Why the numbers mislead
Written down, 30 and 50 look like neighbours. In practice they are not even the same shape of supply.
A 30-amp RV connection is a three-prong plug (hot, neutral, ground) carrying one 120-volt leg at up to 30 amps. Multiply volts by amps and you get 3,600 watts. A 50-amp RV connection is a four-prong plug (two hots, a neutral and a ground) carrying two separate 120-volt legs at up to 50 amps each. That is 6,000 watts per leg and 12,000 watts in total.
People sometimes assume 50-amp means 240 volts in the rig. It does not, in any way you experience. The appliances still run on 120 volts; the rig’s distribution panel simply splits the load across two legs, which is why you can run things on one side of the panel without affecting the other.
What 30 amp and 50 amp actually run
The things that matter are the big three: air conditioning, the water heater on electric, and the microwave. A roof air unit is somewhere around 1,500 to 2,000 running watts, with a much larger surge at start-up. An electric water heater element is around 1,400. A microwave is 1,000 to 1,500.
On 30 amps you can have one air conditioner and one of the other two, with care. Add a hair dryer and you are at the edge. On 50 amps you can run two air conditioners, the water heater, the microwave and a coffee machine and still have room, because the load is spread over two legs of 6,000 watts each.
This is not an abstract argument in coastal Carolina. In July and August the dew point sits where it sits and the air conditioning does not get a rest.
Adapters, and what they cannot do
A “dogbone” adapter lets you plug a 30-amp rig into a 50-amp pedestal, and that direction is entirely safe. Your rig draws what it draws; the extra capacity in the pedestal simply goes unused. Nothing is forced on you.
The other direction is where people get into trouble. A 50-amp rig on a 30-amp pedestal, through a reducing adapter, is a 30-amp rig for the duration, 3,600 watts, across what the panel thinks are two legs. The adapter is not doing anything clever and it cannot create power. It will run one air conditioner and not much else, and the breaker at the pedestal will be the thing that tells you when you have asked for more.
Buy the adapters with a decent moulded body and a loop to hang them by. The cheap ones heat up at the joint, and a hot plug is a plug on its way to failing.
Why the breaker trips, and what to do about it
Almost always it is start-up surge. A compressor pulling its locked-rotor current for a fraction of a second asks for far more than its running figure, and if the water heater and the microwave happen to be awake at that moment, the total crosses the limit.
The fix is sequencing rather than equipment. Switch the water heater to gas when you know the air conditioning will be working hard. Do not microwave while the compressor is starting. If you have two air conditioners on 30 amps through an adapter, run one. A soft-start module on the compressor is the proper engineering answer and is worth the money if you spend a lot of summer on 30 amps.
Protect the rig from the pedestal
This matters more than the amperage argument. Campground pedestals are outdoors, they are old in some places, and they can be miswired, low on voltage, or carrying an open ground. An electrical management system reads the pedestal before it passes power through and refuses if something is wrong; a basic surge protector only catches a spike.
Low voltage is the quiet killer. A long run of undersized cable on a hot afternoon with every rig in the park running air conditioning can sag the supply, and a compressor trying to start on low voltage draws more current, gets hotter, and eventually stops being a compressor. The device that cuts the supply before that happens costs a fraction of the thing it protects.
What we have here
Every RV site here is 50 amp and full hookup (water, sewer and power at the pad), on gravel or concrete pads, with a picnic table, a fire pit and two parking spots. If your rig is 30 amp, that is not a problem: we lend you an adapter free of charge. The park was built new and wired recently, which is worth asking about wherever you book.
If you are not sure what your rig needs, look at the plug. Three prongs, 30 amp. Four prongs, 50. That is the whole test.
Fifty amps at every pad
Full-hookup RV sites, built new, with water and sewer at the pad and room beside the rig for a tent and two cars.