In what situation can an equipotential zone be effective for a Qualified Electrical Worker?

An equipotential zone is an area where the electrical potential is equalized, minimizing the risk of electric shock to workers. In this context, standing on a conductive mat can be highly effective for a Qualified Electrical Worker. The conductive mat helps create an equipotential surface by dispersing electrical charges, allowing the worker to maintain a uniform electrical potential with the surrounding environment. This is essential, especially in areas where there is a risk of step or touch potential, as it helps to ensure that the worker does not come into contact with different electrical potentials, thus reducing the likelihood of electrical shock.

While using insulated boots, being connected to a grounding rod, and wearing rubber gloves are all important safety measures, they do not inherently create an equipotential zone. Insulated boots protect against ground faults but do not equalize potential; a grounding rod can provide a path to ground but might not ensure uniform electrical potential across the worker's body; and rubber gloves serve to insulate the worker's hands, providing protection from direct electrical contact, but again, do not form an equipotential space. Therefore, standing on a conductive mat directly supports the concept of an equipotential zone more effectively than the other options provided.