The "Restricted Approach Boundary" values, listed in NFPA 70E 2018 edition Table 130.4(D)(a) appears to be less than the minimum approach distance calculated by in OSHA 1910.269 Table R-3 as required by 1910.269(I)(3)(i) or Table R-7 as allowed by Table R-3 footnote 2. What is the difference between these requirements and which applies to utility linemen working on distribution and transmission power lines?

NFPA 70E states that the scope does not cover installations under exclusive control of an electric utility.

OSHA 1910.269 states that it is applicable to power generation, transmission and distribution installations of electric utilities.

It just seems strange that for the same hazard level the standard applied to trained linemen/utility workers is higher than for general industry. Typically I would expect utilities to have higher levels of training and therefore less strict absolute requirements allowing them to rely on their training to perform their work safely. I am wondering if anyone knows where the two different distances came from and why they differ for the same voltage level.

The OSHA rule is not absolute as you suggest:



the exceptions follow.