Installing an Ohme Home Pro EV charger: what the job involves

Video reference. "Ohme -- How to install an Ohme Home Pro Charger" is the official installation walkthrough from the Ohme YouTube channel. Ohme is a UK-based EV charging company whose Home Pro integrates directly with smart energy tariffs, including Octopus Intelligent Go. The video covers the current Home Pro model to the manufacturer's UK installation specification.

1. Checking the consumer unit and available load

The first step is to inspect the consumer unit for a spare way and assess what load the property is already drawing. An Ohme Home Pro can pull up to 32A (7.4 kW) continuously during a charging session. Most UK homes on a 100A single-phase supply can accommodate this comfortably alongside normal household loads, but older properties with a 60A or 80A cut-out fuse benefit from a clamp meter check during a busy early evening to confirm there is enough headroom.

If the consumer unit has no spare way, there are two options: fit a twin RCBO in place of an existing single-width device to free up a way, or upgrade to a larger board if the existing one is near the end of its useful life or already using twin adaptors elsewhere.

2. Confirming the earthing arrangement

Most UK homes use PME (Protective Multiple Earthing), also known as TN-C-S. On a PME supply, BS 7671 requires the EV charger circuit to include a Type B RCD, because EV on-board chargers can produce a smooth (DC) residual fault current that a standard Type A device will not detect -- meaning a Type A will not trip in a fault condition on an EV circuit.

The Ohme Home Pro does incorporate a Type A RCD internally, but this does not substitute for the Type B protection required in the consumer unit on a PME supply. A few UK properties, particularly rural ones, use TT earthing (a local earth electrode). On a TT supply, a Type A RCD is sufficient for the charger circuit, though installation specifics differ and the installer should confirm this at the survey stage.

3. Choosing where to mount the charger

The Ohme Home Pro is IP55 rated, suitable for mounting on an outside wall, inside a garage or in a covered car port. The practical choice is the wall closest to where the car parks, at a height between 0.8 m and 1.2 m from the ground, which makes plugging in comfortable without crouching.

The final position is also influenced by the cable route from the consumer unit. For an attached garage or an outside wall of the house, the cable often runs through the cavity or under the floor. For a detached garage, cable either travels overhead through the loft void or underground as armoured SWA cable. Underground cable must be at least 450 mm deep and in conduit wherever it crosses a driveway or vehicle path.

4. Running the supply cable and mounting the unit

Standard Ohme Home Pro installations use 6 mm two-core and earth for runs up to approximately 15 m from the consumer unit. Longer runs, cable routed through a warm roof void, or buried cable without free-air cooling may need 10 mm cable to stay within BS 7671's volt-drop limits. Your installer calculates the correct size for your specific route before ordering materials.

The cable must follow BS 7671 cable safe zones (within 150 mm of an edge or vertically above a socket or switch) unless it is protected in conduit or trunking throughout. The Ohme Home Pro backplate is fixed level to the wall, the cable is routed and connected inside the unit, and the front cover clips on once connections are verified.

5. Connecting at the consumer unit with a Type B RCBO

At the consumer unit end, the supply cable connects to a 32A Type B RCBO. All terminal connections are torqued to the manufacturer's specification -- a loose terminal on a 32A circuit running for six or more hours overnight is a potential fire risk. The installer checks polarity and continuity before closing the board and testing the circuit.

If the board is an older split-load type with a main RCD already, your installer will check whether that main device is Type B. If it is only Type A and cannot be upgraded, a separate Type B RCBO for the EV circuit is the correct solution.

6. Commissioning via the Ohme app and completing Part P notification

Once wiring is complete and tested, the installer connects the Ohme Home Pro to your home Wi-Fi network using the Ohme app. You then add your energy tariff details: Ohme integrates directly with Octopus Intelligent Go, Octopus Go, E.ON Drive Anytime and several other smart tariffs, pulling live half-hourly prices to schedule charging automatically at the lowest-cost periods.

A test charge session confirms the unit operates correctly and communicates with the car before the installer packs up. The installer then notifies the installation to their Part P competent person scheme, which issues a building compliance certificate. You should receive this, along with an Electrical Installation Certificate, within a few days. Keep both with your property documents.

When to call us

Richard is an OZEV-approved EV charger installer covering Sandwich, Deal, Dover, Ramsgate and Canterbury. We install Ohme Home Pro, Pod Point Solo 3S, Zappi and other home chargers, completing Part P notification and providing the full certificate pack on the day of installation.