Circuit breaker technology advancements are emerging, helping engineers balance safety and uptime. Here are some tips:
* Based on application, type of facility, and risk factors, use experience and judgment to optimize the inherent trade-off for reliability (selective coordination) and safety (arc flash mitigation).
* Circuit breakers offer basic wire and equipment / circuit protection, but little protection from significant arc flash dangers, unless you de-energize the equipment.
* The latest generation of smarter communicating circuit breakers communicates in new and better ways.
* Energy reducing maintenance switches (ERMS) compensate for increased arc flash risk from selective coordination requirements.
* ERMS involves human, manual intervention to switch breakers to an instantaneous-trip setting to improve safety working on the equipment and human, manual intervention to reset the equipment for coordination when the job is done or risk more power interruptions and more downtime.
* If an electrical system is designed based on safety, there will likely be nuisance tripping and costly unplanned downtime.
* Integrating the three Cs of safer uptime (circuit protection, coordination selectivity, and communications) can keep our systems up and running safely.
* Making power systems safer from arc flash is about more than Ohm’s Law, lockout/tagout, and following code.
* Time current curves tell us which breakers are going to trip when.
* Uptime is critical in industrial systems and commercial applications. No power means no revenue or, even worse, danger to workers and damage to expensive equipment.
* Zone selective interlocking (ZSI) systems, coordinate protection between upstream and downstream breakers.
* ZSI allows a set of breakers to communicate and automatically change response time to a mid-level (short-time) or ground fault.
