A shore inlet must match the RV's supply arrangement and connect through correctly designed protection and transfer equipment; installation and testing require appropriate competence.
Adding shore power to a van gives you mains-speed battery charging whenever you're at a campground, friend's house, or any 120V outlet. Here's how the wiring flows.
For context on the converter/charger that connects to the inlet: RV converter/charger explained and best RV converter/charger.
120V AC is licensed-electrician territory in most states
The shore power inlet and AC wiring carries line voltage — the same as household wiring. In most US states, this work requires a licensed electrician or must be inspected by one. The 12V DC output from the converter/charger is standard low-voltage work that most van builders handle themselves. Don't skip the 120V portion — a wiring fault here can cause shock or fire.
What you need
- NEMA TT-30 shore power inlet (weatherproof, with cover)
- 10 AWG 3-conductor wire (hot, neutral, ground) from inlet to breaker
- 30A single-pole AC breaker
- Small AC breaker panel or inline breaker holder
- Converter/charger (Victron Blue Smart IP22, PowerMax, etc.)
- 10 AWG wire from converter/charger DC output to house battery
- ANL or inline fuse on DC output side
The wiring flow
Shore power path:
- NEMA TT-30 inlet (exterior mount) → 10 AWG 3-conductor cable
- → 30A breaker (protects the inlet cable and converter/charger)
- → Converter/charger AC input (120V to the charger)
- → Converter/charger DC output → house battery (via 10 AWG cable, fused within 12 inches of battery)
Step 1: Choose and mount the inlet
Mount the NEMA TT-30 inlet on the exterior — driver's side or passenger's side wall, typically 12–18 inches from the floor for easy access. Drill a hole sized for the inlet's barrel, fit from outside, secure with the backing plate inside. Use marine sealant around the edges to waterproof.
Inlet options: Standard RV inlets are fine. For a cleaner look, Marinco or Blue Sea outlets have better weatherproofing and a more finished appearance.
Step 2: Run the AC cable
Run 10 AWG 3-conductor wire (often sold as 10/3 SJOOW or 10/3 THHN) from the inlet to your converter/charger location inside the van. Protect it with conduit or split loom where it passes through walls or near sharp edges. The three conductors are:
- Black (hot): carries current from the outlet
- White (neutral): return path
- Green or bare (ground): safety ground
Step 3: Install the breaker
A 30A single-pole breaker protects the AC circuit between the inlet and converter/charger. This can be:
- A small AC breaker panel (Siemens, Square D — a 2-space or 4-space mini panel)
- An inline 30A breaker in a weatherproof box
- Part of an inverter/charger's built-in circuit protection
Wire hot (black) through the breaker. Neutral (white) connects to the neutral bar. Ground connects to the ground bar.
Step 4: Connect the converter/charger
The AC input of the converter/charger connects to the output of the 30A breaker. Hot to hot, neutral to neutral, ground to ground. Consult the converter/charger manual — most have clear terminal labels.
US equipment options
Decide whether charging alone is enough
If the design also needs an inverter and transfer function, compare an exact US inverter/charger. Keep the inlet, panel, wiring and protection requirements in the installation plan.
120V inverter/charger
Victron MultiPlus-II 12/3000/120-50 120V (UL 458) Inverter Charger
One route for a build that needs both an inverter and shore-power battery charging.
Check before choosing: This exact 12V/120V model, continuous watts versus VA, battery-current limits and qualified AC installation.
These links open our US shop. Check the exact configuration, current price and availability there; affiliate products are purchased from the named supplier. We may earn a commission from qualifying purchases.
Step 5: Wire the DC output to the battery
The DC output of the converter/charger runs to your house battery:
- Positive from converter/charger → ANL fuse (within 12 inches of battery positive terminal) → house battery positive
- Negative from converter/charger → main negative bus bar
Cable sizing: 10 AWG for a 30A charger on runs under 10 feet.
Step 6: Test
Before connecting shore power:
- Confirm all connections are tight
- Confirm the breaker is off
- Connect a shore power cord to the inlet (without plugging into power)
- Plug into a 120V outlet or shore power pedestal
- Turn the breaker on
- The converter/charger should illuminate and begin charging — verify with the VictronConnect app (if using Blue Smart) or the display on your charger
Worked planning check
A 1,500W load at nominal 120V draws 12.5A. Add a 600W charger and the arithmetic becomes 17.5A, beyond a 15A supply's nameplate rating. An adapter changes the connection, not the available circuit capacity; follow the applicable continuous-load requirements too.
The figures or dimensions in this example are explicit planning assumptions, not a product test or an installation specification. Replace them with your equipment data and actual measurements.
Planning questions
Can I choose a fuse just from the appliance current?
No. Check cable ampacity under the installed conditions, equipment instructions, terminal limits, DC voltage and interrupt capacity. Protection must coordinate with the complete circuit.
Does a wiring diagram prove the installation is safe?
No. It is a planning record. Actual routing, termination, protection and commissioning results must agree with the design and applicable requirements.
When should I involve an electrician?
Before work that exceeds your competence, particularly mains design, source transfer, bonding, high-current faults and final inspection or testing. Agree the scope and evidence of verification in advance.
Related
Use the free electrical planner to organise your daily loads and charging assumptions.
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Jack Kennedy is a self-builder who has built two vans. He created Roam Wired to simplify conversion planning and share free tools, supported by affiliate links.
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