# Transformer FAT and Site Commissioning: IEC 60076 Test Plan

> A practical factory and site acceptance plan for power transformers covering routine, type, special and dielectric tests, transport checks and evidence-based commissioning.

- **Category:** Transformer Testing & Commissioning
- **Author:** Voltformer Transformer Testing & Commissioning Engineering
- **Publication Date:** 2026-09-12
- **Reading Time:** 9 min read
- **Key Tags:** #IEC 60076-1, #IEC 60076-3, #IEC 60076-5, #FAT, #SAT
- **Canonical URL:** https://voltformer.com/articles/transformer-factory-acceptance-tests-iec-60076
- **Markdown Source:** https://voltformer.com/articles/transformer-factory-acceptance-tests-iec-60076.md

### 1. Build the Test Plan from the Exact Nameplate

IEC 60076-1 applies to most single-phase, three-phase and autotransformer power-transformer designs. The purchase order should identify the exact unit, winding arrangement, tap range, frequency, cooling stages, liquid or dry-type insulation system and agreed guarantee values before any test result is reviewed.

A FAT dossier is not a generic certificate. It must bind every result to the serial number, tap position, test temperature, instrument calibration and the tested configuration.

### 2. Routine, Type and Special Evidence

| Test family | Typical engineering purpose | Acceptance boundary |
|---|---|---|
| **Routine tests** | Ratio, phase displacement, winding resistance, no-load loss, impedance and dielectric routine checks | Compare with the approved guaranteed data and declared tolerances |
| **Type tests** | Temperature rise, sound, impulse or environmental behaviour for a representative design | Confirm the tested design remains representative of the ordered configuration |
| **Special tests** | Partial discharge, zero-sequence impedance, short-circuit or transport-specific checks | Include only when required by the specification, network owner or risk study |
| **Site tests** | Visual, oil, insulation, wiring, protection, alarms and functional checks after transport | Prove that shipping and installation did not change the factory condition |

### 3. Dielectric and Short-Circuit Boundaries

IEC 60076-3 defines insulation requirements, dielectric tests and recommended external clearances in air. Test levels must come from the equipment highest voltage and the agreed insulation coordination; they must not be copied from a similar-looking transformer.

IEC 60076-5 addresses the ability to withstand thermal and dynamic effects of external short circuits. A successful short-circuit design or type test does not replace the project short-circuit study, bushing duty, neutral grounding review or protection clearing-time check.

### 4. Commissioning Hold Points

- Reconcile nameplate, drawings, tap-changer position, vector group, accessories and bushing identification.
- Check transport impact, tank pressure or leak evidence, liquid level, moisture control, breather, conservator and radiator valves.
- Repeat the agreed ratio, winding-resistance, insulation, functional and alarm checks after connection; record ambient and oil temperature.
- Do not energize until earthing, surge arresters, CT circuits, trip circuits, interlocks and protection settings are independently signed off.

*Reference: IEC 60076-1:2011; IEC 60076-2:2011; IEC 60076-3:2013+A1:2018; IEC 60076-5:2006.*

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