Insulated bushings 300.4(F)

Status
Not open for further replies.
goldstar

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
I recently upgraded a service and installed a length of 1 1/4" Greenfield from an old breaker cabinet to the new breaker panel. There were some 8 circuits (15 and 20 amp) run between the two cabinets. Proper squeeze type terminal fittings were used for the Greenfield. The inspector failed the job because I didn't install insulated bushings on the ends of the 1 1/4" fittings.

Now, from what I read in 300.4(F) I believe I'm in compliance. There are no ungrounded conductors that even come close to # 4AWG. In addition the fittings have a smoothly rounded edge so as not to cause any chaffing of the wires. Can anyone think of any other section of the code that I should be looking at to determine if this inspector is correct?

Thanks in advance.

Phil,
Gold Star Electric
New Jersey

[ December 29, 2005, 05:26 PM: Message edited by: goldstar ]
 
Re: Insulated bushings 300.4(F)

Bushing are required on all raceways if they contain #4 or larger conductors. It doesn't matter if the fitting is smooth edged or not. But back to your OP, the inspector is wrong your installation does not require bushings. However, I would look at the derating issue that Jim brought up if your flex exceeded 24".
 
Re: Insulated bushings 300.4(F)

Perhaps he meant grounding bushings, in case you're using the flex as an EGC.
 
Re: Insulated bushings 300.4(F)

Originally posted by LarryFine:
Perhaps he meant grounding bushings, in case you're using the flex as an EGC.
Click to expand...
When would flex need a grounding bushing? Wouldn't the listed connector provide the grounding path?
 
Re: Insulated bushings 300.4(F)

Originally posted by infinity:
When would flex need a grounding bushing? Wouldn't the listed connector provide the grounding path?
Click to expand...
I'm imagining the inspector not approving the flex alone as an adequate GEC between enclosures, and wanting a grounding conductor bonded at both ends via bonding bushings.

I'm weird that way. ;)
 
Re: Insulated bushings 300.4(F)

Larry may be on to something here. What is the voltage of your panels? Are they 480/277 volt panels? And did you use prefab coincentric ko's?
 
Re: Insulated bushings 300.4(F)

i bet he's just assuming that he understood the requirement in the first place to be the pipe size, not the conductors.
 
Re: Insulated bushings 300.4(F)

Thanks for all the replies guys. Let me try and clear up a few things. The breaker panel is a Square D, 30 breaker/40 circuit remodel residential 120/240 single phase panel. The Greenfield is probably just over 24" but not more than 30". I had pulled a # 6 THHN through it and bonded the cabinets together even though the clamp-down Greenfield fittings should be enough to complete the ground path. The note that was left on the red sticker was that "bushings" were needed on the 1 1/4" flex. He mentioned to the homeowner that "the cheap plastic kind would suffice". There was no mention of "bonding bushings ". The only concentric KO was on the old breaker panel.

There was no mention of de-rating the conductors. There are only 16 conductors (#14 and 12 THHN) and a #6 EGC in an 1 1/4" flex conduit. The loads are lighting and receptacle circuits. There's more than a 40% fill factor remaining in the sleeve. Aside from the fact that these bushings cost about 29 cents @ and I'll probably just cut them, slip them ovet the wires and install them anyway, I don't believe the inspector can site a code violation. I won't be able to speak to him until next week due to the holiday schedule (they're off this friday and monday). Where did I go wrong in life !!!

[ December 30, 2005, 06:37 AM: Message edited by: goldstar ]
 
Re: Insulated bushings 300.4(F)

Originally posted by goldstar:
He mentioned to the homeowner that "the cheap plastic kind would suffice".
Click to expand...
Okay, then he clearly meant "OZ" bushings, which are clearly not required in this instance. I'd opt for showing him the NEC (or asking him to show you) over installing the bushings.

Why? Not for the few cents, or even the 15 minutes, but for setting precedence. In my opinion, mutual respect is much better than a one-sided "do as I say" relationship in the long run.

Next time, it may not be as inexpensive.
 
Re: Insulated bushings 300.4(F)

Not long ago I had an inspector site me for not having a strap within 18 inches of a box on emt.

I did just what was suggesed by Larry. I asked him for the code reference. He backed down and said he prefers it that way. Just to keep him happy I now install them closer when it is practicle. Like I care, the conduit is already offset back to the wall at that point anyway.

The end result has been that I have gained his respect. On walk-throughs, and inspections, he now discussess code issues with me on an equal level.
 
Re: Insulated bushings 300.4(F)

Good points Larry & JB. I intend to speak with the inspector about this. As luck would have it the job is just up the street from my house so putting on the bushings would be no great inconvenience but as you say - it's the principal of the matter. I too think mutual respect is much better than the "do as I say because that's what I like" approach.

Thanks,

Phil
 
Re: Insulated bushings 300.4(F)

Originally posted by goldstar:
Where did I go wrong in life !!!
Click to expand...
There is still hope for you - study up and get your inspectors credentials.
:) :D
 
Re: Insulated bushings 300.4(F)

"I'll probably just cut them, slip them ovet the wires and install them anyway "

Cutting them is not legal.Best thing to do in this case might be to put them on.Normally i would suggest you print this forum out for him ,but doing so would give him a way to site you for the real violation of being over 24 inches.That would cost far more to fix.Perhaps after he passes it have a friendly chat and show him where he is mistaken.

[ December 30, 2005, 07:18 PM: Message edited by: jimwalker ]
 
Status
Not open for further replies.
Top