1. Power supply for important loads such as modern transportation subways, light rails, marinas, and airports.

2. Important power supply equipment such as large hotels, shopping centers, hospitals, parking lots, and high-rise civil buildings.

3. Petroleum, chemical industry, nuclear power, national defense engineering, aerospace, satellite launch, central control center and other important places.

4. Fire-fighting equipment and important supply equipment in steel plants, glass plants, and refineries with high temperature environments.