Find the Answer
"I see all kinds of crazy things working in the field," says EC&M reader Robert Stemmer, owner of Specialized Construction in Lomita, Calif. "Check out the fancy braided wire and termination on the neutral (grounded conductor) from the subpanel to the panel on the left, the missing insulated bushing, and the circuit breaker storage compartment on the bottom right."
Wow, that's a creative homemade jumper cable, isn't it? Something tells me this isn't a listed product. And let's not forget to mention the lack of insulated bushings on each end of the conduit nipple connecting the two cabinets.
As noted in 300.4(G), "Where raceways contain 4 AWG or larger insulated circuit conductors and these conductors enter a cabinet, box, enclosure, or raceway, the conductors shall be protected by a substantial fitting providing a smoothly rounded insulating surface, unless the conductors are separated from the fitting or raceway by substantial insulating material that is securely fastened in place.
Exception: Where threaded hubs or bosses that are an integral part of a cabinet, box, enclosure, or raceway provide a smoothly rounded or flared entry for conductors.
Conduit bushings constructed wholly of insulating material shall not be used to secure a fitting or raceway. The insulating fitting or insulating material shall have a temperature rating not less than the insulation temperature rating of the installed conductors."
We could also question whether the maximum conductor fill limitation has been exceeded in this nipple too.