Fact check: What is the NEC code reference for increasing the equipment ground size when the feeder conductors are increased for voltage drop

1. Summary of the results

The analyses consistently identify NEC Section 250.122(B) as the specific code reference for increasing equipment grounding conductor size when feeder conductors are increased for voltage drop ^{[1] [2] [3] [4]}. This section requires that when ungrounded conductors are increased in size from the minimum ampacity requirements, the equipment grounding conductor must be increased proportionately according to the circular mil area of the ungrounded conductors ^{[1] [4]}.

The calculation method involves determining the proportionate increase based on circular mil area and applying that same ratio to the equipment grounding conductor sizing ^{[3] [5]}. Multiple sources emphasize that this requirement only applies when conductors are increased beyond what is required for basic ampacity needs - specifically for reasons like voltage drop mitigation ^{[1] [4]}.

2. Missing context/alternative viewpoints

The original question lacks several important contextual elements that the analyses reveal:

• Specific conditions for application: The requirement only applies when ungrounded conductors are increased beyond minimum ampacity requirements, not for all conductor size increases ^[4]
• Calculation methodology: The analyses provide detailed step-by-step calculation procedures using circular mil area ratios that weren't mentioned in the original question ^{[3] [5]}
• Code evolution: One source notes that Section 250.122(B) was revised in the 2020 NEC edition to allow qualified persons more flexibility in sizing equipment grounding conductors in certain applications ^[6]
• Related code sections: The analyses reference additional NEC tables and sections like 250.66, 250.102(C)^[7], and 310.15(B) and (C) that provide context for proper grounding conductor sizing ^{[4] [8]}

3. Potential misinformation/bias in the original statement

The original statement contains no apparent misinformation or bias - it is a straightforward technical question seeking specific NEC code references. However, the question's simplicity could lead to incomplete understanding without the additional context provided in the analyses. The question doesn't specify the conditions under which this requirement applies, which could result in misapplication of the code if someone assumes it applies to all conductor size increases rather than only those exceeding minimum ampacity requirements ^{[1] [4]}.