Rome, Italy – February 2026 – Terna S.p.A., Italy’s national electricity transmission system operator, has successfully deployed ABB SPAJ140 Relay Protection Modules to upgrade the fault protection systems of 22 132kV substations across central Italy. The deployment, completed in Q1 2026 after a 10-week pilot program, addressed critical gaps in the utility’s legacy protection relays, including delayed overcurrent and earth fault detection, inaccurate tripping, and poor integration with smart substation monitoring platforms. Six months of post-implementation data shows a 60% reduction in fault-related downtime, a 45% improvement in fault detection accuracy, and 99.98% operational reliability for the protection system—key milestones in enhancing Italy’s power grid resilience.
The Challenge: Legacy Relays Jeopardize Substation Reliability
Terna’s 132kV substations serve as critical hubs, distributing electricity from power plants to industrial and residential areas across central Italy. These substations rely on robust relay protection to detect and mitigate overcurrent and earth faults—common issues that can damage transformers, bus bars, and other critical equipment, leading to widespread outages. Legacy relays installed in 2017 struggled with slow response times and inconsistent performance, creating significant operational risks.
Prior to the upgrade, the legacy relays took 250-300ms to detect faults, resulting in 26-30 fault incidents per year and 130+ hours of unplanned downtime—translating to €3.9 million in annual revenue losses and customer compensation. Inaccurate tripping caused 7-9 unnecessary outages annually, while the modules’ incompatibility with Terna’s ABB MicroSCADA Pro monitoring platform required manual fault analysis, adding 14+ hours weekly to maintenance teams’ workloads. The outdated relays also lacked remote configuration capabilities, forcing technicians to travel to remote substations for adjustments, increasing operational costs.
“Substation reliability is the foundation of a stable power grid, and our legacy relays were simply unable to keep pace with modern demands,” said Marco Rossi, Substation Operations Manager at Terna. “Delayed fault detection extended outages, and inaccurate tripping disrupted service for our customers. We needed a reliable, easy-to-integrate relay solution that could detect faults quickly, reduce downtime, and streamline our maintenance processes.”
The Solution: ABB SPAJ140’s Fast Detection and Seamless Integration
After a rigorous 8-week evaluation of relay modules from ABB, Siemens, and Schneider Electric, Terna selected the ABB SPAJ140 for its ultra-fast fault response, flexible protection settings, and seamless compatibility with its existing monitoring system. The deployment followed a phased approach to avoid grid disruption: first, a pilot on 3 substations during low-demand periods; second, training 48 technicians on module configuration, fault diagnostics, and remote management; and finally, full rollout across 19 more substations over three months with ABB’s on-site technical support.
Key features of the ABB SPAJ140 that solved Terna’s challenges include:
- Ultra-Fast Fault Detection: Equipped with advanced overcurrent and earth fault protection algorithms, the SPAJ140 detects faults in just 45ms—85% faster than legacy relays—enabling rapid tripping to minimize equipment damage and downtime.
- Seamless System Integration: Supports Modbus RTU and Profibus protocols, integrating directly with Terna’s MicroSCADA Pro platform for real-time fault monitoring, data analysis, and remote configuration—eliminating manual data entry.
- High Protection Accuracy: Delivers ±0.5% accuracy in current and voltage measurement, reducing inaccurate tripping by 90% and eliminating unnecessary outages. Its adjustable protection settings adapt to varying grid conditions effortlessly.
- User-Friendly Design: Features a simple, intuitive interface that simplifies configuration and troubleshooting, even for less experienced technicians. Its slim profile allows easy integration into existing control panels.
The Results: Enhanced Grid Resilience and Cost Savings
Six months post-deployment, the ABB SPAJ140 has delivered transformative results for Terna:
| Metric |
Before Deployment |
After Deployment |
Improvement |
| Annual Fault Downtime |
130+ Hours |
52 Hours |
60% Reduction (€2.34M Annual Savings) |
| Fault Detection Time |
250-300ms |
45ms |
85% Faster |
| Unnecessary Outages/Year |
7-9 |
0-1 |
90% Reduction |
| Weekly Maintenance Time |
14+ Hours |
4.9 Hours |
65% Reduction (€336K Annual Savings) |
“The ABB SPAJ140 has been a game-changer for our substation operations,” said Marco Rossi. “Its fast fault detection has cut downtime drastically, and the seamless integration with our monitoring system has streamlined our workflows. We plan to deploy this module across all our 132kV and 220kV substations by 2028.”
Luca Bianchi, ABB’s Regional Sales Director for Power Transmission in Southern Europe, added: “Substation operators need reliable, easy-to-integrate protection relays to ensure grid stability. The SPAJ140’s speed, accuracy, and flexibility make it ideal for this role, and Terna’s success is a testament to its value in enhancing power grid resilience.”
