30-amp vs 50-amp RV hookups

The numbers that matter

Watts are what you actually use, and watts equal volts times amps. A 30-amp RV outlet is a single 120-volt circuit, so it delivers 120 x 30 = 3,600 watts. A 50-amp RV outlet is not one 50-amp circuit; it is two separate 120-volt legs of 50 amps each, so it delivers 2 x 120 x 50 = 12,000 watts. That is why a 50-amp rig has more than three times the capacity, not just 66 percent more.

What you can run on 30 amps

Approximate draws for common RV loads, in running watts:

• 13,500 BTU roof air conditioner: 1,300 to 1,600 W (starting surge 2,500 W or more)
• 15,000 BTU roof air conditioner: 1,500 to 1,900 W
• Microwave: 1,000 to 1,500 W
• Electric water heater element: 1,200 to 1,400 W
• Converter charging batteries: 300 to 800 W
• Residential refrigerator: 150 to 400 W running, higher on startup
• Hair dryer or coffee maker: 1,000 to 1,500 W
• Space heater on high: 1,500 W

On 30-amp service, one air conditioner plus the converter plus the fridge leaves you roughly 1,000 to 1,500 watts. Add a microwave and you are at the limit; add a hair dryer at the same time and the pedestal breaker trips. Practical 30-amp habits: switch the water heater to propane, run the microwave only while the A/C compressor is cycling off, and never plug in a space heater while the air conditioner is on. An energy monitor on your EMS display tells you how close you are.

On 50-amp service you can run two or three air conditioners, an electric water heater, and the kitchen at once. The catch is that each leg is still limited to 50 amps, and RV manufacturers split the loads between legs when they wire the panel. If your rig puts both A/C units on the same leg (it happens), you can still trip a breaker at 6,000 watts on that side while the other leg idles.

Dogbone adapters: what works and what does not

Adapters let you plug into whichever outlet the pedestal has. RVers call the short, thick versions dogbones. Two rules govern them:

• 50-amp RV on a 30-amp pedestal (50-to-30 adapter, female 14-50 to male TT-30). This works and is very common at older parks and state park campgrounds. The adapter bridges the single 30-amp leg to both sides of your panel, so your whole rig now shares 3,600 watts. Run one air conditioner, not two, and watch the microwave.
• 30-amp RV on a 50-amp pedestal(30-to-50 adapter, female TT-30 to male 14-50). Also fine. Your RV still has its own 30-amp main breaker, so you cannot draw more than it allows. The only downside is that the pedestal's 50-amp breaker will not protect your 30-amp cord if a fault occurs before your main breaker; a quality cord and an EMS cover that risk.
• Any RV on a 15- or 20-amp household outlet(30-to-15 or 50-to-15 adapter). Works for battery charging, lights, and the fridge. It will not run an air conditioner for long without tripping the outlet's breaker or overheating the cord.

Buy adapters with a molded handle and a locking ring (Camco PowerGrip, Progressive Industries, or the Southwire versions), not the cheapest plug-in block. A loose or corroded adapter is the number one cause of melted plugs at the pedestal.

Why 50 to 30 matters when booking

Campgrounds list electric service per site, and older parks often have only 30-amp on many loops. If you have a 50-amp rig and it is 100 degrees in Texas or Arizona, a 30-amp site means one air conditioner and a warm afternoon. Reservation systems like Recreation.gov and ReserveAmerica show the amperage on the site detail page; private parks usually charge $3 to $10 more per night for 50-amp. Big rig loops and RV resorts are almost always 50-amp, and the electric hookup category here lists parks that confirm power at the site.

Test the pedestal before you plug in

1. Open the pedestal cover and look for scorched outlets, loose covers, or a breaker that does not click firmly. Any of these is a reason to ask for another site.
2. Turn the breaker off.
3. Plug in your surge protector or EMS. A portable EMS (Progressive Industries EMS-PT50X, Hughes Power Watchdog 50 with Bluetooth, Southwire Surge Guard) shows voltage on each leg and flags open grounds and reversed polarity.
4. Connect your cord, turn on the breaker, and wait: an EMS delays 2 to 3 minutes before passing power to protect the A/C compressor.
5. Read the voltage. 114 to 126 volts is healthy. Below 108 under load, most EMS units cut the power automatically, and the park should move you.
6. Check again on a hot afternoon when the whole loop is running A/C. Voltage sag at 4 pm is a real problem at older parks.

A $25 plug-in outlet tester is not a substitute: it cannot see low voltage or a marginal neutral. A hardwired EMS behind the shore cord does the same job as a portable unit and cannot be stolen from the pedestal.

Cords, length, and heat

A 30-amp cord is 10-gauge; a 50-amp cord is 6-gauge and weighs about 2 pounds per foot. Twenty-five feet is standard and reaches most pedestals; carry a 25-foot extension for oddly placed pedestals rather than parking crooked. Feel the plug after an hour: warm is normal, too hot to hold means a bad connection. Use dielectric grease on the prongs and never leave a cord coiled tightly under heavy load, since coiled cable holds heat.

When you know which service your rig needs, browse RV parks by state and compare the electric line on each listing. Our full hookups guide covers water and sewer.

Frequently asked questions