EV charger installation in Aberdeenshire, built for rural properties, not city driveways.

This is the part no other Aberdeenshire page explains, and it is the part that most often decides what we can fit.

On a PME supply, the neutral and the earth share a conductor on the way to your property. If that combined conductor is ever lost, metalwork connected to it can rise to a dangerous voltage compared with the real ground outside. Indoors that is unlikely to hurt you. Outdoors, plugged into a car, standing on wet gravel, it is a genuine risk. That is precisely why BS 7671 Section 722 says a PME earth must not simply be used for an outdoor charge point unless one of a defined set of protective methods is applied.

In practice there are two routes:

• Open PEN protection built into the charger. The unit monitors for the fault itself and disconnects. Most current mainstream home chargers offer this, and it avoids the need for a separate earth rod on the charging circuit.
• A dedicated earth electrode. An earth rod serving the charging circuit. It is a legitimate route, but it is not a box to tick: the rod has to be sited far enough from buried metalwork connected to the supply, and it has to be tested. Done carelessly it does not achieve what it is meant to.

Rural Aberdeenshire changes the picture again, because a lot of the network out here is overhead, and overhead supplies frequently do not provide a PME earth at all. Those properties run as TT, standing on their own earth electrode. On a genuine TT property the broken conductor problem does not arise in the same way, but the electrode resistance and the disconnection times have to be verified, and older rods are very often corroded, undersized or simply disconnected at some point in the past.

Either way, every charge point gets its own RCD, at least Type A and rated no higher than 30 mA. We confirm the right protective arrangement for your supply at the survey rather than assuming it.

On a city semi the charger goes on the wall next to the board. On a steading, a smallholding or a house with a long drive, the car parks somewhere else entirely, and that distance is the single biggest variable in the price.

The technical limit is voltage drop. BS 7671 allows a maximum of 3% for fixed current using equipment on a supply taken from the public network, and on a submain feeding a charger we design well inside that to leave headroom. The longer the run, the larger the conductor has to be to stay within it. Burying the cable makes that worse rather than better, because buried and ducted cable sheds heat less effectively than cable clipped in free air, so the same load needs a bigger conductor underground.

For anything beyond a short run to an attached garage, the better design is usually not one long dedicated circuit. It is a submain in armoured cable out to a small distribution board at the outbuilding, with the charger fed from there. It costs a little more on the day and it future proofs the building for lighting, sockets or a second charger later, instead of stranding you with a single cable that does one job.

• Cable is sized at the survey against the actual route, burial depth and grouping, never off a chart.
• Armoured cable for any buried or exposed run, correctly protected and terminated.
• Trenching is the honest cost driver, and depth, ducting and reinstatement all count.
• If you want to dig the trench yourself, plenty of customers do, and we will price the job accordingly.

For a worked rural example, see our rural EV charger page for Maryculter.

Plenty of Aberdeenshire holdings already have a three phase supply for dryers, workshops, milking plant or larger pumps. Where it is already there, adding charging to it is not a big step. Where it is not, bringing it in is a separate and usually expensive job that SSEN quote individually.

Here is the honest part that the marketing tends to skip. A 22kW AC charger needs a three phase 32A supply, but most electric cars cap their onboard AC charger at 7.4kW on single phase or 11kW on three phase. Fitting a 22kW unit will not make a 7.4kW limited car charge any faster. The genuine reasons to go three phase on a farm are future proofing, running more than one vehicle, and light commercial or fleet use, not headline speed for a single family car.

What three phase really buys you on a working holding is balance. Chargers can be spread across the phases, or a three phase unit with dynamic load management can work around the dryer and the workshop rather than competing with them. On a farm that matters far more than the number on the box.

• The vehicle rarely parks at the farmhouse, so submain out to a board at the steading is the usual design.
• Competing loads are the design problem, and dynamic load management is not optional.
• Two sockets sharing managed load usually beats one large unit for a two vehicle household.
• Farm shops, campsites, glamping and wedding venues turn a charger into a customer facing asset, which is a different conversation again.