ryan_618
05-11-2005, 09:42 PM
(F) Insulated Fittings. Where raceways containing delete "ungrounded"ungrounded conductors 4 AWG or larger 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.
Change to read:
(F) Insulated Fittings. Where raceways containing conductors 4 AWG or larger 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.
Substantiation:
As written, this important protection requirement does not apply to the grounded conductor. The grounded conductor, in many cases, is every bit as dangerous as the ungrounded conductor. This is especially true when multi-wire circuits are employed. Isolated phase installations permitted by 300.3(B)(1) are an example of where this could apply.
[ May 11, 2005, 09:55 PM: Message edited by: ryan_618 ]
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.
Change to read:
(F) Insulated Fittings. Where raceways containing conductors 4 AWG or larger 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.
Substantiation:
As written, this important protection requirement does not apply to the grounded conductor. The grounded conductor, in many cases, is every bit as dangerous as the ungrounded conductor. This is especially true when multi-wire circuits are employed. Isolated phase installations permitted by 300.3(B)(1) are an example of where this could apply.
[ May 11, 2005, 09:55 PM: Message edited by: ryan_618 ]