FMC 80 foot run in finished ceilung

[bradleymattlin]

For a sub panel they use FMC and use it as the ECG. It's runs thru a finished celing. Is this grandfather in. would it create enough fault to trip the breaker. The run is about 80 feet and not straight. Trying not tear apart his celing.

 

[masterinbama]

Are you sure it's FMC and not a cable such as AC, MC or BX?

 

[bradleymattlin]

It has three number 2 conductors. It's a old house. Did
they make cable with those big of conductors.

 

[Ponchik]

You probably don't have to tear out the ceiling. If it is FMC, you can install #6 as an EGC in the conduit.

 

[masterinbama]

It has three number 2 conductors. It's a old house. Did
they make cable with those big of conductors.

What are the conductors insulated with?

 

[hurk27]

You probably don't have to tear out the ceiling. If it is FMC, you can install #6 as an EGC in the conduit.

At 80 feet and not being straight? good luck with that

 

[infinity]

It has three number 2 conductors. It's a old house. Did
they make cable with those big of conductors.

Yes, type A/C cable has been available with #2 conductors for a long time. There should be paper around the conductors.

 

[Ponchik]

At 80 feet and not being straight? good luck with that

He does need luck, but he can atleast try first, then tear out the ceiling.

 

[bradleymattlin]

The conductors don't have any paper. Just type tw wire.

 

[Ponchik]

The conductors don't have any paper. Just type tw wire.

Then the only thing that is left to do is use a fishtape and see if you can pull your EGC in it.

 

[hurk27]

Not saying it would be imposable but with the conductors in the FMC it would be close with bends, about the only thing I could see that would work is pulling out the conductors and pull in a small high strength rope when you pull them out, add the EGC using a pulling sock pull them back in.

FMC can be a nightmare to try to push a fishtape through if there are any bends, and if it isn't secured very well it will try to straighten out at corners which I seen it come through the drywall because of hard pulling.

 

[ActionDave]

FMC can be a nightmare to try to push a fishtape through if there are any bends,.....

This is very true.
A way to make shoving a fish tape into flex easier is to tape a zip tie to the end of your fish tape with about two inches of the clasping end sticking out.
Makes shoving that fish tape smooth; like driving on the ice with bald tires.

 

[Dennis Alwon]

If it is fmc then you would have some room inside the cable however if it is ac cable (BX) then the armor will be tight to the conductor. Not all ac cable is good as an egc however some of it was.