When comparing wire sizes, what is meant by "one trade size larger" for aluminum wire?

When referring to "one trade size larger" for aluminum wire, it indicates their carrying capacity. This concept is essential in electrical applications because aluminum wire has different electrical and thermal properties compared to copper wire. To safely and effectively conduct electricity, aluminum wire needs to have a larger diameter than copper wire for the same amperage capacity.

The term "trade size" pertained to aluminum wire signifies that the wire's diameter is not just about its physical size, but relates to its ability to handle current without heating up excessively. As such, when a specification states that aluminum wire should be "one trade size larger," it is essentially ensuring that the wire can carry the same amount of electrical current as a standard-sized copper wire, thus maintaining safety and efficiency under load.

In practice, this means if a copper wire is rated for a specific amperage or load, an aluminum wire would need to be one size larger to carry the same load effectively. This understanding is crucial for proper electrical installations and for meeting safety standards.