Project Details

Ashland Solar is a 2.5 MW solar PV plant located in Ashland, ME. The facility uses twenty (20) Sungrow SG125HV string inverters for AC power generation, and 2.5 MVA GSU to step up power to the local utility’s 12.47 kV distribution network. The client commissioned RLC to perform an arc flash risk assessment for all facility equipment, as well as a short circuit study, and a protection and coordination study. The Ashland Solar site was one of eighteen (18) similar PV sites the client contracted with RLC for arc flash risk assessment services.

As with all PV arc flash studies, RLC treated the inverters as constant current devices capable of injecting approximately their rated current for the duration of the fault, as documented by short circuit tests of inverters.

Scope of Services

• Built an impedance model based on gathered facility data including conductor and transformer sizes, breaker settings and fuse sizes, and inverter details.
• Created arc flash scenarios for minimum and maximum expected fault current, and with generators online and offline.
• Suggested changes to breaker and relay settings to maximize worker safety while ensuring reliability and coordination based on arc flash study results.
• Provided a draft arc flash hazard assessment report detailing all model assumptions, arc flash scenario details, label methodology, TCCs of all coordinating protective devices, and worst-case incident energy results for client review.
• Incorporated client comments into final report with arc flash labels generated and ready for printing.