Flexable Metal Conduit with Internal Bonding Strip

[ibew441dc]

Has anybody ever come across FMC with an internal bonding strip, similar to the one in AC cable or Liquid tight?

Just to be clear, not Liquid tight, no cables, but specifically Flexable Metal Conduit.
A friend of mine and I were having a discussion and we disagree that it exists or not. I say it doesn't, he says it does. He can offer no proof, and since I don't think it exists how can I?

Please provide manufacturer, picture, cut sheet, or something like that if it does exist.

 

[ericsherman37]

I googled it and couldn't find anything but Liquidtight flex with an integral bonding wire. Never seen any regular flex with one, either.

 

[jeremysterling]

I've never seen "Greenfield" with an assembled bonding strap.

 

[e57]

Strip the jacket off of liq-tite - VILOIA FMC with a bond strip.

(FWIW - it doesn't stay together very well after you take the plastic off)

 

[K8MHZ]

The guy at Home Depot was telling me about this. He said they may be carrying it soon. He said it wasn't AC, it was MC with a strip like AC.

 

[roger]

The guy at Home Depot was telling me about this. He said they may be carrying it soon. He said it wasn't AC, it was MC with a strip like AC.

MCAP or MC Smart has been around for a few years now, click here

Roger

 

[ibew441dc]

Strip the jacket off of liq-tite - VILOIA FMC with a bond strip.

(FWIW - it doesn't stay together very well after you take the plastic off)

Funny you say that , cause thats what I told him:grin:

 

[ibew441dc]

The guy at Home Depot was telling me about this. He said they may be carrying it soon. He said it wasn't AC, it was MC with a strip like AC.

As stated in the thread starter....I'm talking specifically about FMC......not cables and not liquid tight:smile:

 

[K8MHZ]

As stated in the thread starter....I'm talking specifically about FMC......not cables and not liquid tight:smile:

Nevermind....

 

[SEO]

I have not seen it or even heard about it.

 

[Flex]

searched all over and cant find any

 

[Pierre C Belarge]

Show him 320.100
Then show him that the same section (.100) does not exist in FMC and there is no reference to FMC with a bond conductor.

and
Show him 250.118(5)

It may just help.
If not show him the door to the missing deck on the 13th floor. :grin:

 

[LarryFine]

The guy at Home Depot was telling me about this. He said they may be carrying it soon. He said it wasn't AC, it was MC with a strip like AC.

But the OP is asking about FMC (Greenfield, or "flex") without conductors already installed. MC and AC contain conductors.

 

[K8MHZ]

But the OP is asking about FMC (Greenfield, or "flex") without conductors already installed. MC and AC contain conductors.

I know that now. My bad.

I will be over in the corner, pouting....

 

[ibew441dc]

Show him 320.100
Then show him that the same section (.100) does not exist in FMC and there is no reference to FMC with a bond conductor.

and
Show him 250.118(5)

It may just help.

Already have.....:smile:

If not show him the door to the missing deck on the 13th floor. :grin:

Actually that may be the only effective way:grin:

 

[kjless]

maybe he saw a ecternal bond and thought it came like that (dumbass) lol

 

[drive1968]

Doesn't the metal jacket serve as the bonding strip? I guess I don't understand what the advantage would be of a bonding strip with FMC.

 

[Electrician4life]

Doesn't the metal jacket serve as the bonding strip? I guess I don't understand what the advantage would be of a bonding strip with FMC.

Take a look at 348.60 Grounding and Bonding

Where used to connect equipment where flexibility is required, egc shall be installed. Where flexibility is not required, FMC shall be permitted to be used as an egc when installed in accordance with 250.118(5).

250.118 Types of Equipment Grounding Conductors.

(5) Listed flexible metal conduit meeting all the following conditions

(a) Conduit is terminated in fittings listed for grounding

(b) Circuit conductors contained in the conduit are protected by
overcurrent devices rated at20 apms or less.

(c) Combined length of FMC, FMT, and LFMC in same ground return path does not exceed 6ft.


I don't think I would want to run any length FMC without an egc IMO. I've seen too many instances of the flex being damaged even at short lengths.

 

[iMuse97]

Doesn't the metal jacket serve as the bonding strip? I guess I don't understand what the advantage would be of a bonding strip with FMC.

A EGC is required when using FMC lengths over 6' for the same reason that a bonding strip is required in AC cable as it is constructed. for the same reason you cannot obtain MC cable without an EGC--the reason: when there is no bonding strip, the coiled nature of the product creates an impedance which becomes too great to be an effective EGC at lengths greater than 6'. The bonding strip eliminates this problem, and the EGC bypasses it, in a manner of speaking, IMHO. At least, this is what I've understood to be the case. Did I qualify my answers enough so that nobody will pay me any attention?

 

[hbiss]

Think about it. How would you construct Greenfield so that the bonding strip stays in place until you pull your conductors? The way it works with AC is that the strip is in continuous contact with the armor and it's held there by the factory installed conductor fill. How are you going to do that with empty Greenfield that wouldn't have the fill to hold it against the armor even if it was installed at the factory ?

-Hal