NCCCO Mobile Crane Practice Exam 2025 – Complete Study Guide

The minimum clearance required when operating near high voltage lines of 250 KV is established to ensure the safety of personnel and equipment. ANSI B30.5 outlines safety standards for cranes and other lifting devices, emphasizing the importance of maintaining appropriate distances from power lines to mitigate risks of electric shock or arcing.

The correct answer of 20 feet reflects industry standards that consider the high voltage involved and the potential hazards associated with proximity to electrical lines. This distance is designed to provide a safety buffer against the electrical field around high voltage lines, which can extend beyond the physical lines themselves.

Other options suggested distances that are not sufficient under the guidelines established for such high voltage scenarios, potentially leaving equipment and personnel at risk. Maintaining the correct clearance is crucial for safe crane operation, especially in environments with high voltage infrastructure.