For non-professional manufacturers, no matter what type of busway, if they calculate the conductor specifications in accordance with the "Electrical Manual" or "Electrical Design Manual" and infer the service life of the busway based on the current carrying capacity per mm2, this is an error. Methods.

Whether the busbar conductor is copper or aluminum alloy, the service life of the busbar depends on the operating temperature rise; the higher the operating temperature rise, the faster the aging speed (including copper, aluminum bars and insulating materials. Copper and aluminum alloys for conductors, Its creep strength, oxidation rate and tensile strength are closely related to temperature rise). Due to the different design, structure and heat dissipation of the bus duct, the internal temperature rise is also different. 

According to the ambient temperature of 35℃ in the design manual, the dense bus duct with better heat dissipation will reduce the current-carrying capacity by 5%-15% to meet the temperature rise value of ≤70K, and the dense bus with poor heat dissipation should be reduced by about 20%. , The current-carrying capacity of the air-type bus will drop even more.

To sum up, it is wrong to select the conductor specification only according to the conductor cross-sectional area and the current-carrying capacity per square millimeter, without considering the product structure and skin effect.