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Control Transformer Load Estimate

Estimates required apparent power from user-entered simultaneous steady and pickup VA loads plus an explicit margin; it does not select a standard transformer rating.

Inputs

Range: at least 0 VA

Example starting value: 180 VA steady load. Replace it with the measured or scheduled control load.

Range: at least 0 VA

Example starting value: 300 VA pickup load. Enter the worst simultaneous pickup event, not every mutually exclusive event.

Range: 0–200 %

Example starting value: 25%. Replace it with the documented project margin.

Result

Higher entered load basis (VA)
300.0
Preliminary VA target (VA)
375.0
Higher entered load basis (VA)
\operatorname{max}(\mathrm{Simultaneous\ steady\ load\ (VA)},\mathrm{Worst\ simultaneous\ pickup\ load\ (VA)})
Preliminary VA target (VA)
\mathrm{Higher\ entered\ load\ basis\ (VA)} \cdot (1 + \frac{\mathrm{Design\ margin\ entered\ by\ user\ (\%)}}{100})

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Screening tool. Verify the adopted NFPA 70 edition, AHJ requirements, nameplate data, and project conditions before use.