrical system shutdown, equipment damage and bodily injury. Although they can be used to inspect electrical components at a distance, they do require a direct line-of-sight to record accurate images which often requires a qualified worker, wearing appropriate PPE and trained for the task, to open the enclosure to gain access.
An infrared window installed on an electrical cabinet or panel may eliminate the risks of performing a live inspection it allows the infrared camera a direct line-of-site access to the interior components without having to open the enclosure. This provides an safe alternative to having a qualified person open doors or remove access panels, a source of triggering an arc flash event.
Figure 1: Ground Indicator Lights on Electric Panel
Figure 2: Class J Fast Acting Current Limiting Fuses in AMTEC Simulator Electrical Panel
Figure 3: Panelboard Mount and Portable GFCIs
Figure 4: Using Infrared Device to Troubleshoot at a Distance
(workers may use FR level clothing outside the Limited Approach Boundary)