Insulated Fittings 300.4(F)

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dnem

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PVC connector terminating in an enclosure with larger than 4gauge wires in the PVC
Bushing always required ?

300.4(F) Insulated Fittings
Where raceways containing ungrounded conductors 4 AWG or larger enter a cabinet, box enclosure, or raceway, the conductors shall be protected by a substantial fitting providing a smooth 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.
 
Bushing

Bushing

DNEM

352.46 Even though the adapter is plastic the edges are rather abrasive. I always used an insulating bushing, from expeirence out in the field w/ the use of THHN conductors it tends to tear up the plastic outer cover. Again in the application stated the conductors are normally #4 or larger as stated in 300.4
 
dnem,

I was told that the only raceway that can enter a cabinet,box enclosure,etc.

is a RMC all other raceways end at a fitting and the fitting enters the box,etc.

It may not be the intent but it is the words.
 
True enough, RMC and IMC are normally the only raceways that enter a box. For all the rest, the fittings enter the box. That said, my inspectors enforce the bushing requirement for all raceway types when 4ga and larger conductors are used. I'm happy to spin one on, because I think it makes it look "professional", even if it's not required. Sometimes I'll spin one on a 1/2" EMT for that nostalgic look. ;)
 
IMO there is more than one definition of the word "enter". If I told you to "enter the EMT into that panel" would you just stick it into a KO? I think that you would "enter" it into the panel by using a connector on the end of it. Therefore, even raceways with connectors require bushings for #4 and larger conductors.
 
dnem said:
PVC connector terminating in an enclosure with larger than 4gauge wires in the PVC
Bushing always required ?
Click to expand...

With PVC you can pretty much ignore 300.4(F) because you will be busy complying with 352.46 as lowryder88h pointed out.

352.46 Bushings.
Where a conduit enters a box, fitting, or other enclosure, a bushing or adapter shall be provided to protect the wire from abrasion unless the box, fitting, or enclosure design provides equivalent protection.


FPN:See 300.4(F) for the protection of conductors 4 AWG and larger at bushings.
Click to expand...

IMO 352.46 requires plastic bushings on all PVC male adapters regardless of wire size and type.

For the price of a plastic bushing I could not be bothered auguring if the raceway or the connector enters the box. :)
 
Trevor,
Therefore, even raceways with connectors require bushings for #4 and larger conductors.
Click to expand...
While I completely agree that is the intent of the code. When you apply the wording of the code rule as it is now written it only applies to "raceways" that enter the enclosure. There are only two raceways that actually enter the enclosure...rigid and IMC. This wording will be corrected for the 2008 code.
Don
 
mdshunk said:
True enough, RMC and IMC are normally the only raceways that enter a box. For all the rest, the fittings enter the box. That said, my inspectors enforce the bushing requirement for all raceway types when 4ga and larger conductors are used. I'm happy to spin one on, because I think it makes it look "professional", even if it's not required. Sometimes I'll spin one on a 1/2" EMT for that nostalgic look. ;)
Click to expand...

"that nostalgic look"
Do you think that'll work for an inspection writeup ?

Not Approved
Add bushing to conduit connector for that nostalgic look - 300.4(F)
 
lowryder88h said:
DNEM

352.46 Even though the adapter is plastic the edges are rather abrasive. I always used an insulating bushing, from expeirence out in the field w/ the use of THHN conductors it tends to tear up the plastic outer cover. Again in the application stated the conductors are normally #4 or larger as stated in 300.4
Click to expand...

That's what I love about this site. . I can be as lazy as I like and other people do the research and come up with stuff like 352.46. . I love it !

But seriously, it's good that so many people see these posts and the answers are usable by so many.

iwire said:
IMO 352.46 requires plastic bushings on all PVC male adapters regardless of wire size and type.

For the price of a plastic bushing I could not be bothered auguring if the raceway or the connector enters the box. :)
Click to expand...

"regardless of wire size"
Only if you ignore the FPN
I realize that the FPN isn't code but it's referring you to a code article. . As a reference connection to another code article, I think it establishes the application of 352.46 to the restrictions of 300.4(F).

David
 
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