More than three years after a massive power surge damaged dozens of homes in Georgetown — and set two ablaze — court documents obtained by HaltonHillsToday shed new light on what may have gone wrong.
Halton Hills Hydro recently launched a $5-million lawsuit against multiple companies involved in the construction of a transformer station at 7974 Sixth Line S., alleging negligence, “erroneous” and “confusing” design drawings, and subpar workmanship.
The details of the case are technologically complex, which is not surprising considering the subject matter. But the core accusation is simple enough: a key piece of equipment that controls secondary output voltage at the new station was allegedly “operating in reverse” — increasing the amount of electricity when it should have been lowering it (and vice versa).
That critical flaw, the lawsuit claims, is what triggered the sudden electrical surge on the morning of May 16, 2019, knocking out hydro to 3,800 properties and leaving some homes with heavy smoke and fire damage.
“Unfortunately, although it was only of relatively short duration, the power overage/overvoltage event resulted in damage to numerous residential and commercial properties serviced by the station,” reads the statement of claim, obtained by HaltonHillsToday from the Superior Court of Justice in Toronto. “The exact number of properties affected and the sum total of the damages and losses sustained as a result of the power overage/overvoltage event are still being calculated/quantified.”
Filed in May 2021, the lawsuit was launched by both Halton Hills Hydro (HHH) and EPTCON Ltd., a Cambridge company contracted by HHH to oversee the construction and commissioning of the transformer station, which is just up the road from the Toronto Premium Outlets mall.
The statement of claim targeted five defendants: Regina-based PTI Transformers Inc.; Maschinenfabrik Reinhausen GmbH, based in Germany; Quebec’s Reinhausen Canada Inc.; the engineering firm IBI Group; and Virelec Ltd., an Oakville company retained to design and assemble the station’s automation systems.
For reasons that remain unclear, the lawsuit was discontinued two months ago — before any of the named companies filed statements of defence. None of the parties agreed to comment about whether an out-of-court settlement was reached, or for how much.
What is clear, according to the statement of claim, is that Halton Hills Hydro believed there was plenty of blame to go around. Although none of the allegations were tested in court, the legal filing lays out the clearest picture yet of what happened behind the scenes in the days leading up to the surge.
Construction on the transformer station in Hornby began in September 2017. By May of 2019, EPTCON had begun pre-commissioning tests in advance of the site becoming fully operational.
The lawsuit lays out numerous technical terms relevant to the allegations, including:
- On-load tap changers (OLTCs), which enable the transformers’ secondary output voltage to be raised or lowered while transformers are energized and providing power
- Automatic voltage regulating system (AVR), which measures the transformers’ output voltage, compares those measurements to the programmed voltage settings and signals the OLTCs to either raise or lower the voltage as necessary; an AVR can operate automatically or manually
- Human/machine interfaces (HMIs)
- Supervisory control and data acquisition system (SCADA), which enables communication between various components of the electrical system
According to the statement of claim, the process of energizing the station began on May 13, 2019. Two days later, on May 15, control “was transferred to Oakville Hydro to facilitate the switching and paralleling of feeder circuits that was needed for the final commissioning of the station.” (Oakville Hydro is not a party to the court action and declined to comment when contacted by HaltonHillsToday.)
While the AVR was set to manual control, representatives of EPTCON and Oakville Hydro performed incremental load tests on various station feeders, the lawsuit says. It was during that time, the claim alleges, that EPTCON “noticed an error in the voltage control scheme. Specifically, EPTCON observed that the AVR and OLTCs were operating in reverse such that a ‘raise’ command issued through the AVR resulted in a lowering of the output voltage (and vice versa). No damage resulted from these tests.”
After examining the problem, EPTCON ultimately “proposed reversing the ‘raise’ and ‘lower’ control wiring connections and submitted a change order to IBI in this regard,” the lawsuit says.
“Representatives from EPTCON, HHH, Oakville Hydro and Virelec discussed these issues onsite,” the statement of claim continues. “It was ultimately decided that the station would remain energized overnight and that the AVR would be left in ‘manual control’ mode. EPTCON recommended that the AVR be left in ‘local control’ mode at the end of the day on May 15, 2019.”
That did not happen, the lawsuit alleges.
Instead, the legal filing says Oakville Hydro “requested that it have remote control of the OLTCs so that it could adjust the secondary voltage through the HMI/computer at its offsite control centre.” Instead of alerting staff at Oakville Hydro to operate the system in reverse for the time being, the lawsuit claims that Virelec — unbeknownst to EPTCON — “altered the SCADA programing” so that a raise command resulted in decreased voltage and a lower command led to increased voltage.
“These programming changes were only effective when the AVR was left in both ‘remote’ and ‘manual’ control modes and had no effect if the AVR was put into ‘automatic’ control mode,” the lawsuit says.
That distinction would prove costly, the lawsuit alleges.
First thing the next morning, EPTCON returned to the transformer station to continue load testing. “Unbeknownst to EPTCON, at approximately 9:24 a.m., a command to change the AVR control settings from ‘manual’ to ‘automatic’ control was issued remotely,” the statement of claim says.
At the time, EPTCON was testing the station’s M1 feeder — which means the breaker was closed, resulting in a rise in the transformers’ secondary output voltage. Disaster loomed, according to the lawsuit.
“As the AVR was in ‘automatic’ mode at this time, it detected the rise in voltage and attempted to counter it by sending ‘lower’ commands to the OLTCs; however, as the ‘raise’ and ‘lower’ commands were operating in reverse, this caused the voltage to rise even further,” reads the statement of claim. “Event data recorded by the system indicates that breakers were closed, tripped and re-closed and that various alarms were triggered.”
It was too late. Within minutes, the local 911 system was flooded with phone calls.
Aislin O’Hara was one of the many Georgetown residents impacted by the sudden power surge. At first, she says she had no reason to suspect that her WIFI disconnecting was anything more than a simple blackout. Then she smelled smoke.
“Then we noticed that our outlets were smoldering a little bit,” O’Hara told HaltonHillsToday. Even though her home was one of many damaged by the electrical surge, she was among the lucky ones. Just down the street from her now-former address, a neighour’s house caught fire.
When firefighters arrived to tend to the flames, O’Hara says she and her neighbours were told only that “a transformer explosion had triggered a power surge in Georgetown.” She says she was never told more about the exact cause of the surge, and knew nothing about the lawsuit until a reporter at HaltonHillsToday told her about it.
“No one had followed up on anything,” she said. “I guess we were all kind of under the impression that’s just something outside of everyone’s control.”
For context, HaltonHillsToday asked two electrical engineering professors to read the statement of claim: Peter Lehn and Zeb Tate, both from the University of Toronto. They independently agreed that a miswired AVR could have caused the over-voltage.
Dr. Lehn said he believes this incident was a disaster waiting to happen. “If your AVR is going up when it should be going down and they recognize it…there is no way that this stuff should be deployed,” he said. “If that AVR gets used, it’s going to blow things up.”
While Tate echoed Lehn, he was “surprised that an overvoltage due strictly to the [O]LTC misoperation” is alleged to have “caused so much damage since they don’t normally have the ability to raise/lower the voltage more than 10 per cent.”
There are still many unknowns about this incident. Again, none of the defendants filed statements of defence before the lawsuit was discontinued in September, and none of the allegations were ever tested in court.
Tate, in particular, would like to know the voltage levels the parties were operating under during the commissioning of the station. Without those, a full picture of the cause cannot be known, he said.
He cautioned that “a misoperating AVR or transformer won’t necessarily cause enough of an over-voltage to result in damage, and it’s in the utility’s interests to put all the blame on misoperation of the AVR/transformer.”
HaltonHillsToday reached out to Halton Hills Hydro and the Electrical Safety Authority to ask if an investigation had occurred.
“At the time, HHH was doing their own investigation to determine the cause of the over-voltage event,” said Karen Ras, VP of communications with the Electrical Safety Authority.
When asked if an investigation had taken place, Scott Knapman, the president and CEO of Halton Hills Hydro, replied in an emailed statement last month that “the legal proceedings are currently ongoing, therefore we cannot comment further at this time.”
Delna Contractor, a lawyer representing Halton Hills Hydro, provided further clarification in a follow-up letter to HaltonHillsToday.
“[W]e are in the process of reviewing the status of the on-going proceedings,” she wrote. “We understand that some of these matters may have [been] resolved, but that official dismissal documents may not have been issued. We will get back to you on this once we have completed our review in this matter.”
She declined to comment on follow-up questions regarding whether a settlement had been reached. But she did say that CEP Forensic of Laval Quebec and Crawford and Company of Mississauga conducted an investigation into the incident, but HHH is not privy to the findings.
After this article was published, Contractor provided further details to HaltonHillsToday.
She said the lawsuit was "a subrogated claim continued by Halton Hills Hydro’s insurer," which means the company "did not have any decision-making authority with respect to the claim," including drafting the lawsuit or discontinuing it.
"As you may know, subrogation provisions are a standard part of most insurance policies," Contractor wrote. "It entails the transfer of the legal right of the insured policy holder to pursue a third party to the insurer in the case of an insured loss. As a result of the transfer, the rights and remedies of the insured — in this case, Halton Hills Hydro — against any third-parties vest solely in the insurer."
She also praised the company's response to the power surge.
"The Halton Hills Hydro team took this incident very seriously and activated to engage with the community when it occurred in 2019," she wrote. "We are very proud of the team’s response to this unfortunate incident, and their commitment to ensure that all customers were satisfied with the response."
Was your home or business damaged by the power surge in May 2019? Please reach out to [email protected].
*CORRECTION: A photo of Atura Power’s Halton Hills Generating Station and switchyard, located at 7870 Sixth Line S., was incorrectly included with this story and has since been removed. HaltonHillsToday regrets the error and any confusion it may have caused.*