[Deep Cover]

Pete,

I've wondered why premade fixture whips (3/8" FMC) come with a ground in them. Nothing in the 2011 NEC makes me think that an EGC is required if kept under 20A and less than 6'. Am I missing something?

 

[Deep Cover]

So, maybe the manufacturers are covering their butts for (C)? Otherwise, I don't see anything that would require an EGC.

 

[Deep Cover]

What the OP is describing may be "code worthy" in lengths under 6' but from my personal experience (seeing fires caused by BX cable) I wouldn't trust it.

I do not believe it is a reliable return path for fault current due to the seemingly high impedance.

Pete

I'll be a little more specific about my question (slight side step from the OP)...

If I were to make my own fixture whips with 3/8" FMC, with listed connectors, protect the conductors at 20A, and keep the length under 6', would I have to install an EGC in the whip?

 

[Deep Cover]

Sorry to say this... But, maybe. If the AHJ makes a determination that the FMC is installed to "provide flexibility for equipment that requires movement after installation" then yes an EGC would be required.

For a typical 2X4 lay in fixture I wouldn't see what I quoted as requiring an additional EGC.

Pete

Thanks. We just changed to the 2011 and the wording in the 2008 could be interpreted differently.

d. Where used to connect equipment where flexibility
is necessary after installation, an equipment
grounding conductor shall be installed.

Because of this wording, most EC's decided to run EGC's no matter what the circumstance.

 

[Deep Cover]

You are using it for its flexibility, not because it looks nice.

That is the exact interpretation that was cited previous to the 2011 code cycle. Now, with the new wording, I don't see that as a valid argument.

 

[Deep Cover]

This is where I split hairs. These fixtures are required to be secured to the grid, so after installation, they are not removable. In order to remove them, you would need to "uninstall" them.

 

[Deep Cover]

(C) is describing three different conduit systems which in reality have to be made with about 8 connections to complete the egc system. The margin of error at the connections is a lot and I am wondering why getting all of that within 6 feet would be legal anyway.

(C) is talking about the entire raceway system. Say you had a 3' fixture whip but in order to feed this circuit, you had to fish FMC 5' down to the panel. That 5', combined with the 3' fixture whip would be over the max 6' of flex allowed and you would have to install an EGC in both sections of flex.