No — UK rules do not name a DP RCBO as the required device for an EV charger. The wiring rules set the protection your circuit must have: overcurrent protection plus the correct residual-current (earth fault) protection. A double-pole RCBO is one common way installers provide both in a single device. Whether you need double-pole switching depends on your supply and earthing, which the installer checks at the survey.
Key Takeaways
- No UK rule requires a device called a DP RCBO; the rules require protection functions, not a product.
- An RCBO combines overcurrent and earth-fault protection; double-pole adds isolation of both conductors.
- Installers choose DP RCBOs for per-circuit tripping, isolation needs and tidy consumer units.
- The manual plus your supply and earthing decide the design; ask for the device in the quote.
What an RCBO Is — and What Double-Pole Means
| Device | Protects against | Notes for EV circuits |
|---|---|---|
| MCB | Overload and short circuit | Guards the cable; no earth-fault protection |
| RCD | Earth fault (residual current) | Protects people; no overcurrent protection |
| RCBO | Both — an MCB and an RCD in one device | One device per circuit, so an EV fault trips only that circuit |
| Single-pole (SP) vs double-pole (DP) | — | SP switches the live conductor only. DP switches live and neutral, isolating the circuit completely |
What the Rules Actually Require
The UK wiring rules for EV charging sit in Section 722 of BS 7671, and installers work to the IET Code of Practice for EV charging equipment installation. Neither names a device you must buy. They set outcomes:
- Overcurrent protection sized for a load that runs at full power for hours.
- Residual-current protection that still works when the car’s electronics produce smooth DC fault currents — why an ordinary RCD may not be enough, explained in our guide to RCD protection for EV chargers: Type A, Type B and 6 mA DC detection.
- Safe isolation of the circuit — where the single-pole versus double-pole question comes in.
- Whatever the charger manufacturer specifies upstream of the unit, in its installation manual.
That is why two quotes for the same charger can list different devices: one fits a DP RCBO, another an RCD and MCB pair, a third keeps an existing RCD and adds the missing device. All three can be correct if the protection is genuinely there.
When Installers Choose a DP RCBO Anyway
- One circuit, one device. A fault on the EV circuit trips that circuit only, instead of taking out a bank of circuits sharing one RCD — your fridge stays on when the charger faults.
- Full isolation. Where both conductors must be disconnected — judged from your earthing and supply type — a double-pole device does it in one switch.
- The charger’s built-in protection allows it. Many wallboxes include 6 mA DC detection, which changes which RCD type can sit upstream; pairing it with a matching RCBO is routine design. Two functions in one width of consumer unit is also the tidy route on a crowded board.
A charger suited to this kind of install, such as the EVDANCE EV-ACT3204PE 22 kW wallbox (three-phase, tethered Type 2 cable, RFID and app, CE), states its upstream protection needs in its manual. Consumer-unit work is not DIY: use a qualified electrician, ideally one who installs EV chargers regularly, as our guide to becoming an approved EV charger installer in the UK describes from the trade side. See also what affects EV charger installation cost.
Questions to Ask Before Your Install
- Which device are you fitting — RCBO, or an RCD and MCB pair — and does it switch one pole or two?
- How does the design handle DC fault currents: a Type B device, or DC detection in the charger?
- If the charger faults at night, what else in the house loses power?
- Does my earthing change any of this, and is that in the quote?
Frequently Asked Questions
Is an RCBO the same as an RCD?
No. An RCD detects earth faults only; an RCBO does that job and the MCB’s overcurrent job in one device. What matters is that both protection functions are present somewhere in the circuit design.
My charger has built-in 6 mA DC detection. Do I still need protection in the consumer unit?
Yes. Built-in DC detection can allow a Type A device upstream instead of a Type B, but the circuit still needs overcurrent and residual-current protection at the board. The manual and your installer settle the combination.
Can I fit a DP RCBO myself to save money?
No. Consumer-unit work is for a qualified electrician, and the installation must be tested and certified. Ask for the device to be itemised in the quote instead — that is where the saving conversation belongs.
Related Reading
- RCD Protection for EV Chargers: Type A, Type B and 6 mA DC Detection Explained
- How to Become an Approved EV Charger Installer in the UK (OZEV)
- What Affects EV Charger Installation Cost? 8 Factors to Check
- IP Ratings for EV Chargers: IP54, IP65 and IP66 Compared
