Three-Phase Power Explained: Does Your North East Business Need an Upgrade?

If your business is growing, relocating, or installing new equipment, there is a good chance you have come across the term "three-phase power" and wondered whether you need it. For many North East businesses, upgrading from a single-phase to a three-phase electrical supply is one of the most important infrastructure decisions they will make.

In this guide, we explain the difference between single-phase and three-phase power in plain English, help you work out whether your business needs an upgrade, and walk you through what the process involves.

Single-Phase vs Three-Phase: What Is the Difference?

The electricity that comes into most homes and small commercial premises in the UK is single-phase. It arrives through one live conductor and one neutral, delivering a voltage of around 230V. For most domestic and light commercial applications, this is perfectly adequate.

Three-phase power uses three live conductors, each carrying current that peaks at a different time. This gives you access to a higher total power capacity (around 400V between phases) and delivers that power more smoothly and efficiently. Think of it as having three lanes on a motorway instead of one.

The key practical difference is capacity. A single-phase supply typically provides up to around 60 to 80 amps at 230V. A three-phase supply can comfortably deliver three times that capacity and does so more efficiently, especially for motor-driven equipment, a core part of our industrial electrical service.

What Types of Business Need Three-Phase Power?

Not every business needs a three-phase supply, but many commercial and industrial operations will hit the limits of single-phase sooner than they expect.

• Manufacturing and engineering workshops. CNC machines, lathes, milling machines, compressors, and heavy-duty welding equipment almost always require three-phase power.
• Commercial kitchens and hospitality venues. Large ovens, combi steamers, commercial dishwashers, and walk-in refrigeration can quickly exceed a single-phase supply.
• Warehouses and distribution centres. Dock levellers, conveyor systems, industrial lighting installations, and EV charging infrastructure all increase demand.
• Gyms and fitness centres. Air conditioning systems, large banks of lighting, and commercial laundry equipment add up.
• Automotive workshops and garages. Vehicle lifts, tyre machines, spray booth fans, and compressors are typically three-phase.
• Agricultural businesses. Grain dryers, milking parlours, and large irrigation pumps commonly run on three-phase.
• Offices and retail units with significant HVAC. Larger air conditioning and heating systems, particularly heat pumps or VRF systems, generally require a three-phase supply.

How Do You Know If Your Current Supply Is Not Enough?

• Tripping breakers or blowing fuses when multiple pieces of equipment start up together.
• Voltage drop, lights dimming when large equipment starts, or motors struggling to start.
• You cannot install the equipment you need because your supplier says it requires three-phase.
• Disproportionately high energy bills, motors run less efficiently when starved of power.
• Your electrician has flagged it in your most recent EICR or installation work.

What Does the Upgrade Process Involve?

Upgrading from single-phase to three-phase is not as disruptive as many business owners expect.

• Step 1: Load assessment. A qualified electrician assesses your current installation, measures existing demand, and calculates projected demand based on new equipment or expansion plans.
• Step 2: Application to the Distribution Network Operator (DNO). In the North East, the DNO is Northern Powergrid. Your electrician submits an application on your behalf covering the new supply and meter.
• Step 3: Internal installation. While waiting for the DNO connection, we install a new three-phase distribution board, run new submains, and modify the existing installation to work with the new supply.
• Step 4: Connection and commissioning. Once the DNO has completed their work, we connect the internal installation, carry out full testing and commissioning, and issue the BS 7671 electrical installation certificate.

Most upgrades are completed within 6 to 12 weeks from initial enquiry.

How Much Does It Cost?

Costs vary depending on distance from the nearest three-phase cable in the street, the size of supply required, and the extent of internal work needed. The DNO connection charge is typically the largest single cost, from a few hundred pounds if three-phase is already available at the boundary, up to several thousand if significant groundwork is needed.

Internal electrical work costs will depend on the size and complexity of the installation. A straightforward upgrade for a small workshop will cost considerably less than a full distribution upgrade for a large industrial unit.

Planning Ahead

If you are taking on a new commercial lease, it is worth checking the electrical supply before you sign. Converting a single-phase premises to three-phase after you have moved in adds cost and delay that could be avoided by choosing a premises with an existing three-phase supply.

Similarly, if you are planning a business expansion or equipment purchase in the next 12 to 24 months, getting a load assessment done now gives you time to plan the upgrade without holding up the project.

Talk to LC Electrical Services

LC Electrical Services has over 20 years of experience designing and installing three-phase power systems for commercial and industrial clients across South Tyneside, Gateshead, Sunderland, Newcastle and the wider North East. From initial load assessments through to DNO applications, internal installation, and commissioning, we manage the entire process.

Get in touch today to arrange a site visit and find out what your business needs.