Before turning on the power to the transformer, what actions must be taken?

The correct action before turning on the power to the transformer is to ensure that all doors, devices, and covers are replaced properly. This is crucial because transformers and their enclosures require secured access to prevent accidental electrical contact and to maintain safety standards. If doors or covers are missing or not properly secured, there is a risk of exposing live components, which could lead to electrical shock hazards or equipment damage.

Furthermore, ensuring that safety enclosures are intact promotes compliance with safety regulations and standards governing electrical installations. A transformer can produce high voltage and increased levels of electromagnetic fields when powered, so maintaining these protective measures is imperative for the safety of all personnel working in the vicinity.

While checking voltage levels, installing safety barriers, and notifying personnel are all important safety and operational procedures, they are secondary to ensuring that all access and protective points of the transformer are secure before activation. Properly closed devices help in mitigating risks and establishing a safe working environment once power is restored.