26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. 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. This Guide designates the practices that should be followed by the member firms of the Infrastructure Health & Safety Association (IHSA) when involved in de-energizing isolated electrical circuits or apparatus. This Guide is not designed as a training manual, but contains information, best. A temporary power distribution box (TPDB), often called a spider box, functions as a portable electrical hub that centralizes and protects power distribution on a job site. This device safely takes power from a single source, such as a generator or temporary utility service, and divides it into. Section 12, Installation and Maintenance of Equipment, Paragraph 123 Protective Grounding says in part: “Provisions must also exist for grounding during maintenance. Each DISTRIBUTION BOX and controller must be grounded. Grounding of the units: Attach a ground wire from one of.