Four load categories, each with its own demand factor, combine into a diversified maximum demand that's meaningfully lower than simply adding up connected load.
| Lighting | 40 kW connected, 90% demand factor |
| Socket outlets | 30 kW connected, 70% demand factor |
| HVAC / AC | 60 kW connected, 80% demand factor |
| Motors | 25 kW connected, 75% demand factor |
| Supply | 400 V three-phase, 0.9 power factor |
| Category | Connected load | Demand factor | Demand |
|---|---|---|---|
| Lighting | 40 kW | 90% | 36.0 kW |
| Socket outlets | 30 kW | 70% | 21.0 kW |
| HVAC / AC | 60 kW | 80% | 48.0 kW |
| Motors | 25 kW | 75% | 18.75 kW |
| Check | Requirement | Actual | Status |
|---|---|---|---|
| Diversified maximum demand | n/a (this is the sizing result) | 123.75 kW (79.8% of 155 kW connected) | ✓ PASS |
| Recommended main breaker | n/a (this is the result) | 200 A | ✓ PASS |
Key insight: Demand factors exist because not every category of load runs at its full connected rating simultaneously — sockets in particular (70% here) are heavily diversified since it's unrealistic for every outlet in a building to be drawing rated current at the same instant, while heating loads are often left at 100% because thermostatically-controlled heating genuinely can reach full connected load during cold snaps.
Every input in this example is editable in the live calculator — free, no signup.
Open Maximum Demand calculator →These reflect commonly used general engineering practice (broadly consistent with IEC 60439-style guidance) for how simultaneously different load categories typically operate at their full connected rating — they are starting points, not fixed universal constants, and a real design should always be checked against the specific project's applicable code, utility requirements, or measured load data where available.
Aggregating multiple boards at a site level applies a further site diversity factor on top of each board's own diversified demand (since not every board peaks at exactly the same moment either), which is exactly what this calculator's subscriber-tier multi-board aggregation feature computes — for a single board like this office example, that additional layer of diversity doesn't apply.