T-bar ceiling box with EMT conduit

Status
Not open for further replies.
B

billclou

Member
I am about to start a fire alarm conduit job and the majority of the devices will be ceiling mounted on an existing suspended (T-bar) ceiling. I want to use an EMT conduit system for this project. Without getting into the requirements of the actual box support, something in the back of my mind is telling me that the conduit between the fixed building structure and the flush boxes in the ceiling shall be flexible. I can't find this requirement anywhere in the code. Am I wrong?? Any ideas?? The job is in Southern California.
 
J

John120/240

Senior Member
Location
Olathe, Kansas
billclou said:
... I want to use an EMT conduit system for this project. Without getting into the requirements of the actual box support, something in the back of my mind is telling me that the conduit between the fixed building structure and the flush boxes in the ceiling shall be flexible.
Click to expand...

If you were to use EMT conduit to the devices mounted in ceiling tiles, it sure would be hard to replace the ceiling tiles IMHO. Is conduit required for your Fire Alarm wiring ?
 
F

fmtjfw

Senior Member
Location
Fairmont, WV, USA
John120/240 said:
If you were to use EMT conduit to the devices mounted in ceiling tiles, it sure would be hard to replace the ceiling tiles IMHO. Is conduit required for your Fire Alarm wiring ?
Click to expand...

If you put the box edge by the lip of the t-tab you can do it rather easily. If the box is not at an edge, you have to split the tile.

I suggest going for the edge.
 
plumb bob

plumb bob

Member
I don't know of any NEC code that says you need a flexible connection between structures and a cieling tile mounted device. It's usually easier and faster to install something flexible, IMO. Caddy has a whole host of products for mounting EMT and boxes to cieling grid.
 
B

billclou

Member
fmtjfw said:
If you put the box edge by the lip of the t-tab you can do it rather easily. If the box is not at an edge, you have to split the tile.

I suggest going for the edge.
Click to expand...

While that may work, a round smoke detector would look kinda silly if not centered in the tile. Thanks though....
 
B

billclou

Member
Wildjon3006 said:
Why not run boxes overhead with a piece of flex down to the box in the t-bar? Sure it may add a bit of material cost but I see it saving a bit of labor.
Click to expand...

I agree, however Simplex would have trouble with this design as they are pulling the wire. Thanks
 
B

billclou

Member
plumb bob said:
I don't know of any NEC code that says you need a flexible connection between structures and a cieling tile mounted device. It's usually easier and faster to install something flexible, IMO. Caddy has a whole host of products for mounting EMT and boxes to cieling grid.
Click to expand...

This in a nutshell is where I am questioning myself. I don't think that it is a requirement of NFPA 70, just good standard workmanship. What I'm trying to find is what the actual codes are, and if there are any other requirements (building codes) that are specific. The more I think about it, the more I'm leaning towards a flexible connection. I'll have a heart to heart with the alarm construction manager in a few. Thanks for the input.
 
Status
Not open for further replies.
Top