Independent transformer screening tool

Existing Transformer Load & Expansion Headroom Screener

Document one simultaneous load reading, add planned load and screen arithmetic headroom. This does not select a transformer.

Step 1

Enter nameplate and field evidence

kVA
V
A

A spot reading is not claimed to be peak demand. Record when and how it was taken.

Planned expansion

kVA
%

Without an entered policy, a within-nameplate result remains Caution—not Pass.

Step 2

Screening result

Enter transformer, measurement and expansion details to screen headroom.

How the screening works

Single-phase current uses kVA × 1000 ÷ V. Three-phase current uses kVA × 1000 ÷ (√3 × line-to-line V). Planned kW is converted to kVA using the entered power factor. No diversity factor is assumed.

Critical limits

Arithmetic screening only—not final transformer selection. It does not determine conductors, breakers, relays or protection settings. Motor starting, harmonics, temperature, altitude, duty cycle and future growth require qualified review.

Technical sources

Use this screener to review transformer loading and possible expansion headroom using transformer kVA, power factor, existing demand and planned additional load. Use current project values and keep the units consistent so the screening comparison remains meaningful.

What to enter

Confirm the transformer's kVA rating and the applicable power factor. Use measured or otherwise verified existing demand where available, then enter the planned additional load requested by the screener. The template controls the actual fields and calculations; this supporting copy does not replace its labels, formulas or result logic.

How to read the screening result

Treat loading and headroom outputs as an early planning screen, not approval to connect more load. A simple headroom figure does not by itself account for load profile, starting demand, harmonics, imbalance, temperature, transformer condition, protection or network constraints.

Before expanding the load

Verify the transformer nameplate, actual demand history, planned equipment and operating conditions. Have the utility, transformer owner or a qualified electrical engineer confirm capacity, protection and connection requirements before purchase, installation or energisation.