2020-1-1 · Ampacities and Mechanical Properties of Rectangular Copper Busbars: Table 1. Ampacities of Copper No. 110. Ampacities of Copper No. 110 Busbars - Ampacities in the table below are for bus bars having an emissivity of 0.4. This was observed on samples exposed for 60 days in an industrial environment, and it is probably identical to that of bus bars in service.