Another consideration is the relationship. between insulation class, temperature rise, and ambient temperature. The insulation. class rating designates the maximum. operating temperature for a winding. The. temperature rise is the difference between the.
China claims it has discovered the world's largest hole, and it's in one of the most dangerous places on the planet. 1  Jul.  Good news: China claims it has discovered the world's largest hole. On Wednesday, state broadcaster CCTV announced that the newly found dragon's hole, a 984-foot (300-meter) cavern in the disputed waters of the South China Sea, is now the world's largest hole.
Drone Captures Jaw-Dropping Footage Inside Hang Son Doong, The World's Largest Cave. Hang Son Doong in Vietnam is the largest cave in the world. It's more than 5.5 miles long, comes complete with its own jungle and river and is so gargantuan that it could apparently hold an entire block of 40-story skyscrapers within its walls.