FMC/Greenfield to EVSE inside a garage

Status
Not open for further replies.
N

Nutmegger

Senior Member
Location
Fairfield County, Connecticut
Installing an EVSE inside a resi garage. Need a 40-50 ft homerun from the garage sub to the EVSE disconnect (also inside the garage - not on the exterior).
I know it's overly generic, and might vary from one AHJ to another (I am in Connecticut, Fairfield County), but in general did anyone ever run into any problem with inspection when running THHN inside exposed FMC following the wall and ceiling surfaces? Some of the run is along sheetrock, some - across bare studs/rafters.
The alternative is EMT or PVC, but there are many turns - no easy way to make it a straight rigid pipe run.
The building dept was overly vague on the phone when I asked.
 
348.26 Bends- Number in One Run. There shall not be more than the equivalent of four quarter bends (360 degrees total) between pull points, for example, conduit bodies and boxes.
 
I have really never understood the use of FMC 99% of the time. I would just use MC*

*This is assuming you have good availability of MC. One of my supply houses can get pretty much any size copper or aluminum MC up to 500 MCM next day from their distribution center.
 
electrofelon said:
I have really never understood the use of FMC 99% of the time. I would just use MC*

*This is assuming you have good availability of MC. One of my supply houses can get pretty much any size copper or aluminum MC up to 500 MCM next day from their distribution center.
Click to expand...
It’s nice for small conduit bend under 6’,we’re you need maybe multiple circuits.

My Local inspector allows fmc in more areas then nmb even though they are both subject to physical damage requirement.
 
FMC is nice when you have to transition to something else (going outdoors, say) and don't want to splice. Or if running multiple circuits together. Also it's less of a pain to connect to a box than MC.

Also we do a lot of #8 and larger runs with no neutral and it's a lot easier to obtain than 8/2 and larger cables. They don't even make 4/2 cables.
 
AC\DC said:
It’s nice for small conduit bend under 6’,we’re you need maybe multiple circuits.

My Local inspector allows fmc in more areas then nmb even though they are both subject to physical damage requirement.
Click to expand...

That may be fair. Some things can damage NM that MC will survive. It’s subjective.
 
Nutmegger said:
Installing an EVSE inside a resi garage. Need a 40-50 ft homerun from the garage sub to the EVSE disconnect (also inside the garage - not on the exterior).
I know it's overly generic, and might vary from one AHJ to another (I am in Connecticut, Fairfield County), but in general did anyone ever run into any problem with inspection when running THHN inside exposed FMC following the wall and ceiling surfaces? Some of the run is along sheetrock, some - across bare studs/rafters.
The alternative is EMT or PVC, but there are many turns - no easy way to make it a straight rigid pipe run.
The building dept was overly vague on the phone when I asked.
Click to expand...
I would try to use NM and protect it with 2x4s by stapling to a 2x4. You may have to add a couple extra 2x4s
 
Nutmegger said:
Installing an EVSE inside a resi garage. Need a 40-50 ft homerun from the garage sub to the EVSE disconnect (also inside the garage - not on the exterior).
I know it's overly generic, and might vary from one AHJ to another (I am in Connecticut, Fairfield County), but in general did anyone ever run into any problem with inspection when running THHN inside exposed FMC following the wall and ceiling surfaces? Some of the run is along sheetrock, some - across bare studs/rafters.
The alternative is EMT or PVC, but there are many turns - no easy way to make it a straight rigid pipe run.
The building dept was overly vague on the phone when I asked.
Click to expand...
As far as the raceway of choice is concerned, the limitation to 360* in bends applies to both EMT and FMC. It seems counterintuitive because FMC is so flexible, but the same rule applies. Still limited to 360*

The only issue I can potentially see, is that if the garage was classified as a damp or wet location, but nobody I've EVER worked under in residential has considered a garage to be a damp or wet location. Never. Not once. Ever. Never Ever. Never.

However, now that I look more closely at the 100's.. I suppose the inspector could make the call that a garage is a wet location due to the potential for vehicle washing... and that would change your requirements for the raceway and wire types.

FMC is not suitable for a wet location. EMT is, with corrosion resistant fittings, supports, and screws.
Most THHN is dual rated as THWN for use in a wet location, I believe. But you should be certain your wire is listed for use in a wet location even inside the EMT.
 
Last edited:
Status
Not open for further replies.
Top