ASA Powerplant Mechanic Practice Test

Sizing a wire is all about how long the current will be drawn. If the load is continuous (running three hours or more), you size the conductor to carry 125% of that continuous current so it won’t overheat. If the load is intermittent, you can use a conductor sized closer to the actual current because it won’t heat the wire as much. That’s why intermittent or continuous load is the factor used to determine wire size. Ground fault conditions describe faults, not normal load duration. Insulation color is unrelated to ampacity, and system voltage affects insulation rating and protection, not the duration-based sizing rule.