New RVs with 30-amp or 50-amp electrical service will soon be required to include a grounding monitor interrupter, a safety device designed to stop power from entering the RV if a proper ground connection is not detected.
The RV Industry Association Board of Directors voted unanimously to approve a new timeline for the requirement, setting an effective date of January 1, 2027. Mandatory enforcement will begin at the start of each manufacturer’s 2028 model year production.
The requirement is part of the 2023 and 2026 editions of the National Electrical Code Article 551, according to RVIA.
What the New Device Does
A grounding monitor interrupter, often shortened to GMI, is a loss-of-ground device installed in the RV.
Before electrical current can pass into the RV, the GMI checks whether the receptacle has a proper ground connection. While the RV is plugged in, the device continues to monitor that ground connection.
If the ground connection is lost, the GMI will disconnect power to the RV.
For RV owners, that means a future RV may not accept shore power from a campground pedestal if the device detects a grounding problem.
Why the Requirement Was Delayed
The rule was originally scheduled to take effect January 1, 2026.
RVIA said the requirement was delayed because there were not enough fully developed and listed GMI devices available for RV manufacturing at the time. That made the original compliance date unrealistic.
The Standards Steering Committee has continued to monitor device availability and now expects enough GMIs to be available for manufacturers to meet the new timeline.
Does This Affect Older RVs?
The requirement applies to new RVs with 30-amp or 50-amp electrical service.
At this time, the focus is on new RV production, not older RVs already on the road. There has also been confusion online about where these devices are installed.
Current GMI devices are designed to be installed in the RV, not on the campground pedestal. There also do not appear to be retrofit devices available for older RVs at this time.
What This Means at Campgrounds
Once GMIs become common in new RVs, some campers may run into situations where their RV will not accept power from a pedestal with a grounding problem.
That could lead to more reports of electrical problems at campgrounds, especially at older pedestals or pedestals that have not been tested recently.
RVIA has said that more information, education, and resources will be provided to manufacturers, campground owners, dealers, and consumers as the implementation date approaches.
For campground owners, the change may increase the need to test pedestals and correct wiring problems before guests arrive.
For RV owners, it is another reminder not to assume every power pedestal is safe.
Should RV Owners Still Use an EMS?
Yes.
A grounding monitor interrupter is not the same thing as a full electrical management system.
Many RV owners already use an EMS or surge protector to check for common pedestal problems before plugging in. Those devices can help detect issues such as open ground, reverse polarity, low voltage, high voltage, and other wiring faults, depending on the model.
A GMI adds another built-in layer of protection on future RVs, but it does not replace the habit of checking campground power before using it.
Bottom Line
This new rule does not mean current RV owners need to rush out and modify their rigs.
The requirement is aimed at new RVs with 30-amp or 50-amp electrical service, with enforcement beginning with each manufacturer’s 2028 model year production.
For future RV buyers, it means newer rigs may come with a built-in device that can shut off shore power if a proper ground is not detected.
That may be frustrating if it happens at a campsite, but it could also point to a real electrical problem that needs to be fixed.
Sources
- RV Industry Association: “Board Sets Model Year 2028 Effective Date for GMI Enforcement”
https://www.rvia.org/news-insights/board-sets-model-year-2028-effective-date-gmi-enforcement - RV Industry Association: “Grounding Monitor Interrupters in RVs and Their Impact on RV Parks and Campgrounds”
https://www.rvia.org/news-insights/grounding-monitor-interrupters-rvs-and-their-impact-rv-parks-and-campgrounds - OHI: “Grounding Monitor Interrupters Update”
https://ohi.org/ohi-blog/grounding-monitor-interrupters-update/ - Woodall’s Campground Magazine: “Sokol Sets Record Straight on Grounding Monitor Interrupters”
https://woodallscm.com/sokol-sets-record-straight-on-grounding-monitor-interrupters/
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