HOLT Electricians Practice Exam

How many fixture wires smaller than No. 14 are allowed to be omitted from calculations in equipment grounding?

1. 2

2. 3

3. 4

4. 5

The correct answer is: 4

In the context of equipment grounding as per the National Electrical Code (NEC), the omission of fixture wires smaller than No. 14 needs to be understood in terms of the requirements for grounding conductors. According to NEC guidelines, fixture wires that are smaller than No. 14 may not significantly contribute to the grounding effectiveness of a system due to their limited current-carrying capacity and cross-sectional area. When performing calculations for equipment grounding, it is specifically stated that you can omit a certain number of these smaller wires from your calculations. The rule allows for the omission of up to four fixture wires smaller than No. 14 from the grounding requirements. This is based on the understanding that those particular wires are unlikely to be at risk of carrying fault currents that would necessitate grounding. Therefore, knowing the particulars of grounding calculations is crucial for ensuring safety and compliance with the NEC, and recognizing the specific number of permissible omittances helps electricians efficiently plan their grounding systems without compromising safety standards.