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.
Here is a list of 10 incredible such open-pit mines. 1. Mirny Mine, Russia â Mirny Mine is an inactive diamond mine in Mirny, Eastern Siberia. It is the largest open diamond mine in the world and the second largest excavated hole in the world. It is 525 meters (1,722 ft) deep and has a diameter of 1,200 m (3,900 ft).