Also, grounding at each service box may result in objectionable current over grounding conductors, prohibited by Rule 10-100. Today, we're diving deep into the world of distribution box grounding, breaking down the standards, and shining a light on those sneaky mistakes that even experienced electricians sometimes make. Whether you're a seasoned pro or just starting out, this comprehensive guide will give you practical. Rule 6-402 2) states metering equipment shall be connected on the supply side of a service box within limits placed on voltage and amperage common, but not limited, to residential services. Each DISTRIBUTION BOX and controller must be grounded. 26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. Grounding of the units: Attach a ground wire from one of. Grounding is a mechanism to protect distribution equipment and people under normal operating conditions, abnormal operational (overcurrent and overvoltage) responses, and hazardous conditions such as shocks. The grounding system provides a low-impedance path for fault current and limits the voltage rise on the normally non-current-carrying metallic components of the electrical distribution system. During fault. There are several factors that make substation grounding absolutely necessary.