Substation operators often believe that closed covers and doors mean safe switchgear operation. But when it comes to older equipment, this assumption may be dangerously incorrect. A recent technical review highlights the importance of recognising the difference between bolted faults and arc faults, and the devastating impact the latter can have on personnel and infrastructure.
While bolted faults result in contained short circuits through solid conductors, arc faults occur through air and can cause explosive blasts, extreme heat, and violent equipment damage. Traditional switchgear is tested for bolted faults, but not all are rated to withstand arc events. The presence of arc-resistant switchgear is still rare, primarily due to higher costs and complex testing requirements.
Infrared thermography remains an essential predictive maintenance tool, allowing early detection of potential fault conditions, without removing covers, which may actually increase the risk of an arc fault. Operators are advised to understand their systems, schedule inspections around operational cycles, and avoid complacency.
Further, several practical checks in electrical rooms can improve safety: unusual smells or sounds, warm panel surfaces, cluttered access, or poor ventilation all warrant immediate attention. Transformer areas should remain clear for cooling, and entry must be restricted to authorised personnel.
As the push for operational safety grows, the message is clear: assuming safety based on appearance can be fatal. Proper inspections, predictive maintenance, and a clear understanding of fault types are essential to prevent injury and protect infrastructure.
Source: EEP
