Electrician's Licensing Practice Exam 2026 - Free Electrician License Practice Questions and Study Guide

The assertion that it is not necessary to place a grounding rod inside a commercial building for grounding a transformer is correct. Grounding transformers typically relies on external grounding systems that connect to grounding electrodes located outside the building, such as a grounding rod or other grounding methods.

The primary purpose of grounding a transformer is to ensure safety and to provide a path for fault currents, helping to protect equipment and personnel from electrical hazards. In most cases, the grounding requirements for transformers are governed by the National Electrical Code (NEC), which specifies how and where to properly ground electrical equipment, including transformers.

In commercial settings, grounding systems generally utilize a combination of grounding conductors and grounding electrodes that are designed to direct any potential fault currents safely into the ground, which is why an internal grounding rod is not necessary. Instead, the focus is on creating a connected grounding system that provides adequate safety and compliance with applicable codes and standards.