免费变压器选型计算器
根据负荷计算所需变压器容量。
Required kVA (with growth)
226 kVA
Required kVA (with growth) vs Total Connected Load
公式
## Transformer Sizing The transformer must handle the maximum demand load with adequate margin. ### Method **Maximum demand = Total connected load x Demand factor** **Required kVA = Max demand (kW) / Power factor x (1 + Growth margin)** The demand factor accounts for the fact that not all loads operate simultaneously. The growth margin reserves capacity for future expansion (typically 15-25%).
计算示例
200 kW total connected load, 80% demand factor, 0.85 PF, 20% growth.
- 01Maximum demand = 200 x 0.80 = 160 kW
- 02Required kVA = 160 / 0.85 x 1.20 = 225.9 kVA
- 03Select the next standard size: 250 kVA transformer.
常见问题
What are standard transformer sizes?
Common three-phase ratings: 100, 160, 200, 250, 315, 400, 500, 630, 800, 1000, 1250, 1600, 2000, 2500 kVA. Always select the next size above the calculated requirement.
What is a typical demand factor?
Commercial buildings: 60-80%. Industrial plants: 50-70%. Residential complexes: 40-60%. Hospitals: 70-85%. Higher demand factors apply when loads are more likely to operate simultaneously.
Should I account for starting current of motors?
For the transformer sizing, demand factor typically covers motor starting since not all motors start simultaneously. However, for large individual motors (above 15% of transformer rating), verify the voltage dip during starting is acceptable.
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