The smoky underground utility fire that knocked out power for 1,700 customers in Morristown and Morris Township on June 9 may have been caused by an oil leak, representatives of Jersey Central Power and Light told the Morristown council on Tuesday.
“There was a fault in the vault,” said Stan Prater, a spokesman for the utility.
The power company hopes to have firmer answers later this month or early in July, after removing and dismantling two transformers that were burned in a vault below the sidewalk in front of Walgreen’s on South Street.
An oil compartment that insulates cables as they enter one of the transformers appears to have ruptured, spraying oil in the 9 foot-by-8-foot-by-28-foot vault. A spark or electric arc may have ignited the leaking oil, according to Don Richards, a JCP&L engineer.
“We had a cascading effect,” he said, explaining that power had to be re-routed through other sub-stations.
The heavy black smoke came from burning wires and rubber insulation, Stan said.
The utility representatives acknowledged other potential contributing factors including a hot day (a nearby bank thermometer registered 101 degrees last Thursday), increased power usage by customers with air conditioners, and a vault crammed with cables and electrical gear.
Yet their data indicated the transformers only were operating at 33 percent of capacity when JCP&L learned of the incident at 4:05 pm, they said. Inspections of the transformers in March and April found no hints of trouble, they said.
“I think the temperatures and loading on the system tends to bring out any weak points in the system. But our data shows nothing was even close to being overloaded,” Don said.
Don could not answer a council question about the age of the transformers. But he said about 50 similar models are in vaults beneath Morristown streets and sidewalks.
By Friday, both damaged South Street transformers should be removed from the vault and taken to a facility at Legion Place in Morristown, Stan said.
“We will bring in our cable experts, and the BPU has asked to be involved,” said Don, referring to the state Board of Public Utilities. “We’ll tear (the transformers) apart to see the root cause of the failure.”
After a May 2010 explosion shut portions of the municipal library, JCP&L announced it was upgrading its underground network. Those renovations did not include the vault in front of Walgreen’s, Stan said.
Power was restored to Walgreen’s and the neighboring Rite Aid and Coldwell Banker businesses at 10 pm on Saturday, June 11. Other customers were back online within hours of the fire, the spokesman said.
The fire rekindled interest in the ongoing investigation of the library explosion. JCP&L maintains it did not cause that explosion. Stan said the absence of any smoke at the library suggested the cause there was a “combustible gas.”
Public Service Electric & Gas also has denied responsibility for the library blast, which is being investigated by the library’s insurer, Travelers Insurance.
After the library incident, JCP&L hired a contractor to review the utility’s Morristown network and compare it with other systems. A draft report could be ready this week, Stan said.
Scheduling issues are the main reason the library probe is taking so long, Don said. With so many parties and lawyers involved, it’s hard to bring everyone together.
Two representatives of the BPU met with JCP&L on Tuesday regarding the underground fire on South Street, Stan said.
Morristown Mayor Tim Dougherty said he was glad about the BPU’s involvement. He also commended JCP&L for frequently updating his office about the fire and its aftermath, and praised JCP&L crews and town fire, police and ambulance personnel for their swift response last week.
On June 22 the Mayor is scheduled to meet with state Sen. Tony Bucco and Assemblyman Michael Patrick Carroll (both R-25th Dist.) regarding the library investigation. The public has never been told what caused a 1994 explosion at the library; Sen. Bucco has promised answers this time.
READ MORE ABOUT THE SOUTH STREET FIRE
READ MORE ABOUT THE LIBRARY EXPLOSION
