The practical side of electrical safety gets much easier when this one simple principle is embraced: elimination of risk.
The Risk Control Hierarchy in ANSI Z10 Standard explains that hazard prevention is much more effective than hazard protection. Thus, a worker who is exposed to a hazard—and is protected accordingly—still is in significantly more danger than workers who have no exposure to a hazard. Preventing exposure, in electrical-safety terms, requires keeping workers away from voltage.
Translation: Electrical panels should be designed to allow more tasks to be done without exposure to voltage. Thru-panel programming ports offer that type of solution. They allow workers to program a panel without opening the panel door.
PESDs: safety + compliance
An electrical-safety program is safer when workers can determine a zero electrical-energy state without any voltage exposure to themselves. Permanent Electrical Safety Devices (PESDs) allow for thru-door electrical safety and greater NFPA 70E/CSA Z462 compliance. That’s important for any safety-conscious company.
PESDs inherently enhance any mechanical or electrical lock-out/tag-out procedure because they allow for verification of electrical isolation from outside the panel—without exposing the worker to voltage. An example of such a voltage indicator is a PESD that mounts outside the panel. It is a hard-wired LED indicator permanently wired to the phase(s) and ground, and illuminates when 40VAC/30VDC or greater voltage differential exists between two lone inputs.
Before PESDs, creating an electrically safe work condition depended solely on the portable multimeter. This tool is not just used in electrical safety: Its features make it invaluable for other purposes, including electrical troubleshooting and diagnostics.
A PESD, however, leaves no question or confusion when a worker uses it in creating an electrically safe work condition. That’s because today’s PESDs have been designed, built and installed for a single purpose—voltage indication for electrical safety. MT