Functioning power grids connect and protect a functioning society, providing power to homes, schools and businesses. Mission critical infrastructure across the globe depends on the steady, uninterrupted flow of electricity. 

One of the most important elements in an electric utility grid is its grounding system. Grounding systems provide a pathway to earth for currents in the event of dangerous fault and transient events. Fault and transient currents can result from natural events like lightning strikes and manmade events like accidental contact with ladders, balloons and other interferences coming into contact with energized wires. Without an effective grounding system, fault currents can damage equipment, cause downtime for critical systems and endanger people. 

Copper is typically used for grounding cables because it conducts electricity well and is extremely flexible. However, copper is a valuable raw metal in high demand across the globe, and is often visible and accessible to the public in grounding applications. This makes copper conductor attractive to thieves, who steal copper grounding conductors off utility poles and sell them to scrappers to melt for the raw material. 

Because of the danger ungrounded electrical systems pose, copper theft is a big concern. While utility companies have protections in place to stop overvoltage and fault currents from impacting customers, copper theft that damages grounding systems can be a costly problem. BC Hydro, British Columbia’s largest electric utility company, has first-hand experience with this problem. 

“It turned out that a lot of copper running up wooden poles in easily accessible areas, like the city of Vancouver, was being stolen,” said Fred Dennert, division manager for distribution standards at BC Hydro. “Whenever the copper was replaced, it was stolen soon after.” 

A Costly Concern 

The cost to replace stolen copper wire can be more than 10 times the price of the wire itself due to downtime, materials and labor. Grounding wire theft also affects BC Hydro in more ways than just the obvious equipment damage concerns. BC Hydro shares space on its utility poles with other companies such as cable, phone and internet providers. While those other companies do take measures to protect their own equipment, as the utility company, BC Hydro is responsible for the grounding systems that protect the poles from fault currents. 

At an industry trade show, Dennert raised the issue of grounding conductor theft to the nVent team and asked for help to develop a solution to the problem. Previously, the company had discussed using cheaper steel cable that didn’t have as much value to thieves, but they were not willing to sacrifice the conductivity and flexibility of copper grounding conductor. BC Hydro needed to find a replacement product for stolen grounding wires that would not just be stolen again as soon as it was installed. 

The nVent team realized it could help end the theft and replacement expenses for BC Hydro and help them better serve their customers. The team worked with BC Hydro to modify an existing product– rail jumper cables—to reach a quick solution. 

A New Generation Of Cable 

Rail jumper cables connect train cars and transmit electric currents between them. Copper is the preferred metal for those cables for the same reasons it is the preferred material in grounding wire—conductivity and flexibility. In the 1960s, the cable industry came up with an innovative approach to prevent copper theft from rail lines: making composite cables with steel outer strands and copper inner strands. These cables look like cheap steel cables but are almost as conductive as pure copper. The nVent team used that model to create nVent ERICO Theft Deterrent Composite Cable, fully adapted for grounding use in electric utilities. 

nVent theft-deterrent cable is made of tinned copper wire strands bunched together and surrounded by a ring of steel strands. Because the cables contain a high amount of copper, they maintain the flexibility and conductivity that makes copper so good for use in grounding wires. However, nVent’s theft-deterrent cables are highly inconvenient for thieves. 

The steel strands on the outside of the theft deterrent cable give the entire cable the appearance of steel guy-wire: a cheap cable used in electrical systems that has almost no value to thieves and scrappers. In addition, the cable passes thieves’ “magnet test,” where they apply a magnet to look for coated copper conductor to steal. Even if more resourceful thieves do discover that there is copper on the inside of the theft-deterrent cables, it is difficult to separate steel and copper wires. Scrappers typically do not think the extra effort of separating tightly-wound copper and steel wires would generate enough profit to invest the time in this step, or they are not able to remove the cable from the installation at all. 

Protecting Connections 

Because the nVent team was able to adapt rail jumper cables instead of developing an entirely new solution, they were able to give samples to BC Hydro within weeks of their initial conversation. Now, BC Hydro consistently purchases its theft-deterrent cable from nVent. 

With nVent product in hand, BC Hydro is better positioned to respond to cable theft. They try to protect existing wires, but now when copper grounding conductors are stolen, BC Hydro replaces them with theft-deterrent cable. After the first replacements, some thieves tried to steal the nVent cable, but upon realizing the difficulty of both cutting and trying to sell the material, incidents of theft of nVent cable have all but stopped at all replacement locations. 

With nVent’s theft-deterrent composite cables providing the grounding infrastructure for more and more of BC Hydro’s distribution system, the company can rest assured that poles are protected from danger: both natural and manmade. Now, BC Hydro can focus on what matters—providing essential power to its customers.