Code Quiz: Sizing the Grounding Conductor for a Single Raceway

Aug. 7, 2014
NEC rules for sizing the grounding conductor for a single raceway

Why is the term “grounded conductor” included in the heading of new Table 250.102(C)(1)?

A. It is an error and will be corrected in newer printings of the 2014 NEC.

B. Because the grounded conductor is used as a bonding jumper.

C. In the case of an installation of a service for a single load installed in a single raceway, such as a 460V, 3-phase motor, which has no calculated neutral load per 220.61, this is a method for calculating the size of the required grounded conductor in accordance with 250.24(C)(1), where supplied by a grounded electric utility system.

D. Because there was no substantiation to include the term in Table 250.66.

Find the Answer

Answer: C

Bonding requirements are outlined in Part V of Art. 250. Section 250.102(C)(1) notes how to size bonding jumpers and conductors for supply conductors in a single raceway or cable. In the case of an installation of a service for a single load installed in a single raceway, such as a 460V, 3-phase motor, which has no calculated neutral load per 220.61, this is an example of how to comply with the requirement of 250.24(C)(1). This is a method for calculating the size of the required grounded conductor where supplied by an electric utility system that is grounded.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at [email protected].

About the Author

Steven Owen

Voice your opinion!

To join the conversation, and become an exclusive member of EC&M, create an account today!

Sponsored Recommendations

Electrical Conduit Comparison Chart

CHAMPION FIBERGLASS electrical conduit is a lightweight, durable option that provides lasting savings when compared to other materials. Compare electrical conduit types including...

Fiberglass Electrical Conduit Chemical Resistance Chart

This information is provided solely as a guide since it is impossible to anticipate all individual site conditions. For specific applications which are not covered in this guide...

Considerations for Direct Burial Conduit

Installation type plays a key role in the type of conduit selected for electrical systems in industrial construction projects. Above ground, below ground, direct buried, encased...

How to Calculate Labor Costs

Most important to accurately estimating labor costs is knowing the approximate hours required for project completion. Learn how to calculate electrical labor cost.