Maximum Demand Calculation May 2026

| Step | Action | Example Value | | :--- | :--- | :--- | | 1 | List all loads with kW ratings | Motor: 75 kW, Lights: 30 kW | | 2 | Apply demand factor per load type | Motor: 0.9 (67.5), Lights: 0.8 (24) | | 3 | Sum to get "Total Diversified Load" | 91.5 kW | | 4 | Estimate diversity factor between major groups | 1.15 | | 5 | = Step 3 / Step 4 | 91.5 / 1.15 = 79.6 kW | | 6 | Measure or estimate actual power factor | 0.85 | | 7 | MD (kVA) = Step 5 / Step 6 | 79.6 / 0.85 = 93.6 kVA | | 8 | Add 15-20% future growth | 93.6 × 1.2 = 112.3 kVA | | 9 | Final MD for equipment sizing | 113 kVA (or ~125 kVA transformer) | Conclusion Maximum Demand calculation is not a one-time academic exercise; it is a continuous, living process that directly affects capital expenditure (CAPEX), operational expenditure (OPEX), and system reliability. A 15-minute oversight can result in months of inflated electricity bills.

Wait – be careful. In British (IEC) standards, the relationship is often inverted. The safest universal formula is the "Sum of Individual Demands after applying DF, then divided by Diversity Factor." maximum demand calculation

Simply put, Maximum Demand is the highest average load (in kilowatts, kW, or kilovolt-amperes, kVA) that an electrical installation draws from the supply network over a specified period—typically 15, 30, or 60 minutes. | Step | Action | Example Value |