Metal flexible conduit vs. MC cables

[anbm]

How can we tell the difference between MC and metal flexible conduit by just looking from below? Assuming they both are less than 6 feet long.

 

[roger]

Probably can't in most cases

 

[infinity]

How can we tell the difference between MC and metal flexible conduit by just looking from below?

Depends, 2-wire MC is noticeably smaller than even 3/8" FMC.

 

[LarryFine]

Depends, 2-wire MC is noticeably smaller than even 3/8" FMC.

Exactly. We can usually tell by looking. What's the approximate diameter?

 

[kec]

Also MC seems to have a tighter wound coil in my observation.

 

[roger]

It also has to do with how far underneath and how familiar with flexible wiring methods the observer is. In many of my jobs it could have been 15' or more and even with the more than 100,000 of 12/2 I purchased in my career I wouldn't look up that distance and bet money on what I was looking at.

 

[anbm]

3/4"C

 

[roger]

3/4"C

Well in that case it would be easy to tell difference, 3/4 FMC is considerably larger then say 12/2 MC is

 

[LarryFine]

3/4"C

If that's the OD, then it's 1/2" flex, unless it's something like 2-4 MC.

 

[jap]

As others have said, after a while you get to where you can just tell.
Also, most of the time, FMC is terminated with standard squeeze type flex connectors.
MC cable is generally terminated with push-in type MC Connectors.

JAP>

 

[letgomywago]

Also MC seems to have a tighter wound coil in my observation.

That's more the larger sizes. 4/0 mc has like a 3rd more winding it seams.

 

[letgomywago]

As others have said, after a while you get to where you can just tell.
Also, most of the time, FMC is terminated with standard squeeze type flex connectors.
MC cable is generally terminated with push-in type MC Connectors.

JAP>

Large mc is normally terminated with squeeze type connectors with screws or a compression type for pvc jacketed.

 

[electrofelon]

To tell for sure you would probably need to touch it, shake it, and see how stiff it is. Anyone who wants to giggle can do it in the principal's office

 

[LarryFine]

Heck, if you can reach it, just shake it.

If it's flex, you will feel the added wires inside.

If it's MC, the wires and filler will feel solid.

I took the question to mean it's out of reach.

 

[jap]

Large mc is normally terminated with squeeze type connectors with screws or a compression type for pvc jacketed.

I don't consider a 3/4" diameter flex Large MC.

Jap>

 

[kwired]

There are some MC/AC cables out there with "shrink wrap tags" every few feet and some with colored markings periodically on the sheath to indicate what conductors are contained in it.

If it has a green color to it it is probably health care cable with a bond strip and a green along with whatever other conductors it was made with.

Just a few things that are out there that are easier to identify at a glance.

 

[Little Bill]

Usually, if it's a very long run, it won't be FMC.