Based in Kilpilahti, Finland, Borealis Polymers produces plastics used as raw materials in everything from food packaging to pipes and cable shells. With 550GWh of electricity flowing through its 27 transformers each year, the plant accounts for almost one percent of Finland’s electricity consumption.
A new substation for water treatment at the facility is currently under construction by power plant manufacturer Jonator. Protecting the low-voltage switchgear is ABB’s TVOC-2 Arc Guard system. “Our key priority is the safety of our people, which is why we have been using ABB’s arc protection technologies for more than 30 years,” says Jari Välilä, Borealis Polymers' Director of Electrical Operations.
Although fortunately rare, an electrical arc is the worst possible switchgear fault. When human error or equipment damage cause short circuits. the consequences are potentially very serious – and costly. The ABB TVOC-2 Arc Guard system saves Borealis Polymers' plastic production from these expensive, extended outages.
Every millisecond counts
When an arc ignites, every millisecond counts.
ABB’s system’s optical sensors ensure the Arc Guard responds to the arc’s first spark in just 1-2 milliseconds, transmitting the information via fiber optics to the trip circuit, and resulting in a total breaker opening time of 30-50 milliseconds.
The system verifies the arc hazard using current sensor data from the current sensing unit CSU-2. The Rogowski coil current sensors are easy to install on busbars and conductors and retrofit to old switchgear. They also react faster than conventional current transformers and can measure a wider range of current due to the absence of saturable ferromagnetic core.
A recent Arc Guard alarm for the production plant’s 10 kV switchgear demonstrates the importance of time savings. Directed to the exact point of the alarm by the system’s indicator light, Välilä opened the door to inspect the damage left by the arc’s initial spark.
Thanks to the Arc Guard’s control, the damage was minor: some melted copper on the output terminal that took just a few hours to repair. “Without the Arc Guard, the damage in the Borealis switchgear would have been extensive and safety risks significantly higher”, says Välilä.
Resilience enhanced
A full arc could have stopped the entire plant for 3-4 months – roughly the time required to design, build and deliver a new switchgear. Switchgear are valuable investments, says Välilä, but they don’t compare with the cost of interrupting production and customer deliveries.
Jonator specializes in demanding low-voltage switchboards for critical electricity distribution sites, such as hospitals, process industries and data centers, where uninterruptible power supply is essential. Jonator sales manager, Arttu Uotila says:
“At these types of critical locations and at high rated currents, arc monitoring technology is becoming standard equipment. And, if arc protection is not included in the call for tenders, Uotila offers it as an option. For a small on-cost, you have insurance against long production interruptions and accidents at work. Even for small facilities, it makes a lot of sense.”
