Mechanical Room Conduit

Status
Not open for further replies.
M

mstrlucky74

Senior Member
Location
NJ
Curious as to which conduit others would price/install inthis situation.

Spec reads:
RGS in the following locations:

Raceways run within 8feet of the finished floor in garage areas,
loading docks, elevatormachine rooms, mechanical rooms over
900 square feet, andelsewhere where subject to mechanical
damage.

Two questions:

1. “Where subject to mechanical damage”. Would you consideran entire mechanical room subject to mechanical damage?
2. If you have a motor on the ground being fed from a panelacross the room(in mechanical space) technically you have a few feet at thepanel and motor that are within 8’ of finished floor. Would you put the entirerun in RGS, EMT or change over from EMT to RGS within 8’ of floor?



The subject o mechanical damage is so vague? Where exactly would those areas be?
Thanks.
 
Last edited:
I agree it is pretty vague to just say subject to mechanical damage.

More information on the use of the facility and operations that normally will occur in particular spaces does help to distinguish how severe physical abuse may be.

If you have forklifts, front end loaders, etc that frequently operate in an area, everything in that area is subject to severe physical abuse, and even RMC is possibly going to get damaged at times.

If a mechanical room on same premises has no room for such vehicles to even enter, the severity of potential damage in that area is decreased.
 
mstrlucky74 said:
2. If you have a motor on the ground being fed from a panelacross the room(in mechanical space) technically you have a few feet at thepanel and motor that are within 8’ of finished floor. Would you put the entirerun in RGS, EMT or change over from EMT to RGS within 8’ of floor?
Click to expand...

It used to be common practice to use one stick of rigid conduit to get above the 8' and then switch to EMT.
 
mstrlucky74 said:
1. “Where subject to mechanical damage”. Would you consideran entire mechanical room subject to mechanical damage?
Click to expand...

I probably wouldn't consider the entire mechanical room subject to physical damage but others may. I think most contractors just do everything with 8' of the floor in rigid just to avoid any sort of conflict.
 
The term "mechanical damage" is even more broad (occurring more often) of a condition than that identified in 358.12(1) for EMT not being exposed to "severe physical damage".

It is somewhat similar to the language in 360.12(5) where FMT can't be exposed to "physical damage".

Those terms "physical damage" and "severe physical damage" are not defined in the national code that I'm aware of and gets interpreted by the AHJ differently in each jurisdiction.
 
ron said:
Those terms "physical damage" and "severe physical damage" are not defined in the national code that I'm aware of and gets interpreted by the AHJ differently in each jurisdiction.
Click to expand...
Exactly, the door for interpretation is wide open.

I have said many times that even RMC is subject to physical damage in some situations.

If we can build it we can destroy it for the most part. Otherwise if we made wiring methods that ultimately resisted all possible physical damage we would still have wiring systems completely intact after fires, earthquakes, tornadoes...
 
We use RMC up to 8' and all EMT from there. It would be an extremely rare for the area above 8' in any of those locations to be subject to physical damage.
 
Status
Not open for further replies.
Top