Three Phase Consumer Unit Upgrades for Aberdeen Businesses and Workshops

Many Aberdeen commercial premises operate on single phase electrical supply that was sufficient when the property was built but no longer matches the load profile of a modern business. Workshop machinery, EV charging infrastructure, large heating and cooling systems, fabrication equipment, and commercial kitchens all push the load toward three phase territory. The consumer unit upgrade from single phase to three phase is a substantial commercial electrical project that involves both the local supply (with SSEN) and the on site distribution (the consumer unit and circuits). This guide explains what is involved, what it costs, and how the two elements fit together.

When does an Aberdeen business need three phase?

Three phase electrical supply provides three times the power transmission capacity of single phase at the same current rating. For commercial premises, the practical drivers for upgrading from single phase to three phase are:

Heavy machinery and motors

Three phase motors are smaller, more efficient, and cheaper to run than equivalent single phase motors. Workshop machinery (lathes, milling machines, compressors, large pumps, conveyor systems) is typically rated three phase. A single phase supply limits the size of motors that can be installed and the number that can run simultaneously.

Large heating and cooling systems

Commercial heat pumps, large air conditioning units, electric boilers above 12 to 15kW, and significant electric heating loads all benefit from three phase supply. The starting current for large compressors is also better managed on three phase.

Commercial EV charging

Commercial EV chargers above 11kW (typical destination chargers, fleet chargers, and rapid chargers) require three phase supply. A single phase 7kW charger is the largest practical single phase option. For a forecourt, fleet site, or hospitality venue installing multiple chargers, three phase is the only realistic route.

High electrical demand premises

Commercial premises drawing more than 23kVA (approximately 100A on single phase) routinely benefit from three phase. The supply spreads the load across three phases, reducing imbalance and providing headroom for growth.

Growing businesses

A business that is expanding (additional machinery, additional staff, additional facilities) may find the existing single phase supply at its limit. Upgrading to three phase before the limit becomes a constraint avoids a future emergency when a new piece of equipment cannot be commissioned.

Two parts: SSEN supply upgrade and on site distribution upgrade

A single phase to three phase upgrade involves two separate but coordinated projects:

Part 1: SSEN supply upgrade

The supply from the public network to the property is owned and maintained by SSEN (Scottish and Southern Electricity Networks). Upgrading from single phase to three phase requires SSEN to:

• Confirm that three phase is available at the local network. In most urban Aberdeen locations, three phase is available; some rural locations may need network reinforcement.
• Run a new three phase supply cable from the network to the property meter position. This may involve excavation, underground cable installation, and reinstatement.
• Install a new three phase meter (the meter operator typically does this on SSEN’s behalf).
• Connect the new supply and commission it.

The SSEN supply upgrade is typically the longest lead time element. Standard timescales are 8 to 16 weeks from application to commissioning, longer for sites that require network reinforcement. SSEN provides a written quote at the application stage with the timescale and cost.

Part 2: On site distribution upgrade

Inside the property, the existing single phase consumer unit is replaced with a three phase distribution board. The work includes:

• Removing the single phase consumer unit.
• Installing a new three phase distribution board with appropriate main switch, protective devices, and capacity for the property’s circuits.
• Reconnecting existing single phase circuits across the three phases to balance the load.
• Installing any new three phase circuits required by new equipment.
• Testing and certification.

The on site work is coordinated with the SSEN supply upgrade. The distribution board can be installed in advance of the SSEN connection (so the property is ready when the new supply is energised), or both elements can be sequenced as a single project.

Cost of three phase consumer unit upgrade in Aberdeen

Indicative costs in 2026 for an Aberdeen commercial three phase upgrade:

SSEN supply upgrade

• Standard urban site with three phase available at the network: £800 to £2,500 for the supply upgrade.
• Suburban or industrial estate site: £1,500 to £4,000 depending on cable run length.
• Sites requiring network reinforcement: £5,000 to £25,000 depending on the work needed.
• Very rural or remote sites: substantially higher; SSEN provides a specific quote.

On site distribution upgrade (Faithful Spark)

• Standard three phase distribution board (12 way, suitable for a small workshop or office): £900 to £1,500 fully installed.
• Larger three phase board (24 way, mid sized commercial premises): £1,500 to £2,500.
• Major commercial installation with multiple sub boards and significant circuit reorganisation: £3,000 to £8,000.
• Adding new three phase circuits for specific equipment: £300 to £800 per circuit depending on cable run and rating.

Combined SSEN plus on site cost for a typical small Aberdeen workshop upgrade: approximately £2,500 to £5,000. For a larger commercial site: £6,000 to £15,000.

Coordinating SSEN with the on site work

The two elements need to be sequenced carefully to avoid the property being without power for an extended period:

1. SSEN application: The property owner (or Faithful Spark on the owner’s behalf) applies to SSEN for the supply upgrade. SSEN assesses the application and provides a written quote with the timescale.
2. Quote acceptance and SSEN scheduling: The SSEN work is scheduled. Typical lead time is 8 to 16 weeks.
3. Faithful Spark on site preparation: Before the SSEN connection date, Faithful Spark installs the new three phase distribution board, runs any new circuits, and prepares the property to receive the three phase supply. The existing single phase supply continues operating during this preparation.
4. SSEN connection day: SSEN attends and commissions the new three phase supply. The single phase supply is disconnected. Faithful Spark is on site to commission the new distribution board and verify the property is operating correctly on three phase.
5. Final testing and certification: The complete installation is tested and an Electrical Installation Certificate is issued.

Common Aberdeen three phase use cases

Oil and gas service workshops

Aberdeen has many oil and gas service workshops with significant electrical demand from machine tools, fabrication equipment, and compressed air systems. Three phase supply is typically essential for these workshops to operate efficiently. The Altens, Bridge of Don, and Tullos industrial estates have significant three phase commercial activity.

Commercial and fleet EV charging

Many Aberdeen businesses installing EV charging for staff or fleet vehicles need three phase to support multiple chargers. A site with 4 or more 22kW chargers requires three phase supply. The OZEV Workplace Charging Scheme provides up to £350 per socket toward the charger cost; the supply upgrade is a separate cost typically borne by the business.

Restaurants and hospitality

Commercial kitchens with multiple electric ovens, induction hobs, and refrigeration may need three phase to operate efficiently. Aberdeen’s growing food and drink sector includes many premises that have upgraded from single to three phase as the business grew.

Manufacturing and engineering

Light manufacturing, engineering workshops, and product assembly operations all benefit from three phase distribution. The combination of motor loads and electronic equipment is best served by three phase.

Retail with significant cooling or heating loads

Retail premises with refrigeration cabinets, large air conditioning units, or significant lighting loads may need three phase as the load grows.

Three phase consumer unit options

Several configurations are available for commercial three phase distribution boards:

Modular three phase distribution board

The most common option. A metal clad enclosure with a three phase main switch, sub board sections for each phase, and individual MCBs or RCBOs for each circuit. Easily expanded by adding modules. Suitable for typical Aberdeen workshops and offices.

Custom panel

For larger or more complex installations, a custom built panel includes specific protection devices, motor control gear, automatic transfer switches, or other specialist equipment. Custom panels are typically used in industrial or process environments.

Three phase plus single phase split

Many Aberdeen commercial premises have a mix of three phase loads (machinery) and single phase loads (lighting, sockets, IT equipment). The distribution board provides three phase for the heavy loads and single phase circuits derived from each phase for the lighter loads. This is the most common configuration in practice.

Inspection and certification

Three phase commercial installations are subject to the same Wiring Regulations as single phase domestic installations, but with additional considerations specific to three phase distribution. Faithful Spark provides:

• Pre installation survey identifying the existing supply, the property’s load profile, and any associated work needed.
• Coordination with SSEN on the supply upgrade including the G99 grid notification process.
• Installation of the new three phase distribution board and any new circuits.
• Full electrical testing including phase rotation, earth continuity, insulation resistance, and protective device tripping times.
• Electrical Installation Certificate documenting the new installation.
• Subsequent EICR as part of the standard commercial 3 to 5 year cycle. For more on commercial EICRs, see our companion guide on commercial EICR services in Aberdeen.

Frequently asked questions

How long does the full project take?

Total elapsed time from initial enquiry to completed three phase installation is typically 12 to 20 weeks, with the SSEN supply upgrade being the longest single element. The on site work itself typically takes 1 to 5 days depending on the scale.

Will my existing single phase equipment still work?

Yes. Single phase loads (lighting, sockets, IT, small appliances) work normally from individual phases of the three phase distribution. Faithful Spark balances the existing single phase circuits across the three phases at the time of the upgrade.

Is three phase more expensive to run?

The same total kWh consumption costs the same whether on single or three phase. Three phase supply has a slightly different standing charge structure under most commercial tariffs but the unit cost is comparable. The benefits of three phase (efficiency of three phase motors, headroom for growth, ability to run larger equipment) generally outweigh any small standing charge difference.

Can I keep operating during the upgrade?

The SSEN connection day requires a planned outage typically 4 to 8 hours. The on site distribution board work can be scheduled around the SSEN visit. Faithful Spark plans the sequence to minimise the operational impact on the business.

Does the upgrade affect my insurance?

A three phase upgrade with full Electrical Installation Certificate generally has no negative effect on commercial property insurance. Many insurers view a modern compliant installation positively. Notify your insurer of the upgrade as a property change.

Book a three phase upgrade survey

Faithful Spark provides three phase consumer unit upgrades, commercial distribution board installations, and SSEN supply coordination across Aberdeen, Aberdeenshire, Peterhead, and Fraserburgh. NICEIC certified, fixed price quotes, and full project management from initial enquiry through to commissioning. See our pillar guide on consumer unit upgrades in Aberdeen for the residential context and our companion guide on commercial EICR services for the broader compliance picture.

Book My Three Phase Survey

Faithful Spark Electricians. NICEIC approved. Local Aberdeen team. Three phase consumer unit upgrades, commercial electrical work, and Electrical Installation Certificates for Aberdeen, Peterhead, Ellon, Fraserburgh and across Aberdeenshire.