Adding every nameplate load gives connected load, not necessarily maximum demand, but applying a blanket diversity percentage to a commercial kitchen can badly underestimate real peak operation.
Installation boundary: This article explains design and coordination principles. Drainage, ventilation, fire, electrical and fabrication work must be designed and carried out by competent people using current project documents, manufacturer instructions and the requirements that apply in the relevant UK nation.
The short answer
Build an equipment-by-equipment load schedule, group loads by operating pattern and have the electrical designer assess realistic coincident demand, supply capacity, phase balance and protective arrangements. A breakfast kitchen, banqueting operation and delivery-only kitchen can use identical appliances in very different combinations. Controls may cycle heaters after warm-up, but close-down cleaning can create a different peak when dishwashing, combi cleaning, hot-water recovery and refrigeration all run together.
Connected load, demand and energy are different
Connected load is the sum of rated inputs. Maximum demand is the highest load expected at one time under the assessed operation. Energy use is power over time. An appliance can have a high connected load but cycle once at temperature; another can run at a lower load continuously. The design needs maximum current and protective performance, while the business case may focus on energy consumption—do not substitute one measure for the other.
Use operating scenarios: preheat, full lunch service, simultaneous recovery after doors open, wash-up, overnight cleaning and refrigeration defrost. Identify automatic load-management functions and confirm whether they are included in the quoted appliance. Where a control system limits demand, its failure mode and commissioning become part of the electrical design.
Existing capacity must be measured and verified
A board with spare ways may still have no spare capacity. Review the incoming service, meter, switchgear, feeder, protective devices, measured load profile and any landlord allocation. A short spot reading during a quiet survey is not the same as a representative demand assessment. Planned electric vehicle charging, heating or tenant expansion elsewhere in the building can also compete for capacity.
Electrical load is a premises-suitability issue and belongs in the assessment of converting a shop into a commercial kitchen. Confirm it before committing to an all-electric cookline or signing a lease that makes a supply upgrade difficult.
What common failures reveal
| Site symptom | Likely installation issue | Practical consequence |
|---|---|---|
| Main device trips at close-down | Cleaning and water-heating peak omitted from scenarios | Whole-kitchen outage |
| Cable and board over-specified | Connected load treated as continuous demand without analysis | Unnecessary capital cost |
| One phase reaches limit first | Total kW assessed without phase allocation | Uneven heating and nuisance operation |
| Landlord rejects connection | Tenant allocation or upstream network limit not checked | Programme and lease dispute |
| Load manager does not reduce demand | Optional interface missing or not commissioned | Supply assumptions no longer valid |
Installation and coordination checklist
- Compile exact rated data for every appliance and ancillary component.
- Separate connected load from assessed maximum demand and energy use.
- Model preheat, service, recovery, wash-up and unattended cleaning scenarios.
- Allocate loads by phase and board, not only as one site total.
- Verify incoming service, switchgear, feeder and landlord capacity.
- Use measured profiles where appropriate and record their operating context.
- Document any demand-control assumptions and failure response.
- Allow agreed spare capacity for realistic future replacement or expansion.
Commissioning and handover
Issue the final connected-load and maximum-demand schedules with stated diversity assumptions, operating scenarios and phase allocation. Record measured commissioning values where the test method permits, and identify loads controlled by energy-management systems. Future equipment substitutions should be checked against both circuit capacity and the site demand model.
Questions to ask before approving the work
- Which operating scenario creates the predicted peak?
- What evidence supports each diversity assumption?
- Has the landlord or network capacity been confirmed?
- Are phases balanced under the peak scenario?
- What happens if demand control fails or is overridden?
Capture the installation detail before it becomes a site problem
Plan the full kitchen installation across equipment, utilities, ventilation, safety, hygiene and handover.
Technical sources and further reading
- Electricity at Work Regulations 1989
- HSE: Work using electrically powered equipment
- HSE: Provision and Use of Work Equipment Regulations overview
Last technical review: 14 August 2026. Always check the latest manufacturer instructions, statutory guidance, standards and project approvals before installation.