Protective device coordination studies analyze your electrical protective devices for proper equipment protection and orderly operation during faults.
Equipment that is inadequately protected can cause dangerous situations that could result in injury to personnel or cause damage to equipment and infrastructure. Proper protection is recommended to prevent injury, extended down times, and expensive repairs.
Proper coordination is recommended for all electrical systems to reduce equipment outages. A fault occurring at any location in the electrical system should cause the closest upstream protective device to interrupt the fault. If the system is uncoordinated, a device farther upstream may operate instead, causing unnecessary equipment outages and reducing the system reliability. In addition, troubleshooting the root cause of the fault can become difficult and time consuming. In some applications, such as hospital life safety equipment, it is critical that only faulted equipment be interrupted. A protective device coordination study identifies any coordination issues in the system so that corrective actions can be taken if needed.
The time current characteristics analyzed in the protective device coordination studies, in conjunction with the short circuit studies, are a critical component of the arc flash analysis calculations.
The Process
The protective device coordination studies begin by gathering information from drawings, equipment submittals, on-site inspection, etc. This information is then input into modeling software where it is organized into single line diagrams. The protective devices’ time-current characteristics are then plotted with equipment damage curves and inspected for proper protection and coordination.
The Deliverables
A complete report describing the protective device coordination would be provided. This report would contain a discussion of the coordination findings, including recommendations to correct any issues discovered. This discussion will reference the graphical time current characteristic curves developed, which would be included in the Appendices. In addition, recommended settings sheets showing each protective device recommended, and as-found settings would be provided.
