Single Conductors without Raceway

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PeteHJ

Member
480V. single THWN conductors run to a roof mounted HVAC unit in conduit in the building, but the conduit stops at the bottom of the unit. The conductors are then run freely in the fan/coil and compressor section of the unit, through a nipple to the disconnect and then through the same nipple up to the termination point for the conductors.

I obtained the installation manual for the unit and it does not specifically tell how to route the conductors. The owner (a school district) is concerned with the safety aspects of working around the 480V. exposed conductors during maintenance. I am looking for ammunition to include in a letter citing the concerns and possibible code violations hoping to convince the contractor to fix the installation. The control wiring was installed in seal-tite flex.

Our specifications (electrical engineers) state that all wiring shall be run in raceway, which is one of my arguements. Citing specific code paragraphs would help the cause and here is where I would like help. Any help would be greatly appreciated.

Thanks.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I don't disagree with Bob, but look just beyond those supply conductors and see all the compressor/fan wiring run open :D

makes the argument interesting, but in reality, they probably could have been run in flex farly easily.
 

tkb

Senior Member
Location
MA
It's a very common method for feeding a rooftop unit.
I see it almost everytime.
I don't see a problem since there are no terminals and all of the other wiring is open as well.
 

chevyx92

Senior Member
Location
VA BCH, VA
480V. single THWN conductors run to a roof mounted HVAC unit in conduit in the building, but the conduit stops at the bottom of the unit. The conductors are then run freely in the fan/coil and compressor section of the unit, through a nipple to the disconnect and then through the same nipple up to the termination point for the conductors.

I obtained the installation manual for the unit and it does not specifically tell how to route the conductors. The owner (a school district) is concerned with the safety aspects of working around the 480V. exposed conductors during maintenance. I am looking for ammunition to include in a letter citing the concerns and possibible code violations hoping to convince the contractor to fix the installation. The control wiring was installed in seal-tite flex.

Our specifications (electrical engineers) state that all wiring shall be run in raceway, which is one of my arguements. Citing specific code paragraphs would help the cause and here is where I would like help. Any help would be greatly appreciated.

Thanks.

Once the wiring enters the unit the code doesn't dictate any further as far as how to run wiring. Done that way all the time, no problems, passes inspection everyday.
 

iMuse97

Senior Member
Location
Chicagoland
That's the way I do it. Someone might choose to bundle the conductors with some tywraps or use sealtite, but open conductors run everywhere through RTU's, furnaces, etc.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
I think the rub for me is the fact that it does not go to the disconnect first before running free in the unit. I spent many years in a jurisdiction that would never let this fly. In fact their local code would not even allow the disconnect to attached to the unit.
 

kwired

Electron manager
Location
NE Nebraska
I think the rub for me is the fact that it does not go to the disconnect first before running free in the unit. I spent many years in a jurisdiction that would never let this fly. In fact their local code would not even allow the disconnect to attached to the unit.

How did that jurisdiction treat air handling units with internal breakers? Or any equipment with disconnect within the control panel?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I misread what was initially wrote. I thought it meant that conductors were exposed outside of the unit.

Once they are inside the unit the NEC stops IMO.

I think you need to do the work in a neat and orderly fashion, but beyond that, there are all kinds of options and no need for conduit.
 

kwired

Electron manager
Location
NE Nebraska
Once they are inside the unit the NEC stops ...
Then there are the people love to plead 110.3(B). If you like to use that for other things then why not here? Not picking on anyone in particular.
 
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