What is the maximum resistance to ground permitted for a grounding electrode system consisting of a concrete-encased electrode, building steel electrode, and meter water pipe electrodes?

The correct answer reflects the understanding that there is no specific maximum resistance value established for a grounding electrode system that incorporates a concrete-encased electrode, building steel electrode, and meter water pipe electrodes. Instead, the focus is on ensuring that the grounding system achieves a low impedance path to ground, effectively minimizing the potential for electrical shock hazards and ensuring equipment protection.

The absence of a specified maximum resistance value suggests that the efficiency of grounding can depend on various factors, including soil conditions, moisture levels, and the configuration of the grounding system. Practically, grounding systems are designed to be as low in resistance as possible to enhance safety and equipment performance, but varying site conditions can lead to different optimal resistance levels.

The other options propose specific resistance values, which are not applicable in this context since grounding electrode systems can achieve different levels of effectiveness without being bound by a strict maximum resistance standard. This flexibility is crucial for accommodating diverse installation scenarios and ensuring that grounding is adequate based on the specific conditions and characteristics of the installation site.