Distribution Systems for Recreational Vehicle Parks

An RV park distribution system must have an ampacity of at least 30A.

Sept. 18, 2018

Before installing the distribution system, calculate the loads per Sec. 551.73 of the National Electrical Code (NEC). The distribution system must be capable of supporting the recreational vehicle (RV) receptacles and site supply equipment per those calculations [Sec. 551.72(A)].

An RV park distribution system must have an ampacity of at least 30A. Permitted systems include:

A single-phase system that’s 120V, 120/240V, or 120/208V [Sec. 551.72(A)].
A three-phase system that’s 208Y/120V [Sec. 551.72(B)].

If the latter, the feeders must include one grounded conductor and one equipment grounding (bonding) conductor; the feeders are permitted to also have two ungrounded conductors. Distribute the loads as equally as practicable [Sec. 551.72(B)].

Receptacles rated at 50A must be supplied from a branch circuit that has the same voltage class and rating as the receptacle [Sec. 551.72(C)].

You can reduce the size of neutral conductors below the minimum required size of the ungrounded conductors, but only for 240V, line-to-line permanently connected loads [Sec. 551.72(D)]. However, the small cost-savings is probably not worth the performance hit.

RV parks typically have long circuit lengths, so upsizing the conductors to reduce voltage drop is strongly advised [Informational Notes following Sec. 551.72].

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.