30 Amp vs 50 Amp Shore Power for an RV or Van: What's the Difference?
Shore power at a campground or RV park comes in two standards: 30 amp (NEMA TT-30) and 50 amp (NEMA 14-50). Understanding the difference matters when choosing an inlet for your van build and buying adapters for the road.
For the full shore power setup, see the RV shore power setup guide and charging systems guide.
The key numbers
| 30 Amp (NEMA TT-30) | 50 Amp (NEMA 14-50) | |
|---|---|---|
| Voltage | 120V single leg | 120V/240V two legs |
| Max current | 30A | 50A per leg |
| Max power | 3,600W | 12,000W |
| Plug shape | 3-prong (T-slot, L-slot, round) | 4-prong (two L-slots, one T-slot, round) |
| Common for | Vans, Class B, travel trailers | Class A motorhomes, 5th wheels |
| Campground availability | Universal | Most full-hookup sites |
Why 30 amp is right for almost all van builds
A 30 amp shore power service delivers 3,600W — more than enough for:
- A converter/charger running at 1,500–2,000W to charge your house battery
- A small AC unit (if mounted — unusual in a van)
- Running the inverter for appliances while simultaneously charging the battery
The only scenario where a van builder genuinely needs 50 amp is if they're running dual rooftop AC units simultaneously. Almost no van conversion does this. If you're converting a van and planning shore power, install a 30 amp inlet.
What the plugs look like
NEMA TT-30 (30 amp): The classic RV plug — three prongs in an unusual shape (one T-shaped hot, one L-shaped neutral, one round ground). The outlet at a campground pedestal that accepts this plug is what most travel trailers, Class B RVs, and van builds use.
NEMA 14-50 (50 amp): Four prongs — two hot (L-shaped), one neutral (T-shaped), one ground (round). You've seen this on EV charger outlets and in RV parks. A 50 amp RV shore inlet uses this plug. Running a van build on 50 amp service requires an adapter.
Adapters: mixing 30 and 50 amp
30-to-50 amp (dogbone): Lets your 30 amp van connect to a 50 amp campground outlet. You're still limited to 30A/3,600W — the adapter doesn't give you more power, just physical compatibility. Cost: ~$20–$30.
50-to-30 amp: Lets a 50 amp RV connect to a 30 amp outlet. The RV is now limited to 30A total — with a large motorhome, this means you can't run both ACs or multiple high-draw appliances simultaneously. Cost: ~$20–$30.
Regular household outlet (NEMA 5-15/5-20): A 15A or 20A standard outlet can also charge your van's house battery via a 15-to-30 amp or 20-to-30 amp adapter, or through a dedicated L5-30 extension cord. Charging is slower (15–20A max) but useful at a friend's house or a regular campsite without RV hookups.
Carry a 30-to-50 dogbone
A 30-to-50 amp adapter costs $25 and weighs almost nothing. Pack one — many RV parks only have 50 amp pedestals left at the spots they assign you, and the adapter means you can always plug in.
Surge protectors
Whether you're on 30 or 50 amp service, a shore power surge protector is worth carrying. Campground pedestals can have wiring issues — reversed polarity, miswired grounds, voltage spikes — that can damage your converter/charger or other electronics. A Progressive Industries or Hughes Autoformers unit costs $100–$200 and is cheap insurance.
See the RV surge protector guide.
What you need for a van shore power setup
For a typical van conversion:
- NEMA TT-30 inlet — mounted on the exterior (Blue Sea, Marinco, or standard RV inlet, ~$30–$60)
- 30 amp shore power cord — 25 or 50 feet, rated for 30A, with TT-30 plug ($40–$80)
- Converter/charger — converts 120V AC shore power to 12V DC to charge the house battery (Victron Blue Smart IP22, PowerMax, or similar)
- 120V circuit protection — at minimum a 30A breaker on the shore power inlet
For the full wiring walkthrough: how to wire a shore power inlet and RV shore power setup.