January 25, 2012BERLIN — The Smith Hydroelectric Station at the entrance to the city at 99 Glen Avenue was returned to full service on Dec. 30, following a fire that shut it down on Sept. 1, 2011.
The powerhouse on the Androscoggin River has a single 17.6-megawatt generator interconnected directly with PSNH's 115 kV transmission system.
Public Service of New Hampshire (PSNH) has recently released details of the fire, its aftermath and cleanup, and its restoration to service.
At about 9:45 a.m. on Sept. 1, the fire detection system at the powerhouse initiated a fire alarm, and the Berlin Fire Department immediately responded. The exact cause of the fire was unknown at the time, but fortunately there were no injuries, notes PSNH spokesman Martin Murray.
In order for the Fire Department to safely address the fire inside the plant, PSNH needed to de-energize the connection of the plant to PSNH's electric distribution system. PSNH's Electric System Control Center (ESCC) in Manchester remotely opened the power feed to much of the Berlin area at 10:12 a.m., electrically isolating the powerhouse and cutting off power to 5,230 customers.
A PSNH line crew arrived and quickly disconnected the wires to the plant's auxiliary power at the local street utility pole, and the ESCC began to reenergize the city 50 minutes later at 11:02 a.m., immediately restoring service to nearly 2,000 customers. At about 11:45 a.m., the last switch was re-closed to restore power to the balance of customers affected.
The Federal Energy Regulatory Commission (FERC) and the NH Public Utility Commission (PUC) were notified of the problem almost immediately.
Berlin firefighters, wearing self-contained breathing apparatus, fought the fire with CO2 until the Station was isolated electrically. After that they were able to apply water to ensure cool surfaces. They were able to leave the site after about two hours.
The main generator breaker cubicle and other controls in the area inside the Station were ruined by fire, heat, or water. The dam and associated gates and equipment were not affected by the fire and continued to function normally, and the generator and main transformer were also not damaged
Everyone involved that day, especially the Berlin Fire Dept responders, Hydro Operator Mechanics Mark Bouchard, Darryl Couture, Brad Horne and Dan Roy, Hydro Electric & Control Mechanics Mike Lessard and Joe Gassek, Hydro Electric & Control Working Foreman Steve Crocker and Upper Hydro Working Foreman Rick Cusson (who immediately came in from vacation), Hydro O&M Manager Gil Rainault and the ESCC Systems Operations Supervisor Don Cotnoir did a great job under trying circumstances.
"From my visit the crew at Smith is doing a good job at sorting the situation out and are on the right track," said PSNH vice president for generation John MacDonald, who visited the site late that afternoon. "I'm grateful no one was hurt and the damage to the equipment was contained. Procedures and systems in this case worked well as they were intended."
Clean Harbors, Inc was contracted and performed a thorough top-to-bottom cleanup of the building, which was completed on December 8, 2011.
In order to understand exactly what took place, the damaged equipment was sent off-site for a painstaking disassembly and inspection.
The team's full report will be finalized in early February.