
SWEDEN: In the Swedish capital, Stockholm Exergi operates across five districts, supplying heat to more than 800,000 people and 400 hospitals through a 3,000-kilometre-long district heating network. With a customer base that size, including critical infrastructure such as hospitals and data centers, service interruptions aren’t just inconvenient, they can have serious consequences.
The challenge: Preventive maintenance for diverse applications
At the heart of Stockholm Exergi’s operations are more than 300 variable frequency drives — primarily VACON® and VLT® drives from Danfoss — powering pumps, fans, screws, conveyors and cranes. These range from compact, air-cooled units to 2.3 MW liquid-cooled drives.
The installed base included drives of various ages, and Stockholm Exergi needed a clear overview of the condition of their equipment as well as a plan for how to keep everything running smoothly long term.
To strengthen their preventive maintenance strategy and reduce the risk of unplanned downtime, Stockholm Exergi turned to Danfoss in 2021.

The solution: Tailored lifecycle services
Today, all five of Stockholm Exergi’s heating districts benefit from a tailored DrivePro® service program from Danfoss combining expert services that help keep operations reliable and energy-efficient throughout the lifetime of the drives.
The collaboration began with a DrivePro® Site Assessment, a comprehensive on-site audit to assess the condition of every installed drive and identify where maintenance, upgrades or replacements were needed.
Drives nearing the end of their expected service life were replaced through the DrivePro® Retrofit service. This ensured minimal disruption to operations by planning each replacement and conversion carefully.
Based on the audit and updated installed base, Danfoss developed a custom preventive maintenance plan and carried out necessary repairs as part of the DrivePro® Preventive Maintenance service. This included round-the-clock technical support and a guaranteed 24-hour response time. This is provided in collaboration with certified DrivePro® service partner Styreg, who delivers fast and reliable on-site assistance.
To further boost uptime, Stockholm Exergi also implemented DrivePro® Spare Parts at each site, ensuring critical components are always available. Annual site assessments help keep the maintenance plan updated and the system one step ahead of potential issues.

The outcome: Rapid response and fewer breakdowns
With the customized DrivePro® service program, Stockholm Exergi has reduced unexpected breakdowns and secured fast response when issues do occur, keeping costly service interruptions to a minimum.
And with a trusted service partner like Styreg on call, they know they can count on expert support when it matters most.

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Case stories

SWEDEN: In the Swedish capital, Stockholm Exergi operates across five districts, supplying heat to more than 800,000 people and 400 hospitals through a 3,000-kilometre-long district heating network.

ITALY: Unilever’s Caivano plant ice cream tunnel now enjoys enhanced ventilation efficiency with EC+ concept. Condition-based monitoring boosts productivity.

CZECHIA: When 80-year-old gears were replaced by variable speed control at the Albrechtice hydropower plant, power production increased by 10%.

Belgium: Thanks to Danfoss DrivePro® services, LuxFly has achieved 99,5% uptime in Europe’s largest vertical wind tunnel that is used for skydiving.

