4. Mechanical strength of busbars

4.1 Resistance to expansion

Due to load variations, bars are subject to periodic heating and cooling, resulting in changes in length. For a normal temperature rise of 40 to 50 ×C, the order of magnitude of expansion for both copper and aluminum is one millimeter per linear meter.

This may seem low, or even negligible, but it should be noted that the forces developed in the event of effective blocking are significant (of the order of 1,000 kg/cm ² for the above variations).

This would lead to unnecessary reinforcement of certain components (insulators, bolts, etc.).

Fortunately, busbars are never perfectly rigid, and insulators can be flexible enough to allow conductors...