Ecmweb 1950 205ecwbcqfig1
Ecmweb 1950 205ecwbcqfig1
Ecmweb 1950 205ecwbcqfig1
Ecmweb 1950 205ecwbcqfig1
Ecmweb 1950 205ecwbcqfig1

Code Q&A

April 1, 2002
Knowing how important NEC issues are to our readers, we're introducing a new online Code Q&A column. Updated weekly, visit this link for answers to your latest Code questions and concerns. Q. Let’s say a 5kW generator supplies only equipment mounted on the generator, cord-and-plug-connected equipment through receptacles mounted on the generator, or both. Should the generator have a ground rod connection?

Knowing how important NEC issues are to our readers, we're introducing a new online Code Q&A column. Updated weekly, visit this link for answers to your latest Code questions and concerns.

Q. Let’s say a 5kW generator supplies only equipment mounted on the generator, cord-and-plug-connected equipment through receptacles mounted on the generator, or both. Should the generator have a ground rod connection? A point on the frame of the generator marked "ground" makes me think so.

A. No, a ground rod is not needed, not required, and would serve no purpose [250.34(A)]. This manufacturer provided a ground lug on the generator because it doesn’t know any better.

CAUTION: Creating a bonding jumper connection at both the source and the first disconnecting means will create a parallel path, allowing dangerous neutral current to flow over the grounding conductors or grounding paths, which is a violation of 250.6.


Q. Some of the journeyman electricians on my latest project believe the neutral and grounds should be connected together in a panel fed by a 480V to 120/208V transformer. I’ve always made this neutral-to-ground connection at the transformer, and kept the grounds and neutrals separated. Which method is correct?

A. You must make a neutral-to-case connection on the secondary of the transformer at any point from the source to the first system disconnecting means or overcurrent device [250.30(A)(1)]. It’s important to point out that this connection must be made at the same location as the grounding electrode connection to the grounded (neutral) conductor [250.30(A)(2)].


About the Author

Mike Holt

Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.

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...

Don't Let Burn-Through Threaten Another Data Center or Utility Project

Get the No Burn-Through Elbow eGuide to learn many reasons why Champion Fiberglass elbows will enhance your data center and utility projects today.

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.