What is the approximate minimum approach distance (MAD) when working on a 34.5 kV system at an altitude of 10,152 feet?

The minimum approach distance (MAD) is a critical safety guideline designed to help prevent electrical contact with high-voltage systems. For a 34.5 kV system, the MAD at lower altitudes is typically governed by established standards which outline specific distances based on voltage levels. However, altitude affects these recommendations due to the decreased air density, which reduces the dielectric strength of the air.

At an altitude of 10,152 feet, it is necessary to account for this factor when determining the appropriate MAD. The industry standards provide an adjustment factor for high-voltage work at increased altitudes, which generally leads to the requirement for a greater distance to ensure safety.

For a 34.5 kV system, the appropriate MAD at a standard elevation might be around a couple of feet. But when elevated to 10,152 feet, the required distance increases, and the correct choice reflects this adjusted requirement. Therefore, the correct minimum approach distance in this scenario is 3 feet, 3 inches, ensuring that safety is maintained while working near the high-voltage system.