The customer
SSAB is a highly-specialized global steel company that develops performance steel and provides services for better performance and sustainability. The company is a leading producer of advanced high-strength steels; quenched and tempered steels; strip, plate and tubular products; as well as construction solutions. The company has production plants in Sweden, Finland and the United States, and has an annual steel production capacity of 8.8 million tons.
The challenge
SSAB has a facility in Borlange, Sweden that features a finishing mill that carries out the final step in the production of steel coils. The finishing mill motors were installed and put into production in 1981/1982 but were, for years, plagued by arc flashes that resulted in damage of varying degrees of severity.
An arc flash is the heat and light produced by an arc caused by a fault in electrical equipment. An arc flash is an extremely serious and dramatic event and is one of the most serious incidents that can occur in an electrical installation. Arc-flash temperatures can reach 20,000 C and the energy and shrapnel produced in the blast can cause injury and serious damage.
Normal short-circuit measures are too slow to protect against arcing events like this.
The ABB solution
Much work has been carried out over the years to mitigate the effects of arc flash. ABB has had an effective arc flash countermeasure product, Arc Guard TVOC, on the market for several decades.
In1992, ABB installed Arc Guard systems at the SSAB Borlange facility to reduce the arc flash threat. Other measures to reduce the frequency of arc flashes – such as rotor redesign and a fire alarm upgrade - were also undertaken. These combined measures resulted in significantly reduced arc flash damage and thereby increased reliability and reduced maintenance costs. On top of the Arc Guard units employed in this specific motor protection application, there are over 90 other units in use as arc flash protection devices in distribution switchboards around the factory.
Over the 14 years since installation, the Arc Guard systems have paid for themselves many times over.
The finishing mill motor application is a somewhat unusual one for Arc Guard, but it demonstrates very well the versatility of the system as well as the potential for savings, reduced downtime and increased safety.
Mr Jan Bjork, Strategic Technology Coordinator at SSAB has had a very positive experience with Arc Guard over the years, “The money that SSAB has saved since Arc Guard was installed is substantial: Every shutdown we have related to arcing has been shortened by 10 to 12 hours – in an environment where, typically, there would be six arc events annually and each one would incur a five-figure dollar cost per hour.”