Safegrid’s Solution Enables a Proactive Inspection
For distribution system operators, many developing faults remain invisible to conventional protection systems until the condition has deteriorated significantly. Early-stage insulation degradation, leakage currents, and partial discharge activity can develop over long periods without triggering alarms in relays or causing service interruptions.
This was the case for Norwegian utility Griug AS, where Safegrid’s Intelligent Grid System® identified abnormal activity at a secondary substation and enabled a targeted field inspection.
Early Warnings from the Grid
Safegrid’s solution first detected an Earth Fault (EF) warning at 06:25. A second warning was registered at 08:47. The repeated warnings clearly indicated abnormal electrical activity developing within the monitored section of the network. No alarms or indications were registered by the utility’s protection relays.
The inspection was initiated based on Safegrid’s warnings, demonstrating the value of continuous grid monitoring in identifying developing issues that would otherwise remain unnoticed.
Field Investigation Reveals Multiple Issues
Following Safegrid’s alerts, Griug AS conducted an inspection of the indicated location and discovered several contributing factors. The investigation identified a heat-shrink cable termination exhibiting signs of degradation. The installed termination was not touch-safe, allowing leakage currents to develop over time. The lower part of a switch had sustained visible damage and was identified as a significant source of electrical noise. The utility subsequently replaced the damaged switch component.
The inspection also revealed environmental conditions contributing to the deterioration. Soil had been backfilled up to the substation structure, allowing vegetation growth inside the switchgear compartment.
“Without Safegrid, this issue would likely have remained undetected until it developed further”, says Espen Sørlie, Operations Manager at Griug AS.
Preventive Action Before Failure
By detecting the issue at an early stage, Safegrid enabled the utility to investigate and plan maintenance proactively rather than responding to an unplanned outage or equipment failure.
Strengthening the Value of EF Warnings
This case highlights the growing operational value of Safegrid’s Earth Fault Warning functionality.
The developing fault was not visible in protection relays and had not yet escalated into a service-affecting event. Nevertheless, Safegrid’s monitoring solution identified the abnormal behavior and directed the utility to the affected area, ultimately revealing multiple underlying issues that warranted corrective action.
For Griug AS, the case demonstrates how continuous monitoring provides actionable early warnings, and helps utilities address emerging faults before they impact customers.