In this episode, Russ finds a hole in the wall where some cables are routed to another section of a building. Unfortunately, this opening lacks any type of approved fire-stop material, which is a clear violation of Sec. 300.21 of the 2014 NEC.
NEC guidelines for GFCI protection in dwelling units
How to calculate voltage drop in a branch circuit serving a 460VAC, 3-phase motor.