Electrical Demand & Diversity Estimator
Apply NEC 220 demand factors or IEC 60439-1 diversity to produce a coincident demand schedule for service-entrance sizing.
Method & Standards
This study reads loads from the Load List, automatically categorises each load by its Load Type field, then applies the appropriate code demand factor:
| Category | Detection keywords | NEC Reference | Factor applied |
|---|---|---|---|
| Lighting | light, luminaire, lamp, illum | NEC 220.42 | 100% ≤ 50 kVA; 50% remainder |
| Receptacles | recept, outlet, plug, strip | NEC 220.44 | 100% first 10 kVA; 50% remainder |
| Motors | motor, pump, fan, compressor, drive, VFD | NEC 430.24 | 100% all motors + 25% largest |
| Kitchen / Cooking | kitchen, cook, oven, range, fryer | NEC Table 220.56 | 65%–100% by unit count |
| HVAC / Heating | hvac, heat, cool, AC, chiller, furnace | NEC 220.60 | 100% (non-coincident selection required) |
| EV Charging | ev, electric vehicle, charger, EVSE | NEC 625.42 | 100% / 75% / 50% by charger ordinal |
| Fixed Appliances | appliance, washer, dryer | NEC 220.53 | 75% if ≥ 4 appliances, else 100% |
| Critical / UPS | ups, critical, server, datacen | NEC 220 | 100% |
| General / Other | (all others) | NEC 220 | 100% |
IEC 60439-1 mode applies a single diversity factor to all loads based on consumer count per Table B.1: 1.0 (≤ 2), 0.9 (3–5), 0.8 (6–10), 0.7 (11–40), 0.6 (> 40).
Demand Profile: Select the project type before running NEC mode. Profiles that need a dedicated Article 220 calculation keep unsupported categories at 100% demand and show review notes instead of silently applying commercial/non-dwelling reductions.
Override: Add a necCategory property to any load row to force a specific category.