Grounding Monitor Interrupters on RVs Coming in 2026 – RVBusiness – Breaking RV Industry News
EDITOR’S NOTE: This release from the RV Industry Association (RVIA) serves as clarification of previous information.
When the 2026 Edition of the National Electric Code (NEC) is published later this year, it will finalize the requirement and electrical evolution of protecting RV owners and users from the occurrences known as “hot skin.” All RVs with 30A or 50A electrical service will be required to install a grounding monitor interrupter (GMI), which is a loss-of-ground device. Before electrical current can pass into the RV, a GMI will check the receptacle for a proper ground connection. During use, the GMI will also monitor the ground connection to the RV and, if lost, will disconnect the power to the RV.
Background on the NEC, RVs, RV Parks, and GMIs
The NEC governs electrical installations in the United States. It is updated and published by the National Fire Protection Association (NFPA) every three years. Article 551 of the NEC contains the electrical requirements for both RVs and RV Parks. These requirements work hand in hand to ensure safety for the users of both.
During the last 6 years, there have been several public inputs to Article 551 addressing “hot skin” conditions.
On the RV Park side, it was suggested that Ground Fault Circuit Interrupter (GFCI) receptacles for the 30A and 50A services be installed on the RV pedestal. That suggestion was not adopted because electrical leakage current from the various electrical devices in an RV would cause a nuisance trip of the GFCI. Another suggested remedy was to install a reverse polarity device on the RV. While improving safety, a reverse polarity device failed to protect against a “hot skin” condition. In the 2023 edition of the NEC, the requirement for the reverse polarity device was removed and replaced with a requirement for a loss of ground device. However, because no loss ground device existed in 2023, the requirement was delayed to January 1, 2026.
The loss of ground device requirement was further defined as a GMI resulting in what will be published in the 2026 Edition of the NEC as outlined above.
What is a “hot skin” condition?
“Hot skin” is a term used to describe when an RV’s metal exterior, metal frame, or other metal items become electrified. It is a serious electrical safety hazard caused by improper grounding or electrical faults.
What is a Grounding Monitor Interrupter?
A GMI tests the receptacle it is plugged into to ensure it is wired correctly and has a proper ground connection. If incorrect wiring or a loss of ground connection is detected, the GMI will not allow electricity to pass through or will disconnect power if the loss of ground occurs during operation.
Is a GMI similar to a GFCI receptacle?
No. A GFCI receptacle monitors electrical current flowing through it. If electrical current is out of balance, it trips and disconnects electrical power. A GMI ensures that a proper ground exists.
What things will a GMI address?
On the RV, the GMI will address damage to a power cord, which the NEC refers to as a feeder assembly. Damage to a power cord and the use of dog-bone adapters causing compromised electrical supply are the most common reasons for requesting this update to the NEC.
On the RV Park side, the GMI will address a loss of ground at the RV pedestal or the presence of electrical current on the grounding conductor (wire). Under certain conditions, either of these two items can result in “hot skin.”
When will this new requirement take effect?
The 2026 Edition of the NEC will be adopted and published late in 2025. The RV Industry Association plans to adopt the 2026 edition in May of 2026 and enforcement will start in September of 2026.
What can RV Parks do to get ready for this new requirement?
RV Parks should test their electrical systems to ensure good ground continuity from the RV site pedestals back to the electrical service panels. This should be part of a park’s annual preventative maintenance.
Additionally, several manufacturers are expected to produce portable test devices that an RV Park can use, replicating the testing that the RV GMIs will perform when installed.
What is the RV Industry Association doing to notify the industry and future owners of this new GMI requirement?
The GMI requirement is not new to the RV Industry Association and its technical subcommittees. In the near future the GMI requirement will be discussed which will include a communications plan for manufacturers and all parties involved.
