seen to protect electrical underjordsutrustning and device herfor

摘要

Underground electrical equipment such as a transformer or cable is prevented from thermal runaway by back-filling the trench in which it is laid with a soil which includes water entrapped in highly water-absorbent hydrophilic polymeric gel particles soaked with water. The water-soaked particles preferably are coated with a water-impermeable film. The water may also be entrapped in liquid form in small balloon-like containers. Also, a water impermeable sheath may be formed around the back-fill soil to minimize evaporation from the particles.