NV Energy has filed a lawsuit seeking more than $45 million in damages against a French company blamed for equipment failures that caused multiple catastrophic explosions at electric substations and power plants throughout the state over the last nine years.

The lawsuit, filed in federal court on July 18, alleges that Trench-France and Trench-Canada (both subsidiaries of Siemens, a multinational German electric equipment company) negligently produced and made “material misrepresentations” about the capacity of their bushings — insulating devices used to “protect persons and equipment from high-voltage electricity exceeding 50,000 volts.”

Failure of the bushings, allegedly caused by manufacturing errors and extreme heat, were blamed for causing at least six explosions and fires at NV Energy substations and power plants between 2011 and 2017, costing millions of dollars worth of damage and requiring replacement of all Trench-manufactured bushings at a cost of $35.8 million.

A spokesperson for Siemens declined to comment on the lawsuit.

The lawsuit alleges that the bushings — marketed in a 2003 catalog as able to “last the life of your power transformer” — were “negligently and defectively manufactured,” contributing to at least four explosions and fires at NV Energy substations since 2015.

“Paper layers were cut crudely, and with tools not utilized by other bushing-manufacturers,” the lawsuit states. “The resulting rough edges lead to insulation break-down and sudden catastrophic failures.”

The suit also alleges that the bushings were manufactured in non-hygienic locations, causing “unwanted and dangerous contamination.” It also claims that aluminum layers within the bushings were installed by hand, as opposed to using laser-guided or automated systems, which created inconsistencies and non-symmetrical forces leading to “sudden and catastrophic failures (explosions).”

Those alleged shortcomings meant that Trench-produced bushings were at risk of explosion when loaded at less than 25 percent capacity — contradicting a 2014 claim by the company that the bushings could withstand up to 74 percent of their nameplate capacity.

According to filings made with the Public Utilities Commission, NV Energy had previously identified the bushings as the “root cause for multiple catastrophic transformer failures around the country and within the Company.”

Testimony by NV Energy executives in the utility’s 2017 general rate case states that a bushing failure caused a 2011 fire that saw “flames...shooting 80 to 90 feet high” at the Sinatra substation near the Las Vegas Strip. Another “catastrophic”  failure later in 2011 at a substation north of Las Vegas was also blamed on a bushing device malfunction, which caused “prolonged outages on critical transmission paths” in the summer of 2012.

After the initial set of explosions, the utility began a replacement program for the bushing devices, which included a monitoring system that detected out of 15 transformers, 32 of the 118 bushings produced by Trench were “degraded.”

The utility previously sued Trench and Siemens in 2015 over the explosions, but the case was dismissed by a federal judge, who said the power company failed to state a “legally cognizable claim.” The utility appealed, but voluntarily withdrew its appeal in 2017.

Another explosion allegedly caused by a Trench-produced bushing erupted at the Higgins Generating Station near Primm in October 2015, causing more than $4.6 million in damage to equipment. Another bushing allegedly caused an explosion nearly a year later on August 16, 2016 at the Equestrian Substation near Las Vegas, causing more than $2.2 million in damages.

Two days after that explosion, the lawsuit alleges, Trench delivered a safety notice to NV Energy that in high-temperature environments, the nameplate capacity of the bushings was higher than the equipment could actually and safely handle and recommended that the utility replace all bushings system-wide.

The utility began the work to replace the equipment in October 2016 (at a total cost greater than $35.8 million), but another explosion caused by an alleged faulty Trench bushing happened on Nov. 24, 2016 at the Frias Substation in Las Vegas, which caused more than $1.2 million in damages. Another explosion caught fire at the Cactus Substation near Las Vegas on May 8, 2017, leaving nearly 2,000 people without power and damages estimated at $1.13 million.

NV Energy states in the lawsuit that it expects to replace all bushings before the summer of 2020.

The lawsuit alleges that Trench should have known earlier than 2016 that their bushings were causing explosions at a “dangerous frequency.” It states that issues with the equipment had been documented at a 2010 electrical engineering conference and again at a separate conference in 2012, but that a safety notice had not been sent to the company until after additional explosions had occurred in 2015 and 2016.

Attorneys for NV Energy allege that in 2013, Trench executives reported to Siemens (the parent company) that the bushings were exploding “with a frequency which was far greater than average, and much in excess of customers' experience or expectations.” The lawsuit states that Trench executives created a task force in 2014 and traveled to Nevada to study reliability issues with the equipment.

In addition to the $45 million sought in damages, the lawsuit is seeking prejudgment interest, the cost of the lawsuit and any other compensation deemed just and proper by the court.

A similar case was filed by the Salt River Project Agricultural Improvement and Power District in Arizona against Trench in 2017, over alleged failures of bushing systems that caused roughly three explosions and fires between 2008 and 2011. The case was dismissed in 2018, after both sides reached a confidential settlement.

NV Energy Lawsuit by Riley Snyder on Scribd