Is all power required to be turned off before working on or inside a transformer?

When it comes to working on or inside a transformer, safety regulations and industry standards dictate that all power must be turned off before commencing any work. This is essential to ensure the protection of workers from electrical hazards, such as electric shock or arc flash, which can occur when working with energized equipment.

Transformers can operate at various voltage levels, and even low-voltage transformers can pose significant risks. The potential for stored energy and the presence of hazardous conditions reinforce the necessity of de-energizing the equipment to provide a safe working environment.

By ensuring that all power is turned off, workers can focus on their tasks without the constant risk of accidental contact with live electrical parts, which can lead to serious injuries or fatalities. This practice aligns with the general principle of Lockout/Tagout (LOTO) procedures, which are critical in controlling hazardous energy during maintenance activities.

In contrast, the other options suggest scenarios that do not prioritize the significant safety risks involved. Always approaching transformer work with the mindset that power must be cut off before any interaction is the recommended and safest practice in the electrical field.