What Is a Campervan Consumer Unit?
A campervan consumer unit is a compact AC distribution assembly, also called a breaker box or distribution board. Here, the term means the 230 V AC distribution and protection assembly for the habitation circuits; the battery DC system remains separate.
It receives power from a documented AC source, provides isolation and fault protection, then supplies circuits such as sockets, a battery charger or a fixed appliance.8
“Consumer unit” is the common UK term. Other markets may use “RV breaker panel” or “AC distribution panel”, but the name does not decide which devices belong inside. The source arrangement, supply voltage and frequency, product documentation and applicable installation rules do. For UK projects within its scope, Section 721 of BS 7671 addresses electrical installations in caravans and motor caravans.10 The edition and amendments in force at the time of design must be checked.1
A moving vehicle also brings constraints that a household enclosure may not face in the same way: limited space, cable routing, access for operation and testing, source changes, heat, vibration and moisture exposure. A DIN-rail device fitting inside a box proves mechanical fit only. It does not prove compatibility within the assembly, vehicle suitability or regulatory compliance.
Is a Campervan Consumer Unit 230 V or 240 V?
In Great Britain, the declared nominal single-phase supply is 230 V, not 240 V. The phrase “240 V campervan consumer unit” remains common because Britain used a 240 V nominal supply before 1 January 1995. A 240 V reading also falls within the present statutory range.1112
Regulation 27 permits a public low-voltage supply at the supply terminals to vary from 6% below to 10% above 230 V, or approximately 216.2 V to 253 V.11 That is why 240 V can be a normal reading, but 240 V is not a separate campervan requirement. The consumer unit does not set the voltage. It isolates the supply and distributes and protects the downstream circuits.
In practice, a shore-power design in Great Britain uses 230 V as its nominal context and checks the stated voltage and frequency ratings of the inlet, protective devices and complete assembly. An inverter or portable power station is assessed against the exact output specification and installation instructions for that model. In neither case does the informal 240 V label establish equipment compatibility or regulatory compliance.
MCB, RCD, RCCB and RCBO Do Different Jobs
Start with the job each device performs. RCD is the umbrella term for residual-current protection, while MCBs, RCCBs and RCBOs cover different protection functions. Calling everything in the consumer unit a “breaker” hides differences that matter to the design.
Swipe across to compare functions →
| Device | Primary job | What it does not establish by itself |
|---|---|---|
|
Disconnects the installation or defined section for operation and maintenance | Automatic overload, short-circuit or residual-current protection |
|
Protects a final-circuit conductor against overload and short circuit | Residual-current protection or suitability for every AC and DC source |
| Detects residual current and disconnects the protected circuit under specified conditions | Overcurrent protection unless coordinated with a separate protective device | |
| Combines residual-current and overcurrent functions in one device | Correct RCD type, rating, pole arrangement or system compatibility without design checks |
BS EN 60898-1 covers circuit-breakers for overcurrent protection in AC household and similar installations. It is an AC product standard, and it does not cover breakers that incorporate residual-current tripping.2 RCD provisions for caravan installations must be assessed separately from overcurrent protection under the applicable installation rules.3
Map the Power Sources Before Choosing Breakers
Before creating a consumer unit schedule, map which sources can energise each circuit and in which operating modes. A block diagram of the sources and loads makes the protection problem clearer than beginning with an MCB rating.
Shore-power-only system
In a shore-power-only arrangement, the external hook-up is the AC source. The conceptual path is:
shore inlet → isolation and residual-current protection → branch overcurrent protection → AC loads
This is not a wiring diagram. The applicable rules for the target market govern the inlet, protective conductor, RCD arrangement, means of isolation, cables and testing. The current available at a campsite may also be lower than the combined demand of the connected appliances, so load planning still starts with the source limit.
Inverter-supplied AC system
An inverter creates an AC source from the leisure battery, but its fault behaviour may differ from that of a normal building supply. Selecting the output protection therefore starts with the inverter manufacturer's data for output voltage, frequency, fault behaviour, permitted earthing arrangement, overload response and any required external protective devices.
RCD operation depends on the system's earthing and neutral arrangement. Manufacturer guidance for mobile systems shows that this arrangement can change when an inverter/charger moves between inverting and shore pass-through modes.4 Do not copy a neutral-to-earth link from a generic diagram. The complete inverter manual has to govern the design, and the finished system needs testing in every permitted supply mode.
Shore power plus inverter or inverter/charger
A combined system has at least two potential AC operating states. It must prevent unintended paralleling or backfeed between sources while preserving the required protection as the source changes. An inverter/charger may provide the transfer function when its documented internal arrangement is permitted for the intended installation. Otherwise, the design needs a separately selected and rated changeover arrangement.
Some systems need distinct protection on the AC input and output sides; others use a different architecture permitted by the equipment manufacturer and local rules. A manufacturer's RV example can explain the concept, but it cannot be copied to another inverter model without checking that model's manual.5 A transfer switch performs a separate system function. It does not replace branch overcurrent or residual-current protection, and a general ATS specification does not establish campervan suitability.
What Changes MCB Selection in a Campervan?
The protection principle is unchanged: an MCB has to protect the circuit conductors and operate correctly under fault conditions. What changes in a campervan is the combination of supply modes, limited source capacity, a compact assembly and a mobile environment.
- Source modes. A source map shows which circuits can be energised by shore power, an inverter, a generator or another documented source. Each permitted mode can change the available capacity, fault behaviour and operation of the protective devices, so each mode needs to be assessed separately.
- Conductor and load. Rated current follows the circuit design current together with conductor type and cross-section, routing, grouping, ambient temperature and load inrush.
- Breaking capacity and trip behaviour. Prospective fault current on shore power can differ from an inverter's fault output. The project data, source documentation and required disconnection conditions determine the necessary breaking capacity and trip characteristic.
- Poles, isolation and direction of supply. The arrangement has to identify which live conductors are switched or protected, the isolation duties, any line/load markings and bidirectional suitability where current may be supplied from more than one direction.
- Complete assembly and environment. Use only combinations of MCB, busbar, terminals and enclosure that the assembly manufacturer has declared compatible.9 The actual vehicle project also sets the limits for space, temperature rise, access, cable routing, vibration and moisture.
The specification checklist later in this guide turns these considerations into a supplier-ready brief. If the fault level, conductor capacity, source behaviour or applicable standard is still unknown, there is not yet enough information to choose the device. This is why there is no universal amp rating for campervan sockets.
Why the DC Side Is Not a Smaller Version of the AC Side
A campervan commonly contains both a 230 V AC system and a 12 V, 24 V or 48 V DC battery system. These are separate protection domains.
BS EN 60898-1 applies to AC circuit-breakers. BS EN 60898-2 adds requirements for certain breakers intended for both AC and DC operation, while IEC 60898-3 addresses DC circuit-breakers.6 An AC-only marking therefore does not establish DC suitability. A breaker should be used on the battery side only when its complete product documentation states the maximum permitted DC voltage, current, pole arrangement, breaking capacity, polarity or current-direction conditions and installation method.
Depending on the design and manufacturer instructions, battery circuits may use correctly rated DC fuses with compatible fuse holders or explicitly DC-rated circuit breakers. Maximum circuit voltage, prospective fault current, conductor protection and device breaking capacity all matter. A leisure battery can supply a high fault current even though its nominal voltage is low, so protection follows the DC system design rather than the appearance of the AC consumer unit. A battery management system must not be assumed to replace external circuit protection required by the battery or BMS manufacturer.
- What protects the 230 V AC final circuits supplied by shore power or an inverter?
- What protects the battery, DC feeders and individual DC loads?
How Does a Portable Power Station Fit into a Campervan Electrical System?
A portable power station can simplify a small campervan setup when loads plug directly into its approved outlets. It is not an invitation to connect the unit to fixed wiring: reverse-fed plugs and other undocumented connections are unsafe and must not be used.
The unit combines a battery, inverter, charging electronics and internal protection in one enclosure, but that internal protection does not automatically make it a consumer unit for hard-wired vehicle circuits. Three integration levels show where the boundary changes:
| Use case | Main protection question | Required boundary |
|---|---|---|
| Standalone portable source | Are the connected loads within the documented outlets, ratings and environment? | Manufacturer-permitted ports and cables only |
| Portable source feeding a manufacturer-permitted RV interface | Does the manufacturer permit the connection, and how are earthing, RCD operation and current limits handled? | Follow the exact product and interface manual |
| Hard-wired mobile power system | How are AC input, inverter output, source transfer, branch circuits and DC distribution protected? | Treat it as an engineered fixed installation with inspection and testing |
Some portable power stations have a floating AC output, which can change the behaviour of connected equipment or residual-current protection. One manufacturer describes this arrangement for a specific model and application; it does not establish the output arrangement for other products.7
Once a portable source is intended to energise installed sockets, a charger or other fixed circuits, use only a manufacturer-permitted connection method. Source transfer, earthing, RCD operation, overcurrent protection, inspection and testing then remain part of the fixed-installation design.
Campervan Consumer Unit Specification Checklist
This table captures the project inputs for a converter, panel builder or protective-device supplier. It is a design brief, not a wiring procedure.
| Field | Project input to provide | Why it changes the selection |
|---|---|---|
| Target market | Country and applicable installation rules | Determines product and installation requirements |
| Vehicle and use | Campervan, motorhome or other mobile unit | Defines the installation scope and environment |
| AC sources | Shore, inverter, generator, portable source | Defines energised states and transfer needs |
| AC system | Voltage, frequency and phase | Must match every connected device |
| DC system | Nominal and maximum operating or charging voltage, battery type and source arrangement | Defines the DC protection domain and device voltage requirements |
| Circuit schedule | Loads, design current and inrush | Supports rating and trip-curve selection |
| Conductors | Type, size, routing and temperature conditions | Establishes conductor protection requirements |
| Fault data | Prospective fault current or source fault behaviour | Establishes breaking-capacity and disconnection checks |
| Residual-current needs | Expected load electronics and required RCD type | Prevents selection by residual-current rating alone |
| Poles and isolation | Conductors to switch, protect and isolate | Affects device and assembly configuration |
| Enclosure | Mounting format, ways and rows, DIN rail, busbar, terminals, cable entry, usable and conductor-bending space, heat dissipation, ingress protection, vibration, moisture and temperature environment | Confirms physical, wiring and thermal compatibility |
| Transfer method | Built-in or separate, manual or automatic | Prevents unsafe source interaction |
| Verification | Inspection, test method and responsible person | Confirms the assembled system, not just the components |
How GEYA Supports Campervan and Mobile-Power Projects
GEYA supplies MCBs, residual-current protection and distribution-box enclosures for low-voltage assemblies. Compare the GEYA MCB range and distribution-box options against the checklist above.
Share your power sources, target market and installation requirements. GEYA will help match the protective devices and enclosure, then tailor a practical product-and-distribution proposal to your campervan or mobile-power application.
