The Reno and Sparks fire chiefs are asking the Public Utilities Commission to investigate the safety of smart meters installed by NV Energy on homes throughout the state in the wake of a troubling spate of blazes they believe are associated with the meters, including one recent fire that killed a 61-year-old woman.

Since 2012, four fires have occurred in Reno and five fires have occurred in Sparks that city investigators say are linked to the smart meters manufactured by North Carolina-based Sensus. Those investigators, however, have been unable to conclusively determine what started the blazes.

"We're taking this problem very seriously and we have from the very beginning," Sparks Fire Chief Tom Garrison said Friday. "We tried diligently to determine the scope of the potential problem. We've done many things to conclusively explain why these fires were starting. So far, we don't have a definitive reason."

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Most recently, a late-night fire on Rhinestone Circle in Reno fatally burned 61-year-old Michelle Sherman, who died in the burn unit a day after the blaze broke out in her townhouse in July.

Investigators disagree

The official investigation by Reno Fire Department listed the cause of the fire as "undetermined," because the smart meter had been so damaged in the blaze that it couldn't be conclusively ruled as the cause.

But a forensic expert hired by the city determined that the meter also could not be ruled out as the source of the blaze.

"Based on physical evidence in the Rhinestone matter, the Sensus meter cannot be eliminated as the ignition source," investigator Andrew Thoresen wrote. "Data tends to suggest the meter may have failed."

Thoresen also noted that the smart meter, which continuously transmits information about power usage to NV Energy, last transmitted 49 seconds after the 911 call came in, indicating it continued to function well after the fire started and making it "less likely" that the meter caused the fire.

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An investigator hired by NV Energy, who was given access to all of the fire department's evidence, said the fact the meter continued to transmit information proves it did not spark the Rhinestone Circle fire.

"It is not physically possible for the meter to have communicated normally after an arcing event occurred that had been initiated internally to the electric meter," NV Energy's investigator wrote.

"It is therefore not physically possible that the fire originated at the electric utility meter, hence the meter could not possibly have been the cause of the fire."

"Based on the conclusion of a third-party investigation into this tragic incident, the electric meter did not cause the fire," NV Energy spokeswoman Faye Anderson said in a written statement. "The safety of our customers, our employees and our equipment is paramount to us. This investigation has been a priority since it was brought to our attention and we have cooperated fully with the Reno Fire Department."

'The meter did fail'

Although the definitive cause of the Rhinestone Circle fire remains in dispute, Garrison and Reno Fire Chief Michael Hernandez said they have become increasingly concerned by the number of blazes that appear related to the smart meters.

"Yes, it's a small number, but as fire chief, when I start to see a pattern, it gets my attention," Hernandez said. "That's why we are red-flagging this and reporting it to the proper people who regulate this kind of thing."

Of the nine fires in Reno and Sparks that appear to be linked to the smart meters, seven resulted in very little damage. Only the meter itself was destroyed and the surrounding wall was partially blackened.

But one of the fires in Reno burned a man's face. The meter burst into flames when he flipped a breaker switch, scorching him. He put out the flames with a fire extinguisher and was treated at a local hospital.

Another home in Sparks was significantly damaged, Garrison said. That investigation, however, remains open.

Sparks fire investigators have been unable to conclusively name the smart meter as the culprit in large part because they sent the meter itself to NV Energy for further analysis and still have not received it back.

"This was a meter analyzed by an independent investigator that NV Energy hired," Garrison said. "We turned the meter over to them and have not received that report back yet. We felt we needed a little more expertise to analyze the meter."

The forensic investigator that examined the Rhinestone Circle smart meter also examined three more smart meters associated with fires in Reno and Sparks. He found evidence that each of the three meters—one from Reno on Arletta Drive and two from Sparks—failed.

"It is probable the Arletta meter did fail, resulting in the ignition of the fire," Thoresen wrote.

'This is very alarming to me'

Garrison said meter fires are particularly concerning because they start on the outside of the house, won't be picked up by indoor smoke detectors and can escape immediate notice.

"It can burn a long time and enter the attic or the walls," Garrison said. "The occupants inside may not even be aware the house is on fire. This is very alarming to me."

On Rhinestone Circle, Sherman was found by a neighbor burned and lying on her kitchen floor, according to the fire investigation. The neighbor carried her to safety, but she later died of her injuries.

NV Energy executives steadfastly maintain that its smart meters have never been listed as the official cause of any structure fire in Nevada.

Vice President Pat Egan said the fires he is aware of in Sparks and Reno are either still under investigation or have been found to have an "undetermined cause."

Egan said, however, the company has responded to 70 "consumed meters," since it first started installing them in 2010. The company has installed 1.1 million meters on homes and businesses across the state. None of those consumed meters, he said, resulted in a structure fire.

"That's a consumed meter rate of .006 percent," Egan said. "That is extremely low relative to industry standard."

Egan described a "consumed meter" as one that has had its plastic casing "melted or breached and there can be soot," he said. "It's a simple clean up."

He refused to describe a consumer meter as resulting in flame, despite the fact that they can result in a sooty exterior wall.

Consumed meters can be caused by a voltage overload in the home or a "hot socket," where there is too much "electrical resistance" in the smart meter's connection to the box and it becomes overheated, Egan said.

Problems suspected elsewhere

Reno and Sparks aren't the first jurisdictions to report fires associated with Sensus smart meters.

Portland General Electric replaced 70,000 Sensus smart meters in July after three "small fires" started by the meters, according to the Oregonian. In 2012, Peco Energy in Philadelphia switched out 186,000 Sensus smart meters after fire concerns, according to news accounts. And Sask-Power in Saskatchewan, Canada is in the process of replacing more than 100,000 Sensus smart meters, according to news accounts.

Egan said NV Energy officials are aware of the problems in those jurisdictions and continue to monitor the situation. He also said NV Energy would co-operate in any investigation the PUC may decide to launch at the fire departments' request.

"Our primary concern is our customers' safety," Egan said.

Garrison said it's difficult to tell homeowners how to react at this point.

"I would say be very aware, very vigilant about any type of potential electrical problem they might see in their home," he said. "If you noticed any burned electrical panel, any smoke, even if it's small, wispy smoke, if the meter is extremely hot, or you hear a noise or see any arcing, call 911 and the fire department will come out and ensure the meter is properly checked."

Reno City Manager Andrew Clinger said residents not experiencing any immediate fire, but have had a problem with a malfunctioning meter should report it to the PUC. The complaint line is 684-6100.