Even though a busbar looks like just a flat copper or aluminum strip, its size determines how much electrical load it can handle. If the size is too small, it can overheat, cause voltage drop, or even become a fire hazard. If it is oversized, it increases cost and space requirements unnecessarily. Practical check: A busbar that looks large enough for normal load may still fail if the joints, supports, clearances, or short-circuit withstand are not adequate. However, they are also sophisticated structures that require an understanding of voltage drop due to conductor resistance, materials science, thermal issues. Undersized busbars are one of the leading causes of switchgear failures: they overheat, degrade insulation, and can trigger cascading short circuits.
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