Formula variables
- Row kVA is calculated from the entered kW, kVA, or amps row input.
- Demand factor is an entered row assumption, not a code table lookup.
- Margin percent is a project planning input.
- Recommended kVA is rounded up to a standard rating for screening.
Assumptions
- Each load row converts to connected kVA before the row demand factor is applied.
- Margin is applied after the total demand kVA is calculated.
- The recommended value is the next standard kVA rating in the calculator reference list.
- Transformer impedance, inrush, temperature rise, taps, protection, grounding, conductor sizing, and manufacturer data are outside this screen.
Examples
600 V to 208 V transformer screen. A 42 kVA load plus an 18 kVA load at 80 percent demand gives 56.4 kVA demand. With 15 percent margin, the screen recommends 75 kVA.
Design handoff. Use the result to discuss a standard kVA range, then confirm protection, fault current, inrush, and manufacturer data separately.