Stuttgart, Germany – December 2025 – Mercedes-Benz Group AG has successfully deployed ABB SPAJ140 Relay Protection Modules to upgrade the power distribution system of its Stuttgart manufacturing plant. The upgrade addressed legacy relay issues, including slow overcurrent fault detection, inaccurate tripping, and poor integration with the plant’s energy management system—gaps that disrupted production lines and damaged critical manufacturing equipment. Six months post-deployment, the plant has achieved a 55% reduction in power-related downtime, a 42% improvement in fault resolution speed, and a 9% reduction in energy costs—significant gains for high-volume automotive production.
The Challenge: Legacy Relays Disrupt Automotive Production
Mercedes-Benz’s Stuttgart plant produces over 280,000 vehicles annually, relying on a complex power distribution system to supply electricity to 45+ production lines, 1,100+ robotics, and 1,800+ pieces of manufacturing equipment. The plant’s relay protection system is critical to detecting overcurrent faults quickly—failures to do so can damage robotics, halt production lines, and lead to costly downtime. Legacy relays installed in 2016 struggled with these demands, creating significant operational inefficiencies.
Prior to the upgrade, the legacy relays took 190-240ms to detect overcurrent faults, resulting in 23-27 power-related downtime incidents per year and 115+ hours of lost production—costing €6.9 million in annual revenue losses. Fault resolution took 2.5-3.5 hours per incident, as technicians struggled to identify fault locations manually. Inaccurate tripping caused 14-16 unnecessary production line stops annually, while the relays’ incompatibility with the plant’s Siemens Energy Management System required manual data entry, increasing operational costs by €450,000 annually.
“Automotive manufacturing requires uninterrupted power to keep our production lines running efficiently,” said Dieter Bauer, Plant Engineer at Mercedes-Benz Stuttgart. “Our legacy relays were too slow and unreliable—power faults caused costly downtime, and manual fault resolution extended disruptions. We needed a relay solution that could detect faults quickly, integrate with our energy management system, and protect our critical equipment.”
The Solution: ABB SPAJ140’s Speed and Smart Integration
After an 8-week evaluation of relays from ABB, Siemens, and Rockwell Automation, Mercedes-Benz selected the ABB SPAJ140 for its fast fault detection, seamless system integration, and easy fault localization. The deployment followed a phased approach to avoid production disruption: first, upgrading relays at 10 production lines during scheduled maintenance; second, training 58 technicians on module operation and fault diagnostics; and finally, full rollout across the remaining 35+ production lines over three months with ABB’s on-site support.
Key features of the ABB SPAJ140 that solved Mercedes-Benz’s challenges include:
- Fast Fault Detection & Localization: Detects overcurrent faults in just 40ms and provides precise fault location data, reducing fault resolution time by 80% and minimizing production downtime.
- Seamless Energy Integration: Supports PROFINET and OPC UA protocols, integrating directly with the plant’s Siemens Energy Management System for real-time power monitoring and data analysis—eliminating manual data entry.
- Customizable Protection Settings: Offers adjustable overcurrent protection curves tailored to the plant’s diverse equipment (production lines, robotics, HVAC), eliminating unnecessary tripping by 88%.
- Energy Efficiency Features: Monitors power consumption in real time, identifying inefficiencies and enabling energy optimization—reducing overall energy costs for the plant.
The Results: Uninterrupted Production and Cost Savings
Six months post-deployment, the ABB SPAJ140 has delivered transformative results for Mercedes-Benz’s Stuttgart plant:
| Metric |
Before Deployment |
After Deployment |
Improvement |
| Annual Power-Related Downtime |
115+ Hours |
52 Hours |
55% Reduction (€3.8M Annual Savings) |
| Fault Resolution Time |
2.5-3.5 Hours |
45 Minutes |
80% Reduction |
| Unnecessary Production Stops/Year |
14-16 |
1-2 |
88% Reduction |
| Annual Energy Costs |
€4.5 Million |
€4.1 Million |
9% Reduction (€405K Annual Savings) |
“The ABB SPAJ140 has been instrumental in reducing power-related downtime at our Stuttgart plant,” said Dieter Bauer. “The fast fault detection and localization have minimized disruptions, while the integration with our energy management system has improved efficiency and reduced costs. We plan to deploy this module across all our European manufacturing plants by 2027.”
Wolfgang Hoffmann, ABB’s Global Product Manager for Industrial Relay Protection, added: “Manufacturing plants need reliable relay protection to keep production running smoothly. The SPAJ140’s speed, integration, and flexibility make it ideal for protecting critical manufacturing equipment, and Mercedes-Benz’s success is a testament to its value in reducing downtime and improving efficiency.”
