Transformer kVA Verification Checklist PDF

Full QC Checklist+

Verify load input accuracy, standard series/safety margin selection, sizing result/headroom handling, and full-load current/installation code compliance.

✓22 Inspection Points

✓4 Verification Categories

✓Load Input Accuracy+

Correct load input mode selected (Voltage & Current vs. Power & Power Factor) matching the data actually available
Voltage entered matches the actual system voltage on the side being sized, not a different voltage class
Current or kW figure reflects the actual/design connected load, not a downstream device's individual nameplate rating
Power factor (Power mode) reflects the actual connected load type, not a blindly assumed default
Phase selection (single vs. three) matches the actual electrical service supplying the load

✓Standard Series & Safety Margin Selection+

Correct standard series selected (ANSI/IEEE vs. IEC) matching your region and procurement source
Understood that ANSI, IEC, and (within ANSI) single-phase vs. three-phase standard size lists don't line up one-to-one — the same load can round to a different recommended size in each
Safety margin percentage set appropriately for expected load growth, diversity, and operating headroom — not left at a default without thought
Safety margin not set to 0% without a specific, documented reason for sizing to the bare calculated load
An unusually high safety margin (approaching the calculator's 50% clamp) flagged for a second look rather than accepted at face value

✓Sizing Result, Headroom & Exceeds-Largest Handling+

Recommended kVA confirmed as the nearest standard size at or above the margin-loaded demand, never rounded down
Headroom kVA/percent understood as spare capacity between the margin-loaded demand and the recommended standard size, not the whole safety margin itself
Utilization percent understood as the base (pre-margin) load's share of the recommended size, not the margin-loaded figure's share
"Exceeds largest standard size" result (if shown) understood and acted on — not overlooked or dismissed
Recommended size cross-checked against an actual manufacturer datasheet or a second sizing method before finalizing procurement
Cost estimate (if enabled) understood as a rough budgetary planning figure only, not a quotable price

✓Full-Load Current, Installation & Code Compliance+

Full-load current at the recommended standard size (not the raw base load current) used for downstream protection and conductor sizing
Three-phase √3 (1.732) multiplier confirmed applied only for a genuine three-phase system, not a single-phase or split-phase service
Transformer energization inrush current (a short-duration multiple of full-load current) considered separately for upstream protective device coordination
Transformer impedance and voltage regulation under load recognized as not modeled by this calculator — verify against the actual unit's datasheet
Grounding scheme, overcurrent protection sizing, and applicable NEC/IEC installation requirements verified separately from this sizing result
Licensed electrical engineer review required before procurement and installation, not a substitute for professional design

Inspection Notes+

Use the latest approved drawings, specifications, and site measurements.

Complete all critical checks before proceeding to the next work stage.

Record deviations and confirm rectification where required.

Inspection Notes

Use the latest approved drawings, specifications, and site measurements.

Complete all critical checks before proceeding to the next work stage.

Record deviations and confirm rectification where required.

Related Calculators & Guides

Transformer kVA CalculatorOpen the related calculator and verify the current project inputs.

FAQ

Use it after collecting the project inputs and again before approving or closing the relevant work stage.

No. It supports verification but does not replace approved drawings, specifications, codes, manufacturer requirements, or professional inspection.