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110 V transformer loading

Job / reference: ______________________________Printed date: ____

Formula registry version 1.0.0 · researched 2026-07-24

TL-03 · Power & supply

110 V transformer loading

Add the electrical input power and power factor for each concurrent load. The tool reports arithmetic demand only and does not select a transformer.

PLANNING ESTIMATE

Entered concurrent loads

Load 1
Load 2

An explicit user assumption; zero is valid.

Method and worked example

Sᵢ (kVA) = Pᵢ (kW) ÷ PFᵢ

S_run = ΣSᵢ

S_plan = S_run × (1 + entered margin ÷ 100)

Worked example: 1.6 kW at PF 0.9 plus 0.7 kW at PF 0.8 gives 2.653 kVA running. With an entered 20% margin: 3.183 kVA with entered margin.

Blank worksheet

Load / electrical input kW / PF:
Load / electrical input kW / PF:
Load / electrical input kW / PF:
Sum of P ÷ PF:
Entered margin / result:

Transformer loading result

Result recordPLANNING ESTIMATE

Worked example — default entered values

2.653 kVA running
3.183 kVA with entered margin

Entered margin: 20% — compare the result with a verified continuous rating.

Assumptions register

Load 1: 1.6 kW ÷ PF 0.9 = 1.778 kVA · Load 2: 0.7 kW ÷ PF 0.8 = 0.875 kVA · Entered margin: 20%

Entered kW is electrical input power and all entered loads operate concurrently.

Each entered power factor applies at the expected operating point.

The entered margin is a planning assumption, not a regulatory value.

Starting demand, harmonics, voltage drop, ambient derating and duty cycle are not modelled.

△ Check the complete supply arrangement

Compare against a verified continuous rating. Starting/inrush demand, duty or intermittent rating, plug/input, individual outlet current and manufacturer instructions can govern. Supplier, manufacturer or competent-person confirmation is required.

PLANNING ESTIMATE. Compare against the verified continuous rating. Starting/inrush demand, duty or intermittent rating, plug/input, individual outlet current and manufacturer instructions can govern. Supplier, manufacturer or competent-person confirmation is required.

Source register · registry version 1.0.0

Health and Safety Executive, Electricity – Systems in buildings — accessed 2026-07-24

Health and Safety Executive, Work using electrically powered equipment — accessed 2026-07-24

Fluke, Power Factor: What it is and How to Calculate it — effective 2026-02-16 — accessed 2026-07-24

Faithfull Tools, Site Transformer 110V 3.3kVA — accessed 2026-07-24

Formula researched 2026-07-24