Hoarfrost causes outage, power bumps throughout Fort St. John

FORT ST. JOHN, B.C. —  BC Hydro says the recent appearance of hoarfrost in the Fort St. John area caused a power outage on January 3rd and multiple power bumps that followed. 

The January 3rd outage left over 4,000 BC Hydro customers in Fort St. John without electricity for approximately three hours. 

Hoarfrost is the deposit of ice crystals that forms on cold and clear nights when the air is moist, according to weather.com. 

Mike Kellett, BC Hydro’s manager of community relations for northern B.C., says in the case of the recent outage and power bumps, hoarfrost had built up on the power lines, causing “phase slap.” 

“Because of the current winter conditions lately, [hoarfrost] can build up on the powerlines and basically causes a bit of slap or snap on the line,” said Kellett. 

“The components of this can sometimes cause an outage or a bit of a bump in power until the circuit recloses. It’s kind of an environmental situation.”

According to Kellett, “phase slap” occurs sometimes when a vibration or disturbance causes built up ice, frost, or snow on powerlines to break off suddenly, causing one line to slap into another line.

BC Hydro’s electrical system has safety components called circuit reclosers, which detect when anything makes contact with power lines. 

When contact occurs, reclosers open briefly and close again to ensure the disruption has passed and the line can be restored safely without risk of fire. 

The recloser will complete this set a number of times to see if the contact has passed to minimize power disruption for customers. If the contact remains, power can’t safely be restored, and BC Hydro crews are dispatched to investigate. 

“We believe the power bumps are the circuit reclosers doing their job,” said Kellett. 

“Customers may experience brief power fluctuations as the reclosers open and close, trying to restore power safely.”

Kellett says BC Hydro crews have been trying to knock the hoarfrost from the powerlines around town to prevent the surges from continuing, and on January 3rd, the outage “fixed itself.”

“I think what happened on January 3rd was that crews were out patrolling, trying to find the source of the issue,” said Kellett. 

“What happened is the circuit actually reclosed itself. It’s frost, it comes and goes, and in this case, it just went away and restored itself.”

Some Fort St. John residents contacted Energeticcity.ca to voice their concerns about the effects of the power bumps in their homes, with one resident saying a power bump had blown the circuit board on his furnace and would cost $400 to replace.

Kellett advises customers seeking compensation for matters such as this to head to BC Hydro’s website for more information.