When more than two nonmetallic sheathed cables pass through wood framing members, what adjustment must be made?

In situations where more than two nonmetallic sheathed cables pass through wood framing members, ampacity must be adjusted to account for the potential for increased heat generation from the cables bundled together. When cables are grouped, they can create a condition where the heat dissipation is reduced, leading to potential overheating.

The National Electrical Code (NEC) specifies that when multiple conductors are installed together, their allowable ampacity must be derated. This means that the maximum current-carrying capacity of each conductor is decreased based on the number of conductors bundled together.

Adjusting the ampacity ensures that the conductors can operate safely without exceeding their temperature ratings, therefore minimizing the risk of insulation breakdown or fire hazards. This adjustment is crucial for maintaining safety and compliance with electrical codes. Understanding this concept helps reinforce proper installation practices and emphasizes the importance of following regulations related to cable management and ampacity calculations.