Electrical Load Schedule Calculator
Build a proper load schedule the way it appears on a design drawing. List your lights, sockets, motors, HVAC, cookers, water heaters and other loads — each with its quantity, unit rating, power factor and diversity — and the calculator returns the connected load, the diversified maximum demand, a balanced allocation across the three phases, and a recommended incomer rating from standard breaker sizes.
Once you have the incomer current, size its cable with the Cable Sizing and Voltage Drop Calculator.
| Description | Category | Qty | Unit load (W) | PF | Diversity | Phases |
|---|
Load summary CALC-03 · REV 2026-07
| Connected load | – |
|---|---|
| Diversified load (maximum demand) | – |
| Overall diversity factor | – |
| Maximum demand current | – |
| Incomer required incl. spare capacity | – |
| Recommended incomer | – |
| Spare capacity at recommended rating | – |
| Phase | Demand (VA) | Current (A) |
|---|---|---|
| L1 | – | – |
| L2 | – | – |
| L3 | – | – |
| Imbalance | – | |
Guidance tool only. Diversity is a matter of engineering judgement — the defaults follow IET On-Site Guide practice but every factor is editable and the final assessment, protective-device coordination and KPLC connection application must be confirmed by a registered engineer.
How this calculator works
- Connected load. Each row contributes quantity × unit rating in watts, converted to VA through its power factor. Defaults per category are typical values and fully editable.
- Diversity. Not everything runs at once. Each row carries a diversity factor — defaults follow IET On-Site Guide practice (lighting 0.90, sockets 0.40, motors 0.80, HVAC 0.80, cookers 0.60, water heaters 1.00, other 0.80), simplified to a single multiplier. The diversified total is the maximum demand.
- Phase allocation. On a three-phase supply, balanced three-phase loads (motors, larger HVAC) contribute one third to each phase; single-phase loads are then packed largest-first onto the least-loaded phase. The table reports VA and amperes per phase and the resulting imbalance, flagging anything above 15%.
- Recommended incomer. The worst-phase current (or the total, on single phase) is increased by your chosen spare-capacity allowance — 25% is a common design margin — and matched to the next standard breaker rating (32–1600 A). Above 1600 A the tool refers you to transformer and HV intake design.
Assumptions and limits
- Diversity is engineering judgement, not law — a hospital theatre and a student hostel with the same connected load deserve different factors. Edit them per row for your building type.
- Voltages assume the Kenyan LV system, 230/400 V, with the phase voltage editable.
- Demand above about 60 A on single phase, or 100 A per phase on three phase, triggers advisory notes on supply upgrade and KPLC CT metering.
- The tool does not perform protective-device discrimination, fault-level or earthing calculations — all part of a full design.
Need a stamped, submission-ready design or a KPLC connection application? See our consultancy services, browse the design document library, or learn the method yourself in a training program.