Transformer Testing Procedure for Transformers up to 5 MVA — Step‑by‑Step Guide
Introduction Transformers up to 5 MVA are common in distribution and industrial networks. Proper testing at the factory and on‑site before commissioning prevents failures, ensures performance, and protects personnel and equipment. This guide walks through the essential tests, acceptance criteria, safety measures, and reporting you need to commission a transformer reliably. Pretest Preparation and Safety Safety and responsibilities Roles: Test engineer (lead), technicians, earthing/line guards, site supervisor. PPE: Arc‑rated clothing; insulated gloves; safety helmet; safety shoes; eye and hearing protection. Work controls: Lockout‑tagout; verify zero energy; apply temporary earthing on HV and neutrals; confined space and hot work permits where required. Documentation and calibration Documents to review: Nameplate data, wiring diagrams, tap‑changer chart, factory test certificates, and handling/transport reports. Instruments: Megger (5/10 kV), turns‑ratio meter, DC milliohm m...