The power supply of the third-level biosafety laboratory meets all the power requirements of the laboratory and should have redundancy; a special distribution box should be set up in a safe location; biological safety cabinets, air supply fans, exhaust fans, automatic control systems . The power supply of the third-level biosafety laboratory meets all the power requirements of the laboratory and should have redundancy; a special distribution box should be set up in a safe location; biological safety cabinets, air supply fans, exhaust fans, automatic control systems . That is, a distribution electric box is arranged under the general distribution box, and a switch box is arranged under the switch box, and electrical equipment is arranged under the switch box to form a three-level distribution. "Two-level protection" mainly refers to the use of leakage protection. Generally, first level distribution does not allow direct use of electrical equipment, and second level distribution will be by power equipment because it is three-phase electricity, while third level distribution is mains electricity (220V). It takes the incoming power and safely distributes it to different circuits throughout your building. According to inspection standards, the permissible vertical deviation for boxes with a height less than 50cm is 1. 5mm, and for boxes 50cm or taller, it is 3mm.