Before connecting your RV to shore power, take a moment to verify the pedestal with a multimeter. A quick check can reveal potentially unsafe wiring before it reaches your RV's electrical system.
Know hot, neutral, and ground
On a standard 20-amp receptacle, the smaller slot is hot, the larger slot is neutral, and the round opening is ground. RV outlets are often installed with ground at the top.
On a 30-amp RV receptacle with ground at the top, the left opening is hot and the right is neutral. You should measure approximately 120 volts from hot to neutral and from hot to ground. You should not measure meaningful voltage from neutral to ground.
Testing a 50-amp RV pedestal
With ground at the top, a 50-amp RV receptacle has two hot legs on the left and right, with neutral at the bottom. Each hot leg should measure approximately 120 volts to neutral. Across the two hot legs, the reading may be approximately 240 volts or 208 volts depending on the park's electrical distribution.
The critical safety check
Check neutral to ground on 20-, 30-, and 50-amp service. Significant voltage between neutral and ground is a red flag. Do not connect the RV; report the pedestal to the campground or a qualified electrician.
Electrical testing carries shock and arc hazards. Use an appropriately rated meter and leads, keep fingers behind the probe guards, and have a qualified professional perform the test if you are not comfortable working around energized equipment.
Need help planning your RV power system? Complete our System Design Form, and the Big Beard Battery team will help you determine the right batteries, inverter, solar, and supporting components for the way you travel.