Ampacity

Ampacity is a conductor's current-carrying capacity: the current it can carry continuously under its conditions of use. The ampacity a conductor needs depends on the maximum circuit current, the size of the overcurrent device, the ambient temperature, the conductor and insulation type, conduit fill, and any limits set by the terminals. Ampacity also changes with conductor material and size. For example, one design table lists aluminum conductors at 75 °C, with size 4 rated at 65 A and size 4/0 at 180 A. Wire sizing in PV systems is among the most complex because many factors must be considered, and rated module short-circuit current is used to size PV circuit conductors. Ampacity calculations should be checked against the NEC articles on overcurrent protection, conductors and PV systems.

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• sentence 1: support check: partial - Passages call ampacities 'current-carrying capacities' but do not state the 'carry continuously under conditions of use' definition.
• sentence 5: support check: partial - u9 cites NEC Articles 240, 310, and 690 for confirming conductor ampacity calculations, but the article topics (overcurrent, conductors, PV) are not stated and the u2 passage cites Article 480.
• sentence 1: review: partial - Passage equates ampacity with current-carrying capacity, but the 'carry continuously under its conditions of use' definition is not stated. -->