Washington Administrative Code(WAC) and Revised Code of Washington (RCW) Electrical Practice Exam

How far apart must ground rods be unless a resistance test shows otherwise?

1. 10 feet

2. 8 feet

3. 6 feet

4. 6 inches

The correct answer is: 6 feet

The requirement for the spacing of ground rods is informed by electrical safety standards and practices. When installating ground rods, they must typically be positioned at least 6 feet apart, unless a resistance test indicates that a smaller distance is acceptable. This guideline is based on ensuring proper grounding effectiveness and minimal interference between the grounding systems. The rationale behind the spacing distance is to reduce the possibility of electrical interference and ensure that each ground rod operates independently, which enhances the overall grounding system's reliability. Spacing the rods too closely can lead to increased resistance in the grounding path, compromising the safety and functionality of the system. Therefore, adhering to the 6-foot minimum spacing is crucial, unless the results from resistance testing demonstrate otherwise, allowing for potential adjustments based on the specific site's conditions. While there may be other distances mentioned in the choices, such as 10 feet or 8 feet, they do not align with the standard practice unless specifically mandated by local codes or conditions that would warrant larger spacing. The choice of 6 inches is insufficient as it does not provide adequate separation for effective grounding. Thus, the 6-foot requirement is the accepted standard unless tested otherwise.